tag:theconversation.com,2011:/ca/topics/flights-7068/articlesFlights – The Conversation2023-12-07T21:52:07Ztag:theconversation.com,2011:article/2189962023-12-07T21:52:07Z2023-12-07T21:52:07ZThe sky’s the limit: A brief history of in-flight entertainment<figure><img src="https://images.theconversation.com/files/563048/original/file-20231201-21-2dzmmo.jpg?ixlib=rb-1.1.0&rect=9%2C4%2C3105%2C2069&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The in-flight entertainment and connectivity market grew to US$5.9 billion in 2019.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/the-skys-the-limit-a-brief-history-of-in-flight-entertainment" width="100%" height="400"></iframe>
<p>As the winter holidays draw near, many of us are already booking flights to see friends and family or vacation in warmer climates. Nowadays, air travel is synonymous with some form of in-flight entertainment, encompassing everything from the reception offered by the aircrew to the food choices and digital content.</p>
<p>These services all add value to flying for customers. Passengers are now so familiar with in-flight entertainment that to travel without it is unthinkable.</p>
<p><a href="https://www.globenewswire.com/news-release/2023/10/19/2762903/0/en/In-Flight-Entertainment-Connectivity-Market-to-Worth-21-03-Bn-by-2030-Exhibiting-With-a-15-9-CAGR.html">The in-flight entertainment and connectivity market grew to US$5.9 billion as of 2019</a>, a testament to its economic impact on both the airlines and the GDP of countries with airline carriers.</p>
<p>In-flight entertainment is so ubiquitous that, even if all other airline services were offered, <a href="https://travel.stackexchange.com/questions/19427/will-airlines-compensate-me-if-my-entertainment-system-is-not-working">the airline ensures a refund is made to the passenger affected</a> if television content cannot be accessed.</p>
<h2>A brief history</h2>
<p>In-flight entertainment has evolved significantly over the years. Before in-flight entertainment media was introduced, passengers entertained themselves by reading books or with food and drink services.</p>
<p>The original aim of bringing in-flight entertainment into cabins was to attract more customers, drawing inspiration from a variety of sources, including the theatrical and domestic media environments. It was not initially for the comfort and ease of travelling, as it is today. </p>
<p><a href="https://www.academia.edu/5023683/A_History_of_INFLIGHT_ENTERTAINMENT">Inflight entertainment began as an experiment</a> in 1921, when 11 Aeromarine Airways passengers were shown the film <em>Howdy Chicago!</em> on a screen hung in the cabin during the flight. Four years later, another experiment was carried out in 1925 when 12 passengers on board an Imperial Airlines flight from London were shown the film <em>The Lost World</em>. </p>
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<img alt="Black-and-white photo of a group of men watching a movie projection from behind" src="https://images.theconversation.com/files/564039/original/file-20231206-29-iwrx4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564039/original/file-20231206-29-iwrx4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=459&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564039/original/file-20231206-29-iwrx4l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=459&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564039/original/file-20231206-29-iwrx4l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=459&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564039/original/file-20231206-29-iwrx4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=577&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564039/original/file-20231206-29-iwrx4l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=577&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564039/original/file-20231206-29-iwrx4l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=577&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The first in-flight movie was shown on board an Aeromarine Airways plane that flew at the Chicago Pageant of Progress in 1921.</span>
<span class="attribution"><span class="source">(Motion Picture News)</span></span>
</figcaption>
</figure>
<p><a href="https://www.smithsonianmag.com/air-space-magazine/when-did-inflight-movies-become-standard-on-airlines-180955566/">It wasn’t until the 1960s</a> that in-flight movies became mainstream for airlines. Trans World Airlines became the first carrier to regularly offer feature films during flights, using a unique film system developed by <a href="https://www.newyorker.com/magazine/1962/06/02/inflight">David Flexer, then-president of Inflight Motion Pictures</a>.</p>
<p>Starting in 1964, in-flight entertainment evolved to include various media types like 16-mm film, closed-circuit television, live television broadcasts and magnetic tape. In the 1970s, for example, airplanes might feature a large screen with a 16-mm projector in one part of the plane, while small screens hung overhead in another section.</p>
<p><a href="https://www.smh.com.au/traveller/reviews-and-advice/when-did-airlines-install-seatback-entertainment-20190711-h1g51b.html">Seatback screens were introduced in 1988</a> when Airvision installed 6.9-centimetre screens on the backs of airline seats for Northwest Airlines. They have since morphed into the larger screens we are familiar with today, which are found on nearly every airline.</p>
<h2>In-flight entertainment today</h2>
<p>Most airlines nowadays have personal televisions for every passenger on long-haul flights. On-demand streaming and internet access are also now the norm. Despite initial concerns about speed and cost, in-flight services are becoming faster and more affordable.</p>
<p>In-flight entertainment now includes movies, music, radio talk shows, TV talk shows, documentaries, magazines, stand-up comedy, culinary shows, sports shows and kids’ shows.</p>
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Read more:
<a href="https://theconversation.com/inflight-wi-fi-highlights-challenges-of-satellite-broadband-delivery-on-land-and-in-the-sky-75381">Inflight Wi-Fi highlights challenges of satellite broadband delivery on land and in the sky</a>
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<p>However, the rise of personal devices, like tablets and smartphones, <a href="https://www.telegraph.co.uk/travel/comment/the-weird-and-wonderful-history-of-in-flight-entertainment/">could spell the end for seatback screens</a>. A number of U.S. airlines, including American Airlines, United Airlines and Alaska Air, have <a href="https://www.bloomberg.com/news/articles/2019-10-09/airline-seatback-screens-may-soon-become-an-endangered-species">removed seatback screens from their domestic planes</a>.</p>
<p>This decline is par for the course. To arrive at the complex system used by aircraft today, in-flight entertainment went through a number of different stages, <a href="https://doi.org/10.1007/978-981-19-0641-1_10">as identified by aviation scholar D.A. Reed</a>.</p>
<figure class="align-center ">
<img alt="A person, seen from behind, looking at a screen mounted on the back of an airplane seat" src="https://images.theconversation.com/files/563044/original/file-20231201-25-a14lv8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/563044/original/file-20231201-25-a14lv8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/563044/original/file-20231201-25-a14lv8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/563044/original/file-20231201-25-a14lv8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/563044/original/file-20231201-25-a14lv8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/563044/original/file-20231201-25-a14lv8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/563044/original/file-20231201-25-a14lv8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">With the widespread usage of personal electronic devices, seatback screens are on the decline.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>It started with an idea phase, which saw the conception of the idea, followed by an arms race phase where most airlines adopted some form of it. Currently, airlines are facing challenges in the final — and current — phase of evolution, and are dealing with failures linked to business concept flaws or low revenue.</p>
<p>Now that most air travellers carry electronic devices, fewer airlines are installing seatback screens. From an economic standpoint, this makes sense for airlines: removing seatback screens <a href="https://mobile.nytimes.com/2018/01/01/business/airlines-travel-entertainment.html">improves fuel costs</a> and allows airlines to <a href="https://www.flightglobal.com/systems-and-interiors/united-ups-757-density-with-new-slimline-seats/126574.article">install slimmer seats</a>, allowing for more passengers.</p>
<h2>More than entertainment</h2>
<p>At some point in the evolution of in-flight entertainment, it started to serve as more than just a form of entertainment or comfort. Now, it’s also a competitive tool for airline advertisements, and a form of cultural production.</p>
<p>In-flight entertainment has become an economic platform for investors, business people, manufacturers and entertainment providers, especially Hollywood. It also plays a key role in promoting the national culture of destination countries.</p>
<p>However, the evolution of in-flight entertainment hasn’t been without its challenges. As a form of cultural production, it often reflects the interests of advertisers, governments and business entities. It also follows that <a href="https://doi.org/10.1007/978-981-19-0641-1_10">certain ideas, products and cultures are sold to passengers</a> via in-flight entertainment. </p>
<p>The lucrative practice of capturing and selling passengers’ attention to advertisers was not limited to screens, either. In-flight magazines have always been packed with advertisements, and by the late 1980s, these advertisements had spread to napkins and the audio channels.</p>
<p>Despite its shortcomings and precarious future, in-flight entertainment still offers passengers a sense of comfort, alleviating concerns about being suspended over 30,000 feet above sea level. If you end up flying during the holidays, remember your comfort is partly thanks to this innovation.</p><img src="https://counter.theconversation.com/content/218996/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Olusola Adewumi John does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>In-flight entertainment has evolved significantly over the years, from a one-off experiment to the on-demand streaming services many of us are now used to.Olusola Adewumi John, Visiting Researcher, Centre for Socially Engaged Theatre, University of ReginaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2107782023-08-09T12:55:43Z2023-08-09T12:55:43ZAir travel is in a rut – is there any hope of recapturing the romance of flying?<figure><img src="https://images.theconversation.com/files/540440/original/file-20230801-15-96mm6.jpg?ixlib=rb-1.1.0&rect=6%2C0%2C4019%2C2685&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The high-risk adventure of air travel has been subdued, yet today's long flights can paradoxically feel torturous.</span> <span class="attribution"><span class="source">Christopher Schaberg</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Amelia Earhart broke a transcontinental speed record 90 years ago, in July 1933, by flying <a href="https://airandspace.si.edu/multimedia-gallery/web11183-2009640jpg">her signature red Lockheed Vega</a> from Los Angeles to New Jersey in just 17 hours, seven and a half minutes. Earlier that year, Earhart had flown as an observer on a Northwest Airways winter flight across the U.S., testing the possibilities of a “Northern Transcontinental” route. </p>
<p>Because those early airplanes couldn’t reach high altitudes, they weaved through dangerous peaks and the erratic weather patterns that mountain ranges helped create. One co-pilot <a href="https://www.deltamuseum.org/about-us/blog/from-the-hangars/2019/07/24/delta-stories-amelia-earhart">remembers the journey</a> as “seat-of-the-pants flying across the Dakota and Montana plains and through, over and around the Western mountain ranges.” </p>
<p>How does air travel today compare? </p>
<p>I’ve studied <a href="https://www.theatlantic.com/technology/archive/2018/02/engine-failure/552959/">airplane technology</a>, <a href="https://www.theatlantic.com/technology/archive/2013/09/a-forgettable-passage-to-flight/279346/">airport design</a> and <a href="https://www.upress.umn.edu/book-division/books/grounded">cultural attitudes</a> toward air travel, and I’ve noticed how aspects of flying seem to have calcified over time. </p>
<p>Long-distance flight <a href="https://theconversation.com/longing-for-the-golden-age-of-air-travel-be-careful-what-you-wish-for-34177">advanced rapidly between the 1930s and the early 1960s</a>, shaving off the number of hours in the sky by half. But over the past 60 years, the duration of such flights has remained roughly the same. Meanwhile, the ecosystem of air travel has grown more elaborate, often leaving passengers squirming in their seats on the tarmac before or after flight. </p>
<p>Coast-to-coast air travel is in a rut – but there are still efforts to improve this mode of transit.</p>
<h2>Just another ordinary miracle</h2>
<p>Transcontinental air journeys are clearly different 90 years after Earhart’s record-breaking exploratory flights: Travelers now take such trips for granted, and often find them to be pure drudgery. </p>
<p>In 2018, <a href="https://thepointsguy.com/reviews/united-757-200-first-class-ewr-sea/">travel blogger Ravi Ghelani reviewed in minute detail</a> a United Airlines flight from Newark, New Jersey, to Seattle – roughly the same northern route that Earhart explored in 1933. </p>
<p>But for Ghelani, seated in first class, it wasn’t the terrain or frigid temperatures that were the most cumbersome part of his adventure. It was a cheap complimentary blanket, which “barely qualified as one – it was very thin, very scratchy.” </p>
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<a href="https://images.theconversation.com/files/541779/original/file-20230808-21-f9i0u2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Black and white photo of woman smiling and waving in front of an airplane." src="https://images.theconversation.com/files/541779/original/file-20230808-21-f9i0u2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/541779/original/file-20230808-21-f9i0u2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=807&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541779/original/file-20230808-21-f9i0u2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=807&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541779/original/file-20230808-21-f9i0u2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=807&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541779/original/file-20230808-21-f9i0u2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1015&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541779/original/file-20230808-21-f9i0u2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1015&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541779/original/file-20230808-21-f9i0u2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1015&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Amelia Earhart grins in Newark, N.J., after completing her first nonstop flight across the U.S. in 1932.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/newark-new-jersey-a-wide-grin-covers-the-face-of-amelia-news-photo/104404070?adppopup=true">Keystone-France/Getty Images</a></span>
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<p>The dreaded blanket reappears in Ghelani’s summary of his trip: “My main qualm with this flight was the lack of a decent blanket – the tiny, scratchy blanket that was provided wasn’t cutting it for the six-hour flight.” </p>
<p>I can imagine Earhart rolling in <a href="https://airandspace.si.edu/stories/editorial/legend-amelia-earharts-disappearance">her watery grave</a>: “You zip across the continent in six hours and you complain about a scratchy blanket?”</p>
<p>Yet Ghelani’s account of a mundane cross-country flight reveals a truth: Commercial air travel just isn’t the adventure it was back in Earhart’s time.</p>
<p>As one captain of a major U.S. airline who regularly flies long routes told me, “Today jetliners fly across the country from Los Angeles to New York, or Boston to Seattle, full of passengers oblivious to the commonplace practice it has become.” </p>
<p>This pilot compared coast-to-coast flights to “iPhones, microwaves or automobiles” – just one more ordinary miracle of modern life. </p>
<h2>Little indignities multiply</h2>
<p>The high-risk adventure of air travel has been subdued, yet long flights today can paradoxically feel torturous. </p>
<p>As philosopher Michael Marder puts it in his 2022 book “<a href="https://mitpress.mit.edu/9780262543712/philosophy-for-passengers/">Philosophy for Passengers</a>”: “When crew members wish passengers a ‘pleasant journey,’ I hear a dash of cruel irony in their words. How pleasant can the passenger experience be when you are crammed in your seat, with little fresh air, too hot or miserably cold, and sleep deprived?” </p>
<p>I asked my colleague and <a href="http://airplanereading.org/story/55/frequent-flight">frequent flier</a> Ian Bogost about his experience of coast-to-coast trips, and his reply was illuminating: “The same trip seems to get longer every year, and less comfortable. There are reasons – consolidation, reduced routes, pilot and air-traffic labor shortages, decaying technical infrastructure – but it still feels like moving backwards.” In spite of widespread attempts to update aircraft and modernize terminals, the vast system of air travel can seem cumbersome and outdated. </p>
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<img alt="Glum-looking people in an airport terminal stand in a line that snakes out of the frame." src="https://images.theconversation.com/files/541783/original/file-20230808-19-5kb2r6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541783/original/file-20230808-19-5kb2r6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=404&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541783/original/file-20230808-19-5kb2r6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=404&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541783/original/file-20230808-19-5kb2r6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=404&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541783/original/file-20230808-19-5kb2r6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=507&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541783/original/file-20230808-19-5kb2r6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=507&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541783/original/file-20230808-19-5kb2r6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=507&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Passengers wait in line amid a series of cancellations at Newark (N.J.) International Airport in June 2023.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/people-queue-for-their-flight-reschedule-inside-of-the-news-photo/1259132586?adppopup=true">Kena Betancur/Getty Images</a></span>
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<p>Recently at The Atlantic, reporter <a href="https://www.theatlantic.com/technology/archive/2023/07/clear-airport-security-lines-tsa-infrastructure/674809/">Amanda Mull wrote about</a> the biometric screening company Clear, describing this firm’s high-tech service to skip the ubiquitous toil of identity checks before flight, at the cost of surrendering some privacy and personal information. Mull concludes the reason more travelers will likely enroll in this service is that “traversing American airport security is simply that grim.” </p>
<p>For Mull, the adventure of contemporary air travel isn’t the destination, or even the journey itself – it’s what you must do to get through the airport. </p>
<p>Still, it’s worth noting that the majority of the human population has never boarded an airplane; flying cross-country remains <a href="https://www.smithsonianmag.com/air-space-magazine/how-much-worlds-population-has-flown-airplane-180957719/">a relatively exclusive experience</a>. For most people, the closest they’ll get to a coast-to-coast flight is seeing a small white scratch across the sky, as another airliner makes its arc at 35,000 feet. </p>
<h2>2 futures of cross-country flight</h2>
<p>Coast-to-coast travel is no longer about breakneck speed or defying elemental odds, and Earhart’s quests to push the limits of aviation couldn’t be further from the bland routines of contemporary air travel. Nor does it involve people dressing to the hilt to step aboard a jetliner for the first time, with passengers stowing their fancy hats in spacious overhead bins. </p>
<p>Where are the new frontiers for transcontinental flight today? </p>
<p>One area of innovation is in a greener form of flight. Solar Impulse, a completely solar-powered plane, took two months to fly coast-to-coast in 2013. It averages a plodding 45 mph at cruising altitude. As <a href="https://apnews.com/ded34ccc19f24aeea67ba3da130a2be0">The Associated Press reported</a>: “Solar Impulse’s creators view themselves as green pioneers – promoting lighter materials, solar-powered batteries, and conservation as sexy and adventurous. Theirs is the high-flying equivalent of the Tesla electric sports car.” Solar Impulse was more recently <a href="https://aviationweek.com/aerospace/aircraft-propulsion/solar-powered-skydweller-completes-first-autonomous-flights?check_logged_in=1">reconfigured as a remotely piloted aircraft</a>, with new experiments in long-distance solar flight underway. </p>
<figure class="align-center ">
<img alt="Futuristic looking plane with long wingspan flies over bay and city." src="https://images.theconversation.com/files/541781/original/file-20230808-16-r1r69n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541781/original/file-20230808-16-r1r69n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541781/original/file-20230808-16-r1r69n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541781/original/file-20230808-16-r1r69n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541781/original/file-20230808-16-r1r69n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541781/original/file-20230808-16-r1r69n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541781/original/file-20230808-16-r1r69n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Solar Impulse 2 flies over the Golden Gate Bridge in San Francisco in 2016.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/solar-impulse-2-a-solar-powered-plane-piloted-by-swiss-news-photo/523604684?adppopup=true">Jean Revillard/Getty Images</a></span>
</figcaption>
</figure>
<p>The comparison of Solar Impulse to a Tesla is handy because a different extreme can be found in Elon Musk’s company SpaceX. As part of the relentless development of its biggest vehicle, “Starship,” SpaceX has advertised the possibility of “<a href="https://www.spacex.com/human-spaceflight/earth/">point-to-point</a>” travel on Earth: for example, flying on a commercial rocket from Los Angeles to New York in 25 minutes. Never mind the physical tolls of a normal <a href="https://theconversation.com/why-would-anyone-want-to-sit-on-a-plane-for-over-18-hours-an-economist-takes-the-worlds-longest-flight-122433">19-hour flight</a>; it’s hard to imagine what such a brief yet fast trip would feel like, not to mention what sort of class divisions and bleak industrial launch sites such jaunts would rely on.</p>
<p>Get there as fast as possible, using as much fuel as necessary; or glide lazily along, powered by the sun, saving the planet. These are two starkly different visions of coast-to-coast flight, one a dystopian nightmare and the other a utopian dream. </p>
<p>In the middle, there’s what most flying mortals do: wait in lines, board unceremoniously and be relieved if you get to your destination without too much discomfort or delay.</p><img src="https://counter.theconversation.com/content/210778/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher Schaberg does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Over the past 60 years, the duration of flights has remained roughly the same, while passengers have been subjected to more indignities, longer waits and more cancellations.Christopher Schaberg, Director of Public Scholarship, Arts & Sciences at Washington University in St. LouisLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2110992023-08-07T20:02:19Z2023-08-07T20:02:19ZHow air travellers can cut their door-to-door emissions right now – by as much as 13% on the Sydney-Melbourne route<figure><img src="https://images.theconversation.com/files/541373/original/file-20230807-21-46i2be.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C3994%2C2658&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">MDRX/Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Our climate is changing, and airlines are under pressure to reduce emissions from air travel. For many of us, especially in Australia, flying is an essential form of transport, so how can we reduce its environmental impact? Getting to and from the airport is an overlooked aspect of air travel that offers an immediate way to cut total carbon emissions from the trip by a surprisingly large amount.</p>
<p>Our newly published <a href="https://www.sciencedirect.com/science/article/pii/S1361920923002468">research</a> shows for an average economy passenger flying from Sydney to Melbourne, the carbon emissions from using a fossil-fuelled car to get to and from the airports make up a staggering 13.5% of the total door-to-door emissions. At a global scale, this number reaches 12.1% for long-haul flights and up to 22.8% for short-haul air journeys.</p>
<p>For comparison, in the International Air Transport Association’s <a href="https://www.iata.org/en/programs/environment/roadmaps/">2050 net-zero emission roadmap</a>, 13% of global airline decarbonisation will come from electric and hydrogen propulsion. A further 65% is to come from mass adoption of sustainable aviation fuel. This is fuel produced from non-petroleum-based renewable sources such as some municipal solid waste, woody biomass, fats, greases and oils.</p>
<p>Each of these big lifters requires a mammoth level of investment and technological breakthroughs, and comes with limitations and risks. Some solutions might make air travel prohibitively expensive. Airlines are moving mountains to decarbonise, but there are increasing concerns their net-zero plans might not stack up.</p>
<p>In contrast, a 13.5% emission reduction on a Sydney-Melbourne door-to-door journey today may sound like a dream. Yet our research shows it’s easily achievable if travellers can be persuaded to change how they get to and from the airport.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/541375/original/file-20230807-25-gylca6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541375/original/file-20230807-25-gylca6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=367&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541375/original/file-20230807-25-gylca6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=367&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541375/original/file-20230807-25-gylca6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=367&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541375/original/file-20230807-25-gylca6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=461&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541375/original/file-20230807-25-gylca6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=461&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541375/original/file-20230807-25-gylca6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=461&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Travel to and from the airport by a fossil-fuelled car accounts for a surprisingly large proportion of emissions from the whole journey.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/theres-a-buzz-about-sustainable-fuels-but-they-cannot-solve-aviations-colossal-climate-woes-205484">There’s a buzz about ‘sustainable’ fuels – but they cannot solve aviation's colossal climate woes</a>
</strong>
</em>
</p>
<hr>
<h2>So how can travellers be convinced to switch?</h2>
<p><a href="https://www.cambridge.org/core/journals/agricultural-and-resource-economics-review/article/future-of-carbon-labeling-factors-to-consider/FDBC62244F2ACA29A7602886085B4A91">Research</a> has shown carbon “labelling” helps shift consumer behaviour towards greener choices. It’s a bit like how the nutrition label on the back of our cereal box helps us choose healthier options. </p>
<p>For instance, when searching for a flight on online travel platform Skyscanner, all flight options are displayed with carbon emissions, so consumers can make a more informed choice.</p>
<p>Two <a href="https://escholarship.org/uc/item/5n53672m">recent</a> <a href="https://journals.sagepub.com/doi/abs/10.1177/03611981211046924">studies</a> at the University of California, Davis, suggest showing consumers the emission outcomes of different gate-to-gate flight choices, such as aircraft types and transit stops, can prompt them to choose greener flights, reducing emissions by up to 3.8%. </p>
<p>But air journeys don’t start or end at airports. They start at home and end at destinations, or vice versa. Our air-travel carbon emissions are divided into ground and air segments and counted as airport and airline emissions respectively. While airlines focus on gate-to-gate decarbonisation through future technologies, the door-to-door emissions produced by travel to and from airports can be reduced immediately.</p>
<p>Let’s look at an example of a Sydney-to-Melbourne trip. Say you travel from North Sydney to Sydney Airport by car, then fly to Melbourne Airport and catch a taxi to the city centre. That trip emits 82 kilograms of CO₂ door-to-door. But if you use a train, bus or electric vehicle (charged from a renewable source) to travel to and from the airport, the emissions from your trip drop to 71kg: a 13.5% fall door-to-door. </p>
<p>Although travel platforms are increasingly communicating gate-to-gate emissions to consumers, we’re not aware of any that are including door-to-door emissions. Helping climate-conscious consumers understand the door-to-door carbon impact of airport ground connections could drive them to choose greener options such as public transport and electric vehicles.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/541364/original/file-20230807-15-mp3dlr.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Google Flights chart of air travel options showing emissions and cost" src="https://images.theconversation.com/files/541364/original/file-20230807-15-mp3dlr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541364/original/file-20230807-15-mp3dlr.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=464&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541364/original/file-20230807-15-mp3dlr.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=464&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541364/original/file-20230807-15-mp3dlr.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=464&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541364/original/file-20230807-15-mp3dlr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=583&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541364/original/file-20230807-15-mp3dlr.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=583&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541364/original/file-20230807-15-mp3dlr.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=583&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Travel aggregator search platforms are now labelling carbon emissions when offering flight options.</span>
<span class="attribution"><span class="source">Google Flights</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/bucking-the-trend-is-there-a-future-for-ultra-long-haul-flights-in-a-net-zero-carbon-world-183212">Bucking the trend: Is there a future for ultra long-haul flights in a net zero carbon world?</a>
</strong>
</em>
</p>
<hr>
<h2>Give airlines an incentive to inform passengers</h2>
<p>Governments and airports have long collaborated in driving consumers towards greener ground transit options. For instance, Transport for NSW has set a 50% emission-reduction <a href="https://www.future.transport.nsw.gov.au/sites/default/files/2022-09/Future_Transport_Strategy_2.pdf">target</a> for 2030. </p>
<p>However, consumer adoption of these options has remained low. <a href="https://www.ttf.org.au/wp-content/uploads/2016/09/TTF_Accessing_Sydney_Airport.pdf">Most airport trips</a> in Australia today are still made by conventional car.</p>
<p>As consumers, we have relationships with airlines that we don’t have with airports. When it comes to flying, we choose our airline carefully. Yet we rarely think about how we get to the airport.</p>
<p>Airlines are experts in customer communication and engagement. They operate some of the largest frequent-flyer programs in the world. Last time we checked, Qantas had <a href="https://www.finder.com.au/frequent-flyer/qantas">15 million</a> program members and Virgin had <a href="https://newsroom.virginaustralia.com/release/velocity-frequent-flyer-soars-11-million-members">11 million</a>. </p>
<p>Through these channels, airlines learn about us and how we tick when it comes to making flying choices. This puts them in an ideal position to keep us informed about door-to-door travel and drive the transition towards greener airport ground-connection options. To give them an incentive to do so, their efforts should be recognised through emission accounting.</p>
<figure class="align-center ">
<img alt="Air travellers enter the airport train station" src="https://images.theconversation.com/files/541376/original/file-20230807-17-tiylg0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541376/original/file-20230807-17-tiylg0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541376/original/file-20230807-17-tiylg0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541376/original/file-20230807-17-tiylg0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541376/original/file-20230807-17-tiylg0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541376/original/file-20230807-17-tiylg0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541376/original/file-20230807-17-tiylg0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">It makes sense to give airlines an incentive to play a greater role in promoting low-emissions travel to and from the airport.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/blue-sky-thinking-net-zero-aviation-is-more-than-a-flight-of-fantasy-171940">Blue-sky thinking: net-zero aviation is more than a flight of fantasy</a>
</strong>
</em>
</p>
<hr>
<h2>A cost-effective way to cut emissions</h2>
<p>Travellers using the Sydney Airport train station must pay an <a href="https://www.opal.com.au/en/opal-fares/airport_station_access_fee/">access fee</a>, which adds <a href="https://airportlink.com.au/trip-information/price/">A$15.74</a> to the cost of the journey. As our <a href="https://www.sciencedirect.com/science/article/pii/S1361920923002468">paper</a> highlights, the average customer using the airport train removes 2.7kg of CO₂. Achieving the same amount of decarbonisation during the flight using more sustainable aviation fuel – which is more expensive – would cost the customer about the same: between $10 and $16.</p>
<p>So there is an opportunity for airlines to highlight this decarbonisation outcome as a way to persuade travellers to reconsider driving a car or catching a taxi, and instead take the airport train or bus. Airlines could also consider collaborating with airports to build airport charging facilities for electric vehicles as uptake in Australia approaches a <a href="https://www.theguardian.com/australia-news/2023/jul/31/australian-electric-vehicles-ev-sales-rise-increase">double-digit share</a> of new vehicle sales.</p>
<p>This overlooked opportunity to cut door-to-door emissions from air travel has a substantial upside. It deserves far more attention from airlines, airports and consumers.</p><img src="https://counter.theconversation.com/content/211099/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rico Merkert receives funding from the ARC and various industry partners. </span></em></p><p class="fine-print"><em><span>David Li's research has received financial support from iMOVE Australia and in-kind support from Air New Zealand.</span></em></p>Air travel emissions are proving difficult and costly to cut, but travellers can make a surprisingly big difference simply by changing how they travel to and from the airport.Rico Merkert, Professor in Transport and Supply Chain Management and Deputy Director, Institute of Transport and Logistics Studies (ITLS), University of Sydney Business School, University of SydneyDavid Li, PhD Candidate, Institute of Transport and Logistics Studies, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2056042023-06-20T12:29:24Z2023-06-20T12:29:24ZPassengers whose flights are canceled or delayed may soon get better treatment in the US – where airlines have long set their own rules<figure><img src="https://images.theconversation.com/files/531703/original/file-20230613-27-g7q22s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In Europe, customers are entitled to cash compensation for flight delays and cancellations.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/young-traveler-sleeping-at-airport-royalty-free-image/1172692318">Murat Deniz/E+ Collection/Getty Images</a></span></figcaption></figure><p>U.S. airline passengers in early 2023 faced the <a href="https://www.transtats.bts.gov/HomeDrillChart.asp">highest rate of flight delays</a> since 2014. That heightened level of delays came shortly after December 2022, when Southwest Airlines experienced an epic meltdown, canceling <a href="https://www.cnn.com/travel/article/flight-cancellations-christmas-2022-winter-storm/index.html">71% of its flights</a>.</p>
<p>In response, on May 8, 2023, the Biden administration <a href="https://www.msn.com/en-us/travel/news/biden-proposes-that-airlines-offer-cash-compensation-for-flight-cancellations-or-big-delays/ar-AA1aTT7v">proposed new rules</a> that would require airlines to <a href="https://www.transportation.gov/briefing-room/dot-propose-requirements-airlines-cover-expenses-and-compensate-stranded-passengers">compensate passengers</a> whose flights are canceled or significantly delayed because of causes – unlike bad weather – that are under the control of the airlines. Under the new rules, the airlines would need to offer meal vouchers, overnight accommodations and ground transportation to and from a hotel when customers are stranded. </p>
<p>If enacted, those new rules would provide U.S. passengers with rights and protections more in line with those currently afforded passengers in the <a href="https://eur-lex.europa.eu/legal-content/EN/TXT/?qid=1476179175834&uri=CELEX:32004R0261">European Union</a> and <a href="https://otc-cta.gc.ca/eng/publication/flight-delays-and-cancellations-a-guide">Canada</a>. </p>
<p>As a <a href="https://udayton.edu/directory/artssciences/history/bednarek_janet.php">professor of history</a> who researches American aviation, I’m aware that consumer advocates have pushed for greater passenger rights for airline travelers in the U.S. since at least the early 1970s – when <a href="https://www.washingtonpost.com/archive/politics/1978/01/11/nader-awarded-15010-in-airline-suit/2b8bd978-962a-4130-b597-73a2074a8beb/">Ralph Nader sued an airline</a> for bumping him from an overbooked flight. For the most part, especially since the <a href="https://www.congress.gov/bill/95th-congress/senate-bill/2493">Airline Deregulation Act</a> in 1978, such efforts have failed, and airlines have been able to set and enforce their own policies.</p>
<h2>Limits of Rule 240</h2>
<p>Ralph Nader’s suit, which unsuccessfully sought to end the practice of overbooking flights, highlighted that there were regulations already in place concerning passengers bumped from <a href="https://sgp.fas.org/crs/misc/IN10693.pdf">flights because of overbooking</a>. Those regulations, however, did not cover passengers whose flights were delayed or canceled. </p>
<p>There was, however, something <a href="https://www.fly.faa.gov/FAQ/faq.html">known as Rule 240</a>. As part of the Civil Aeronautics Board’s oversight of U.S. airlines, airlines had to <a href="https://www.seatmaestro.com/rule-240/#:%7E:text=Rule%20240%20was%20in%20fact%20a%20convenient%20way,history%20after%20the%20airlines%20were%20deregulated%20in%201978">submit information on all aspects of their operations</a>, including their flight delay and cancellation policies. In these required documents, that information was often listed under Rule 240. However, each airline determined its own flight delay and cancellation policies under Rule 240. The airlines were not required to compensate passengers in any particular way, only to state what their policy was. </p>
<p>As U.S. airlines became deregulated in the late 1970s and early 1980s, many, though not all, included the provisions they had previously submitted to the Civil Aeronautics Board in their contracts of carriage – <a href="https://www.flyertalk.com/articles/contract-of-carriage-for-dummies-buy-the-ticket-take-the-ride.html">the “fine print</a>” associated with airline tickets. <a href="https://www.tripsavvy.com/airlines-rule-240-54480">Many contracts of carriage</a> stated that in the case of a delay or cancellation, the airline would book a passenger on its next available flight or place them on a flight on another airline that would get them to their destination sooner. </p>
<p>Rule 240 or its equivalent under the contract of carriage <a href="https://www.tripsavvy.com/airlines-rule-240-54480">varies by airline</a> and primarily focuses on rebooking passengers. Some airlines do offer meal vouchers and hotel accommodations, but only when the problem is caused by the airline and not something like weather or a labor strike. Consumer advocates encourage passengers to invoke Rule 240, but airlines will likely provide only what is stated in their contract of carriage.</p>
<figure class="align-center ">
<img alt="Airport worker stands in front of a flight arrivals digital screen that shows many canceled flights" src="https://images.theconversation.com/files/532251/original/file-20230615-15-li31w1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/532251/original/file-20230615-15-li31w1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/532251/original/file-20230615-15-li31w1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/532251/original/file-20230615-15-li31w1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/532251/original/file-20230615-15-li31w1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/532251/original/file-20230615-15-li31w1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/532251/original/file-20230615-15-li31w1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Southwest Airlines canceled over 2,500 flights a day in late December 2022, leaving many customers stranded over the holidays.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/passengers-effected-by-cancellation-of-more-than-2-500-news-photo/1245858598">Irfan Khan/Los Angeles Times/Getty Images</a></span>
</figcaption>
</figure>
<h2>Push for a passenger bill of rights</h2>
<p>In recent decades, consumer advocates and even some lawmakers have sought to enshrine more substantial air passenger protections into federal law. </p>
<p>In December 2006, American Airlines held passengers on a plane on the tarmac in Austin, Texas, <a href="https://www.nbcnews.com/id/wbna17173370">for eight hours</a> with little food or water. Kate Hanni, a passenger on that flight, lobbied Congress to pass an extensive <a href="https://www.pressdemocrat.com/article/news/partial-mission-accomplished-for-napa-passenger-rights-leader/">passenger bill of rights</a>. In response, the Department of Transportation did <a href="https://www.transportation.gov/briefing-room/us-department-transportation-expands-airline-passenger-protections">announce new rules</a> in 2009 that said airlines could not hold domestic flights on the tarmac for more than three hours and must provide access to water and lavatories during such delays. </p>
<p>Those rules were <a href="https://www.transportation.gov/briefing-room/us-department-transportation-expands-airline-passenger-protections">expanded in 2011</a> to reimburse baggage fees to customers whose bags are lost, increase compensation for passengers bumped from oversold flights, and extend the rule concerning tarmac delays to international flights, with a four-hour limit.</p>
<p>More recently, in November 2021, Sen. Richard Blumenthal of Connecticut introduced <a href="https://www.congress.gov/bill/117th-congress/senate-bill/3222?s=1&r=14">Senate Bill 3222</a> to establish an airline passengers’ bill of rights. However, it never made it past the Committee on Commerce, Science and Transportation.</p>
<h2>EU paves the way</h2>
<p>U.S. passengers flying within the European Union can experience what it is like when passenger rights are guaranteed under law rather than left to the discretion of airlines. </p>
<p><a href="https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52016XC0615(01)">EU legislation</a> mandates that airlines provide passengers with certain levels of care including flight rebooking, meals, hotel vouchers and, in some instances, cash compensation – which varies depending on the length of the delay and the distance of the flight. All travelers who are flying within the EU, or whose flight arrives to the EU on an EU carrier, or departs from the EU on any carrier, are covered under that legislation. </p>
<p>The Biden administration proposal would bring <a href="https://rollcall.com/2023/05/08/biden-administration-drafting-airline-passenger-protection-rules/">U.S. airline passenger protections</a> more in line with the EU where such protections are mandated and not at the discretion of the airline. Such an effort, while likely welcomed by passengers, is also likely to meet opposition from the airlines – which have enjoyed a long history of setting their own rules.</p><img src="https://counter.theconversation.com/content/205604/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Janet Bednarek does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Consumers and politicians are pushing for greater protections for air travelers. A historian explains why the US trails the EU and Canada when it comes to passenger rights.Janet Bednarek, Professor of History, University of DaytonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1981422023-01-19T00:05:41Z2023-01-19T00:05:41ZQantas flight mayday: can a plane normally fly on just one engine? An aviation expert explains<p>You may have seen the news Qantas flight 144 from Auckland landed safely in Sydney yesterday after the pilot was forced to shut down an engine and issue a mayday call while flying over the Pacific Ocean.</p>
<p><a href="https://www.sbs.com.au/news/article/heard-a-bang-investigation-launched-into-qantas-flight-that-sparked-mayday-call/wpyvcthe6">The plane was reportedly</a> a ten-year-old, twin-jet Boeing 737 and was carrying 145 passengers, all of whom disembarked normally after landing yesterday afternoon. </p>
<p>These events do, unfortunately, happen occasionally in aviation – I myself have lost an engine while flying – but the good news is it’s extremely rare. That makes aviation the safest form of transport in the world.</p>
<p>These are highly trained pilots who spend a lot of time in full-motion simulators going over events exactly like this.</p>
<p>When you’re down an engine and you have lot of water under you, you have a process to follow.</p>
<p>It becomes rote; you don’t panic, you don’t go off the rails, you remember your training, and that’s what happened here.</p>
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Read more:
<a href="https://theconversation.com/heres-the-real-reason-to-turn-on-aeroplane-mode-when-you-fly-188585">Here's the real reason to turn on aeroplane mode when you fly</a>
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<h2>Can planes fly on just one engine?</h2>
<p>Absolutely. That is what they are designed to do. </p>
<p>By law, planes have to be able to fly from point A to point B, over water, on just one engine. The <a href="https://www.casa.gov.au/sites/default/files/2021-08/caap-82-1-extended-diversion-time-operations.pdf">guidance set by safety regulators</a> in Australia mandates that any plane that takes off with the intention of getting to a certain destination has to be able to get there on one engine – based on the departure loads determined before takeoff. </p>
<p>That rule ensures that even if one engine goes down – as appears to have happened here – the plane can still arrive safely. It can fly until it runs out of fuel. Basically, these planes are built to fly as well on one engine as they can on two. </p>
<p>Having just one engine operating means you won’t have the maximum thrust power for take off, but you’d be able to fly and land just fine.</p>
<p>But while a plane can fly on one engine, it is very rare for an engine to go down in the middle of a flight.</p>
<p>Airline maintenance procedures are meticulous and technicians are licensed at the same level and quality as pilots. Typically you have someone do the maintenance on a plane on the ground, but they have someone come after them and inspect it and test it to make sure it is operating at 100% performance. </p>
<p>There are ground tests and flight tests and certification processes that need to be followed before a plane can take passengers. That’s why these events are so unusual.</p>
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<h2>A bang and air-con shutdown</h2>
<p>Passengers <a href="https://www.sbs.com.au/news/article/heard-a-bang-investigation-launched-into-qantas-flight-that-sparked-mayday-call/wpyvcthe6">said they heard</a> a bang during the Qantas flight yesterday.</p>
<p>Details on what exactly happened are yet to emerge, but it’s certainly possible for engine failure to make a sound. It depends on the type of failure. If it was a section within the engine breaking, that could make a noise loud enough for passengers to hear it.</p>
<p>But normally if the pilot needed to isolate the engine and could see pressure fluctuation or engine temperature exceeding normal levels, then the pilot could choose to shut it down even before they heard a bang.</p>
<p>Reports the plane’s air conditioning subsequently stopped working suggests to me the crew probably had to turn off some systems to achieve their goal of landing successfully back in Sydney.</p>
<h2>Anatomy of a crisis</h2>
<p>When an event like this happens, pilots have a process for scanning their instrumentation to isolate and figure out what’s happening. </p>
<p>Once they do, we have what’s known as a <a href="https://www.skybrary.aero/articles/quick-reference-handbook-qrh">Quick Reference Handbook</a> to consult. It lists all the potential emergency situations that might happen on a plane. The pilots then follow that handbook to analyse each step and each possibility, which helps isolate and solve the problem.</p>
<p>In this case, it appears the solution was to shut that engine down.</p>
<p>For the sake of precaution, aviators announce a mayday call when we have a situation we think means we need priority help. The mayday call clears out the airspace to permit this plane to be number one in the queue for priority; all other aircraft have to get out of the way. </p>
<p>The air traffic controllers put everyone else in the air in a holding pattern or give them a big turn to keep them out of the area.</p>
<p>However, sometime after the pilot on QF144 issued a mayday call, <a href="https://www.sbs.com.au/news/article/heard-a-bang-investigation-launched-into-qantas-flight-that-sparked-mayday-call/wpyvcthe6">it was downgraded</a> to what’s known as a PAN – that stands for Possible Assistance Needed. </p>
<p>A PAN is a less extreme event; it still signals it is an emergency, and meant yesterday there were emergency vehicles on the runway and the plane retained its priority status in the queue. But it is not quite as serious as a mayday.</p>
<p>From here, a very thorough review will help shed light on what happened. The pilots typically go through drug and alcohol testing and there will be a full investigation to ensure nothing was missed and help Qantas return to normal operations.</p>
<h2>Remembering your training</h2>
<p>I wasn’t there on the flight deck yesterday and can only infer from what I have heard and read that the pilots on this plane did exactly what they are trained to do.</p>
<p>Airlines spend a lot of money on training so pilots and crew can handle events like this. </p>
<p>As we begin the conversation toward single pilot planes and autonomous aircraft, it’s worth asking how AI and autonomous systems might respond to circumstances that are not normal events.</p>
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Read more:
<a href="https://theconversation.com/what-happens-to-your-body-on-a-long-haul-flight-183034">What happens to your body on a long-haul flight?</a>
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<img src="https://counter.theconversation.com/content/198142/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Doug Drury does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>When you’re down an engine and you have lot of water under you, you have a process to follow. You don’t panic, you don’t go off the rails, you remember your training, and that’s what happened here.Doug Drury, Professor/Head of Aviation, CQUniversity AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1900982022-09-19T12:21:03Z2022-09-19T12:21:03ZElectric planes are coming: Short-hop regional flights could be running on batteries in a few years<figure><img src="https://images.theconversation.com/files/484695/original/file-20220914-9158-ybu2z4.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5043%2C3351&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Small planes are easier to electrify, but larger ones aren't far behind.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/traffic-at-airport-during-sunset-royalty-free-image/1139652369">Chalabala/istock via Getty Images</a></span></figcaption></figure><p><em>Electric planes might seem futuristic, but they aren’t that far off, at least for short hops.</em></p>
<p><em>Two-seater Velis Electros are already <a href="https://investor.textron.com/news/news-releases/press-release-details/2022/Textron-Completes-Acquisition-of-Pipistrel/default.aspx">quietly buzzing around Europe</a>, <a href="https://harbourair.com/harbour-air-and-magnix-announce-successful-flight-of-worlds-first-commercial-electric-airplane/">electric sea planes</a> are being tested in British Columbia, and larger planes are coming. <a href="http://heartaerospace.com/heart-aerospace-unveils-new-airplane-design-confirms-air-canada-and-saab-as-new-shareholders/">Air Canada</a> announced on Sept. 15, 2022, that it would buy 30 electric-hybrid regional aircraft from Sweden’s Heart Aerospace, which expects to have its 30-seat plane in service by 2028. Analysts at the U.S. National Renewable Energy Lab note that the <a href="https://www.nrel.gov/docs/fy22osti/80220.pdf">first hybrid electric 50- to 70-seat</a> commuter plane <a href="https://www.electricaviationgroup.com/electric-flight/">could be ready</a> not long after that. In the 2030s, they say, electric aviation could really take off.</em></p>
<p><em>That matters for managing climate change. About 3% of global emissions come from aviation today, and with more passengers and flights expected as the population expands, aviation could be producing <a href="https://www.nrel.gov/docs/fy22osti/80220.pdf">three to five times more</a> carbon dioxide emissions by 2050 than it did before the COVID-19 pandemic.</em></p>
<p><em>Aerospace engineer and assistant professor <a href="https://scholar.google.com/citations?user=KIbLE10AAAAJ&hl=en">Gökçin Çınar</a> develops sustainable aviation concepts, including hybrid-electric planes and hydrogen fuel alternatives, at the University of Michigan. We asked her about the key ways to cut aviation emissions today and where technologies like electrification and hydrogen are headed.</em></p>
<h2>Why is aviation so difficult to electrify?</h2>
<p>Aircraft are some of the most complex vehicles out there, but the biggest problem for electrifying them is the battery weight.</p>
<p>If you tried to fully electrify a 737 with today’s batteries, you would have to take out all the passengers and cargo and fill that space with batteries just to fly for under an hour.</p>
<p>Jet fuel can hold about 50 times more energy compared to batteries per unit mass. So, you can have 1 pound of jet fuel or 50 pounds of batteries. To close that gap, we need to either make lithium-ion batteries lighter or develop new batteries that hold more energy. New batteries are being developed, but they aren’t yet ready for aircraft.</p>
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<img alt="Illustration of an Air Canada Heart Aerospace electric plane." src="https://images.theconversation.com/files/484951/original/file-20220915-37168-hs6bel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/484951/original/file-20220915-37168-hs6bel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/484951/original/file-20220915-37168-hs6bel.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/484951/original/file-20220915-37168-hs6bel.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/484951/original/file-20220915-37168-hs6bel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/484951/original/file-20220915-37168-hs6bel.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/484951/original/file-20220915-37168-hs6bel.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Air Canada and United Airlines have ordered 30-seat regional hybrid-electric planes from Heart Aerospace that can go about 125 miles (200 km) fully electric and 250 miles (400 km) as hybrids. With a 25-passenger configuration, the company says the hybrid distance doubles.</span>
<span class="attribution"><a class="source" href="http://heartaerospace.com/heart-aerospace-unveils-new-airplane-design-confirms-air-canada-and-saab-as-new-shareholders/">Heart Aerospace</a></span>
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<p>An <a href="https://www.mdpi.com/2071-1050/14/10/5880">electric alternative</a> is hybrids.</p>
<p>Even though we might not be able to fully electrify a 737, we can get some fuel burn benefits from batteries in the larger jets by using hybrid propulsion systems. We are trying to make that happen in the short term, with a 2030-2035 target for smaller regional planes. The less fuel burned during flight, the fewer greenhouse gas emissions.</p>
<h2>How does hybrid aviation work to cut emissions?</h2>
<p>Hybrid electric aircraft are similar to hybrid electric cars in that they use a combination of batteries and aviation fuels. The problem is that no other industry has the weight limitations that we do in the aerospace industry.</p>
<p>That’s why we have to be very smart about how and how much we are hybridizing the propulsion system.</p>
<p>Using batteries as a power assist during takeoff and climb are very promising options. Taxiing to the runway using just electric power could also save a significant amount of fuel and reduce the local emissions at airports. There is a sweet spot between the added weight of the battery and how much electricity you can use to get net fuel benefits. This optimization problem is at the center of my research.</p>
<p>Hybrids would still burn fuel during flight, but it could be considerably less than just relying entirely on jet fuel.</p>
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<figcaption><span class="caption">How hybrid electric aviation could work on large aircraft.</span></figcaption>
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<p>I see hybridization as a mid-term option for larger jets, but a near-term solution for regional aircraft.</p>
<p>For 2030 to 2035, we’re focused on hybrid turboprops, typically regional aircraft with 50-80 passengers or used for freight. These hybrids could <a href="https://arc.aiaa.org/doi/10.2514/1.C036919">cut fuel use by about 10%</a>.</p>
<p>With electric hybrids, airlines could also <a href="https://sacd.larc.nasa.gov/sacd/wp-content/uploads/sites/167/2021/04/2021-04-20-RAM.pdf">make more use of regional airports</a>, reducing congestion and time larger planes spend idling on the runway.</p>
<h2>What do you expect to see in the near term from sustainable aviation?</h2>
<p>Shorter term we’ll see more use of sustainable aviation fuels, or SAF. With today’s engines, you can dump sustainable aviation fuel into the same fuel tank and burn it. Fuels made from <a href="https://www.energy.gov/eere/bioenergy/2016-billion-ton-report">corn, oilseeds</a>, <a href="https://biomassmagazine.com/articles/18484/honeywell-technology-enables-jet-flights-with-saf-from-algal-oil">algae</a> and other fats are already being used.</p>
<p>Sustainable aviation fuels can reduce an aircraft’s net carbon dioxide emissions <a href="https://www.iata.org/en/programs/environment/sustainable-aviation-fuels/">by around 80%</a>, but supply is limited, and using more biomass for fuel could compete with food production and lead to deforestation.</p>
<p>A second option is using synthetic sustainable aviation fuels, which involves capturing carbon from the air or other industrial processes and synthesizing it with hydrogen. But that’s a complex and costly process and does not have a high production scale yet.</p>
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<img alt="A pilot walks away from a small plane at an airport" src="https://images.theconversation.com/files/484694/original/file-20220914-9420-x9isjy.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/484694/original/file-20220914-9420-x9isjy.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/484694/original/file-20220914-9420-x9isjy.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/484694/original/file-20220914-9420-x9isjy.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/484694/original/file-20220914-9420-x9isjy.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/484694/original/file-20220914-9420-x9isjy.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/484694/original/file-20220914-9420-x9isjy.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Ampaire reported that its hybrid electric EEL had fuel savings up to 40% compared with a standard version of the similar Cessna Skymaster.</span>
<span class="attribution"><a class="source" href="https://www.ampaire.com/press">Ampaire</a></span>
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<p>Airlines can also optimize their operations in the short term, such as <a href="https://theconversation.com/why-the-aviation-industry-must-look-beyond-carbon-to-get-serious-about-climate-change-186947">route planning</a> to avoid flying nearly empty planes. That can also reduce emissions.</p>
<h2>Is hydrogen an option for aviation?</h2>
<p>Hydrogen fuel has been around a very long time, and when it’s <a href="https://www.energy.gov/eere/fuelcells/hydrogen-production-electrolysis">green hydrogen</a> – produced with water and electrolysis powered by renewable energy – it doesn’t produce carbon dioxide. It can also hold more energy per unit of mass than batteries.</p>
<p>There are two ways to use hydrogen in an airplane: either in place of regular jet fuel in an engine, or combined with oxygen to power hydrogen fuel cells, which then generate electricity to power the aircraft.</p>
<p>The problem is volume – hydrogen gas takes up a lot of space. That’s why engineers are looking at methods like keeping it very cool so it can be stored as liquid until it’s burned as a gas. It <a href="https://www.iata.org/contentassets/d13875e9ed784f75bac90f000760e998/fact_sheet7-hydrogen-fact-sheet_072020.pdf">still takes up more space</a> than jet fuel, and the storage tanks are heavy, so how to store, handle or distribute it on aircraft is still being worked out.</p>
<p>Airbus is doing a lot of research on hydrogen combustion using modified gas turbine engines with an A380 platform, and <a href="https://www.airbus.com/en/innovation/zero-emission/hydrogen/zeroe">aiming to have mature technology by 2025</a>. Australia’s Rex airline expects to start <a href="https://australianaviation.com.au/2022/07/rex-to-trial-electric-planes-on-short-routes-in-2024/">testing a 34-seat, hydrogen-electric airplane</a> for short hops in the next few years.</p>
<p>Due to the variety of options, I see hydrogen as one of the key technologies for sustainable aviation.</p>
<h2>Will these technologies be able to meet the aviation industry’s goals for reducing emissions?</h2>
<p>The problem with aviation emissions isn’t their current levels – it’s the fear that their emissions will increase rapidly as demand increases. By 2050, we could see three to five times more carbon dioxide emissions from aviation than before the pandemic. </p>
<p><iframe id="5mb3z" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/5mb3z/6/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>The <a href="https://www.icao.int/about-icao/Pages/default.aspx">International Civil Aviation Organization</a>, a United Nations agency, generally defines the industry’s goals, looking at what’s feasible and how aviation can push the boundaries.</p>
<p>Its long-term goal is to <a href="https://www.icao.int/Meetings/2022-ICAO-LTAG-GLADS/Pages/default.aspx">cut net carbon dioxide emissions 50%</a> by 2050 compared with 2005 levels. Getting there will require a mix of different technologies and optimization. I don’t know if we’re going to be able to reach it by 2050, but I believe we must do everything we can to make future aviation environmentally sustainable.</p><img src="https://counter.theconversation.com/content/190098/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gökçin Çınar receives research funding from the government and other entities to work on sustainable aviation technologies. </span></em></p>Air Canada and United Airlines both have orders for hybrid electric 30-seaters. An aerospace engineer explains where electrification, hydrogen and sustainable aviation fuels are headed.Gökçin Çınar, Assistant Professor of Aerospace Engineering, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1752152022-01-25T16:02:23Z2022-01-25T16:02:23ZCould 5G really ground planes? Why the US has delayed rolling out the mobile internet technology around airports<figure><img src="https://images.theconversation.com/files/442003/original/file-20220121-15-15nrib1.jpg?ixlib=rb-1.1.0&rect=4%2C4%2C2991%2C1989&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hoersching-austria-17-march-2021-airbus-1938324136">Simlinger/Shutterstock</a></span></figcaption></figure><p>Several international airlines recently <a href="https://www.theguardian.com/business/2022/jan/19/airlines-cancel-some-us-flights-over-5g-concerns">cancelled flights</a> into certain US airports over concerns the rollout of 5G mobile communication technology could interfere with some planes’ equipment. </p>
<p>After warnings about the potential problem from aviation bosses and the Federal Aviation Administration, telecommunications companies AT&T and Verizon <a href="https://www.thetimes.co.uk/article/ba-grounds-flights-to-us-over-5g-fears-7k2fhwgh2">delayed activating</a> some 5G masts around US airports.</p>
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<p>But how could 5G interfere with planes? And can the problem be fixed? Let’s take a look.</p>
<p>Currently being deployed in several countries around the world, 5G is the fifth generation of mobile phone technology. It could offer network speeds up to <a href="https://edition.cnn.com/interactive/2020/03/business/what-is-5g/">100 times faster</a> than what we’ve experienced with 4G.</p>
<p>To ensure high speeds with the widest possible coverage, AT&T and Verizon had planned to generate 5G internet using something called <a href="https://www.cnbctv18.com/aviation/explained-c-band-5g-frequency-and-how-it-can-affect-aircraft-altimeters-12186632.htm">C-band frequencies</a>, a type of radio frequencies (or radio waves) between 3.7 and 3.98 gigahertz (GHz).</p>
<p>These frequencies are adjacent to those used by modern aircraft to measure altitude. An important piece of an aircraft’s equipment, called a <a href="https://skybrary.aero/articles/radio-altimeter">radio altimeter</a>, operates on C-band frequencies between 4.2-4.4GHz. Pilots rely on radio altimeters to land the plane safely, particularly when visibility is poor, for example, when the airport is surrounded by high mountains or when conditions are foggy.</p>
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<a href="https://theconversation.com/why-5g-conspiracy-theories-prosper-during-the-coronavirus-pandemic-136019">Why 5G conspiracy theories prosper during the coronavirus pandemic</a>
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<p>The concern is that, due to the narrow gap between the frequencies of the 5G and the radio altimeters, the radio waves from 5G towers near airports could cause interference. That is, people using 5G on their phones could inadvertently distort or damage the radio altimeter’s signal. </p>
<p>If this happens, even for a few seconds, it could mean the pilot doesn’t receive the correct information during landing. It is for this reason that the US Federal Aviation Administration raised concerns.</p>
<figure class="align-center ">
<img alt="A person using their mobile phone." src="https://images.theconversation.com/files/442501/original/file-20220125-23-l1oy44.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442501/original/file-20220125-23-l1oy44.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=389&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442501/original/file-20220125-23-l1oy44.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=389&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442501/original/file-20220125-23-l1oy44.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=389&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442501/original/file-20220125-23-l1oy44.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=489&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442501/original/file-20220125-23-l1oy44.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=489&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442501/original/file-20220125-23-l1oy44.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=489&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Countries around the world have started to roll out 5G technology.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-waiting-on-station-platform-background-735607483">Maria Savenko/Shutterstock</a></span>
</figcaption>
</figure>
<h2>So what can be done?</h2>
<p>Other countries rolling out 5G are using C-band frequencies that overlap with or are close to those of radio altimeters, without <a href="https://inews.co.uk/news/technology/5g-aircraft-safety-row-us-airlines-flights-uk-europe-asia-1412971">any reported problems</a>. For example, <a href="https://www.newscientist.com/article/2304975-will-5g-mobile-networks-in-the-us-really-interfere-with-aircraft/">in the UK</a>, 5G goes up to 4GHz. Having no or few mountains around airports reduces the risk.</p>
<p>Some other countries operate their 5G on a frequency slightly further away from that of the aircraft equipment. In <a href="https://www.newscientist.com/article/2304975-will-5g-mobile-networks-in-the-us-really-interfere-with-aircraft/">the European Union</a>, for example, 5G goes up to 3.8GHz. This could be a good option for US airports.</p>
<p>The best option, in the long run, would be to use a much higher band for 5G, such as 24GHz to 47GHz. At these frequencies, data speeds are significantly higher, although the coverage area of each cell will be much less (so you would need more towers).</p>
<p>There’s also an option to reduce the signal strength from the towers around airports, which has reportedly been done <a href="https://www.newscientist.com/article/2304975-will-5g-mobile-networks-in-the-us-really-interfere-with-aircraft/">in France and Canada</a>. This is not about changing the frequency –signal strength is measured in decibels, not GHz – but limiting the signal power can reduce the likelihood of interference with neighbouring bands.</p>
<p>Another potential solution would be to adjust the frequency range of radio altimeters. But this would take a long time and probably be resource intensive for the aviation industry.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/nikola-tesla-5g-network-could-realise-his-dream-of-wireless-electricity-a-century-after-experiments-failed-158665">Nikola Tesla: 5G network could realise his dream of wireless electricity, a century after experiments failed</a>
</strong>
</em>
</p>
<hr>
<p>While the risk of an in-flight complication due to 5G interference may be very low, as we’re talking about human safety, we need to take any possible risks very seriously. The move to delay rolling out 5G masts near US airports is a good option while the relevant authorities determine the safest way forward.</p><img src="https://counter.theconversation.com/content/175215/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sufian Yousef does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The radio frequency at which 5G operates in the US is close to that of an important piece of aircraft equipment, called radio altimeters.Sufian Yousef, Associate Professor, Director of the Telecommunications Engineering Research Group, Faculty of Science and Engineering, Anglia Ruskin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1711842021-11-05T14:12:35Z2021-11-05T14:12:35ZReducing air travel by small amounts each year could level off the climate impact<figure><img src="https://images.theconversation.com/files/430219/original/file-20211104-27-q5x093.jpg?ixlib=rb-1.1.0&rect=1%2C1%2C1276%2C848&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Aviation is a significant contributor to global greenhouse gas emissions.</span> <span class="attribution"><a class="source" href="https://pixabay.com/photos/airport-travelers-persons-business-731196/">Free-Photos/Pixabay</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Just before the pandemic, aircraft engines were burning <a href="https://www.iata.org/en/iata-repository/pressroom/fact-sheets/industry-statistics/">one billion litres</a> of fuel a day. But then the number of daily civil aviation flights fell from <a href="https://www.iata.org/en/iata-repository/pressroom/fact-sheets/industry-statistics/">110,000</a> to less than 50,000 during 2020, on average. With the easing of travel restrictions, air traffic is increasing back towards its pre-pandemic peak.</p>
<p>Most world leaders and delegates will have flown to Glasgow to attend COP26 – the 26th annual UN climate change summit – in person. But as they haggle over emissions targets to limit global warming to 1.5°C, and not <a href="https://theconversation.com/cop26-what-would-the-world-be-like-at-3-c-of-warming-and-how-would-it-be-different-from-1-5-c-171030">3°C or more</a>, aviation is unlikely to be included in them, given the lack of low-carbon alternatives to long-haul flights.</p>
<p>But it should be. <a href="https://iopscience.iop.org/article/10.1088/1748-9326/ac286e">In new research</a>, my colleagues and I calculated that if the aviation sector continues to grow on its present trajectory, its jet fuel consumption will have added 0.1˚C to global warming by 2050 – half of it to date, the other half in the next three decades. </p>
<p>Aviation is responsible for 4% of the 1.2°C rise in the global mean temperature we have already experienced since the industrial revolution. Without action to reduce flights, the sector will account for 17% of the remaining 0.3°C left in the 1.5°C temperature target, and 6% of the 0.8°C left to stay within 2°C. Airlines effectively add more to global warming <a href="http://globalcarbonatlas.org/en/CO2-emissions">than most countries.</a></p>
<h2>Warming footprints</h2>
<p>At the current rate, the world will have warmed by 2°C <a href="https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM_final.pdf">within three decades</a>. To quantify how different activities contribute to warming, scientists measure carbon emissions. This is because how much the Earth warms is proportional to cumulative carbon emissions in the atmosphere. This is a very good approximation in many cases, but it is inaccurate for emissions caused by aeroplanes travelling at altitudes of up to 12 kilometres.</p>
<p>As well as CO₂, aircraft engines emit nitrogen oxides, water vapour, sulphur and soot, causing <a href="https://www.nature.com/articles/s41467-018-04068-0">contrail cirrus clouds</a> and other complicated chemical reactions in the atmosphere. The sum of these so-called non-CO₂ effects adds more warming on top of the CO₂ emissions. So the total warming footprint of aviation is between two and three times higher than a conventional carbon footprint.</p>
<figure class="align-center ">
<img alt="An aeroplane's trail viewed from between two tall buildings" src="https://images.theconversation.com/files/430221/original/file-20211104-21-xa7pet.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430221/original/file-20211104-21-xa7pet.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430221/original/file-20211104-21-xa7pet.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430221/original/file-20211104-21-xa7pet.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430221/original/file-20211104-21-xa7pet.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430221/original/file-20211104-21-xa7pet.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430221/original/file-20211104-21-xa7pet.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Condensation trails produced by aircraft engines contribute to global warming.</span>
<span class="attribution"><a class="source" href="https://pixabay.com/photos/architecture-skyscraper-skyline-3984725/">MichaelGaida/Pixabay</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>While a large share of a flight’s CO₂ emissions remain in the atmosphere for many thousands of years, the non-CO₂ effects diminish over time, <a href="https://doi.org/10.1016/j.atmosenv.2020.117834">vanishing within about ten years</a>. So any growth in aviation, measured in global jet fuel consumption, has an amplified impact as both CO₂ and non-CO₂ effects add up. </p>
<p>But a decline in aviation can partly reverse some warming, as the non-CO₂ effects disappear over time until only the CO₂ effects remain. Think of the non-CO₂ effects like a bathtub – it fills up when the taps are turned further and further, despite a slow outflow down the plughole. But the same bathtub will eventually empty if the taps are gradually turned down.</p>
<p>The non-CO₂ effects of flights on the atmosphere will slowly disappear if fewer and fewer flights are taken, so that aviation’s contribution to warming eventually levels off. In that situation, the increase from continued CO₂ emissions would balance the fall in non-CO₂ effects, and although aviation would still contribute to climate change, the total warming from both would remain constant over time. How much would aviation need to shrink to level off its influence on global warming? </p>
<p>Our calculations show that flying does not need to stop immediately to prevent aviation’s contribution to global warming expanding. Flying has already caused 0.04°C of warming to date. But with a yearly decrease of 2.5% in jet fuel consumption, currently only achievable with cuts in air traffic, this warming will level off at a constant level over the coming decades.</p>
<h2>When do we really need to fly?</h2>
<p>COVID-19 had a huge impact on the aviation sector. Air traffic is still approximately 10-20% below pre-pandemic levels, but is <a href="https://doi.org/10.1088/1748-9326/ac286e">rebounding quickly</a>. Politicians should shift subsidies from flying to more sustainable modes of transport, such as train journeys. And there is much more that can be done.</p>
<figure class="align-center ">
<img alt="An aeroplane parked at an airport" src="https://images.theconversation.com/files/430217/original/file-20211104-25-1v0sxdb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430217/original/file-20211104-25-1v0sxdb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430217/original/file-20211104-25-1v0sxdb.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430217/original/file-20211104-25-1v0sxdb.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430217/original/file-20211104-25-1v0sxdb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430217/original/file-20211104-25-1v0sxdb.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430217/original/file-20211104-25-1v0sxdb.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Forced changes in flying habits due to the pandemic have led some to permanently cut back on flights.</span>
<span class="attribution"><a class="source" href="https://pixabay.com/photos/airplane-aircraft-airport-travel-4885803/">Dmncwndrlch/Pixabay</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Lockdowns and the shift to remote working made many people rethink the necessity of flying. People resolving to fly less can contribute considerably to reducing the number of unnecessary flights. Combining in-person and virtual attendance in hybrid meetings wherever possible is a great way to support that shift.</p>
<p>Reducing the space that business classes take on aeroplanes is another way to cut the number of flights, as it allows more passengers to travel on one flight. </p>
<p>Not allowing airport expansions could also have a big impact. The UK’s Climate Change Committee, an expert body which advises the UK government, has recommended <a href="https://www.theccc.org.uk/wp-content/uploads/2020/12/Sector-summary-Aviation.pdf">not expanding airports</a> to align the sector with climate targets. Yet the expansion of Heathrow airport is currently <a href="https://www.bbc.co.uk/news/explainers-51646562">planned to go ahead</a>.</p>
<p>Sustainable aviation fuels, and hydrogen or electric planes, are being developed, but none of these technologies are currently available at the necessary scale. At the moment, there is little chance of the aviation industry meeting any climate targets if it aims for a return to its pre-pandemic rate of growth.</p>
<hr>
<figure class="align-right ">
<img alt="COP26: the world's biggest climate talks" src="https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong>This story is part of The Conversation’s coverage on COP26, the Glasgow climate conference, by experts from around the world.</strong>
<br><em>Amid a rising tide of climate news and stories, The Conversation is here to clear the air and make sure you get information you can trust. <a href="https://page.theconversation.com/cop26-glasgow-2021-climate-change-summit/"><strong>More.</strong></a></em> </p>
<hr><img src="https://counter.theconversation.com/content/171184/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Milan Klöwer receives funding from the UK's Natural Environmental Research Council, the Copernicus Programme of the European Commission and the European Research Council.</span></em></p>Reducing jet fuel consumption by 2.5% each year could halt aviation’s growing influence on climate change.Milan Klöwer, Postdoctoral Researcher in Weather and Climate Modelling, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1511802021-01-25T13:29:51Z2021-01-25T13:29:51ZWhy does it take longer to fly from east to west on an airplane?<figure><img src="https://images.theconversation.com/files/378155/original/file-20210111-17-hrdaro.jpg?ixlib=rb-1.1.0&rect=0%2C50%2C1533%2C970&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The jet stream can have a big impact on how long a plane ride will last.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/w/index.php?title=Special:Search&limit=500&offset=500&profile=default&search=boeing+747&advancedSearch-current=%7B%7D&ns0=1&ns6=1&ns12=1&ns14=1&ns100=1&ns106=1&searchToken=6ddmgacgqvctsdphhxwo6ty0n#%2Fmedia%2FFile%3AG-CIVA_Boeing_747_British_Airways_%288401802240%29.jpg">Aeroprints via Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p><strong>Why does it take longer to fly from east to west on an airplane? – Henry D, Age 7, Cambridge, Massachusetts</strong></p>
</blockquote>
<hr>
<p>I am a retired <a href="https://www.unomaha.edu/college-of-public-affairs-and-community-service/aviation/about-us/faculty-staff/skip-bailey.php">United States Air Force pilot and flight instructor</a>, and a few years ago I was sitting in the cockpit of a Boeing 747 airplane. I was 29,000 feet in the sky, flying from New Jersey to Sacramento, California, and then to Hawaii. It took six hours to fly and land the plane safely in Sacramento. After a few hours in California, I continued to Hawaii,which took almost another five hours of flying. That was 11 total hours of flying. </p>
<p>After enjoying the sunshine in Hawaii, it was time to fly back to New Jersey. This trip went much faster. I didn’t stop in California this time, but flying back only took about eight and a half hours. I was still flying the same airplane, and New Jersey wasn’t any closer to California or Hawaii than it had been a few days before. </p>
<p>So why was my flight to Hawaii, from east to west, so much longer than my flight home?</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/378134/original/file-20210111-13-mc63ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A graphic showing the rough locations of jet streams around the globe." src="https://images.theconversation.com/files/378134/original/file-20210111-13-mc63ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/378134/original/file-20210111-13-mc63ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=345&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378134/original/file-20210111-13-mc63ul.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=345&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378134/original/file-20210111-13-mc63ul.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=345&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378134/original/file-20210111-13-mc63ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=433&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378134/original/file-20210111-13-mc63ul.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=433&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378134/original/file-20210111-13-mc63ul.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=433&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Jet streams always blow from west to east and can found in many places around the world.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Jet_stream#/media/File:Jetstreamconfig.jpg">Lyndon State College Meteorology via Wikipedia</a></span>
</figcaption>
</figure>
<h2>Riding on a river of air</h2>
<p>The reason it took so much longer to fly back is the <a href="https://en.wikipedia.org/wiki/Jet_stream">jet stream</a>, a river of fast-moving air high up in the sky. </p>
<p>Jet streams are usually about 100 miles wide. They can be thousands of miles long and are found all over the earth. To be called a jet stream, the wind must be moving faster than 60 mph. </p>
<p>Jet streams generally blow from the west to the east around the Earth, often <a href="https://doi.org/10.1029/2008GL033614">following a meandering, curved path</a> just like a river on land. The jet stream over the United States never stays in one place – it tends to move <a href="https://doi.org/10.1175/1520-0469(1961)018%3C0172:TSJSOW%3E2.0.CO;2">farther south and blow stronger in the winter</a>, and to move farther north and not blow as strong in the summer. </p>
<p>So what does this have to do with planes?</p>
<h2>Flying into the wind</h2>
<p>Airplane pilots measure speed in two different ways. First is airspeed – how fast the wind would feel if you stuck your hand out the window. The second is ground speed – how fast the plane is moving over the ground. When you fly in the jet stream, your airspeed always stays the same, but your ground speed can change a lot because the air around the plane is moving.</p>
<p>On the way to Hawaii, I was flying with an airspeed of 562 mph. But because the jet stream was blowing against my airplane – called a headwind – at 140 mph, I was actually only moving across the ground at 422 mph.</p>
<p>But flying from Hawaii to New Jersey, the jet stream blows from behind the plane and pushes it forward. I was still flying with an airspeed of 562 mph, but the 140 mph tailwind meant that my airplane was moving across the ground at 702 mph.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/378135/original/file-20210111-15-4p9wus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A graphic showing how routes differ when a plan flies from east to west or west to east." src="https://images.theconversation.com/files/378135/original/file-20210111-15-4p9wus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378135/original/file-20210111-15-4p9wus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=275&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378135/original/file-20210111-15-4p9wus.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=275&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378135/original/file-20210111-15-4p9wus.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=275&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378135/original/file-20210111-15-4p9wus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=346&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378135/original/file-20210111-15-4p9wus.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=346&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378135/original/file-20210111-15-4p9wus.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=346&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Planes will try to avoid the jet stream when flying east to west, but try to hitch a ride on the way back.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Jet_stream#/media/File:Greatcircle_Jetstream_routes.svg">ChaosNil via Wikipedia</a></span>
</figcaption>
</figure>
<h2>Pilots plan to go fast</h2>
<p>When pilots plan the route of their flights, they often use weather forecasts <a href="https://doi.org/10.1175/1520-0493(1981)109%3C2450:COTWPJ%3E2.0.CO;2">to find where the jet stream is blowing</a>. When they fly from the east to the west, they try <a href="https://simpleflying.com/why-aircraft-dont-fly-in-a-straight-line-from-origin-to-destination/">to plan their flight</a> so the jet stream isn’t blowing against their airplane and giving them a bad headwind. When they plan their flight from the west to the east, they look for the jet stream and try to fly so it can give them a big tailwind and help them fly faster. A good plan can help conserve fuel too.</p>
<p>The next time you are flying high across the country from east to west, don’t be surprised when it takes a little longer than you expect. But be excited knowing that when you fly back your pilot is probably hitching a ride along the jet stream to get you home fast.</p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/151180/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Skip Bailey does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>When planes fly from east to west, they are flying against a river of air called a jet stream. These air currents can make your flight longer or shorter, depending on which way you are going.Skip Bailey, Aviation Institute Flight Training Coordinator and Instructor, University of Nebraska OmahaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1374722020-05-27T13:48:29Z2020-05-27T13:48:29ZGreen bailouts: relying on carbon offsetting will let polluting airlines off the hook<figure><img src="https://images.theconversation.com/files/337949/original/file-20200527-20215-8iv9h9.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3992%2C2992&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/D59013q1Um4">Dan Meyers/Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The coronavirus pandemic has grounded thousands of aircraft, contributing to the <a href="https://www.theguardian.com/environment/2020/may/19/lockdowns-trigger-dramatic-fall-global-carbon-emissions">largest-ever annual fall in CO₂ emissions</a>. At some point though, the planes will soar again and with them, global emissions.</p>
<p>Most airlines in the UK have committed to achieving <a href="https://www.sustainableaviation.co.uk/wp-content/uploads/2020/02/SustainableAviation_CarbonLeaflet_20200129.pdf">net zero carbon emissions by 2050</a>. From 2026, it will become mandatory for airlines worldwide to ensure that <a href="https://www.icao.int/environmental-protection/Pages/A39_CORSIA_FAQ2.aspx">their annual emissions</a> stay flat. But the UK aviation industry also plans to <a href="https://www.theguardian.com/business/2020/feb/04/uk-air-industry-sets-zero-carbon-target-despite-70-more-flights">increase the number of passengers it serves by 70%</a> in the next three decades.</p>
<p>To pull this off, airlines will be planning to fly planes at or near full passenger capacity and use cleaner burning fuels. But the rest of the emissions airlines hope to cut – between one-third and half of the total – are expected to come from <a href="https://www.sustainableaviation.co.uk/wp-content/uploads/2020/02/SustainableAviation_CarbonLeaflet_20200129.pdf">market-based measures</a>, such as carbon offsetting and emissions trading. </p>
<p>You’ve probably encountered an option to offset your carbon footprint when buying a flight. The payment page of Ryanair’s website suggested a “carbon offset contribution” of £2 for a return flight from Gatwick to Alicante. <a href="https://theconversation.com/why-airline-bailouts-are-so-unpopular-with-economists-137372">Airlines seeking government bailouts</a> are likely to use carbon offsetting and emissions trading to show they’re serious about putting their emissions on a downward trajectory. But what do they involve and are they really a solution to climate change? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/336997/original/file-20200522-124840-1qas24c.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/336997/original/file-20200522-124840-1qas24c.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/336997/original/file-20200522-124840-1qas24c.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=244&fit=crop&dpr=1 600w, https://images.theconversation.com/files/336997/original/file-20200522-124840-1qas24c.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=244&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/336997/original/file-20200522-124840-1qas24c.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=244&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/336997/original/file-20200522-124840-1qas24c.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=306&fit=crop&dpr=1 754w, https://images.theconversation.com/files/336997/original/file-20200522-124840-1qas24c.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=306&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/336997/original/file-20200522-124840-1qas24c.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=306&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Tick this box and all your carbon sins will be forgiven.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/stoweboyd/1469456837/in/photolist-3eRmjH-eMPDB9-ceV8do-ceV8H9-3vkiDp-8YkrtQ-LKh7H-59BuXW-tJMJzL-5fwiRo-5jx4F6-5QDWAz-575MBS-5iutK6-53qkut-77Wqba-bpXWK4-8c6Mna-9XiR4p-9XmEJ9-7X6BBh-858mMs-7fCXr7-2hthWEi-uUfxN5-5JRFqN-5L57Pf-ud1r3q-2gxxtJc-2eoQVoH-4iWPJ5-8iNFe9-2eAH8Tf-fyB5JC-6d3YK2-7e3pSP-2h1TfAv-8PnmQ9-cegdfG-22pqecU-ceV58w-59njvL-wbdDxQ-9GbQPC-6d3YPF-48B6X3-apX3zY-9LS1XC-7YbYsa-2kq32V">Stowe Boyd/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Avoiding upsets with offsets</h2>
<p>The idea of offsets is to cancel out your own emissions by reducing equivalent emissions elsewhere. This could be by purchasing carbon credits from an <a href="https://www.theguardian.com/environment/2011/jul/05/what-is-emissions-trading">emissions trading scheme</a>, where one credit typically equals one metric tonne of CO₂. When a carbon credit is “retired” – essentially ripped up – it saves one tonne of CO₂ from being emitted by the countries or companies that sell them. </p>
<p>Alternatively, you can invest in offsetting schemes – called clean development mechanisms – which aim to reduce future emissions in developing countries by providing greener cooking stoves, for example. There are also carbon removal schemes which aim to actively absorb carbon by planting trees, or developing technologies that can absorb carbon from the air.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-airline-bailouts-are-so-unpopular-with-economists-137372">Why airline bailouts are so unpopular with economists</a>
</strong>
</em>
</p>
<hr>
<p>Only a decade ago, carbon offsetting was largely voluntary and schemes were unverified and unregulated. Broken promises and schemes causing <a href="https://www.telegraph.co.uk/science/2019/08/20/carbon-offsetting-may-increase-pollution-experts-warn-rich-cant/">more harm than good</a> abounded. Today, there are several trustworthy schemes that can verify the work of offsetting projects, such as the <a href="https://verra.org/project/vcs-program/">Verified Carbon Standard</a>. As the popularity of offsetting schemes increases, regulation continues to improve. Even the Intergovernmental Panel on Climate Change trusts carbon offsetting to ensure its meetings – which involve delegates flying from around the world – are <a href="https://www.ipcc.ch/2018/06/15/ipcc-meetings-go-carbon-neutral/">carbon neutral</a>.</p>
<p>But whether these schemes actually make sufficiently deep carbon cuts over an effective timescale to actually slow climate change is another matter. With tree planting, it can take a long time for newly planted trees to start storing carbon, and it’s difficult to accurately predict how much carbon each tree will put away during its lifetime. That carbon is easily re-released during forest fires or as a result of deforestation.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/337957/original/file-20200527-20229-u4lup3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/337957/original/file-20200527-20229-u4lup3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/337957/original/file-20200527-20229-u4lup3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/337957/original/file-20200527-20229-u4lup3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/337957/original/file-20200527-20229-u4lup3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/337957/original/file-20200527-20229-u4lup3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/337957/original/file-20200527-20229-u4lup3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Tree planting isn’t the panacea for climate change many would like it to be.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/tree-planting-uganda-close-many-small-756780151">Dennis Wegewijs/Shutterstock</a></span>
</figcaption>
</figure>
<p>Carbon credit trading and carbon offsetting schemes can support projects which reduce emissions and remove carbon from the atmosphere if they’re sufficiently ambitious – and they should be going ahead anyway, without their benefits being cancelled out by businesses using these schemes to continue polluting. For example, a tax on airlines and customers could fund offsetting projects that aim to cut at least double the units of carbon emitted per flight, with frequent flyers being taxed more heavily.</p>
<p>But sustainability targets for airlines need to be based on real emissions cuts at their source. That would mean drastically reducing the number of flights each year, especially those with reasonable travel alternatives such as rail. As a condition for any post-COVID-19 bailout, airlines should invest heavily in the research and development of technologies that can make flights carbon-neutral, such as <a href="https://www.theguardian.com/world/2020/may/27/worlds-largest-all-electric-aircraft-set-for-first-flight?CMP=share_btn_tw">electric engines and batteries</a>. The marketing of rescued airlines should also be honest with customers about the climate impact of their flight.</p>
<p>Aviation will need to change drastically to shrink its contribution to climate change. As governments consider state aid for flagging airlines, they have a rare opportunity to enforce lasting changes. But if offsetting is earmarked as the principal way for them to reach net zero emissions – with no reduction in the number of flights or control over how airlines invest their revenue, these efforts could become little more than greenwashing. When it comes to meaningful action on aviation emissions, now is the time to get our heads out of the clouds.</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1137472">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/137472/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ben Christopher Howard does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Carbon offsetting is better regulated than it once was, but it’s no solution to the climate crisis.Ben Christopher Howard, Doctoral Researcher in Nature-based Solutions, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1380672020-05-13T09:46:20Z2020-05-13T09:46:20ZGrounded aircraft could make weather forecasts less reliable<figure><img src="https://images.theconversation.com/files/334307/original/file-20200512-175219-10h3lol.jpg?ixlib=rb-1.1.0&rect=0%2C561%2C3350%2C927&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/plane-cemetery-mojave-desert-47675509">Darren J. Bradley/Shutterstock</a></span></figcaption></figure><p>Thanks to travel restrictions and plummeting customer demand, the number of flights in the first week of April 2020 was down <a href="https://www.businessinsider.com/air-traffic-during-coronavirus-pandemic-changes-effects-around-the-world-2020-4?r=US&IR=T">61%</a> compared with the same period in 2019. The pandemic has emptied the skies of aircraft, but it’s not just the airline industry that’s reeling from the sudden change. </p>
<p>Aircraft possess some of the most advanced electronic equipment available, some of which monitors the atmosphere during flight. You might not realise it during your flight, but aeroplanes automatically feed data to meteorologists who use it to create weather forecasts.</p>
<p>Since 1998, the Aircraft Meteorological Data Relay (AMDAR) system has collected data from 43 airlines, using devices on <a href="https://www.wmo.int/pages/prog/www/GOS/ABO/data/statistics/">thousands of aircraft</a>. These aeroplanes continuously record air temperature and pressure, wind speed, turbulence and water vapour and relay this via radio or satellite. On the ground, meteorologists input this data, along with data from ocean buoys, weather balloons and ground stations, into weather prediction models.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/334312/original/file-20200512-175246-xashei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334312/original/file-20200512-175246-xashei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334312/original/file-20200512-175246-xashei.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334312/original/file-20200512-175246-xashei.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334312/original/file-20200512-175246-xashei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334312/original/file-20200512-175246-xashei.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334312/original/file-20200512-175246-xashei.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A solar-powered buoy collects weather data in the Gulf of Mexico.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/solar-powered-buoy-gulf-mexico-off-1432924634">EngineerPhotos/Shutterstock</a></span>
</figcaption>
</figure>
<p>Weather data from aircraft is <a href="https://www.ecmwf.int/en/about/media-centre/news/2020/drop-aircraft-observations-could-have-impact-weather-forecasts">considered</a> “second only to satellite data in their impact on forecasts”, according to experts. Aircraft collected more than one million meteorological observations <a href="https://www.theguardian.com/news/2020/apr/09/decline-aircraft-flights-clips-weather-forecasters-wings-coronavirus">each day in 2019</a> around the world, but aircraft-based observations in 2020 have fallen by up to <a href="https://public.wmo.int/en/media/press-release/covid-19-impacts-observing-system">90%</a> in some regions. How is all this affecting the weather forecast we check each day?</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-future-do-airlines-have-three-experts-discuss-135365">What future do airlines have? Three experts discuss</a>
</strong>
</em>
</p>
<hr>
<h2>Filling the gaps</h2>
<p>Mathematical models use current weather conditions and complex atmospheric physics to generate a forecast. Aircraft observations taken during take-off and landing are most useful for surface weather forecasting, whereas those taken in flight are important for forecasting the weather at altitudes where aeroplanes fly. </p>
<p>But even high altitude observations are relevant for surface weather predictions, as water vapour measurements are used for modelling cloud formation. <a href="https://www.tandfonline.com/doi/pdf/10.1080/16742834.2012.11446995">Research</a> has also shown that aircraft observations help improve the accuracy of hurricane forecasts. Global climate models need global observations and, for many parts of the planet, particularly over the oceans, AMDAR is the only data source.</p>
<p>Studies have demonstrated that aircraft-based observations can reduce errors in forecasts by up to <a href="https://www.wmo.int/pages/prog/www/GOS/ABO/AMDAR/publications/Benefit_of_AMDAR_Data_to_Meteorology_and_Aviation.pdf">20%</a>. It’s thought that losing all aircraft data would reduce the accuracy of short-term flying level forecasts that are crucial for flight planning by up to <a href="https://www.ecmwf.int/en/about/media-centre/news/2020/drop-aircraft-observations-could-have-impact-weather-forecasts">15%</a>. </p>
<p>A similar drop in forecast accuracy was seen in <a href="https://www.wmo.int/pages/prog/www/GOS/ABO/AMDAR/publications/Benefit_of_AMDAR_Data_to_Meteorology_and_Aviation.pdf">Europe and the North Atlantic</a> in 2010, when the Icelandic volcano Eyjafjallajökull erupted and forced the airspace in the region to close. One of the implications of aircraft weather observations being down 90% is that aeroplanes that continue flying have less accurate forecasting to guide them, particularly over parts of the Earth with less regular monitoring.</p>
<p>Organisations such as the European National Meteorological Service are <a href="https://www.eumetnet.eu/working-together-to-minimise-the-impact-of-covid-19/">launching additional weather balloons</a> to try to fill the data gaps left by grounded aeroplanes. <a href="http://flyht.com/flyht-distribute-complimentary-tamdar-data-covid-19-national-emergency/">Efforts are afoot</a> to ensure that any aircraft data that is gathered is made available to members of the World Meteorological Organisation – the UN agency for weather forecasting. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/334309/original/file-20200512-175224-10qscu0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334309/original/file-20200512-175224-10qscu0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334309/original/file-20200512-175224-10qscu0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334309/original/file-20200512-175224-10qscu0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334309/original/file-20200512-175224-10qscu0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=525&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334309/original/file-20200512-175224-10qscu0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=525&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334309/original/file-20200512-175224-10qscu0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=525&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A meteorologist launches a weather balloon from Australia’s most remote weather station.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/giles-western-australia-august-19-2010launching-1226482195">Edward Haylan/Shutterstock</a></span>
</figcaption>
</figure>
<p>Meteorologists can also rely on satellite sensors monitoring cloud cover, rainfall and temperature. With impeccable timing, the new <a href="https://www.esa.int/Applications/Observing_the_Earth/Aeolus/Introducing_Aeolus">Aeolus</a> satellite <a href="https://www.ecmwf.int/en/about/media-centre/news/2020/ecmwf-starts-assimilating-aeolus-wind-data">started delivering data</a> on wind direction and speed from January 2020. Before, all of these measurements over oceans and remote regions were done by aircraft.</p>
<p>So in spite of COVID-19, weather forecasting will continue but, with fewer observations, forecasts in the short term may become less reliable, particularly in remote regions where less data was collected already. Pilots will only fly if they are content with the quality of forecasts, so there’s unlikely to be any risk to human life. But as we enter the Atlantic hurricane season, which is predicted <a href="https://engr.source.colostate.edu/csu-researchers-predicting-active-2020-atlantic-hurricane-season/">to be more active than usual</a>, the most reliable forecasts may be harder to come by initially. That could make the outcomes of hurricane tracking models less certain.</p>
<p>Flight numbers are expected to <a href="https://www.iata.org/en/pressroom/pr/2020-04-21-01/">recover to normal slowly</a>. Until they do, patchy weather forecasts are another effect of the pandemic that’s going to take some getting used to.</p><img src="https://counter.theconversation.com/content/138067/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Blackett does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>More than one million weather observations were made by aircraft each day in 2019. Since the pandemic started, these have dropped by 90%.Matthew Blackett, Reader in Physical Geography and Natural Hazards, Coventry UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1173502020-02-14T16:01:45Z2020-02-14T16:01:45ZPlane, train, or automobile? The climate impact of transport is surprisingly complicated<p>The 2020s will have to involve some very big decisions about transport – <a href="https://www.independent.co.uk/environment/air-pollution-uk-transport-most-polluting-sector-greenhouse-gas-emissions-drop-carbon-dioxide-a8196866.html">the UK’s most polluting sector</a>. The UK government’s response so far has been erratic, choosing to <a href="https://news.sky.com/story/flybe-set-for-crunch-whitehall-talks-over-bailout-terms-11932524">intervene to prevent the collapse of Flybe</a> (Europe’s biggest regional airline) and give the <a href="https://www.theguardian.com/uk-news/2020/feb/11/hs2-to-go-ahead-boris-johnson-tells-mps">green light for the high-speed rail project, HS2</a>.</p>
<p>Decarbonising transport would eliminate <a href="https://theconversation.com/decarbonising-britains-railways-demands-urgent-action-heres-how-it-could-be-done-124905">26% of UK CO₂ emissions</a> that come from how people get around. But Prime Minister Boris Johnson recently said that doing this poses “<a href="https://www.theguardian.com/uk-news/2020/feb/11/hs2-to-go-ahead-boris-johnson-tells-mps">difficult and complicated</a>” questions. On this, Johnson is almost certainly right.</p>
<p>The <em><a href="https://theconversation.com/uk/topics/gilets-jaunes-62467">gilets jaunes</a></em> protests against fuel duty rises in France show <a href="https://theconversation.com/emmanuel-macrons-carbon-tax-sparked-gilets-jaunes-protests-but-popular-climate-policy-is-possible-108437">the delicate balancing act</a> between decisive climate action and continued economic growth and convenience. But shouldn’t the government allow a regional flight operator to fail and invest in high-speed rail instead? The answer is not so simple.</p>
<h2>Carbon footprints can be misleading</h2>
<p>Aviation is one of the <a href="https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/grl.50161">fastest growing fossil fuel consumers</a>, with airlines contributing about <a href="https://www.sciencedirect.com/science/article/pii/S1352231009004956#tbl1">3.5% of all man-made greenhouse gas emissions</a>. This might seem small, but a single transatlantic flight from London to New York can grow your personal <a href="https://ec.europa.eu/clima/policies/transport/aviation_en">carbon footprint</a> by as much as the entire heating budget of the average European.</p>
<p>At high altitudes, contrails – the white lines we see in the sky – are formed in the wake of aircraft. These high altitude clouds are too thin to reflect much sunlight, but the ice crystals inside them can trap heat. Unlike low-level cloud, which has a net-cooling effect, contrails contribute significantly to global warming, effectively boosting the aviation industry’s share of greenhouse gas emissions to around <a href="https://www.sciencedirect.com/science/article/pii/S1352231009004956#tbl1">4.9%</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/315513/original/file-20200214-11011-8hr434.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/315513/original/file-20200214-11011-8hr434.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/315513/original/file-20200214-11011-8hr434.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/315513/original/file-20200214-11011-8hr434.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/315513/original/file-20200214-11011-8hr434.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/315513/original/file-20200214-11011-8hr434.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/315513/original/file-20200214-11011-8hr434.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Flights warm the atmosphere by more than the contribution of their CO₂ emissions alone.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/airplane-big-four-engines-aviation-airport-597813428">Aapsky/Shutterstock</a></span>
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<p>For the most part, the environmental benefit of high-speed rail is taken for granted. Most, but not all, research suggests that <a href="https://theconversation.com/with-planning-high-speed-rail-could-reduce-flight-demand-21687">high-speed rail can offset emissions from aviation</a> if it can attract enough passengers from alternative air routes. But the relative climate impacts of aviation to other modes of transport depend on more than just engines and altitude.</p>
<p>We can compare the emissions of different forms of transport by calculating the emissions produced by each one when moving <a href="https://ec.europa.eu/eurostat/statistics-explained/index.php/Glossary:Passenger-kilometre">one passenger one kilometre</a>. This effectively compares how much CO₂ leaves each vehicle’s exhaust, but it ignores greenhouse gas emissions from the building and maintenance of the vehicles, the infrastructure – such as tracks, runways and airports – and the production of fuel.</p>
<p>The warming effects of different greenhouse gases <a href="https://pubs.acs.org/doi/pdf/10.1021/es9039693">happen over different time periods</a>, from a few days of short intensive warming to centuries of gentle influence. In order to provide a common unit to measure the impact of different gases, warming effects are standardised over a given time period. The time period normally used is <a href="https://www.epa.gov/ghgemissions/understanding-global-warming-potentials">100 years</a>. </p>
<p>But if it were five years, the effect of contrails would account for more global warming than all the cars in the world. They raise the temperature of the atmosphere in short, intense bursts. On longer timescales, like 20 years, the short term effects are less important and make aviation look considerably better – with flying looking potentially less damaging than some cars over the same distance.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/315510/original/file-20200214-10995-1vqbls4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/315510/original/file-20200214-10995-1vqbls4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/315510/original/file-20200214-10995-1vqbls4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/315510/original/file-20200214-10995-1vqbls4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/315510/original/file-20200214-10995-1vqbls4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/315510/original/file-20200214-10995-1vqbls4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/315510/original/file-20200214-10995-1vqbls4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Most comparisons only consider the emissions that come from vehicles while they’re in use.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/close-car-exhaust-pipe-1144696811">Khunkorn/Shutterstock</a></span>
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<p>This is still not the whole story though. The energy inputs for different modes of travel vary. The direct burning of fossil fuels in engines, for example jet kerosene in aircraft, emits greenhouse gases. In electrically powered high-speed rail, operating the train produces no emissions, except from the fossil fuels used to generate that electricity elsewhere. </p>
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Read more:
<a href="https://theconversation.com/electric-cars-wont-save-the-planet-without-a-clean-energy-overhaul-they-could-increase-pollution-118012">Electric cars won't save the planet without a clean energy overhaul – they could increase pollution</a>
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<p>Developing HS2 will mean deploying stations, tracks and centres of communication, and they’ll need ongoing maintenance. These all need energy and material investments, which will create further greenhouse gas emissions through manufacture, transport, and use. That could <a href="https://iopscience.iop.org/article/10.1088/1748-9326/4/2/024008/pdf">increase the carbon footprint of rail by between 1.8 and 2.5 times</a>, over just accounting for the operation of the trains. For aviation, the same infrastructure requirements are relatively small, and are responsible for a 1.2–1.3 increase, with road transport showing a 1.4–1.6 increase.</p>
<h2>Comparing life cycles</h2>
<p>A life cycle approach gives a better understanding of where emissions are occurring and compares transport modes on a much more level playing field. This helps us understand that most greenhouse gas emissions in <a href="https://iopscience.iop.org/article/10.1088/1748-9326/4/2/024008/pdf">air and road travel come from flying and driving</a>, whereas in rail travel, the climate effects are dominated by those emissions produced building the infrastructure itself. Emissions from operating trains are generally lower because of the heavy reliance on electricity. But there are still emissions from the manufacture and maintenance of <a href="http://www.world-nuclear.org/uploadedFiles/org/WNA/Publications/Working_Group_Reports/comparison_of_lifecycle.pdf">renewable energy technologies</a> to consider.</p>
<p>All modes of high-speed travel come with a <a href="https://www.sciencedirect.com/science/article/pii/S1361920911001155#b0075">cost to the environment</a>. Being able to accurately compare the energy requirements and emissions of different transport options is the first step towards addressing their climate impact.</p>
<p>Governments often try to encourage people to change their behaviour and <a href="https://www.sciencedirect.com/science/article/pii/S0959652610003549">reduce the number of flights they take</a>. But in the case of HS2, the continued availability of regional flights means that only <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/365065/S_A_1_Economic_case_0.pdf">4% of drivers and only 1% of aeroplane passengers</a> are likely to change their behaviour. </p>
<p>It’s easy to point the finger at aviation and view rail as a low carbon alternative. But governments need to consider and carefully balance the true climate impacts of a transport project, in every phase of its development.</p><img src="https://counter.theconversation.com/content/117350/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laurie Wright is affiliated with the American Center for Life Cycle Assessment (ACLCA) and the Forum for Sustainability through Life Cycle Innovation (FSLCI) . He receives funding from the EU Interreg program.</span></em></p>All modes of high-speed travel come with a cost to the environment.Laurie Wright, Senior Lecturer, Warsash School of Maritime Science and Engineering, Solent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1316132020-02-13T15:23:23Z2020-02-13T15:23:23ZClimate change means longer take-offs and fewer passengers per aeroplane – new study<figure><img src="https://images.theconversation.com/files/315259/original/file-20200213-11044-e62imy.jpg?ixlib=rb-1.1.0&rect=308%2C0%2C2660%2C1990&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/airplane-take-off-manchester-airport-england-69698059">Andrew Barker/Shutterstock</a></span></figcaption></figure><p>The connection between your next flight and climate change is likely clear in your head. More aeroplanes emitting <a href="https://www.icao.int/environmental-protection/Pages/aircraft-engine-emissions.aspx">greenhouse gases</a> means more global warming. Simple enough, but there’s an opposite side that you probably hadn’t thought of. </p>
<p>As the local climates at airports around the world have changed in the past few decades, the conditions that pilots have relied on in order to take off safely have changed too. <a href="https://link.springer.com/article/10.1007%2Fs10584-019-02634-z">Our new research</a> suggests that higher temperatures and weaker winds are making take-off more difficult. In the long run, this means that airlines are delivering fewer passengers and cargo for the same amount of fuel.</p>
<p>“Climate” essentially <a href="https://www.nasa.gov/audience/forstudents/5-8/features/nasa-knows/what-is-climate-change-58.html">means the average weather conditions</a> at any given place. Scientists know this is changing, but not uniformly. While global temperatures <a href="https://www.gov.uk/guidance/climate-change-explained">have risen by about 1°C on average</a>, some places have warmed by much more already – and others may be getting cooler. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/travel-the-world-without-destroying-it-imagine-newsletter-5-121269">Travel the world without destroying it – Imagine newsletter #5</a>
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<p>But climate change isn’t just about temperature – <a href="https://www.conservationmagazine.org/2014/09/the-forgotten-part-of-climate-change-slower-winds/">winds are slowing down and changing direction around the world too</a>. This is a problem for airport runways that were built many years ago to align with the prevailing winds at the time. </p>
<p>Research has predicted that take-off distances <a href="http://www.theurbanclimatologist.com/uploads/4/4/2/5/44250401/coffeletal2017aviationtakeoff.pdf">will get longer</a> as the climate warms. This is because higher temperatures reduce air density, which the wings and engines need to get airborne. With reduced headwinds, aeroplanes also need to generate more groundspeed just to get into the air. Once they’re up there, they’re subject to <a href="https://phys.org/news/2019-08-jetstream-aircraft-turbulence-climate.html">in-flight turbulence, which is getting worse</a> due to climate change increasing the energy in jet stream winds. </p>
<p><a href="https://www.weforum.org/agenda/2016/07/this-visualization-shows-you-24-hours-of-global-air-traffic-in-just-4-seconds/">More than 100,000 aircraft</a> regularly take off and land around the world each day. The record so far is <a href="https://www.independent.co.uk/travel/news-and-advice/flights-sky-map-worldwide-air-traffic-aviation-busiest-day-june-a8428451.html">202,157, on June 29 2018</a>. How are all these changes likely to be affecting them? With colleagues in Britain and <a href="https://www.athena-innovation.gr/en/environment_network_technologies_unit_dm">Greece</a>, we decided to look at what has happened so far. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1013088775973556224"}"></div></p>
<h2>Running out of runway</h2>
<p>We have been recording the weather at ten Greek airports since 1955. For each year, we took the average wind and overnight minimum temperatures, and then plugged that into performance graphs. These are used to calculate the safe runway lengths and aeroplane weights that are needed to ensure that airlines can carry their passengers safely.</p>
<p>Temperature changes varied a lot between the airports we studied, between a 2°C and 5°C temperature rise over the 62 years we had data for. So did wind. At one airport, the average speed of wind passing down the runway towards the aeroplane as it took off (known as headwinds) increased by about 25%. At the other extreme, another airport saw average headwinds on the airport’s runway fall by 90% over 43 years. </p>
<p>We found that in every case the conditions had changed over the 62 years to make aeroplane take-off more difficult. Safety regulations ensure that aeroplanes are never allowed to take off without enough runway, but on the longer runways we studied, the take-off distances necessary to get a large jet plane into the air had increased by about 1.5% every decade, and about 1% for a smaller turboprop airliner. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/315079/original/file-20200212-61935-1l0sexc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/315079/original/file-20200212-61935-1l0sexc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/315079/original/file-20200212-61935-1l0sexc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/315079/original/file-20200212-61935-1l0sexc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/315079/original/file-20200212-61935-1l0sexc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/315079/original/file-20200212-61935-1l0sexc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/315079/original/file-20200212-61935-1l0sexc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This Boeing 737 is used for research at Cranfield University. Small aircraft like this are the mainstay of smaller airports, and likely to be the most affected by climate change.</span>
<span class="attribution"><span class="source">Guy Gratton</span>, <span class="license">Author provided</span></span>
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<p>In airports with shorter runways, aircraft have to reduce weight. This is all worked out before take-off – cargo, passenger numbers and fuel loads are adjusted accordingly. In the most extreme case we studied this meant that planes were taking off with one passenger fewer (or about 40 kilometres worth of fuel less) each year. These aeroplanes are climbing less steeply after take-off, creating more pollution and noise nuisance on the ground.</p>
<p>We conducted this research in Greece, but other global studies <a href="http://www.theurbanclimatologist.com/uploads/4/4/2/5/44250401/coffeletal2017aviationtakeoff.pdf">have found similar trends</a> elsewhere in the world. Small airports – such as those on <a href="https://www.visitscotland.com/travel/getting-around-scotland/air/">islands off Scotland</a> or in the <a href="https://www.tripsavvy.com/airport-info-every-caribbean-destination-1487877">Caribbean</a> – are likely to suffer the most as the climate continues to change.</p>
<p>That could mean that airlines must reduce the numbers of passengers they carry on flights, or search for ways to lengthen their runways. In some extreme cases, it could become impossible for some aeroplanes to use some airports altogether. This is another reminder of how rapidly and extensively human actions are transforming the world around us, and how ill equipped we are to deal with the consequences.</p>
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<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1131613">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/131613/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul D. Williams has received funding from the Royal Society, Natural Environment Research Council, Leverhulme Trust, and Heathrow Airport.</span></em></p><p class="fine-print"><em><span>Guy Gratton does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Weaker winds and higher temperatures are making airlines less efficient.Guy Gratton, Associate Professor of Aviation and the Environment, Cranfield UniversityPaul Williams, Professor of Atmospheric Science, University of ReadingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1303342020-01-22T15:22:31Z2020-01-22T15:22:31ZCould sleeper trains replace international air travel?<figure><img src="https://images.theconversation.com/files/311434/original/file-20200122-117927-152ikmd.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5395%2C3214&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/railway-line-night-train-motion-electric-767205820">Artmans/Shutterstock</a></span></figcaption></figure><p>Dutch airline KLM recently launched a new advertising campaign called “<a href="https://www.youtube.com/watch?v=L4htp2xxhto">Fly Responsibly</a>”. Remarkably, it seems to encourage viewers to fly less. “Do you always have to meet face-to-face?”, the advert asks. “Could you take the train instead?”.</p>
<p>The influence of climate campaigner Greta Thunberg likely explains why airlines feel obliged to say these things. <a href="https://theconversation.com/flight-shame-flying-less-plays-a-small-but-positive-part-in-tackling-climate-change-125440">Flight shame</a> – or “<em>flygskam</em>” – has gripped many regular flyers with a sense of unease about the aviation industry, which <a href="https://www.sciencedirect.com/science/article/abs/pii/S1352231014004889">consumes five million barrels of oil a day</a> and is predicted to account for around <a href="http://www.europarl.europa.eu/RegData/etudes/STUD/2015/569964/IPOL_STU(2015)569964_EN.pdf">22% of global carbon emissions</a> by 2050.</p>
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Read more:
<a href="https://theconversation.com/travel-the-world-without-destroying-it-imagine-newsletter-5-121269">Travel the world without destroying it – Imagine newsletter #5</a>
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<p>European high-speed rail networks already offer an alternative to air traffic between European countries for distances shorter than 1,000 kilometres. For longer journeys, sleeper trains are becoming increasingly popular. These services run through the night and offer passengers a berth to sleep in. As more and more consumers question the ethics of their next flight, rail companies see an opportunity – and competition with airlines is heating up. </p>
<p>But can night trains help offset the international journeys that most people currently make by aeroplane?</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/311384/original/file-20200122-117938-1gi386a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311384/original/file-20200122-117938-1gi386a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311384/original/file-20200122-117938-1gi386a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311384/original/file-20200122-117938-1gi386a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311384/original/file-20200122-117938-1gi386a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311384/original/file-20200122-117938-1gi386a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311384/original/file-20200122-117938-1gi386a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Because of the altitude at which aeroplanes fly, their carbon emissions have more of an immediate warming effect than ground transport.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/large-four-engine-plane-cruising-altitude-740298673">Peter Gudella/Shutterstock</a></span>
</figcaption>
</figure>
<h2>The renaissance of European night trains</h2>
<p>From 2009 until 2018, the European night train network shrank steadily. The same is true for conventional intercity train networks, especially in southern and western Europe. This made air travel the only alternative on many routes. But that <a href="https://www.theguardian.com/world/2020/jan/20/brussels-vienna-night-train-returns-as-europe-eyes-flying-alternatives">appears to be changing</a>.</p>
<p>When German Rail decided to withdraw its network of overnight passenger trains in 2015, Austrian Federal Railways (ÖBB) decided to take over some of its services. In 2017, ÖBB’s Nightjet services carried around <a href="https://www.railjournal.com/in_depth/obb-expands-abroad">1.4 million passengers</a>, more than doubling its total passengers from the previous year. </p>
<p>In 2018, ÖBB achieved another 10% increase in passenger numbers. ÖBB CEO, Andreas Matthä, said that “<a href="https://www.railjournal.com/passenger/main-line/nightjet-passenger-traffic-up-10-says-obbs-ceo/">overnight services are a viable alternative to short-haul flights</a>” and committed to continue investing in new services. As a result, ÖBB is expanding its routes on the <a href="https://www.nightjet.com/en/">NightJet network</a> of sleeper trains. From January 2020, night trains will once again run between Vienna and Brussels, 16 years after the service closed.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1219198861618696197"}"></div></p>
<p>In the UK, <a href="https://www.nationalrail.co.uk/tocs_maps/tocs/GW.aspx">Great Western Railway</a> plans to <a href="https://www.gwr.com/travel-updates/planned-engineering/west-cornwall">renovate</a> the sleeper trains it runs to Cornwall. <a href="https://www.scotrail.co.uk/plan-your-journey/travel-connections/caledonian-sleeper">The Caledonian Sleeper</a>, which runs between London, Edinburgh, Glasgow and Aberdeen has been revamped with a £150 million investment in new trains. </p>
<p>In response to a public petition, the Swedish government plans to <a href="https://back-on-track.eu/swedish-draft-night-train-report-will-set-night-trains-on-the-tracks-from-scandinavia-in-2022/">reintroduce night train services</a> to other European countries. A sleeper train service <a href="https://www.independent.co.uk/travel/news-and-advice/sweden-london-train-sleeper-malmo-amsterdam-cologne-munich-rail-a9288206.html?fbclid=IwAR3hXu2UX4z0wRqFiuCr1yTIfXJLlDM5sq0ExrgVxmxTlqRpXaEVzu0sMrI">from Malmö in southern Sweden to London</a> has been planned for 2022 at the earliest. The service could set off in the evening and arrive in the English capital at lunchtime the next day. At almost 1,300 kilometres, the trip is typical of the many rail journeys that could offset those currently taken between European countries by aeroplane.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/transport-emissions-have-doubled-in-40-years-expand-railways-to-get-them-on-track-122794">Transport emissions have doubled in 40 years – expand railways to get them on track</a>
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<h2>An alternative to air travel?</h2>
<p>Aviation industry CEOs are worried that flight shame could <a href="https://aviationanalyst.co.uk/2019/08/02/exclusive-domestic-air-travel-could-shrink-because-of-flight-shaming-lufthansa-munich-ceo/">threaten passenger traffic</a> and in some countries this already seems to be happening. Swedavia, an airline which operates ten of Sweden’s busiest airports, <a href="https://www.swedavia.com/about-swedavia/swedavias-newsroom/#gref">reported a 4% fall</a> in passengers in 2019 compared with the previous year. The decrease was primarily in domestic travel, while the number of international passengers fell to a lesser extent. Despite this, European air traffic still <a href="https://go.updates.iata.org/l/123902/2019-07-11/83d46z?utm_source=IATA.org&utm_medium=product-page&utm_campaign=BIS007-MonthlyStats-2019">grew by 4.2% in 2019</a>. </p>
<p>It’s too soon to say whether the night train revival is a permanent trend prompted by <em>flygskam</em>. Nevertheless, environmental awareness still motivates the choices of travellers. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/311435/original/file-20200122-117954-1x4tcrj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311435/original/file-20200122-117954-1x4tcrj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311435/original/file-20200122-117954-1x4tcrj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311435/original/file-20200122-117954-1x4tcrj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311435/original/file-20200122-117954-1x4tcrj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311435/original/file-20200122-117954-1x4tcrj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311435/original/file-20200122-117954-1x4tcrj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sleeper train operators promise comfort to entice would-be flyers.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/close-tired-girl-sleeps-her-sleeper-1510918502">Flystock/Shutterstock</a></span>
</figcaption>
</figure>
<p><a href="https://www.westminster.ac.uk/research/groups-and-centres/transport-studies-research-group">Researchers</a> who study consumer profiles in different markets recently identified a new one: the “<a href="https://dataset2050.eu/">environmental traveller</a>”. People who fall into this market segment try to maintain a lifestyle that is as environmentally friendly as possible – and that includes reducing the number of flights they take. </p>
<p>But the researchers found that awareness of the environmental crisis doesn’t automatically translate into behaviour changes, such as choosing other transport modes over air travel. Most often, distance or cost are more powerful motivations, particularly for short and medium-haul routes.</p>
<p>A <a href="https://repository.tudelft.nl/islandora/object/uuid%3A21e9731a-6ec3-4230-847f-38ffa364ba8a">recent study</a> from the Netherlands found that passengers who travel for leisure purposes seem to be most attracted to the option of night trains. It’s possible that night train services could simply generate new demand from these customers instead of substituting existing airline passengers. The researchers found that 40% of business travellers still opted to fly the day before and stay in a hotel instead, though many thought the relative comfort of sleeper trains was appealing. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/311380/original/file-20200122-117954-1mlw0vj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311380/original/file-20200122-117954-1mlw0vj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311380/original/file-20200122-117954-1mlw0vj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311380/original/file-20200122-117954-1mlw0vj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311380/original/file-20200122-117954-1mlw0vj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311380/original/file-20200122-117954-1mlw0vj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311380/original/file-20200122-117954-1mlw0vj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sleeper trains might appeal to backpackers, but can they offer an alternative to frequent flying businesspeople?</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/male-female-backpackers-resting-while-travelling-1238782927">Flystock/Shutterstock</a></span>
</figcaption>
</figure>
<p><a href="http://www.europarl.europa.eu/thinktank/en/document.html?reference=IPOL_STU(2017)601977">Research</a> conducted on behalf of the European parliament is much more pessimistic, concluding that there are more challenges than opportunities for night trains to grow in Europe. Chief among them is the continued growth of low-cost airlines. <a href="http://www.nachtzug-retten.de/wp-content/uploads/2016/05/2013-04-30_uic_study_night_trains_2.02.pdf">Infrastructure costs</a> currently prohibit long-distance night trains which might be able to tempt more passengers out of these aeroplanes. Subsidy and investment to expand rail networks may be necessary for the sector to compete with aviation. <a href="https://www.aef.org.uk/issues/economics/taxation/">Making airlines pay fuel duty</a> could also help.</p>
<p>In the meantime, <em>flygskam</em> could still be effective if it means people keep the pressure on the aviation industry to reform and reduce its growing carbon footprint.</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1130334">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/130334/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Enrica Papa does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Since 2019, night train networks have seen a remarkable revival across Europe.Enrica Papa, Reader in Transport Planning, University of WestminsterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1254402019-10-25T10:23:03Z2019-10-25T10:23:03ZFlight shame: flying less plays a small but positive part in tackling climate change<figure><img src="https://images.theconversation.com/files/298515/original/file-20191024-170449-1gpmbty.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5958%2C3202&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/ONpGBpns3cs">Nils Nedel/Unsplash.</a>, <a class="license" href="http://artlibre.org/licence/lal/en">FAL</a></span></figcaption></figure><p>“Flygskam” – the Swedish word for “flight shame” – describes a phenomenon that <a href="https://www.bbc.co.uk/news/business-49890057">has taken off</a> around the world, as travellers face growing pressure to reduce their carbon emissions by switching to alternative modes of transport. Climate activists <a href="https://www.businessinsider.com/alexandria-ocasio-cortez-greta-thunberg-flight-shame-movement-germany-sweden-2019-8?r=US&IR=T">have denounced air travel</a>, settling for boats, trains or, at a pinch, paying to <a href="https://www.theguardian.com/environment/2011/sep/16/carbon-offset-projects-carbon-emissions">offset the carbon emissions</a> from their flights. Celebrities <a href="https://www.bbc.co.uk/news/uk-49398852">face criticism</a> for flying by private jet – and Germany’s Green Party has even put forward plans to <a href="https://www.citylab.com/transportation/2019/08/air-travel-climate-change-germany-trains-flying-pollution/595279/">ban domestic flights</a> within the country. </p>
<p>Yet according to our calculations based on the the <a href="https://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy.html">BP Statistical Review of World Energy 2019</a> (which we both contributed to), CO₂ emissions from aviation fuels account for a mere 3% of global CO₂ emissions and 8% of worldwide oil consumption. This may not sound like much, but in the past 30 years, aviation fuel consumption has almost doubled, consistently contributing to the growth in global oil consumption. </p>
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<p>To see whether the efforts of individuals to cut down on air travel can make a meaningful difference to global emissions, we took a closer look at how fuel consumption by the aviation industry has changed over time, and what trends are set to take hold in the future. </p>
<h2>Fuelling demand</h2>
<p>A common way of estimating CO₂ emissions for individual passengers is to take the aircraft type and distance travelled into account. This is the method used by carbon offsetting organisation <a href="https://www.atmosfair.de/en/air_travel_and_climate/atmosfair_airline_index/">atmosfair</a>, and the International Civil Aviation Organisation’s <a href="https://www.icao.int/environmental-protection/CarbonOffset/Pages/default.aspx">carbon footprint calculator</a>. </p>
<p>By contrast, our approach to quantifying CO₂ emissions from flights involves looking at the consumption of aviation fuel. This eliminates the need to rely on estimates of passenger numbers, aircraft type and how full or empty planes are, and can easily be compared to other means of transportation. </p>
<p>An important caveat is that our method ignores the effects of condensation trails or nitrogen oxides (NOx) emitted by planes. Including these in the estimates is challenging because their effects only last for a matter of minutes, hours or days. But <a href="https://www.transportenvironment.org/news/aviation-2-3-times-more-damaging-climate-industry-claims">research suggests</a> that the warming effects of aviation can be much larger, depending on where in the atmosphere NOx are emitted. So our approach only gives a conservative estimate of the emissions from aviation.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/298187/original/file-20191022-55679-18c810p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/298187/original/file-20191022-55679-18c810p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/298187/original/file-20191022-55679-18c810p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=311&fit=crop&dpr=1 600w, https://images.theconversation.com/files/298187/original/file-20191022-55679-18c810p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=311&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/298187/original/file-20191022-55679-18c810p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=311&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/298187/original/file-20191022-55679-18c810p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=391&fit=crop&dpr=1 754w, https://images.theconversation.com/files/298187/original/file-20191022-55679-18c810p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=391&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/298187/original/file-20191022-55679-18c810p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=391&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Global oil consumption by fuel type. Consumption measured in million tonnes of oil equivalent (mtoe) on the left axis, and share of aviation in global oil consumption on the right axis.</span>
<span class="attribution"><span class="source">Jan Ditzen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The figure above shows global oil consumption, measured in million tonnes of oil equivalent (mtoe). Over the past 30 years oil consumption has risen continuously, amounting to a 50% increase since 1990. Over the same period consumption of aviation fuel almost doubled from 185 mtoe to 343 mtoe. </p>
<p>Compared to other means of transportation, such as road and rail, aviation accounts for a relatively small but growing percentage of oil consumption. In 2018, aviation <a href="https://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy.html">was a major driver</a> of the 1.2% global increase in oil consumption. </p>
<h2>Global growth</h2>
<p>A large share of aviation fuels are consumed in developed countries. In 2018 the US alone accounted for more than 20% of aviation fuel consumption. In the same year half of all aviation fuel consumption took place in OECD countries – a club of mostly developed countries <a href="https://population.un.org/wpp/">which represent about 15% of world population</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/298189/original/file-20191022-55685-mnbqsd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/298189/original/file-20191022-55685-mnbqsd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/298189/original/file-20191022-55685-mnbqsd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=372&fit=crop&dpr=1 600w, https://images.theconversation.com/files/298189/original/file-20191022-55685-mnbqsd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=372&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/298189/original/file-20191022-55685-mnbqsd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=372&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/298189/original/file-20191022-55685-mnbqsd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=467&fit=crop&dpr=1 754w, https://images.theconversation.com/files/298189/original/file-20191022-55685-mnbqsd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=467&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/298189/original/file-20191022-55685-mnbqsd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=467&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Aviation fuel consumption by country.</span>
<span class="attribution"><span class="source">Jan Ditzen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Meanwhile, China, Russia and non-OECD countries in Europe and Asia, which account for almost 60% of world population, consumed 32% of all aviation fuels. Given that the populations of these countries <a href="https://population.un.org/wpp/">are forecast</a> to grow, we can expect air travel passenger numbers to increase. In fact the International Air Transport Association estimates that <a href="https://www.iata.org/pressroom/pr/Pages/2018-10-24-02.aspx">China will replace the US</a> as the biggest aviation market by the mid-2020s.</p>
<p>To put things into perspective, if China, Russia, non-OECD Europe and the rest of Asia were to fly as much as the OECD countries, total aviation fuel consumption would almost triple from its current level of 343 mtoe to about 935 mtoe. It would further increase to 1,560 mtoe, if the entire world flew as much as OECD countries. This amounts to more than the current global consumption of gasoline and diesel.</p>
<p>It’s worth noting that consumption is normally attributed to the country that represents the “point of sale”: for example, if a Norwegian plane refuels in Iceland en route to the US, this counts as Icelandic consumption and emissions. This matters, because any attempts by individual countries to tax aviation fuel would be unlikely to succeed, since planes would simply go out of their way to refuel in low-tax countries, meaning a transnational policy is required.</p>
<h2>Future efficiency</h2>
<p>Since 2000 the number of air passengers has almost tripled, reaching a new high of <a href="https://www.icao.int/Newsroom/Pages/Solid-passenger-traffic-growth-and-moderate-air-cargo-demand-in-2018.aspx">4.3 billion in 2018</a>. The main driver of growth is budget airlines, which offer primarily short and medium-haul flights in the American and European markets.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/298191/original/file-20191022-55660-1nz19fk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/298191/original/file-20191022-55660-1nz19fk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/298191/original/file-20191022-55660-1nz19fk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=305&fit=crop&dpr=1 600w, https://images.theconversation.com/files/298191/original/file-20191022-55660-1nz19fk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=305&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/298191/original/file-20191022-55660-1nz19fk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=305&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/298191/original/file-20191022-55660-1nz19fk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=384&fit=crop&dpr=1 754w, https://images.theconversation.com/files/298191/original/file-20191022-55660-1nz19fk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=384&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/298191/original/file-20191022-55660-1nz19fk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=384&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Passenger numbers and fuel efficiency over time. Fuel efficiency in MTOE per million passengers on the left axis, million passengers on the right axis.</span>
<span class="attribution"><span class="source">Jan Ditzen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>It’s not all bad, though. As shown in the figure above, the amount of fuel required per passenger has decreased steadily over the years, although the rate seems to have slowed after 2010, despite the introduction of <a href="https://www.iata.org/whatwedo/ops-infra/fuel/Pages/fuel-efficiency.aspx">more fuel-efficient planes</a>. The IPCC estimates that <a href="https://archive.ipcc.ch/ipccreports/sres/aviation/index.php?idp=10">18% of CO₂ emissions</a> from planes can be saved, if air traffic control management and other operational procedures become more efficient.</p>
<p>Based on current information it still seems the increase in passenger numbers is likely to outstrip the increase in fuel efficiency, leading to an increase in overall fuel consumption. </p>
<h2>A greener alternative</h2>
<p>Low-carbon sustainable aviation fuels can reduce CO₂ emissions, although only <a href="https://aviationbenefits.org/environmental-efficiency/climate-action/sustainable-aviation-fuel/the-leading-edge/">six airports in the world</a> (Bergen, Brisbane, Los Angeles, Oslo, San Francisco and Stockholm) offer them on a regular basis. The <a href="https://www.iea.org/newsroom/news/2019/march/are-aviation-biofuels-ready-for-take-off.html">International Energy Agency (IEA) estimates</a> that, in 2018, sustainable aviation fuels only accounted for 0.1% of aviation fuel production – so much more could be done to promote their use around the world. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/298192/original/file-20191022-55660-cwdzw4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/298192/original/file-20191022-55660-cwdzw4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/298192/original/file-20191022-55660-cwdzw4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=335&fit=crop&dpr=1 600w, https://images.theconversation.com/files/298192/original/file-20191022-55660-cwdzw4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=335&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/298192/original/file-20191022-55660-cwdzw4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=335&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/298192/original/file-20191022-55660-cwdzw4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=420&fit=crop&dpr=1 754w, https://images.theconversation.com/files/298192/original/file-20191022-55660-cwdzw4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=420&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/298192/original/file-20191022-55660-cwdzw4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=420&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">CO₂ emissions by fuel type. Emissions on the left axis and contribution of aviation to global emissions (in %) on the right axis.</span>
<span class="attribution"><span class="source">Jan Ditzen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In 2018, passenger planes emitted around 960m tonnes of CO₂, representing 8.5% of emissions from oil products and less than 3% of CO₂ from all fossil fuels – leaving other oil products and coal as the main sources of emissions. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/flying-cars-could-cut-emissions-replace-planes-and-free-up-roads-but-not-soon-enough-115123">Flying cars could cut emissions, replace planes, and free up roads – but not soon enough</a>
</strong>
</em>
</p>
<hr>
<p>But the fact remains that alternative means of travel, especially trains, have a much better carbon footprint than flying. The <a href="https://www.lner.co.uk/tickets-savings/the-best-way-to-travel/carbon-calculator/">London North Eastern Railway</a> estimates that it takes about 17kg of CO₂ per passenger to travel from Edinburgh to London, which equates to heating the <a href="https://www.bbc.co.uk/news/science-environment-46459714">average UK home</a> for two days. <a href="https://www.atmosfair.de/en/air_travel_and_climate/atmosfair_airline_index/">Atmosfair</a> estimates the same journey by plane would produce 145kg of CO₂ – equivalent to heating a home for 22 days.</p>
<p>In wealthy nations across the Western world, where people can choose to take alternative transport over short and medium distances at little to no extra cost, “flyskam” may well have its place. But when it comes to tackling climate change, flying less is small piece in a big puzzle.</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1125440">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/125440/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jan Ditzen collaborates with BP for the Statistical Review of World Energy and Energy Outlook, but the views expressed here are his own.</span></em></p><p class="fine-print"><em><span>Erkal Ersoy collaborates with BP for the Statistical Review of World Energy and Energy Outlook, but the views expressed here are his own. </span></em></p>As the notion of flight shame is taking off around the world, emissions from aviation are making a small but growing contribution to global warming.Jan Ditzen, Research Associate (Centre for Energy Economics Research and Policy), Heriot-Watt UniversityErkal Ersoy, Assistant Professor of Economics, Heriot-Watt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1232152019-09-10T15:31:12Z2019-09-10T15:31:12ZHow big data can affect your bank account – and life<figure><img src="https://images.theconversation.com/files/291554/original/file-20190909-109939-1aq6zgp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/brown-leather-wallet-money-credit-discount-490684894">ULU_BIRD/Shutterstock.com</a></span></figcaption></figure><p>Mustafa loves good coffee. In his free time, he often browses high-end coffee machines that he cannot currently afford but is saving for. One day, travelling to a friend’s wedding abroad, he gets to sit next to another friend on the plane. When Mustafa complains about how much he paid for his ticket, it turns out that his friend paid less than half of what he paid, even though they booked around the same time.</p>
<p>He looks into possible reasons for this and concludes that it must be related to his browsing of expensive coffee machines and equipment. He is very angry about this and complains to the airline, who send him a lukewarm apology that refers to <a href="https://blog.blackcurve.com/personalised-airline-pricing-is-here-to-stay">personalised pricing models</a>. Mustafa feels that this is unfair but does not challenge it. Pursuing it any further would cost him time and money.</p>
<p>This story – which is hypothetical, <a href="https://www.theguardian.com/global/2017/nov/20/dynamic-personalised-pricing">but can and does occur</a> – demonstrates the potential for people to be harmed by data use in the current “big data” era. Big data analytics involves using large amounts of data from many sources which are linked and analysed to find patterns that help to predict human behaviour. Such analysis, even when perfectly legal, can harm people. </p>
<p>Mustafa, for example, has likely been affected by personalised pricing practices whereby his search for high-end coffee machines has been used to make certain assumptions about his willingness to pay or buying power. This in turn may have led to his higher priced airfare. While this has not resulted in serious harm in Mustafa’s case, instances of serious emotional and financial harm are, unfortunately, not rare, including the <a href="https://theconversation.com/six-ways-and-counting-that-big-data-systems-are-harming-society-88660?utm_content=buffer0c4fa&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer">denial of mortgages</a> for individuals and risks to a person’s general credit worthiness based on associations with other individuals. This might happen if an individual shares some similar characteristics to other individuals who have <a href="https://digitalcommons.law.yale.edu/cgi/viewcontent.cgi?article=1122&context=yjolt">poor repayment histories</a>.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1029154119070756865"}"></div></p>
<p>Instances of emotional harm can also occur. Imagine a couple who find out they are expecting a much wanted child, but suffer a miscarriage at five months. The couple may find they continue to receive advertisements from shops specialising in infant products months later, celebrating which should have been key “milestones”, causing distress. This is another hypothetical but entirely <a href="https://books.google.co.uk/books/about/Healthcare_and_Big_Data.html?id=yOwmDQAAQBAJ&redir_esc=y">possible scenario</a>.</p>
<h2>The law – or lack of it</h2>
<p>In many of these cases, because the harmful practice may not have broken any laws, those who were harmed by data use have limited or no legal options open to them. What happened to Mustafa, for example, was perfectly legal, as there are no current laws forbidding personalised pricing as such. Our current legal systems do not adequately protect people from the harms emerging from big data.</p>
<p>This is because it is very difficult to trace how our data is linked and used. Even if the airline company had done something unlawful, such as broken data protection laws, it would be near impossible for Mustafa to find out. People who feel they have been harmed by data use may struggle to show how their data has been used to cause this harm, which data was involved or which data controller used it. And so they may lack the proof they’d need to get a legal remedy.</p>
<p>Furthermore, even if they show how something someone did with their data harmed them, that particular use of <a href="https://www.citizensadvice.org.uk/Global/CitizensAdvice/Consumer%20publications/Personalised%20Pricing%20Report%202018.pdf">customer information</a>, to adjust pricing for example, may <a href="https://www.oecd.org/competition/personalised-pricing-in-the-digital-era.htm">not be unlawful</a>.</p>
<p>Equally, the harm may be caused not by one’s own data but by the use of other people’s data (third party data). For example, in Mustafa’s case it might be that other individuals who were also interested in expensive coffee machines had very high incomes, or bought expensive items. This may have been used to suggest that Mustafa also fell into this category, which may have resulted in higher prices for him for other products. An individual harmed through the use of third party data will often not have remedies under current data protection laws.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/291764/original/file-20190910-190012-1sef6tu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/291764/original/file-20190910-190012-1sef6tu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/291764/original/file-20190910-190012-1sef6tu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/291764/original/file-20190910-190012-1sef6tu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/291764/original/file-20190910-190012-1sef6tu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/291764/original/file-20190910-190012-1sef6tu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/291764/original/file-20190910-190012-1sef6tu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Companies may presume things about you from your browsing habits.</span>
<span class="attribution"><span class="source">Crew/Unsplash</span>, <a class="license" href="http://artlibre.org/licence/lal/en">FAL</a></span>
</figcaption>
</figure>
<h2>A new system</h2>
<p>To help address such issues, <a href="https://academic.oup.com/medlaw/advance-article/doi/10.1093/medlaw/fwz016/5543530">we argue</a> that we need to accept that some risks from data usage are not preventable. Instead of focusing solely on trying to minimise or avoid such risks, we also need to find ways to better support people who suffer harms from data use, for example by actively monitoring and responding to harms caused by data use, including legal uses of data.</p>
<p>We think that as part of this system, a new type of institution should be set up. We call them harm mitigation bodies. These would be set up at a national level, and people who felt they were harmed by data use, but did not qualify for legal remedies, could go to them to report the harm they think arose from data use. Unlike traditional remedies, harm mitigation bodies could provide support even in cases where no laws were broken. They would be easy for people to use, and flexible, so that they could support people where and how they most need it, giving individuals more power and strengthening collective responsibility for data use.</p>
<p>These proposed bodies would collect information on what types of harm occur: currently there are no national or international bodies that collect information on data harms systematically. They would also feedback information to policy makers and data users to help improve how things are done. And in cases where people suffer financial harms but do not have access to legal help, they might provide financial support as well.</p>
<p>Big data analytics is rightly lauded for the many new opportunities that it offers. But it will be inevitable that some people will be harmed. As a society, we need to face this truth, and provide better assistance to those who suffer harms, so that nobody who bears the costs for these new practices is left alone.</p><img src="https://counter.theconversation.com/content/123215/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alena Buyx has received funding from the German Ministry of Education and Research and is a member of the German Ethics Council.</span></em></p><p class="fine-print"><em><span>Barbara Prainsack has received funding from AHRC, ESCR and The Nuffield Council on Bioethics and is a member of the Austrian National Bioethics Council, and the European Group on Ethics in Science and New Technologies.</span></em></p><p class="fine-print"><em><span>Aisling McMahon does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The use of big data by companies, even when perfectly legal, can harm people.Aisling McMahon, Assistant Professor in Law, National University of Ireland MaynoothAlena Buyx, Professor in Ethics, Technical University of MunichBarbara Prainsack, Professor of Comparative Policy Analysis, Universität WienLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1224332019-08-28T11:48:22Z2019-08-28T11:48:22ZWhy would anyone want to sit on a plane for over 18 hours? An economist takes the world’s longest flight<figure><img src="https://images.theconversation.com/files/289512/original/file-20190826-8889-j6yaz5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A customer waits for the world's longest flight from Singapore to Newark.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Singapore-Flight-New-York/bafca6aa739745bbbf2197235dc678b7/1/0">AP Photo/Wong Maye-E</a></span></figcaption></figure><p>Recently <a href="https://www.qantasnewsroom.com.au/media-releases/qantas-to-operate-project-sunrise-research-flights-direct-new-york-london-to-australia/">Qantas announced</a> plans to conduct test flights from New York and London to Sydney and two other Australian cities. </p>
<p>If commercialized, these routes would become the longest in the world at about 19 hours. Qantas said it will conduct test flights <a href="https://www.wsj.com/articles/qantas-wires-up-people-for-19-hour-endurance-flight-11566471393">with only employees</a> on board to ensure the flights are safe and comfortable enough for paying customers. </p>
<p>I heard this news after finishing a round-trip on what is currently the world’s <a href="https://www.travelandleisure.com/airlines-airports/longest-flights-in-the-world">longest flight</a>, the 18 hours and 45 minutes Singapore Airlines schedules to get from <a href="https://www.forbes.com/sites/ericrosen/2018/10/11/worlds-new-longest-flight-from-singapore-to-newark-launches-today/#6a42a6a12aca">Newark, New Jersey, to Singapore</a>, a route that began last October. The return trip is slightly quicker. Fortunately for me, there were favorable winds so each way took about 30 minutes less than scheduled.</p>
<p>Being aloft twice for the better part of a day gave me plenty of time to ponder the origins and <a href="http://businessmacroeconomics.com/">economics</a> of long-distance flights – with plenty of time to spare for binge watching.</p>
<h2>Talk about a long flight</h2>
<p>Pilots and airlines have been pushing the boundaries of flight times since the earliest days of air travel. In fact, 19 hours is rather quick for the industry’s trailblazers.</p>
<p>The <a href="https://www.wired.com/2009/06/dayintech-0609/">first plane to make it across the Pacific</a> took off from Oakland, California, in 1928. It took the aircraft, dubbed the “Southern Cross,” <a href="https://www.thisdayinaviation.com/tag/southern-cross/">three long flights</a> to get to its final destination in Australia: 27 and a half hours to Hawaii, 34 and a half hours to Fiji and a final 21 and a half hours to Brisbane. In all, the pilot and his crew covered about 7,000 miles in 10 days – all without losing any luggage.</p>
<p>A few years later, in 1931, two daredevils in search of a US$25,000 prize <a href="https://www.wired.com/2010/10/1005first-nonstop-transpacific-flight">flew from Tokyo to the state of Washington</a> in the first nonstop flight over the Pacific Ocean. To save weight and fuel, the pilots even threw out their landing gear after takeoff. When they reached the U.S., they crash landed – but survived to claim the prize. The flight took 41 hours and covered more than 5,500 miles.</p>
<p>These super-long flights, of course, were taken by daredevil pilots with no passengers. And they were very dangerous. One of the most famous aviation failures involved <a href="https://www.usatoday.com/story/news/nation/2019/07/19/amelia-earhart-found-disappearance-theories/1475518001/">Amelia Earhart</a>, who disappeared in 1937 while attempting to cross part of the Pacific on a world circling flight.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/289516/original/file-20190826-8856-1rxgxj3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/289516/original/file-20190826-8856-1rxgxj3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=449&fit=crop&dpr=1 600w, https://images.theconversation.com/files/289516/original/file-20190826-8856-1rxgxj3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=449&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/289516/original/file-20190826-8856-1rxgxj3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=449&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/289516/original/file-20190826-8856-1rxgxj3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/289516/original/file-20190826-8856-1rxgxj3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/289516/original/file-20190826-8856-1rxgxj3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The first trans-Pacific flight included three layovers, with legs as long as 34.5 hours.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Charles_Kingsford_Smith#/media/File:StateLibQld_1_139254_Landing_the_aircraft,_Southern_Cross_in_Brisbane,_Queensland,_ca._1928.jpg">John Oxley Library</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Six days and 60 hours</h2>
<p>The <a href="https://www.clipperflyingboats.com/transpacific-airline-service">first service</a> to ferry paying customers across the Pacific was created by Pan Am in October 1936. </p>
<p>The trip started from San Francisco and ended in Manila, capital of the Philippines. It took six days and about 60 hours of flying time. The plane flew during the day and made stops in Hawaii, Midway, Wake and Guam at night. The longest leg, from San Francisco to Hawaii, <a href="https://airandspace.si.edu/exhibitions/hawaii-by-air/online/pan-am-clippers/pan-am-spans-the-pacific.cfm">took 18 and a half hours</a>. </p>
<p>Pam Am’s planes, called the “Clippers,” <a href="https://www.clipperflyingboats.com/">didn’t need airports</a>. They were specially designed to <a href="https://airandspace.si.edu/exhibitions/hawaii-by-air/online/pan-am-clippers/pan-am-spans-the-pacific.cfm">take off and land in the water</a>. The planes <a href="https://airandspace.si.edu/exhibitions/hawaii-by-air/online/pan-am-clippers/what-was-it-like-to-fly.cfm">were also quite luxurious</a> and even had separate areas for eating and sleeping.</p>
<p>But all that luxury while spanning the globe was quite expensive. </p>
<p>The one-way fare from San Francisco to Manila <a href="https://www.sfgate.com/bayarea/article/China-Clipper-s-flight-made-history-75-years-ago-3165474.php">was $950</a>, or $17,400 in <a href="https://www.bls.gov/data/inflation_calculator.htm">today’s dollars</a>.</p>
<p>Fortunately, the cost of flying these long routes – in terms of both money and time – has come down dramatically. These days you can fly direct from San Francisco to Manila in business class for around $3,000, including the return flight. The trip to Manila takes just 14 hours.</p>
<p>Today’s flights are also a lot safer. The concern for many passengers is not crashing but instead <a href="https://www.popsci.com/are-long-airplane-flights-bad-for-your-health/">health risks like deep vein thrombosis</a>, a type of blood clot. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/289517/original/file-20190826-8880-1gukbch.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/289517/original/file-20190826-8880-1gukbch.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=486&fit=crop&dpr=1 600w, https://images.theconversation.com/files/289517/original/file-20190826-8880-1gukbch.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=486&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/289517/original/file-20190826-8880-1gukbch.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=486&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/289517/original/file-20190826-8880-1gukbch.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=611&fit=crop&dpr=1 754w, https://images.theconversation.com/files/289517/original/file-20190826-8880-1gukbch.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=611&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/289517/original/file-20190826-8880-1gukbch.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=611&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Amelia Earhart disappeared while attempting to circumnavigate the globe.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Watchf-AP-A-APHS245875-Amelia-Earhart/e473225ce73d48db80cefd8f7c091c00/6/1">AP Photo</a></span>
</figcaption>
</figure>
<h2>Saving time, money and bags</h2>
<p>Still, even if things have improved, I think most of us agree that <a href="https://www.cleveland.com/pdworld/2008/02/flying_isnt_fun_anymore.html">flying is not fun</a>. Airlines <a href="https://www.forbes.com/sites/danielreed/2018/04/26/airline-customer-satisfaction-scores-fell-in-2018-even-as-more-people-flew-on-them-than-ever-before/#3e9ae4ca2ddc">regularly rank near the bottom</a> among industries in customer satisfaction surveys. </p>
<p>So why would we want to increase the amount of time spent 30,000 feet above the ground in a metal tube with wings? </p>
<p>For one thing, it means less total travel time. For example, my flight to Singapore would have taken three and a half hours longer with a layover in Hong Kong. </p>
<p>But if you’re someone who might prefer a break during a long flight halfway around the world, a more practical benefit is that removing the connection also reduces the chance <a href="https://pp.bme.hu/tr/article/view/1870">your luggage is lost</a>, since bags are handled fewer times. Almost half of all bags delayed in 2017 <a href="https://www.sita.aero/resources/type/surveys-reports/baggage-report-2018">were a result</a> of baggage handlers missing connections.</p>
<p>Flying a full plane load of passengers directly also saves airlines money – which often translates into lower prices for consumers too. An extra layover at a major airport <a href="https://www.fraport.com/en/misc/binaer/business-and-partner/airlines-cargo/airport-charges/infographic--airport-charges-at-frankfurt-airport/_jcr_content.file/fraport_entgelte_eng.pdf">can be expensive</a>, with fees for landing, takeoff, parking, noise abatement and security. Airports also charge extra for <a href="https://www.fraport.com/en/misc/binaer/business-and-partner/airlines-cargo/airport-charges/list-of-service-charges/_jcr_content.file/list-of-service-charges---july-2019.pdf">optional services</a> like cleaning, towing and providing electricity to a plane while it is parked at the gate. </p>
<h2>Expect more ultra-long flights</h2>
<p>One thing that was interesting about the Qantas announcement is all the research it plans to do during its test flights – scheduled for October through December – on the passengers themselves. </p>
<p>Scientists and medical experts will monitor sleep patterns, food and beverage consumption, lighting, physical movement and in-flight entertainment to assess their impact on health and well-being – and prevent any blood clots in the legs.</p>
<p>Using this data, Qantas hopes to make ultra-long flying a more pleasant experience. After all, the main reason to take a single 19-hour flight is to arrive faster and feeling better than taking multiple flights to the same destination.</p>
<p>Whether you love or hate flying, expect longer flights in the future as more efficient planes allow airlines to go ever farther. Given we seem to be <a href="https://theconversation.com/despite-hectic-multitasking-lives-were-wired-to-binge-on-tv-24158">wired for binge watching</a>, I don’t think this trend is so bad. </p>
<p>I could have actually used a longer flight. My effort to binge the second season of “Star Trek: Discovery” was abruptly interrupted as we descended back into Newark, with just 10 minutes left in the final episode.</p><img src="https://counter.theconversation.com/content/122433/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jay L. Zagorsky does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The day and a half it takes to get from New York to Singapore and back offers plenty of time to ponder the economics of ultra-long-haul flights – and wonder why we’d want to make it any longer.Jay L. Zagorsky, Senior Lecturer, Boston UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1212692019-08-22T16:16:35Z2019-08-22T16:16:35ZTravel the world without destroying it – Imagine newsletter #5<figure><img src="https://images.theconversation.com/files/288037/original/file-20190814-136208-a2lnow.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6067%2C2623&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/ecofriendly-air-transport-concept-plane-flies-1275591949?src=MS5FJiNyNhUukN0_4xGTgw-1-4">Sergey Tinyakov/Shutterstock</a></span></figcaption></figure><p>Look with your eyes, not your hands. You were probably told that at some point growing up, as your eagerness to see and experience something new was checked by a wary adult. Humans now handle the Earth in a similarly precarious manner. Our desire to explore the world is increasingly plagued by an awareness that international travel harms the very places we spend so much to visit.</p>
<p>There are more commercial flights taking off today than at any other time in history. Many of them will take tourists to see the world’s most striking natural beauty. <a href="https://theconversation.com/climate-change-tourism-and-the-great-barrier-reef-what-we-know-60108">Snorkelling on the Great Barrier Reef</a>, <a href="https://www.vice.com/en_ca/article/9kxe43/climate-change-tourism-stride-is-cashing-in-on-environmental-devastation">trekking in the Amazon</a>, <a href="https://www.theguardian.com/world/2019/aug/13/polar-cruise-increase-harming-the-arctic-explorer-arved-fuchs-warns">boat tours in the Arctic</a> – cheap air travel has opened more of the world to tourism and ensured more people can afford to see it. </p>
<p>But it has come at a heavy cost to the planet. <a href="https://ec.europa.eu/clima/policies/transport/aviation_en">Aviation currently accounts for 2-3%</a> of all annual carbon dioxide (CO₂) emissions. That may not sound a lot, but aeroplanes heat the atmosphere by <a href="https://www.transportenvironment.org/news/aviation-2-3-times-more-damaging-climate-industry-claims">up to three times more</a> than their CO₂ emissions alone because they release nitrogen oxides – powerful greenhouse gases – and create <a href="https://theconversation.com/two-crucial-omissions-that-could-jeopardise-paris-climate-deal-52341">contrails</a> in their wake which trap even more heat in the atmosphere.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1013088775973556224"}"></div></p>
<p>A single flight from London to New York is estimated to melt about <a href="https://shameplane.com/?fromCity=London&fromCode=LHR&toCity=New%20York&toCode=JFK&roundtrip=false&typeofseat=3">3.3 square metres</a> of Arctic ice. <a href="https://theconversation.com/uk/topics/greta-thunberg-65412">Greta Thunberg</a> – the campaigner who started the <a href="https://theconversation.com/uk/topics/climate-strikes-66457">youth climate strikes</a> – is making that journey to attend the UN annual climate summit in September. Rather than take a transatlantic flight and contribute to yet more ice melting, she’s sailing from Plymouth on <a href="https://www.theguardian.com/environment/2019/aug/14/greta-thunberg-sets-sail-plymouth-climate-us-trump">a zero-carbon yacht</a>. </p>
<p>Meanwhile, the aviation industry is <a href="https://leehamnews.com/2017/01/17/aircraft-market-will-double-20-years/">predicted to double by 2040</a> – doubling the number of flights and the number of people taking them. Earth has warmed by 1°C since pre-industrial times and already many <a href="https://theconversation.com/the-great-barrier-reef-has-been-bleaching-for-at-least-400-years-but-its-getting-worse-101691">coral reefs are struggling</a> beyond their thermal limits, while <a href="https://theconversation.com/amazon-rainforests-that-were-once-fire-proof-have-become-flammable-91775">rainforests are drying out</a>. Without drastic action, there may be little cause for exploring the world’s natural beauty in future, as there’ll be much less of it to see.</p>
<p>In this fifth issue of Imagine, we asked researchers to scan the horizon of air travel. Does the climate crisis demand we turn our backs on the skies and remain permanently grounded? Or could a technological breakthrough keep our travel obsessions afloat?</p>
<hr>
<p><em><strong>What is Imagine?</strong></em></p>
<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1114168">Imagine</a> is a newsletter from The Conversation that presents a vision of a world acting on climate change. Drawing on the collective wisdom of academics in fields from anthropology and zoology to technology and psychology, it investigates the many ways life on Earth could be made fairer and more fulfilling by taking radical action on climate change.</em></p>
<p><em>You are currently reading the web version of the newsletter. Here’s <a href="http://theconversation.createsend.com/t/ViewEmail/r/3B198A7EB72026A72540EF23F30FEDED/C67FD2F38AC4859C">the more elegant email-optimised version</a> subscribers receive. To get Imagine delivered straight to your inbox, <a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1116320">subscribe now</a>.</em></p>
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<hr>
<h2>We’re flying towards the climate emergency</h2>
<p>“<a href="https://www.theguardian.com/environment/2019/jan/25/our-house-is-on-fire-greta-thunberg16-urges-leaders-to-act-on-climate">Our house is on fire</a>”, Thunberg said, as she addressed the World Economic Forum in January 2019. Few analogies capture the urgency of the climate crisis so succinctly. Political recognition of the crisis has been sluggish, but at the time of writing four countries have declared a <a href="https://www.climatechangenews.com/2019/06/24/four-countries-declared-climate-emergencies-give-billions-fossil-fuels/">climate emergency</a>: the UK, France, Canada and Ireland. Worldwide, <a href="https://climateemergencydeclaration.org/climate-emergency-declarations-cover-15-million-citizens/">935 local government bodies</a>, which cover 206m people in 18 countries, have done the same.</p>
<p>In the UK, parliament voted to declare a <a href="https://www.bbc.co.uk/news/uk-politics-48126677">climate emergency</a> on May 1 2019. But less than a year before that, MPs <a href="https://www.bbc.co.uk/news/uk-politics-44609898">voted by 415 votes to 119</a> to build a third runway at London’s Heathrow airport – already the <a href="https://www.aef.org.uk/2019/05/02/ccc-net-zero-report-well-still-be-flying-in-2050-but-government-can-no-longer-ignore-aviation-emissions-in-its-climate-policies/">largest single source of CO₂ in the UK</a>. Had Britain’s parliamentarians suddenly realised their error a year on? More likely, they are like most of us who recognise the threat of the climate crisis but aren’t aware of – or would rather not think about – the scale of the change that’s needed to avert it.</p>
<p>That’s a problem that undermines many pledges to reduce emissions – and not just those made on the international stage. Within the towns and cities we live, councils commit to radical action in one breath while approving plans that will ramp up emissions in the next. The city council of Leeds recently <a href="https://theconversation.com/uk-becomes-first-country-to-declare-a-climate-emergency-116428">declared a climate emergency</a> and signed off on a strict carbon budget which commits the city to emitting no more than 42 megatonnes of CO₂ between 2018 and 2050. At the same time, the council has <a href="http://www.leedsgrowthstrategy.co.uk/wp-content/uploads/2018/06/Leeds-Inclusive-Growth-Strategy-FINAL.pdf">endorsed</a> the expansion of <a href="https://www.leeds-live.co.uk/news/leeds-news/climate-emergency-declaration-slammed-leeds-16106116">Leeds Bradford Airport</a> – promising new transport links and a commercial centre nearby.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-cant-expand-airports-after-declaring-a-climate-emergency-lets-shift-to-low-carbon-transport-instead-120740">We can't expand airports after declaring a climate emergency – let's shift to low-carbon transport instead</a>
</strong>
</em>
</p>
<hr>
<ul>
<li><p><strong>Airport expansion</strong> – In 2018, four million passengers used Leeds Bradford Airport. With the expansion of the main terminal, the number is predicted to double to eight millioin by 2030.</p></li>
<li><p><strong>Climate impact</strong> – All those additional flights would amount to more than double the 2030 target emissions for the entire city of Leeds.</p></li>
<li><p><strong>Up and up from 2030?</strong> – If passenger numbers continue growing after 2030, even at a slower rate, emissions from Leeds Bradford Airport would overshoot the city’s carbon budget by a factor of nine by 2040.</p></li>
</ul>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/285285/original/file-20190723-110170-i5v7lp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/285285/original/file-20190723-110170-i5v7lp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=451&fit=crop&dpr=1 600w, https://images.theconversation.com/files/285285/original/file-20190723-110170-i5v7lp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=451&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/285285/original/file-20190723-110170-i5v7lp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=451&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/285285/original/file-20190723-110170-i5v7lp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=567&fit=crop&dpr=1 754w, https://images.theconversation.com/files/285285/original/file-20190723-110170-i5v7lp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=567&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/285285/original/file-20190723-110170-i5v7lp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=567&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Climate impact of all flights through Leeds Bradford Airport if passengers increase to 8m (red), remain at 2018 level of 4m (yellow) or fall to 1m by 2030 (green), compared to the target emissions for Leeds as a whole (black dashed curve).</span>
<span class="attribution"><span class="source">Jefim Vogel</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>But even if the airport doesn’t expand and the number of passengers using Leeds Bradford remains at today’s levels, all flights between 2018 and 2050 would still consume the city’s entire carbon budget.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/285286/original/file-20190723-110170-1lhpc5b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/285286/original/file-20190723-110170-1lhpc5b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/285286/original/file-20190723-110170-1lhpc5b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/285286/original/file-20190723-110170-1lhpc5b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/285286/original/file-20190723-110170-1lhpc5b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/285286/original/file-20190723-110170-1lhpc5b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/285286/original/file-20190723-110170-1lhpc5b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Even if passenger numbers remain at 2018 levels, air traffic at Leeds Bradford would overshoot the city’s carbon budget.</span>
<span class="attribution"><span class="source">Jefim Vogel</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Only rapidly reducing the number of flights that take off from the world’s airports each year will lower emissions sharply enough to meet carbon budgets like that of Leeds, which are intended to limit global warming to 1.5°C at best. That could be done, say Jefim Vogel, Joel Millward-Hopkins and Yannick Oswald – researchers in sustainability and ecological economics at the University of Leeds – but we have to start right now. They said:</p>
<blockquote>
<p>If cut in half by 2022 and 75% by 2030, the flights of Leeds residents alone would use up 8% of the city’s carbon budget. This might be just low enough to squeeze all other activities in Leeds into the remaining carbon budget – if these are also radically decarbonised.</p>
</blockquote>
<h2>How did we get here?</h2>
<p>Airlines have proved wily in avoiding regulation. They are often totally omitted from emission accounting and <a href="http://www.emissions.leeds.ac.uk/">aren’t subject to fuel taxes</a>. But even when measures have been taken to rein in their emissions, they’ve often failed.</p>
<p>In Australia, a carbon price of A$23-$24 (roughly £13) per tonne of CO₂ was levied on flights between July 2012 and July 2014. This measure proved <a href="https://crawford.anu.edu.au/publication/crawford-school-working-papers/9816/impact-carbon-price-australias-electricity-demand">very effective at reducing emissions in the energy sector</a>, but it had no detectable effect on the number of kilometres flown – and therefore CO₂ emitted – from Australian airports. Why?</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-our-carbon-emission-policies-dont-work-on-air-travel-99019">Why our carbon emission policies don't work on air travel</a>
</strong>
</em>
</p>
<hr>
<p>An investigation led by Francis Markham – a research fellow in human geography at Australian National University – and Arianne C. Reis – a senior lecturer in leisure studies at Western Sydney University – found that a fall in ticket prices of 55% between 1992 and 2018 had eclipsed any cost increase from the carbon levy. Even when the cost was passed on to customers in full, the carbon price was too small to reduce demand as intended.</p>
<p><iframe id="CJiPw" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/CJiPw/2/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p><a href="https://theconversation.com/explainer-fuel-hedging-and-its-impact-on-airlines-and-airfares-36773">Airlines spend between 30 and 40%</a> of all their expenses on fuel, and the cost of jet fuel has fluctuated wildly since 2005. When the carbon price came into effect in 2014, oil cost as much as USD$100 per barrel, but it fell to <a href="https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=RCLC4&f=M">half that just a year later</a>. </p>
<p>“Compared to the volatility in the cost of fuel, the carbon price was negligible”, Markham said.</p>
<p><iframe id="QssWQ" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/QssWQ/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Carbon prices work to decarbonise the energy sector because electricity generators can switch to solar or wind power which aren’t subject to the levy. But currently, cleaner fuels and technology to which the airlines might switch don’t exist on the same scale.</p>
<p>Instead, passengers might be dissuaded from flying with a frequent flyer levy which increases taxes in line with the number of flights a person takes. But this would be <a href="https://theconversation.com/how-will-we-travel-the-world-in-2050-121713">inherently unfair</a>, argues Keith Baker, a research associate in sustainable urban environments at Glasgow Caledonian University.</p>
<blockquote>
<p>Most plane passengers are already relatively wealthy. <a href="https://www.dw.com/en/to-fly-or-not-to-fly-the-environmental-cost-of-air-travel/a-42090155">Only 18% of the world’s population</a> have ever flown and in any given year, an elite 3% of the world flies. That’s about 230m people, but flights carried four billion passengers in 2017. So the average flyer takes eight return flights and aeroplanes rack up <a href="http://www.darrinqualman.com/global-air-travel-climate-change/">seven trillion air miles each year</a>.</p>
</blockquote>
<p>Frequent flyer taxes could price poorer people out of air travel while ensuring the richest can still afford flying to excess. Rationing the number of flights a person can take each year meanwhile would be much fairer, Baker says. This could work by setting an allowance of 500km for everyone to use in the first year of the scheme. If someone didn’t use it, their allowance would double to 1,000km the year after – and would continue doubling while it’s unspent.</p>
<p>People could bank their flight kilometre credits for a big trip, or trade them in for cash. If anyone exceeded their allowance, they could be fined or have their right to travel revoked for a period of time.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/288029/original/file-20190814-136213-oahfzr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288029/original/file-20190814-136213-oahfzr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288029/original/file-20190814-136213-oahfzr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288029/original/file-20190814-136213-oahfzr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288029/original/file-20190814-136213-oahfzr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288029/original/file-20190814-136213-oahfzr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288029/original/file-20190814-136213-oahfzr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Passports could be linked to a credit system which would prevent people from flying if they had exceeded their allowance.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/businessman-taking-back-his-passport-ticket-1038207094?src=0-_1V-AkSVsZQij2ZtUxKA-1-47">Pressmaster/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Rail against climate change</h2>
<p>By restricting how much people can fly, the intention is to encourage them to use trains instead. Rail travel is a lower-carbon alternative to flying, but understandably, it’s not as practical for long distances. That didn’t stop Roger Tyers though, a research fellow in environmental sociology at the University of Southampton.</p>
<p>After pledging to go “flight-free” in 2019 and 2020, he won a fellowship to study Chinese attitudes to sustainability. That, unfortunately, involved field work in China, but rather than break his commitment, Tyers resolved to get the train from Southampton to Shanghai instead. He said:</p>
<blockquote>
<p>The cost of the trains was over £2,000, dwarfing the £700 I could pay for a London to Beijing return flight. Time-wise, the train trip took just under two weeks each way. But in terms of carbon emissions my trip was a steal, contributing <a href="https://www.gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2019">just 10%</a> of the emissions of the equivalent flights.</p>
</blockquote>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/southampton-to-shanghai-by-train-one-climate-change-researchers-quest-to-avoid-flying-120015">Southampton to Shanghai by train – one climate change researcher's quest to avoid flying</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1003%2C1003&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The track stretches for miles across the Mongolian plains on the first leg of Tyers’ trip to China.</span>
<span class="attribution"><span class="source">Roger Tyers</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Greta Thunberg’s decision to abstain from flying is perhaps the most high-profile of such commitments. In her native Sweden, her example has helped cultivate a nascent taboo around air travel. <em>Flygskam</em> – or “flight shame” – was coined to describe the feeling that you’re pushing the world a little deeper into the climate crisis every time you book a plane journey. Already, it’s reported to have helped <a href="https://www.bbc.co.uk/newsround/49032117">cut the number of passengers</a> at Sweden’s ten busiest airports by 8% from January to April 2019.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1161639849012559874"}"></div></p>
<p>Individual actions, though laudable, won’t drive a sufficiently large shift from air travel to trains on their own, particular <a href="https://www.bbc.co.uk/news/business-49331238">when rail journeys are more expensive</a>. Huge infrastructure changes and massive investment are needed to expand and improve mass public transport. With proper planning, Holly Edwards – a PhD researcher in low-carbon technologies at the University of Leeds – believes that high speed rail could replace many flights.</p>
<ul>
<li><p><strong>Planes versus trains</strong> – Out of the world’s <a href="https://www.economist.com/graphic-detail/2014/08/15/top-flights">top ten busiest air routes</a>, all but one are domestic flights that could be replaced by rail journeys.</p></li>
<li><p><strong>Faster by train</strong> – For many of these flight routes, such as São Paulo to Rio de Janeiro in Brazil, high-speed rail would be faster and emit between <a href="https://environment.leeds.ac.uk/transport">75 and 97% less CO₂</a>.</p></li>
<li><p><strong>Global potential</strong> – There’s about <a href="https://uic.org/IMG/pdf/20181001-high-speed-lines-in-the-world.pdf">43,000km of high-speed rail</a> currently operating worldwide and a further 55,000km planned for the near future.</p></li>
</ul>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/with-planning-high-speed-rail-could-reduce-flight-demand-21687">With planning, high speed rail could reduce flight demand</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/288336/original/file-20190816-192250-77y17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288336/original/file-20190816-192250-77y17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=457&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288336/original/file-20190816-192250-77y17.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=457&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288336/original/file-20190816-192250-77y17.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=457&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288336/original/file-20190816-192250-77y17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=575&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288336/original/file-20190816-192250-77y17.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=575&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288336/original/file-20190816-192250-77y17.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=575&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">China has more high speed rail than the rest of the world combined.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/highspeed-trains-shanghai-lujiazui-city-background-89928202?src=L5q0B1EzGkiDGF15pFmQEw-1-5">ArtisticPhoto/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Flights of the future?</h2>
<p>It’s now well over a century since humans first took to the skies in aeroplanes – a feat <a href="https://www.newscientist.com/article/dn13556-10-impossibilities-conquered-by-science/">thought impossible by many</a> right up until it happened. Are we due another revolution in human flight, one which powers air travel with zero-carbon technology? The great hope is that electric aeroplanes could oust the current fleet of commercial airliners which rely on fossil fuels.</p>
<p>Electric batteries are replacing combustion engines in road vehicles at such a rate that by 2030, electric cars are expected to make up <a href="https://theconversation.com/electric-vehicles-are-changing-the-world-and-theyre-only-just-getting-started-90402">one-third of the car market</a>. Meanwhile, most electric aeroplane prototypes are grounded on the drawing board. Venkat Viswanathan, Shashank Sripad and William Leif Fredericks – all experts in mechanical engineering at Carnegie Mellon University in the US – believe it’s because batteries can’t store as much energy per weight as liquid fuels. This, they say makes batteries relatively heavy for aviation. As they explain:</p>
<blockquote>
<p>Although the best batteries store about 40 times less energy per unit of weight than jet fuel, a greater share of their energy is available to drive motion. Ultimately, for a given weight, jet fuel contains about <a href="https://www.wired.com/2017/05/electric-airplanes-2/">14 times more usable energy</a> than a state-of-the-art lithium-ion battery. </p>
</blockquote>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-arent-there-electric-airplanes-yet-103955">Why aren't there electric airplanes yet?</a>
</strong>
</em>
</p>
<hr>
<p>But a breakthrough could come sooner than expected. Alice, the world’s first all-electric commercial airliner was unveiled in Paris in June 2019. It carries nine passengers for up to 650 miles (1,040km) at 10,000ft (3,000 metres) at 276mph (440km/h) on a single charged battery. It’s expected to enter service in 2022.</p>
<p>Alice is still too small to <a href="https://www.ponderweasel.com/how-many-people-can-fit-on-a-plane/">carry the hundreds of people</a> that most commercial flights manage today, but flying it is surprisingly cheap, according to John Grant, a senior lecturer in natural and built environments at Sheffield Hallam University.</p>
<blockquote>
<p>The fossil fuel costs of small aircraft are about <a href="https://www.bbc.co.uk/news/business-48630656">US$400 per 100 miles</a>. For Alice, the costs are projected to be as little as US$8 for the same distance, and if the electricity is from renewable energy – perhaps generated by solar panels at the airport – then the plane could be zero-carbon.</p>
</blockquote>
<p>Instead of waiting for mass electric air travel, Grant believes there are alternatives that could be built right now. Orbital rings sound like something straight out of science fiction, but Grant insists that the technology needed to build them already exists – all that’s missing is the ambition to do it.</p>
<p>An orbital ring is a steel cable that would surround Earth 80km above its surface. Connected to the ground by steel cables, which would also host passenger elevators, the ring could support two train tracks – one on its underside and the other on the outside – which would <a href="https://theconversation.com/can-magnetically-levitating-trains-run-at-3-000km-h-27615">use magnets to propel trains without friction</a> at great speeds above the Earth. Spun at the correct speed, the combined forces of gravity – pulling the ring towards Earth – and velocity would hold the ring in place, allowing passengers to reach the other side of the world in perhaps as little as 45 minutes.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/288035/original/file-20190814-136230-pfx520.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288035/original/file-20190814-136230-pfx520.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=366&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288035/original/file-20190814-136230-pfx520.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=366&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288035/original/file-20190814-136230-pfx520.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=366&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288035/original/file-20190814-136230-pfx520.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=459&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288035/original/file-20190814-136230-pfx520.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=459&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288035/original/file-20190814-136230-pfx520.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=459&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Once installed, the orbital ring could transport people across the world in under an hour.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/3d-rendering-space-elevators-pointing-giant-1142335202?src=H_Wqy3wbnkVSHFDjv86ISw-1-0">3000ad/Shutterstock</a></span>
</figcaption>
</figure>
<p>Sound far fetched? Well it’s no more crazy than letting the world descend into catastrophic climate change by not changing how we travel, Grant argues. He says we could actually return to a tried and tested method of flight that predates aeroplanes.</p>
<blockquote>
<p>For as long as humans have <a href="http://www.historyofballoons.com/balloon-history/montgolfier-brothers/">taken to the skies</a> we’ve had a low-carbon alternative to burning vast amounts of fossil fuels to keep us up there – balloons. <a href="https://www.airships.net/hindenburg/disaster/">The Hindenburg disaster</a> may have condemned the industry to relative obscurity for almost a century, but it has never really gone away.</p>
</blockquote>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/288023/original/file-20190814-136199-ymprvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288023/original/file-20190814-136199-ymprvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=446&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288023/original/file-20190814-136199-ymprvf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=446&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288023/original/file-20190814-136199-ymprvf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=446&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288023/original/file-20190814-136199-ymprvf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=560&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288023/original/file-20190814-136199-ymprvf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=560&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288023/original/file-20190814-136199-ymprvf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=560&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Airships travel slowly, but they could allow holidaymakers a beautiful view.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/airship-over-island-sea-3d-render-421798390?src=MOugPfN8hKjH2Eqmtkx3Zg-1-14">Iurii/Shutterstock</a></span>
</figcaption>
</figure>
<ul>
<li><p><strong>Safer fuels</strong> – the Hindenburg ignited due to its explosive hydrogen fuel, but modern airships use sacs of helium or safer forms of hydrogen which are cheap and relatively abundant.</p></li>
<li><p><strong>Low energy costs</strong> – unlike jet aircraft, airships don’t need lots of energy to stay aloft. At that point, energy costs become <a href="https://www.withouthotair.com/cC/page_281.shtml">comparable with rail travel</a>.</p></li>
<li><p><strong>Air cruises</strong> – airships are relatively slow, but they afford passengers stunning views of the world below. These “<a href="https://medium.com/predict/flying-hotels-the-romantic-age-of-air-travel-blimps-zeppelins-dirigibles-63346f507bc7">flying hotels</a>” were originally designed to accommodate dining rooms and ballrooms.</p></li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/288334/original/file-20190816-192210-11goyfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/288334/original/file-20190816-192210-11goyfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288334/original/file-20190816-192210-11goyfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=419&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288334/original/file-20190816-192210-11goyfk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=419&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288334/original/file-20190816-192210-11goyfk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=419&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288334/original/file-20190816-192210-11goyfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=526&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288334/original/file-20190816-192210-11goyfk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=526&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288334/original/file-20190816-192210-11goyfk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=526&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The dining room aboard the Hindenburg airship.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/LZ_129_Hindenburg#/media/File:Bundesarchiv_Bild_147-0640,_Luftschiff_Hindenburg_(LZ-129),_Speisesaal.jpg">Bundesarchiv, Bild/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Thunberg’s transatlantic crossing is expected to take two weeks, while the record from Frankfurt to New York <a href="https://www.theguardian.com/world/2014/aug/20/hindenburg-zeppelin-new-york-frankfurt-archive-1936">by Zeppelin was 44 hours</a>. Today people prize speed and convenience above all else, but the ongoing political awakening to the <a href="https://www.clubofrome.org/project/the-club-of-rome-climate-emergency-plan/">global climate emergency</a> might finally herald a new age.</p>
<p>There are, after all, benefits to not being squashed into a metal tube and hurled across the world at high speed. For all those seeking a slower and less frantic pace of life, the retirement of hydrocarbon-powered aeroplanes could finally make the journey as satisfying as the destination.</p>
<h2>Further reading</h2>
<ul>
<li><p><a href="https://theconversation.com/climate-change-and-air-travel-why-we-have-a-responsibility-to-countries-dependent-on-tourism-120462">Climate change and air travel: why we have a responsibility to countries dependent on tourism</a></p></li>
<li><p><a href="https://theconversation.com/researchers-set-an-example-fly-less-111046">Researchers, set an example: fly less</a></p></li>
<li><p><a href="https://theconversation.com/climate-strikes-greta-thunberg-calls-for-system-change-not-climate-change-heres-what-that-could-look-like-112891">Climate strikes: Greta Thunberg calls for ‘system change not climate change’ – here’s what that could look like</a></p></li>
<li><p><a href="https://theconversation.com/its-time-to-wake-up-to-the-devastating-impact-flying-has-on-the-environment-70953">It’s time to wake up to the devastating impact flying has on the environment</a></p></li>
</ul>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader121269">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/121269/count.gif" alt="The Conversation" width="1" height="1" />
Your next flight could be the single biggest contribution to global warming you make all year. Experts imagine how we might travel in future, without the ‘flygskam’.Jack Marley, Environment + Energy Editor, UK editionLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1200152019-07-23T15:10:48Z2019-07-23T15:10:48ZSouthampton to Shanghai by train – one climate change researcher’s quest to avoid flying<figure><img src="https://images.theconversation.com/files/285331/original/file-20190723-110195-1ntqhbu.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5466%2C3641&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/train-stop-railway-station-sunset-104477651?src=xC7pBUFuP-UiS7rNWIiP1w-1-46&studio=1">Zhu Difeng/Shutterstock</a></span></figcaption></figure><p>Academics travel a lot. Whether for fieldwork or conferences, we’re often <a href="https://theconversation.com/university-sector-must-tackle-air-travel-emissions-118929">encouraged</a> to do it. Often internationally, invariably by aeroplane. But while globetrotting might make us feel important, a recent <a href="https://www.sciencedirect.com/science/article/pii/S0959652619311862">study</a> suggests there’s no connection between academic air-miles and career advancement.</p>
<p>With the obvious realities of the climate crisis, and with air travel being the <a href="https://theconversation.com/its-time-to-wake-up-to-the-devastating-impact-flying-has-on-the-environment-70953">single quickest</a> way an average person can contribute to climate change, some academics are trying to stay on the ground whenever possible. Within a broader <a href="https://www.flightfree.co.uk/">campaign</a> to encourage people to go “flight-free”, there’s a community of <a href="https://academicflyingblog.wordpress.com/">academics</a> challenging the reliance on flying that’s typically sat uneasily at the heart of their careers.</p>
<p>I’m a member of that community. I pledged not to fly in 2019 and 2020, and then won a fellowship to study Chinese attitudes to sustainability which required me to go to China for fieldwork. Suddenly, the consequences of my pledge became very real.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/285327/original/file-20190723-110154-1grcjbv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/285327/original/file-20190723-110154-1grcjbv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=388&fit=crop&dpr=1 600w, https://images.theconversation.com/files/285327/original/file-20190723-110154-1grcjbv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=388&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/285327/original/file-20190723-110154-1grcjbv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=388&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/285327/original/file-20190723-110154-1grcjbv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=488&fit=crop&dpr=1 754w, https://images.theconversation.com/files/285327/original/file-20190723-110154-1grcjbv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=488&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/285327/original/file-20190723-110154-1grcjbv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=488&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Not only do planes release a lot of CO₂ during flight, the white ‘contrails’ they leave behind warm the atmosphere further.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/passenger-airplanes-on-air-busy-traffic-1089042554?src=lgi_phsJCpzeLwXItWfMbw-1-17&studio=1">FotoHelin/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Life on the rails</h2>
<p>When I told my managers that I intended to get to China by train, I was met with a mixture of responses. Some thought I was mad, some admired my principles, some thought I was an awkward bugger. Maybe they were all right. In any case, what I was doing had certainly created more work for myself.</p>
<p>I began trying to convince senior staff to release funds from my research budget to arrange visas, and thinking through the nitty-gritty of a trip across Europe, Russia and a big chunk of China itself. The cost of the trains was over £2,000, dwarfing the £700 I could pay for a London to Beijing return flight. Time-wise, the train trip took just under two weeks each way. But in terms of carbon emissions my trip was a steal, contributing <a href="https://www.gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2019">just 10%</a> of the emissions of the equivalent flights.</p>
<p>The cost, complexity and discomfort of such a long solo trip did occasionally make me wonder if it wouldn’t just be easier to fly (answer: it would). But I was determined to honour my pledge and show other academics – by my own extreme example – that it is possible to do international work without flights.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/285316/original/file-20190723-110175-szuvp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/285316/original/file-20190723-110175-szuvp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/285316/original/file-20190723-110175-szuvp8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/285316/original/file-20190723-110175-szuvp8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/285316/original/file-20190723-110175-szuvp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/285316/original/file-20190723-110175-szuvp8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/285316/original/file-20190723-110175-szuvp8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The author meets a train guard in Siberia.</span>
<span class="attribution"><span class="source">Roger Tyers</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Considering it involved 21 train connections, my journey went surprisingly smoothly. I took a series of “short” trips from Southampton, changing in London, Brussels, Cologne, Berlin and then onto my first sleeper train from Warsaw to Kiev (avoiding Belarus which would have required another visa). </p>
<p>My first experience on the Kiev-bound, Soviet-style sleeper train was something of a shock. Unsure of the etiquette when sharing a tiny cabin with two or three others with limited English, I soon learned that body language, Google translate and sharing food breaks the ice. Luckily, my no-flying trip was a recurring source of conversation, fascination and bafflement for many of my fellow travellers.</p>
<p>After one night in Kiev, I took another overnight train to Moscow. Russia was something of a test – on my return journey I travelled 2,600 miles between Irkutsk and Moscow, spending 90 hours on a single train. Had this not been a work trip, I would have gladly stopped more often. Making friends with fellow passengers – mainly Russians on work trips or family visits, or European and Chinese tourists doing the bucket list Trans-Siberian route – certainly helped pass the time. The Siberian scenery – millions of trees on a seemingly endless loop – became somewhat repetitive, but the monotony afforded me time to read, write, plan and contemplate.</p>
<p>The most spectacular journey was the Trans-Mongolian section, passing the edge of Lake Baikal, the world’s largest lake rimmed with snow-capped mountains, over the green steppes of northern Mongolia, across the Gobi desert, and finally through the mountainous valleys encircling Beijing. It’s hard not to be awed and inspired that these train lines exist in such remote parts of our planet.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1003%2C1003&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1003%2C1003&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/285302/original/file-20190723-110154-qqgn2n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The track stretches for miles across the Mongolian plains.</span>
<span class="attribution"><span class="source">Roger Tyers</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Calling at Beijing</h2>
<p>China now has more high-speed railways than the rest of the world combined, and they do it in style. Beijing to Shanghai, a trip covering 1,300km, takes less than four and a half hours, with a solid internet connection throughout and the most legroom I enjoyed on any of my trips. The downer is that China’s electrified trains will, <a href="https://theconversation.com/china-wrestles-with-insecure-gas-supplies-but-stays-strong-on-longer-term-plan-for-renewables-117445">like most of their electricity</a>, be powered by coal. But on the upside, these trains are likely to take passengers off domestic flights – a lesson for Europe and the US. </p>
<p>I enjoyed using them to visit my other field sites in Hangzhou and Ningbo before finally retracing my steps back, over 6,000 miles to the UK, clutching a load of new data, a heap of memories, and a sore back. The focus group data I collected in China, with members of their urban middle classes, has enforced my view that both ‘bottom-up’ social and cultural pressure, as well as “top-down” infrastructure and fiscal policy will be required in any country facing up the complex challenges of climate change.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/285360/original/file-20190723-110162-1jhj505.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/285360/original/file-20190723-110162-1jhj505.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/285360/original/file-20190723-110162-1jhj505.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/285360/original/file-20190723-110162-1jhj505.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/285360/original/file-20190723-110162-1jhj505.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/285360/original/file-20190723-110162-1jhj505.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/285360/original/file-20190723-110162-1jhj505.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The author at the end of his outward journey in Tiananmen Square.</span>
<span class="attribution"><span class="source">Roger Tyers</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>I admit that my story is somewhat privileged – not everyone can take the train to China for work, and I doubt I’ll make a habit of it. Much depends on geography too. The UK is relatively well connected by surface transport options like rail, but many still fly - the UK has the <a href="https://www.iata.org/pressroom/pr/Pages/2018-10-24-02.aspx">third largest</a> air passenger market, behind only the US and China. </p>
<p>The bigger policy goal is to make train tickets less expensive relative to flights. In the meantime, academics can play a leadership role, both individually and <a href="https://theconversation.com/researchers-set-an-example-fly-less-111046">institutionally</a>. Universities could consider publishing records of staff flights, building low-carbon travel modes into grant proposals by default, and making videoconferencing facilities fantastic. </p>
<p>Recent <a href="https://www.sciencedirect.com/science/article/pii/S0959652619311862">research</a> has shown, unsurprisingly, that climate researchers are taken more seriously if they practise what they preach. If we can lead by example in reducing our own flying carbon footprints while still conducting great research, then others – students, policymakers and other professionals – are far more likely to take notice.</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1120015">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/120015/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Roger Tyers receives funding from the Economic and Social Research Council.</span></em></p>How far would you go to limit your carbon footprint?Roger Tyers, Research Fellow in Environmental Sociology, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1000432018-07-17T10:40:07Z2018-07-17T10:40:07ZWhy Ryanair passengers were bleeding from the ears<figure><img src="https://images.theconversation.com/files/227789/original/file-20180716-44088-1yv8mjl.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1000%2C562&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/722932888?src=Qfa4DrFaCdw24iyeubZX9g-1-3&size=medium_jpg">pio3/Shutterstock.com</a></span></figcaption></figure><p>A Ryanair flight from Dublin to Croatia had to make an <a href="https://www.bbc.co.uk/news/world-europe-44832235">emergency landing</a> in Frankfurt recently after the cabin lost pressure. Following the ordeal, 33 passengers were treated in hospital, with some bleeding from their ears. </p>
<p>So why did the sudden descent cause ears to bleed? </p>
<p>Aircraft usually fly at an altitude above 30,000ft, climbing or descending to get there at a rate of about 2,000ft per minute. At 30,000ft the outside air pressure is <a href="https://www.avs.org/AVS/files/c7/c7edaedb-95b2-438f-adfb-36de54f87b9e.pdf">about a third</a> of that at sea level, causing gases to expand.</p>
<p>For comfort and safety, aircraft cabins are “pressurised” to an altitude of somewhere between <a href="https://www.ncbi.nlm.nih.gov/pubmed/23304996">5,000-8,000ft</a>, which is lower than pressure at sea level. This is why if you take a bag of crisps on the flight, it looks like it is about to burst, or when you get to your destination your shampoo has leaked into your bag. This pressurisation also helps to keep oxygen at a level that is safe for humans.</p>
<p>Normally, as the plane climbs, the air in the inner ear (see the diagram below) is at a greater pressure than the cabin because it is still the same pressure as when the aircraft left the ground, so the eardrum bulges out. During the climb, yawning, talking, drinking or swallowing cause the pressure in the inner ear to equal that of the cabin pressure at cruise level.</p>
<p>When the plane descends, the air pressure in the cabin begins to increase towards that at sea level, while the inner ear remains at the lower cruise-level pressure, and so the eardrum gets forced inwards, causing muffled hearing – which you may have experienced when flying.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/227863/original/file-20180716-44079-1pnugx7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/227863/original/file-20180716-44079-1pnugx7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/227863/original/file-20180716-44079-1pnugx7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/227863/original/file-20180716-44079-1pnugx7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/227863/original/file-20180716-44079-1pnugx7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/227863/original/file-20180716-44079-1pnugx7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/227863/original/file-20180716-44079-1pnugx7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/anatomical-structure-human-ear-780609469?src=zVwTr8X7QNXHxY5KY593gQ-1-2">Svetlana Verbinskaya/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>During normal ascent and descent, if you suck on a hardboiled sweet, take a drink or yawn, it can help open the Eustachian tube – which runs from your middle ear to the back of the nose – to allow the pressure in the inner ear to equalise with that outside the ear. Doing these things causes the opening in the back of the nose to stretch, allowing the air pressures to equalise.</p>
<h2>Barotrauma</h2>
<p>The Ryanair incident resulted from a loss of cabin pressure. This is where the mechanically maintained cabin air (held at the pressure representing 5,000-8,000ft) escapes to outside the aircraft where the pressure is much lower. This means that the air within the ear, which was also at a higher pressure (5,000-8,000ft), tries to escape. This is because the cabin has now dropped to the lower pressure of the outside of the aircraft. </p>
<p>At this high altitude, the pressure difference may result in <a href="https://www.ncbi.nlm.nih.gov/pubmed/24896105">“barotrauma”</a>, rupturing the eardrum and small blood vessels in the ear, causing hearing problems and bleeding. At this point, the packet of crisps would also explode. </p>
<p>Images on social media also showed blood-filled oxygen masks, probably the result of the rupture of small vessels in the roof of the nose as the change in pressure occurred. This was also likely the result of expanding liquids and gases that have to escape somewhere.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1018365220526403584"}"></div></p>
<p>The biggest danger to passengers when a loss of cabin pressure occurs is asphyxiation. As the aircraft climbs into the atmosphere, the amount of naturally available oxygen in the outside air reduces to a level that is insufficient for effective breathing. </p>
<p>As well as maintaining pressure, the aircraft also ensures there is enough oxygen in the cabin. At sea level, 21% of air is oxygen, which is ideal for humans to breath. At 30,000ft and above, there is only about a third of that amount <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1114067/">of oxygen available</a>. </p>
<p>Oxygen saturation in the blood of a healthy human is usually between <a href="https://bnf.nice.org.uk/treatment-summary/oxygen.html">94-98%</a>. During flight, this reduces to the <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2044.2005.04124.x">low 90s</a> and in some cases into the 80s. The reduction in oxygen saturation towards 90% could have even more significant effects on those with heart or breathing conditions. This is why the oxygen masks deploy when cabin pressure drops – it ensures that every passenger has enough oxygen to saturate the blood. </p>
<p>Deployment of oxygen masks happens at the same time as the pilots descend as <a href="https://eu.usatoday.com/story/travel/columnist/cox/2016/06/05/ask-captain-how-long-can-you-breathe-through-oxygen-masks/85350902/">rapidly as possible</a> to get to an altitude (usually below 10,000ft) where passengers can breathe without the aid of oxygen masks. This is because there is only a limited supply of oxygen (about 15 minutes) that is generated by special oxygen generators in the overhead panel. </p>
<h2>Other unpleasant side effects</h2>
<p>Luckily, these sorts of events are very rare. Air travel is extremely safe, with 2017 marked as the <a href="https://news.aviation-safety.net/2017/12/30/preliminary-asn-data-show-2017-safest-year-aviation-history/">safest year</a> to date. However, flying is probably never going to be entirely pleasant, even when things go well. </p>
<p>Ear problems – such as muffled hearing and popping ears – are experienced by everyone. But they are particularly unpleasant for people with colds, as their sinuses are full of mucus, which can block the opening of the Eustachian tube.</p>
<p>Teeth can also become sore <a href="https://www.ncbi.nlm.nih.gov/pubmed/12380041">during or after</a> flights as air in the fillings and around the nerves expands and contracts. Unlike ear pain, chewing gum or sweets won’t help.</p>
<p>And ears and teeth aren’t the only places affected by rising and falling air pressure. During normal flight, the gas of the bowel also expands and contracts. As the aircraft climbs this gas expands, then on descent it becomes compressed again, often needing somewhere to escape. This is where people have to make the trade-off between social discomfort and physical discomfort. </p>
<p>As a result of this well-known problem, a group of researchers have suggested <a href="https://www.nzma.org.nz/journal/read-the-journal/all-issues/2010-2019/2013/vol-126-no-1369/view-pommergaard">embedding active charcoal</a> in aircraft seats to act as an odour absorber. Things can get better, even if they can never be perfect.</p><img src="https://counter.theconversation.com/content/100043/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Taylor is affiliated with the Anatomical Society. </span></em></p>Flying plays havoc with people’s ears. But it’s a lot worse if your cabin suddenly loses pressure.Adam Taylor, Director of the Clinical Anatomy Learning Centre and Senior Lecturer, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/703882017-01-11T19:53:22Z2017-01-11T19:53:22ZLife in a post-flying Australia, and why it might actually be ok<figure><img src="https://images.theconversation.com/files/150448/original/image-20161216-26062-xzuj56.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cancelled flights might be your worst nightmare, but imagine a world with no flights. </span> <span class="attribution"><span class="source">Flight image from www.shutterstock.com</span></span></figcaption></figure><p>In Australia, the amount of aviation fuel consumed per head of population has more than doubled since the 1980s. We now use, on average, <a href="https://industry.gov.au/Office-of-the-Chief-Economist/Publications/Documents/aps/2016/Australian_Petroleum_Statistics_242_September2016.pdf">2.2 barrels (or 347 litres) of jet fuel</a> per person per year. </p>
<p>This historically unprecedented aeromobility has enormous <a href="http://www.sciencedirect.com/science/article/pii/S1352231009003574">environmental costs</a>. Aviation is contributing to around 4.9% of <a href="http://www.sciencedirect.com/science/article/pii/S1352231009003574">current global warming</a> and this is forecast to <a href="http://www.sciencedirect.com/science/article/pii/S1352231009003574">at least triple by 2050</a>. <a href="https://www.environment.gov.au/system/files/resources/cab3140e-5adb-479f-9af4-a7c605d762dc/files/national-inventory-report-2014-revised-vol-1.pdf">Domestic aviation in Australia</a> produces around 8.6 million tonnes of greenhouse gases each year.</p>
<p><a href="https://theconversation.com/aviation-has-an-emissions-problem-and-cop-21-wont-solve-it-50583">Offsetting schemes</a>, <a href="http://www.sciencedirect.com/science/article/pii/S1361920916000158">technology solutions</a> and other attempts to lower the carbon emissions of aviation have failed dismally.</p>
<p>The only solution to these intractable environmental impacts is the dramatic reduction, or complete elimination, of air travel. It might be hard to imagine life without the plane, but the idea is not as crazy as it sounds.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/150266/original/image-20161215-2509-gaees2.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/150266/original/image-20161215-2509-gaees2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/150266/original/image-20161215-2509-gaees2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=436&fit=crop&dpr=1 600w, https://images.theconversation.com/files/150266/original/image-20161215-2509-gaees2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=436&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/150266/original/image-20161215-2509-gaees2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=436&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/150266/original/image-20161215-2509-gaees2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=548&fit=crop&dpr=1 754w, https://images.theconversation.com/files/150266/original/image-20161215-2509-gaees2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=548&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/150266/original/image-20161215-2509-gaees2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=548&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Australian aviation fuel consumption per capita 1985-2015. Sources: Australian Petroleum Statistics and the ABS Estimated Residential Population.</span>
</figcaption>
</figure>
<p>Here are nine common objections to grounding planes, and our counterpoints:</p>
<h2>1. There are no fast, cheap and clean transport alternatives to the plane.</h2>
<p>So we build them. We construct a national high-speed rail network and more efficient intercity, rural and urban transport systems. These projects would involve Australian steel, thousands of new jobs and large-scale regional planning and infrastructure development. </p>
<p>These programs would ameliorate urban congestion, the <a href="http://infrastructureaustralia.gov.au/projects/files/Australian_Infrastructure_Plan-Infrastructure_Priority_List.pdf">most pressing priority of Infrastructure Australia</a>, revitalise regional communities and dramatically reduce our <a href="http://dfat.gov.au/trade/resources/trade-at-a-glance/pages/top-goods-services.aspx">imports of crude and refined petroleum</a>.</p>
<p>The continual development of communications technologies, including fast internet and virtual reality, will make much business travel redundant. Investing in virtual technologies and forcing the political and corporate elite to use other transport modes would hasten political support for, and investment in, the development of transport alternatives.</p>
<h2>2. What about the economic value of tourism?</h2>
<p>If we abandoned all tourist flights, the economy would be A$14.4 billion better off. International visitors spent <a href="https://www.tra.gov.au/documents/ivs/IVS_one_pager_June2016.pdf">A$38.1 billion</a> in Australia in 2015-16. But, Australians travelling overseas spent far more – <a href="https://www.tra.gov.au/documents/nvs/NVS_onepager_June-2016.pdf">A$52.4 billion</a> – in the same period.</p>
<p>International tourism, both in and outbound, would continue under a no–aviation scenario. As an island nation we will become reliant on ships. Travel by cruise ship is already <a href="http://www.cruising.org/docs/default-source/research/2016_clia_sotci.pdf?sfvrsn=0">booming</a>. While cruise ships are currently highly polluting, their <a href="http://www.raeng.org.uk/publications/reports/future-ship-powering-options">conversion to non-fossil-fuel energy</a>, in contrast to the plane, is more achievable.</p>
<h2>3. What about our education export industry?</h2>
<p>Transnational education, teaching of students by Australian university offshore programs and via online distance education, is already significant, accounting for <a href="https://internationaleducation.gov.au/research/Research-Snapshots/Documents/Transnational%20education_HE_2015.pdf">30.2% of all higher education international students in 2015</a>. We would invest more heavily in these educational platforms and technologies.</p>
<h2>4. What about the jobs in the aviation industry?</h2>
<p>Technological replacement and offshoring have decimated full-time jobs in Australia’s aviation industry. The employment generated by growth in domestic tourism and the construction of high-speed rail, ships and other transport alternatives would more than compensate.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/150268/original/image-20161215-2539-18j9x7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/150268/original/image-20161215-2539-18j9x7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/150268/original/image-20161215-2539-18j9x7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=486&fit=crop&dpr=1 600w, https://images.theconversation.com/files/150268/original/image-20161215-2539-18j9x7j.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=486&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/150268/original/image-20161215-2539-18j9x7j.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=486&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/150268/original/image-20161215-2539-18j9x7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=610&fit=crop&dpr=1 754w, https://images.theconversation.com/files/150268/original/image-20161215-2539-18j9x7j.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=610&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/150268/original/image-20161215-2539-18j9x7j.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=610&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Aviation jobs per 1000 revenue passenger kilometres for domestic flights. Sources: BITRE Australian Domestic Aviation Activity data and the ABS Labour Force Survey statistics on employment in the air and space transport industries.</span>
</figcaption>
</figure>
<h2>5. What about the needs of farmers and hospitality industries who rely on backpackers?</h2>
<p>We would still have a backpacker labour force under conditions of “<a href="http://www.tandfonline.com/doi/abs/10.1080/09669582.2010.524704">slow tourism</a>” that uses alternatives to cars and planes. Particularly for longer-stay tourism, arrival and departures by boat would be a small component of a trip.</p>
<p>We could also start using our own population for these jobs by paying higher wages. This might also reduce unemployment and dependency on social welfare and raise additional tax revenue. In the longer term we would transition to agriculture and hospitality industries that are not reliant on <a href="https://www.fairwork.gov.au/about-us/news-and-media-releases/2016-media-releases/october-2016/20161015-417-inquiry-media-release">exploited and underpaid</a> holiday-workers.</p>
<h2>6. What about medical, military and rescue flights?</h2>
<p>We need to keep essential flights for <a href="https://www.flyingdoctor.org.au/">medical</a>, <a href="http://www.rescuehelicopter.com.au/">rescue</a> and <a href="http://www.abc.net.au/news/2016-12-11/adelaide-hills-new-country-fire-service-base/8110202">firefighting</a> purposes, and some military capacity. For essential flights, mitigation strategies like offsets may work as emissions would be low in aggregate.</p>
<h2>7. What about sport and culture?</h2>
<p>Sport and air travel are closely linked. Our national rugby union team is the <a href="http://www.qantas.com/travel/airlines/wallabies/global/en">Qantas Wallabies</a>. Although teams travel, <a href="https://theconversation.com/new-gadgets-and-gimmicks-to-keep-us-watching-sport-live-on-tv-36138">more spectators than ever are staying put</a> – preferring to watch live sports on TV. Technological improvements will continue to produce a <a href="https://theconversation.com/new-gadgets-and-gimmicks-to-keep-us-watching-sport-live-on-tv-36138">better-than-real home experience</a>. And the <a href="https://theconversation.com/will-super-mario-ever-be-an-olympic-sport-64274">eSports</a> teams of the future may not have to leave home either.</p>
<h2>8. Prohibition never works!</h2>
<p>Banning things like alcohol has proven historically difficult, <a href="https://web.archive.org/web/20160313051323/http:/yourmemento.naa.gov.au/2013/04/prohibition-in-canberra-king-omalley-and-the-dry-capital/">even in Canberra</a>. But <a href="https://en.wikipedia.org/wiki/No-fly_zone">no-fly zones</a> are easier to enforce – you couldn’t smuggle an A380 into the country and fly it around without anyone noticing.</p>
<h2>9. It’s too radical a change – it would cause chaos!</h2>
<p>Arguably, the controllable outcomes of grounding aircraft will be far less severe than the chaos of uncontrolled <a href="http://ipcc-wg2.gov/AR5/report/final-drafts/">global climate change</a>. A transformed, low-emissions transportation system can be planned for and, while there will be significant readjustment, life will go on. </p>
<p>A “business as usual” climate change scenario will unleash destruction unparalleled in human history, including the genuine <a href="http://users.physics.harvard.edu/%7Ewilson/pmpmta/Mahoney_extinction.pdf">threat of species extinction</a>.</p>
<p>As an island nation we are more dependent than most on the aeroplane. Rather than giving us special dispensation, this puts us in a position to be world leaders in sustainable transport. Our proposal to ground planes and dramatically reduce emissions would need tremendous action in terms of civic will, and a state apparatus politically capable of taking radical action.</p>
<p>Liberal democracies are capable of such action, as evidenced by Australia’s <a href="https://en.wikipedia.org/wiki/Snowy_Mountains_Scheme">Snowy Mountains Scheme</a>. And <a href="http://www.abc.net.au/news/2016-12-01/donald-trump-infrastructure-building-spree-economy-australia/8084064">Trump’s mandate to build infrastructure</a> shows nation-building projects still command public support. An aviation-free Australia is a genuine and necessary alternative.</p><img src="https://counter.theconversation.com/content/70388/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>With little hope of finding alternatives to jet fuel, we need to seriously consider a world without flying.Martin Young, Associate Professor, School of Business and Tourism, Southern Cross UniversityFrancis Markham, PhD Candidate, The Fenner School of Environment and Society, Australian National UniversityJames Higham, Professor of Tourism, University of OtagoJohn Jenkins, Professor, School of Business and Tourism, Southern Cross UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/702412016-12-21T00:28:25Z2016-12-21T00:28:25ZObstacle avoidance: The challenge for drone package delivery<figure><img src="https://images.theconversation.com/files/150527/original/image-20161216-18030-1ld27eo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Look out!</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/pic-451886950/">Delivery drone illustration via shutterstock.com</a></span></figcaption></figure><p>The <a href="http://www.nytimes.com/2016/12/14/technology/amazon-drone-england-delivery.html">world’s first drone deliveries</a> have begun trial runs in the United Kingdom <a href="https://techcrunch.com/2016/12/20/7-eleven-delivers-77-packages-via-drone-in-first-month-of-routine-service/">and the U.S.</a> Once primarily used by militaries, small quadcopter and octocopter drones are now so commonplace they are for sale at <a href="https://www.lowes.com/pl/Drones-drone-accessories-Electrical/1236481888">home improvement stores</a> and <a href="http://www.toysrus.com/category/index.jsp?categoryId=114577256&ab=TRU_Header:Utility3:Vehicles-Trains-RC:Drones:Home-Page">toy stores</a>. People are flying drones for fun, for entertainment and for commercial purposes as diverse as <a href="http://motherboard.vice.com/read/submissions-are-open-for-the-2017-new-york-city-drone-film-festival">filmmaking</a> and <a href="https://theconversation.com/farmers-of-the-future-will-utilize-drones-robots-and-gps-37739">farming</a>.</p>
<p>All these uses have one thing in common: The drone’s human operator is required by law to be able to see the drone at all times. Why? The answer is simple: to make sure the drone doesn’t hit anything.</p>
<p>Beyond just wanting not to crash and damage their drones or themselves, <a href="https://www.faa.gov/uas/media/Part_107_Summary.pdf">drone operators must avoid collisions with people, property and other vehicles</a>. Specifically, <a href="https://www.faa.gov/regulations_policies/faa_regulations/">federal aviation regulations</a> forbid aircraft – including drones – from flying “<a href="http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFAR.nsf/0/962A5F17CD0CBBB8852566CF00614B41?OpenDocument">so close to another aircraft as to create a collision hazard</a>.” The rules also require that “<a href="http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFAR.nsf/0/934f0a02e17e7de086256eeb005192fc!OpenDocument">vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft</a>.” These requirements are commonly referred to simply as “see-and-avoid”: Pilots must see and avoid other traffic.</p>
<p>But that places a significant limitation on drone operations. The whole point of drones is that they are unmanned. Without a human operator on board, though, how can a drone steer clear of collisions? This is a crucial problem for Amazon, Google and any other company that wants to <a href="http://motherboard.vice.com/read/amazons-delivery-drones-may-face-new-regulatory-roadblocks">deliver packages with drones</a>.</p>
<p>To be practical, delivery drones would have to be able to fly long distances, well out of sight of a human operator. How, then, can the operator prevent the drone from hitting a tree, building, airplane or even another drone? Although cameras could be mounted on the drone for this purpose, current civil drone video transmission technology is <a href="http://www.digitaltrends.com/drone-reviews/dji-mavic-pro-review/">limited to a range of a few miles</a>. As a result, in order to perform long-distance deliveries, the drone must autonomously detect nearby objects and avoid hitting them. </p>
<p>As a drone operations researcher, I keep a close eye on ways to achieve this. New research into sensors – at least some of which come from development of autonomous cars – is making increased autonomy possible for drones, potentially opening the skies to even more innovation.</p>
<h2>Radar and lidar</h2>
<p>There are two main technologies available for drones to detect nearby objects. The first is radar, <a href="https://www.britannica.com/technology/radar/History-of-radar">developed just before World War II</a>, that sends out radio waves and measures their reflections from obstacles. Radar is still used as the primary system for air traffic controllers <a href="http://web.mit.edu/6.933/www/Fall2000/mode-s/atcrbs.html">to track planes in the sky</a>. <a href="http://www.boats.com/how-to/marine-electronics-101-how-to-use-radar/">Ships also use radar</a> to avoid collisions at night or in foggy conditions.</p>
<p><a href="http://oceanservice.noaa.gov/facts/lidar.html">Lidar</a>, developed more recently, uses laser beams instead of radio waves, and can provide extremely detailed images of nearby features. The catch is that both radar and lidar systems have been <a href="https://www.washingtonpost.com/news/innovations/wp/2015/12/04/the-75000-problem-for-self-driving-cars-is-going-away/?utm_term=.6463cadd4ba3">bulky, heavy and expensive</a>. That makes them hard to fit on relatively small drones; also, heavier drones require more battery power to stay aloft, which requires bigger (and heavier) batteries.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/150384/original/image-20161215-26027-1wmuv12.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/150384/original/image-20161215-26027-1wmuv12.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/150384/original/image-20161215-26027-1wmuv12.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/150384/original/image-20161215-26027-1wmuv12.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/150384/original/image-20161215-26027-1wmuv12.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/150384/original/image-20161215-26027-1wmuv12.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/150384/original/image-20161215-26027-1wmuv12.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A small lidar sensor.</span>
<span class="attribution"><span class="source">Velodyne</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>There is hope, though. Research in obstacle sensors and collision avoidance technology for autonomous automobiles has spurred the development of small, lower-cost <a href="http://www.drone360mag.com/news-notes/2016/05/echodyne-releases-small-radar-that-could-be-big-for-drones">radar</a> and <a href="https://www.washingtonpost.com/news/innovations/wp/2015/12/04/the-75000-problem-for-self-driving-cars-is-going-away/?utm_term=.6463cadd4ba3">lidar</a> devices. Once they are sufficiently small, and energy-efficient enough not to quickly drain drone batteries, both types of sensors could help solve the drone “see-and-avoid,” or really, because drones don’t have eyes, the “detect-and-avoid” problem.</p>
<h2>An in-flight view</h2>
<p>A recent test flight here at Ohio University involved a lidar sensor mounted on a drone. When the drone was approximately five feet above the ground, the lidar was able to create an image of its surroundings.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/150382/original/image-20161215-26027-1k8hs9w.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/150382/original/image-20161215-26027-1k8hs9w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/150382/original/image-20161215-26027-1k8hs9w.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/150382/original/image-20161215-26027-1k8hs9w.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/150382/original/image-20161215-26027-1k8hs9w.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/150382/original/image-20161215-26027-1k8hs9w.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/150382/original/image-20161215-26027-1k8hs9w.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/150382/original/image-20161215-26027-1k8hs9w.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A lidar image from a drone in flight.</span>
<span class="attribution"><span class="source">Michael Braasch</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>On one side, the image had bushy-looking areas representing trees and foliage. One the other there were parallel lines indicating the location of a building wall. And in the middle were some circular shapes representing the ground. This sort of obstacle detection capability and discernment will be essential for routine drone operation, particularly during takeoff and landing.</p>
<p>We are currently in what might be called the “Wright Brothers era” of drone development. Removing the human from the cockpit has challenged innovators and designers in a number of ways – including solving the task of obstacle detection. But as our technology advances, eventually – just like elevators that used to be operated by humans – people will grow used to the idea of these machines operating autonomously.</p><img src="https://counter.theconversation.com/content/70241/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Braasch has received funding from the FAA and NASA for drone research. </span></em></p>Without a human operator on board, how can a drone steer clear of collisions? Technology from autonomous cars can help.Michael Braasch, Professor of Electrical Engineering, Ohio UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/702972016-12-14T03:39:57Z2016-12-14T03:39:57ZPerth to London non-stop: great for travellers, but little help for emissions<p>This week, Qantas <a href="http://www.qantasnewsroom.com.au/media-releases/qantas-to-fly-non-stop-perth-to-london/">announced</a> that passengers will soon be able to fly non-stop between Perth and London – the first ever air service to link Australia and Europe directly. Seats on the new route will go on sale in April 2017, with flights starting in March 2018. </p>
<p>It’s a journey made possible by the technological advancements of long-haul aircraft – in this case, the <a href="http://www.qantas.com/travel/airlines/aircraft-boeing-787/global/en">Boeing 787-9 Dreamliner</a>. </p>
<p>The Dreamliner (with capacity to carry 236 passengers) will take 17 hours to complete the 14,498-kilometre journey. It’s the longest Qantas route and the third-longest passenger flight in the world. </p>
<p>Qantas chief executive Alan Joyce <a href="http://www.qantasnewsroom.com.au/media-releases/qantas-to-fly-non-stop-perth-to-london/">described</a> the announcement as a watershed for travel, tourism and trade. But while the travel opportunities are indeed potentially game-changing, the environmental benefits are less so. </p>
<h2>The non-stop footprint</h2>
<p>Of course, non-stop flights are generally <a href="http://www.worldwatch.org/planes-utilize-most-fuel-during-takeoff">better</a> for the environment than flights that stop en route. Flying a long-haul route non-stop produces less greenhouse gas than stopping along the way, largely because the aircraft can take a more direct route. </p>
<p>The additional fuel needed to carry the weight of extra fuel required for ultra long-haul flights does, however, contribute to the overall emissions of the flight (and may very well lead to an increased cost to passengers).</p>
<p>Fuel efficiency is crucial, because aviation fuel (kerosene) is the primary source of aviation emissions. Researchers have <a href="http://www.cate.mmu.ac.uk/wp-content/uploads/Bridging_the_aviation_emissions_gap_010313.pdf">calculated</a> that total aviation emissions in 2006 were 630 million tonnes of carbon dioxide. By 2050, those emissions are projected to be between 1 billion and 3.1 billion tonnes, depending on the growth in air traffic and the success of efforts to reduce emissions through fuel effiency, biofuels and <a href="https://theconversation.com/the-new-un-deal-on-aviation-emissions-leaves-much-to-be-desired-66768">offsetting</a>.</p>
<p>A flight’s environmental impact grows exponentially whenever the aircraft is required to make a stop. During take-off, more fuel is consumed (and more emissions produced) than at any other stage of the flight. On short flights, take-off accounts for <a href="http://www.worldwatch.org/planes-utilize-most-fuel-during-takeoff">as much as 25%</a> of total fuel consumption. </p>
<h2>Fuel efficiency from Perth to London</h2>
<p>So is the advent of super-range passenger aircraft the solution to the aviation emissions problem?</p>
<p>The rate of fuel consumption varies widely between aircraft models, ranges and manufacturers; fuel efficiency even varies between aircraft of the same model, depending on the condition, age and use of the aircraft and its engines. </p>
<p>Boeing <a href="http://www.boeing.com/commercial/787/by-design/#/dreamliner-advantages-overview">estimates</a> that its 787 family “uses 20-25% less fuel on a per passenger basis than the airplanes they replace”. </p>
<p>The 787-9 Dreamliner itself offers a <a href="http://www.boeing.com/commercial/787/by-design/#/787-9-characteristics">range</a> of efficiencies in terms of kilometres travelled and stops required, while carrying more passengers and cargo than its predecessor, the 787-8.</p>
<p>So, as noted above, the Perth-to-London non-stop route will generate fewer greenhouse emissions than the most direct existing routes, which stop in various Middle Eastern locations including Dubai and Doha. </p>
<p>But how much of an impact will this have on the reduction of aviation emissions? Not very much. </p>
<h2>Short stuff</h2>
<p>The availability of super-long routes does nothing to curb the ongoing expansion of short-haul aviation. For instance, <a href="http://www.worldwatch.org/planes-utilize-most-fuel-during-takeoff">roughly half</a> of all flights within the European Union are shorter than 500km, while hundreds of short-haul routes are available in the United States. These routes typically fall a long way short of the most fuel-efficient flight length, which has been <a href="http://www.worldwatch.org/planes-utilize-most-fuel-during-takeoff">estimated at 4,300km</a> – or three-quarters of the way from <a href="http://www.distancefromto.net/distance-from-new-york-to-london-gb">London to New York</a>. </p>
<p>Bear in mind that air travel is the <a href="http://www.theguardian.com/sustainable-business/2014/oct/08/boeing-biofuels-uae-peak-travel-airlines-sxsw-eco">most carbon-intensive form</a> of travel. Regardless of what the aviation industry achieves in terms of emission reductions, these will be <a href="http://www.sciencedirect.com/science/article/pii/S1352231014004889">overwhelmed by its predicted growth</a>. </p>
<p>This growth will outweigh the improvements delivered even by dramatic measures to cut emissions. What’s more, those measures are a still long way off – and if you’ll pardon the pun, improving aviation’s environmental impact will be a long haul.</p><img src="https://counter.theconversation.com/content/70297/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rebecca Johnston does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Qantas’s new non-stop route from Perth to London might be a watershed for travel times between Australia and Europe. But super-long-haul routes won’t do much to cut aviation’s greenhouse emissions.Rebecca Johnston, Faculty of Law, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/572012016-04-07T04:53:24Z2016-04-07T04:53:24ZNew relaxed drone regulations will help the industry take off<figure><img src="https://images.theconversation.com/files/117573/original/image-20160406-28945-uvilu3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">CASA makes it easier for low risk flying of drones.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/rthorek-photography/6798508919/">Flickr/Richard Thorek</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>The Australian drone industry is set for a shake up following the announcement of a long-awaited relaxation of regulations on their operation. </p>
<p>Australia’s Civil Aviation Safety Authority (<a href="https://www.casa.gov.au/">CASA</a>) says the <a href="https://www.casa.gov.au/publications-and-resources/media-release/red-tape-cut-remotely-piloted-aircraft">amended regulations</a> will come into effect in late September 2016, and with them comes the introduction of new categories of what are known as remotely piloted aircraft systems (RPAS).</p>
<p>The regulations define new low-risk commercial RPAS operations, which will allow operators of <a href="https://www.legislation.gov.au/Details/F2016L00400/Explanatory%20Statement/Text">sub-2kg craft</a> to fly without the need for an approval or licence. </p>
<p>A drone must be operated in daytime and within visual line of sight of the remote pilot to be classified as low risk. It must not be flown over populous areas and must be kept at least 30 metres from other people.</p>
<p>The drone cannot be flown greater than 130m above ground and it must not be flown within 5.5km of a controlled airport.</p>
<p>Commercial operators in this new category will have to register their operations with CASA on a yet-to-be live website.</p>
<p>Relaxed regulations will also apply to private owners of RPAS of up to 150kg. This is provided they only fly their drone over their private property and they do not operate their aircraft for direct commercial reward. </p>
<h2>Why the change?</h2>
<p>In 2002, CASA was the first in the world to <a href="https://www.casa.gov.au/standard-page/casr-part-101-unmanned-aircraft-and-rocket-operations">regulate the operation of drones</a>. </p>
<p>The regulations, contained in <a href="https://www.casa.gov.au/standard-page/casr-part-101-unmanned-aircraft-and-rocket-operations">Part 101</a> of the Civil Aviation Safety Regulation (CASR 1998), were long considered ground breaking. Much of the success of the Australian unmanned aircraft industry is owed to the flexible approach outlined in the regulations. </p>
<p>In 2007, there were fewer than 25 certified drone operators in Australia. By March 30, 2016, <a href="http://www.aviationbusiness.com.au/news/casa-issues-500th-uav-operator-certificate">this number had grown to 500</a>, with most operating small multi-rotor RPAS.</p>
<p>But with this rapid growth came the increasing need for regulatory reform. CASA recognised that the regulations needed to keep pace with increasingly capable technology, and the changing operational needs of the sector.</p>
<p>It also realised that processing an ever increasing number of regulatory applications was not sustainable.</p>
<h2>Welcome news</h2>
<p>The new changes <a href="http://www.abc.net.au/news/2016-04-01/new-drone-regulations-to-benefit-farmers/7293392">will significantly reshape</a> the drone industry. </p>
<p>Operators already licensed by CASA are expected to face increased competition from the new sub-2kg RPAS operators. These new operators will be able to provide equivalent <a href="http://voices.nationalgeographic.com/2014/03/05/so-you-want-to-shoot-aerial-photography-using-drones/">aerial photography and inspection services</a> without the same regulatory overhead.</p>
<p>Similarly, there will be an <a href="http://fortune.com/2014/10/08/drone-nation-air-droid/">increase in the number of end-users</a> choosing to own and operate their own internal RPAS capability instead of contracting existing RPAS service providers. Examples include the use of small <a href="http://www.gizmag.com/drones-building-construction-industry/36306/">inspection drones on building sites</a> and the use of drones by <a href="http://www.brisbanetimes.com.au/queensland/queensland-police-recruit-drones-in-forensic-first-20150528-ghbi70.html">tactical police units</a> to assist them in hostage situations.</p>
<p>But it is not all doom and gloom for the current licensed RPAS operators. The standard operating conditions applicable to the new low-risk categories are restrictive.</p>
<p>Larger and more reliable drones will still be needed to carry bulky and more expensive payloads such as laser scanners, and hyper-spectral and cinema-quality cameras. These drones will still need to be operated by licensed operators.</p>
<p>Approval is still required for first person view (<a href="https://theconversation.com/explainer-what-is-fpv-drone-racing-54047">FPV</a>) outdoor flying operations, where the remote pilot flies by means of a camera mounted on board the drone. </p>
<p>Similarly, <a href="https://theconversation.com/robots-in-the-skies-how-outback-joe-was-found-and-rescued-34234">autonomous drones</a>, which operate without any input from a pilot, also require CASA approval on a case-by-case basis.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/117308/original/image-20160404-27125-18ijsxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/117308/original/image-20160404-27125-18ijsxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/117308/original/image-20160404-27125-18ijsxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/117308/original/image-20160404-27125-18ijsxn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/117308/original/image-20160404-27125-18ijsxn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/117308/original/image-20160404-27125-18ijsxn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/117308/original/image-20160404-27125-18ijsxn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/117308/original/image-20160404-27125-18ijsxn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A large drone that will still require licensed operators for commercial use.</span>
<span class="attribution"><span class="source">Stefan Hrabar/CSIRO/UAV Challenge</span></span>
</figcaption>
</figure>
<p>Research and educational institutions, such as universities, are also expected to benefit from the new categories, provided they operate their aircraft over their own property and in accordance with all other operational restrictions. </p>
<p>Previously, these institutions were subject to the same licensing requirements as commercial operators. </p>
<h2>Hobby users</h2>
<p>The amended regulations do not address concerns posed by the rapidly growing number of hobby drone users.</p>
<p>Regulations applicable to hobby or recreational users are contained in CASR 1998 Part 101.G, which is the subject of a separate CASA regulatory reform project.</p>
<p>There is growing concern over the risks hobby users pose to other aircraft and to members of the public. Some of these hobby users are not aware of the potential danger their drone may pose. </p>
<p>There have been numerous <a href="http://www.theguardian.com/uk-news/2016/feb/01/drone-near-miss-should-be-a-wake-up-call-for-review-says-shadow-minister">near misses of small drones with passenger aircraft</a> in recent years. As the rate of these incidents increases, there is real concern that a drone will eventually be ingested into an aircraft engine causing catastrophic damage – or worse, an airline crash.</p>
<p>Others are well aware of the dangers their drones may pose to the public but they <a href="http://www.digitaltrends.com/cool-tech/10-dumb-uses-of-drones-that-ruin-drones-for-everyone/">are deliberately mischievous anyway</a>.</p>
<p>Education remains the only effective tool, with CASA leading a campaign <a href="https://www.casa.gov.au/sites/g/files/net351/f/_assets/main/lib100071/flying_with_control_model.pdf">to educate hobby users on the safe operation</a> of their aircraft and the regulations that apply to them. </p>
<p>Without doubt, the release of the amended regulations will mark a significant milestone in the history of the Australian drone industry. They will help to sustain the safe and viable growth of the sector.</p>
<p>But the devil may still lie in the detail, of course, with the accompanying manual of standards yet to be released by CASA. The manual will contain more detailed requirements including those for remote pilot licences, flights in controlled airspace, and flights beyond visual line of sight of the pilot.</p>
<p>CASA’s exact interpretation of “Aerial Work” and “Commercial Reward” also remain unclear.</p><img src="https://counter.theconversation.com/content/57201/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Reece Clothier's primary area of research is the safety and regulation of unmanned aircraft systems (UAS) for which he has previously received research funding from CASA. Dr Clothier is the President of the Australian Association for Unmanned Systems and former Industry Co-chair of the CASA Standards Consultative Committee, UAS Sub-Committee. </span></em></p><p class="fine-print"><em><span>Jonathan Roberts is the co-founder of the UAV Challenge, an international competition that sees teams develop robot aircraft to demonstrate their use for saving people lost or in need of medical assistance. The UAV Challenge has been co-sponsored in the past by CASA. Jonathan is an academic and researcher with QUT's Australian Research Centre for Aerospace Automation (ARCAA).</span></em></p>Long awaited changes to the regulations on some drone flights in Australia are set to give the industry a shake up.Reece Clothier, Senior Lecturer, RMIT UniversityJonathan Roberts, Professor in Robotics, Queensland University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/445432016-01-25T17:00:10Z2016-01-25T17:00:10ZThe race to hypersonic speed: will air passengers feel the benefits?<figure><img src="https://images.theconversation.com/files/88544/original/image-20150715-26325-fo17wo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An impression of the X-51 Waverider, the US hypersonic aircraft programme.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:X-51A_Waverider.jpg">NASA</a></span></figcaption></figure><p>When Concorde entered service 40 years ago, it more than doubled the speed of air travel at a stroke. Following Concorde’s retirement, airliners today fly once more at subsonic speeds, but engineers worldwide are looking to a future in which high-speed flight is an everyday occurrence. Except they want to go one better: not at supersonic, but hypersonic speeds.</p>
<p>Aerospace giant Airbus was last year <a href="http://www.theguardian.com/business/2015/aug/05/airbus-patents-hypersonic-plane-paris-tokyo-three-hours">awarded a patent</a> that details how a future hypersonic aircraft, with delta wings reminiscent of Concorde, could travel at Mach 4.5 – fast enough to carry passengers between Paris and Tokyo in just three hours. </p>
<p>But inevitably, technology that has reached the commercial realm will already have been investigated by the military. The US, Russia and China have all carried out test flights of hypersonic vehicles – those which travel at around five times the speed of sound – with varying degrees of success. Each also has plans for weapons systems that could be developed from them.</p>
<p>Because while these are often referred to as “<a href="http://www.thetimes.co.uk/tto/technology/article4481252.ece">fighter jets</a>”, in truth the machines are more similar to missiles. Without pilots, they sit atop rockets which boost them to high supersonic speeds (Mach 4 and above), at which point they start up their own engines (if equipped) and accelerate to even faster cruise speeds - but not for long, as they usually run out of fuel quickly, and most of their flight time is spent in a glide, albeit an extremely fast one.</p>
<p>Current missiles have operated in this fashion for decades. Intercontinental ballistic missiles (ICBM) and some shorter-range versions use the same sort of flight path, with the missile formed of multiple rocket stages to provide enough power to arc high into the atmosphere, only flying faster and higher. The now retired US <a href="http://fas.org/man/dod-101/sys/missile/aim-54.htm">AIM-54 Phoenix air-to-air missile</a> had a top speed of Mach 5. What makes the current generation of hypersonic aircraft designs different is their capability to manoeuvre, making them harder to intercept.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/88543/original/image-20150715-26325-1kwmtmp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/88543/original/image-20150715-26325-1kwmtmp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/88543/original/image-20150715-26325-1kwmtmp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/88543/original/image-20150715-26325-1kwmtmp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/88543/original/image-20150715-26325-1kwmtmp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/88543/original/image-20150715-26325-1kwmtmp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/88543/original/image-20150715-26325-1kwmtmp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/88543/original/image-20150715-26325-1kwmtmp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">X-43 rocket plane dropped from a B-52, seconds before igniting its scramjet engines and reaching a world record-holding 10,000km/h (Mach 9.8).</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:B-52B_with_X43.jpg">NASA</a></span>
</figcaption>
</figure>
<h2>The need for speed</h2>
<p>Why bother? There are two main reasons for the fresh interest shown by the military in hypersonic aircraft. The first is that a very fast, highly manoeuvrable weapon is not easy to counter: it can be difficult to detect and its speed means that there is little time for defences to react, much less to actually take any action to stop it. This makes it a threat to supposedly heavily defended targets – and most discussion of the Chinese hypersonic craft, dubbed <a href="http://missilethreat.com/china-confirms-hypersonic-missile-test-2/">Wu-14</a>, and the Russian equivalent, the <a href="http://www.ibtimes.com/russias-secret-hypersonic-nuclear-missile-yu-71-can-breach-existing-missile-defense-1987590">Yu-71</a>, mention penetrating US missile defence systems as a primary aim.</p>
<p>The second relates to a requirement that has become more urgent in recent years, namely to shorten response time and to attack mobile targets. While drones, satellites and the like can locate them easily enough, highly mobile enemy units – anything from terrorist groups to Scud missile launchers – will not hang around waiting for the inevitable airstrike to be called in. A very fast weapons platform with the ability to manoeuvre means that once found, a target will have little time and less opportunity to escape.</p>
<h2>Material shortfall</h2>
<p>Of course, to create a workable hypersonic vehicle, engineers have to overcome, or at least cope with, the severe environment encountered by something moving that fast. The main problem (from which most if not all the others stem) is <em>heat</em> – heat from air friction and from the shock waves generated by moving faster than the speed of sound. </p>
<p>The temperatures a hypersonic vehicle encounters are so high that conventional materials can’t withstand them and maintain their strength. There are materials that can insulate a structure from the heat, but they tend not to be very strong in themselves, and so any breach of insulation can quickly lead to catastrophic failure – as demonstrated by the tragic <a href="http://www.bbc.com/future/story/20150130-what-caused-the-columbia-disaster">loss of the space shuttle Columbia</a> in 2003, and also of some <a href="http://www.thetimes.co.uk/tto/news/world/americas/article3122654.ece">current test vehicles</a>. Research into new heat-resistant materials and suitable manufacturing techniques is therefore a priority.</p>
<p>High air temperatures also reduce the thrust of an air-breathing jet engine, so new propulsion concepts are also needed – relying on rocket engines tends to lead to overly large and heavy aircraft. Among the companies leading the way on propulsion technology is British company Reaction Engines, which is testing the revolutionary <a href="http://www.reactionengines.co.uk/sabre_howworks.html">Sabre variable-cycle engine</a>.</p>
<p>Travelling at very high speeds will also require advanced sensors and controls. New materials will be needed again, as conventional radomes and antennae would never withstand the heat. Conformal antennae – where the craft’s fuselage skin is used as the transmitter and receiver – are a possibility, though this is not guaranteed to work. Depending on just how fast the vehicle is designed to travel, ionisation of the air around it could interfere with radio-frequency sensors and communications.</p>
<h2>Hypersonic flight for all?</h2>
<p>Whether it’s possible to create a crewed or passenger hypersonic aircraft is still up for debate. But producing any sort of hypersonic vehicle is a long-term project that will take a lot of time and effort – and a whole lot of money. Patents mark the ground as to where some may follow. But who out there has the will, the persistence and the funds to do so?</p><img src="https://counter.theconversation.com/content/44543/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Phillip Atcliffe does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The military is interested – but the rest of us could also get from Paris to Tokyo in three hours.Phillip Atcliffe, Senior Lecturer in Aeronautical Engineering, University of SalfordLicensed as Creative Commons – attribution, no derivatives.