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Global drought has not increased, but climate change is still a threat

Global drought has not increased significantly over the past 60 years, a report in Nature has found. Previous assessments…

Global drought is not an effective way to measure climate change. AAP / Jim Lo Scalzo

Global drought has not increased significantly over the past 60 years, a report in Nature has found.

Previous assessments of global drought have relied on the Palmer Drought Severity Index, which only accounts for temperature, and does not consider sunlight, humidity or wind. These assessments have falsely indicated that global drought will increase as the planet warms.

The paper’s authors show that when these additional factors are included, worldwide drought has actual changed very little since 1950.

Paper co-author Michael Roderick from the Australian National University said global warming does not necessarily lead to more droughts.

“Drought has not been an effective way of measuring climate change over the past 60 years,” he said.

“The Palmer Drought Severity Index looks at the balance between supply and demand.”

“The supply side is just a matter of estimating the rainfall, the problem comes in how the demand is estimated.”

“In the previous calculations the demand is increasing, but when you get measurements of humidity, wind and sunlight and you do the proper calculation, it shows that in some places the demand has gone up, in some places it has gone down and overall there has been little change.”

He uses different regions of Australia to explain why increased temperature does not necessarily mean drier conditions.

“If you took the annual average temperature, Darwin is warmer than Alice Springs and yet where would your clothes dry faster if you put them on the line? Alice Springs.”

“There’s more to it than just the temperature, that’s where we’ve gone wrong,” he said

“On average, a warmer world is a wetter world.”

But the authors stress that just because global drought patterns have not changed in 60 years, does not mean climate change is not happening.

CSIRO Fellow Michael Raupach said the paper addresses a well-known problem with drought measurement among the scientific community.

But he urged caution in the interpretation of the findings.

“Drought remains a major issue and diagnosing drought in the past record - working out how it’s related to meteorology, rainfall, temperature and other drivers - is a substantial challenge.”

“I don’t think that any of this means that we should relax about drought in the current record, and it certainly doesn’t mean we should be complacent about the possible changes in drought conditions in the future.”

And while drought records have not altered greatly on a global scale, regions such as southern Australia may still be at greater risk due to climate change.

“Our own backyard is not the same as the globe on average,” Raupach said.

“We’ve experienced a major drought from before 2000 to 2009, and it was a hot drought compared with previous droughts.

“There is evidence from work we’re doing right now that there has been an increase in water loss from plants due to these raised temperatures.”

“Statements that a particular thing such as drought is not being observed at a global scale as a result of climate change can be picked up and misconstrued by people as meaning climate change is not happening,” he warned.

“There’s no way the paper is saying that and no way that it’s a logical conclusion.”

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87 Comments sorted by

  1. John Coochey

    Mr

    Few that is a relief! The world is not going to end after all.

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    1. Neil Gibson

      Retired Electronics Engineer

      In reply to John Coochey

      John I am really relieved also after all the gloom and doom predictions from Tim Flannery. I will be able to sleep at night again.

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    2. Felix MacNeill

      Environmental Manager

      In reply to John Coochey

      Wow! Vacuous, evidence-free, un-nuanced sarcasm! What a novelty from Coochey and Gibson!

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    3. Mark Harrigan

      PhD Physicist

      In reply to John Coochey

      Still nothing intelligent to offer from the resident deniers. Still ill informed. Still misrepresenting the article and the science.

      Sigh - nice to know there are some constants in the world :) We certainly know the climate inside their head is never changing or warm - it's frozen solid in denial. If only such psychological projection could influence the real world we'd all be better off :)

      Understood the baseline issue of US temperatures yet Gibbo?

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  2. Michael Wilbur-Ham (MWH)

    Writer (ex telecommunications engineer)

    Sad that two of our regular climate change deniers both failed to read to the end of the article. If they had they would have read:

    “Statements that a particular thing such as drought is not being observed at a global scale as a result of climate change can be picked up and misconstrued by people as meaning climate change is not happening,” he warned.

    “There’s no way the paper is saying that and no way that it’s a logical conclusion.”

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    1. John Coochey

      Mr

      In reply to Michael Wilbur-Ham (MWH)

      That means no matter what we see it is still proof of the alarmist position? Or put more simply do not let the facts get in the way of a good story.

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    2. John Coochey

      Mr

      In reply to Michael Wilbur-Ham (MWH)

      So MWH doesn't like the article if it promotes what he is incapable of describing as denialism but likes exactly the same article when he considers it does not? Strange. Well actually not strange at all!

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    3. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to Michael Wilbur-Ham (MWH)

      John Coochey.

      My first reply to Carmen Lahiff-Jenkins slammed the idea of this website allowing posts that said that fiction was better than science for predicting the future.

      I apologised to Carmen because she did NOT say this.

      But you say about SF writers "They also have more predictive history than any alarmist the current paper being a case in point !"

      So you have said it.

      I find it very sad that a website which says it "values and promotes new thinking and evidence-based research" has turned into a platform for promoting climate change denial.

      I hope that TC soon changes how it operates so that posters such as you can be down voted and your comments disappear unless a reader clicks to see them (as is done on Reddit).

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    4. Mike Hansen

      Mr.

      In reply to Michael Wilbur-Ham (MWH)

      The problem for deniers like Coochey and his sidekick Gibson is that they are so busy spamming the climate change threads with their invincible ignorance that they never actually read the articles that they spam.

      If they did, then the science in this article would not come as a surprise.

      https://theconversation.edu.au/droughts-and-flooding-rains-what-is-due-to-climate-change-6524
      https://theconversation.edu.au/decade-to-decade-changes-in-our-climate-whats-really-going-on-7226
      https://theconversation.edu.au/a-land-of-more-extreme-droughts-and-flooding-rains-5184

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    5. John Nicol

      logged in via email @bigpond.com

      In reply to Michael Wilbur-Ham (MWH)

      Michael,

      It is true that the findings, which clearly indicate that the prevalence of droughts across the globe have not increased or decreased - i.e. have not changed, does not have any direct indication as to whether increased carbon dioxide causes a significant increase in global warming or not - (Is there a significant Enhanced Green House Effect, or just a standard, fairly static, Green House effect!)

      However, along with the increased number and severity of other weather events such as…

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    6. John Nicol

      logged in via email @bigpond.com

      In reply to Michael Wilbur-Ham (MWH)

      I thought it might be useful to read again what Tim Flannery had to say in 2005 about the continuation of drought - in Australia:.

      "Climate change 'will prolong' drought conditions
      Updated Sat Jun 11, 2005 7:31am AEST

      PHOTO: Warning: Professor Flannery says Australia can expect ongoing drought conditions.
      VIDEO: Flannery issues global warming warning (Lateline)
      MAP: Sydney 2000
      Leading environmentalist Professor Tim Flannery has warned that Australia is now entering long-term climate change…

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    7. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to Michael Wilbur-Ham (MWH)

      John Nicol - Thanks for proving that Flannery never said anything wrong.

      There is a huge difference between saying climate change COULD leave Sydney's dams dry in just two years from saying that climate change WILL leave Sydney's dams dry in just two years.

      Note that most of your quote is him being reported, and not his exact words.

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    1. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to Carmen Lahiff-Jenkins

      This is another post that I think people should be able to vote down so that once it got to -4 it would not be seen unless a reader clicked to see it.

      Surely a post that promotes fiction writing above science is pure trolling on a website which aims to"Give experts a greater voice in shaping scientific, cultural and intellectual agendas by providing a trusted platform that values and promotes new thinking and evidence-based research."

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    2. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to Carmen Lahiff-Jenkins

      A huge apology to Carmen.

      I misread her post and thought that she was promoting climate change denial. Her post is doing the opposite - accepting the science and pointing out how SF writers have given us visions of what may be to come.

      I wish there were some way to delete my earlier post, or to be able to edit that post.

      Once again, sorry Carmen and readers.

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    3. John Coochey

      Mr

      In reply to Carmen Lahiff-Jenkins

      They also have more predictive history than any alarmist the current paper being a case in point !

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    4. Geoffrey Henley

      Research Associate

      In reply to Carmen Lahiff-Jenkins

      Speaking of science fiction, you might well watch Al Gore's "24 hours of reality. The dirty weather report."

      Any similarity between this program and real world science is purely coincidental!

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  3. Tim Scanlon

    Debunker

    These conclusions don't surprise me as much as the title made me think I would.

    Drought cycles are pretty much part of the natural cycles of climate and weather. The changes we have seen have been to the shift in normals, the spread of good and bad years. http://fryingpannews.org/files/2012/08/Bellcurve2.jpg

    So not seeing more droughts makes sense, as they are the normal cycles. The impact and severity, well we already have data on how frequent and impactful southern Australia is experiencing drier seasons. http://www.bom.gov.au/cgi-bin/climate/change/trendmaps.cgi?map=rain&area=aus&season=0112&period=1970

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    1. Danderson

      logged in via Twitter

      In reply to Tim Scanlon

      Mike, above we have the latest peer reviewed science view, as published in Nature.

      What's this "alternate view" we find at Skeptical Science?

      Surely Skeptical Science will take on board this latest peer reviewed development won't they? Though I notice they haven't reported it yet - early days I suppose.

      From your link,

      "The goal of Skeptical Science is to explain what peer reviewed science has to say about global warming."

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    2. Mike Hansen

      Mr.

      In reply to Tim Scanlon

      @Danderson
      Are you suggesting that because this is the "latest" peer reviewed science, it must be the correct science. That would never have occurred to me but I will be sure to take it on board.

      That said, there does appear to be widespread agreement among the subject matter experts that the criticism of the PDSI index in this paper is warranted.

      The dissenting view comes from drought researcher, Aiguo Dai who argues that using the new improved index does not substantially alter the drought record.

      Who is correct? I do not know. If Dai has a case, I imagine it will be made in the appropriate peer-reviewed journal.

      Are they scare quotes you have around "alternate view" ? Are you suggesting that Dai is guilty of something - perhaps undue skepticism in the pursuit of science?

      As to SKS's publishing schedule, you need to ask them.

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  4. Mike Hansen

    Mr.

    Can Megan provide a link to the actual paper in Nature?

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    1. Megan Clement

      Deputy Editor, Politics + Society at The Conversation

      In reply to Mike Hansen

      Hi Mike,

      Thanks for flagging this. I have added the link to the text so it is there as well as in the comments.

      Cheers,
      Megan

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  5. John Coochey

    Mr

    And as always the bed wetters have been hoist with their own petards and are shouting foul but not providing any data. So what is new?

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    1. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to John Coochey

      I say the IPCC reports are a starting point for accepting the science.

      John has never provided any reason to doubt these reports, nor an explanation of how the climate change scientists in every country for the last 20 years have got it so wrong.

      So nothing new in the endless back and forth between denier vs science.

      And nothing new about The Conversation now being a platform for deniers to sprout their rubbish even though their aim is to enable rational, evidence based discussion.

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    2. Mike Hansen

      Mr.

      In reply to John Coochey

      Coochey has the read the headline and believes he has found a climate science paper that he likes even though he has not read it. He will have forgotten it all in a few days and be back to claiming climate science is a big left-wing conspiracy.

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    3. John Coochey

      Mr

      In reply to John Coochey

      In response to MWH here is a reason to doubt

      “The Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) summarized the evidence in the following terms: ‘‘More intense and longer droughts have been observed over wider areas since the 1970s, particularly in the tropics and subtropics. Increased drying linked with higher temperatures and decreased
      precipitation has contributed to changes in drought’’.

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  6. Sean Lamb

    Science Denier

    I think this demonstrates that there is a publication bias (in all disciplines) towards reporting strong effects - which in climate science manifests itself as alarmism.

    In an ideal world a paper that reports on no effects or minimal changes ought to be as publishable as one reporting large effects. But in practice that isn't really the case. So that you see a continuing pattern of a strong initial thesis (the Great Barrier Reef in danger of collapse) slowly being watered down by subsequent…

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    1. Mike Hansen

      Mr.

      In reply to Sean Lamb

      The other possibility is that it demonstrates that you have a cartoon version of climate science acquired from reading science as "interpreted" by climate science denial blogs and never reading beyond the headlines of articles published here.

      Here is an article from May this year.
      https://theconversation.edu.au/a-land-of-more-extreme-droughts-and-flooding-rains-5184

      Here are some relevant quotes - they need to be read in context but they give the general idea,

      Talking about a twin planet…

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  7. John Coochey

    Mr

    “The Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) summarized the evidence in the following terms: ‘‘More intense and longer droughts have been observed over wider areas since the 1970s, particularly in the tropics and subtropics. Increased drying linked with higher temperatures and decreased
    precipitation has contributed to changes in drought’’.

    So now we do not have to take the IPCC as holy writ

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    1. Mark Harrigan

      PhD Physicist

      In reply to John Coochey

      @ John Coochey - no John. No one uses the word "Holy Write" except for denialists like yourself.

      This article about the frequency and extent of drought is a great example of what science is all about. It is about increasing our understanding of how the real world works based on evidence. When evidence is available that leads to a different conclusion the science adjusts - unlike pseudo-sceptics such as yourself who are incapable of altering their views regardless of the evidence and make a…

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    2. John Coochey

      Mr

      In reply to John Coochey

      Well I note how the bed wetters are now trying to change the subject incorrectly stating arctic ice is at an all time low and forgetting about the antarctic being at a high. Yet at the same time the best temperature increase they can come up with is 0.08 over sixteen years. Arctic seems very sensitive. We are actually having trouble finding anything in the IPCC reports which is actually correct and here I am referring to the published reports not the internal working papers which often have a more scientific basis but that does not guarantee future funding.

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  8. John McLean

    logged in via email @connexus.net.au

    The word "denial" is thrown around on this site with gay abandon, usually at those who simply doubt that manmade climate change is as significant and dangerous as others claim. The shoe is really on the other foot. It's the "alarmist" camp that is in denial, and with them Raupach.

    1 - Sustained drought causes higher temperatures, so a "hot drought" is no surprise. Why? Because a reduction in surface moisture combined with dry vegetation means that some of the incoming solar radiation isn't…

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    1. Michael Shand
      Michael Shand is a Friend of The Conversation.

      Software Tester

      In reply to John McLean

      So what are you suggesting? that Climate Change is real - that the experts are right about this but those same experts are wrong about the extent of it?

      I often find this type of weasling from deniers now a days, where they are starting to realise they can no longer par take in flat denial so now they have to claim that its just not as bad as experts think

      Whenever you use experts data to show that experts dont know what they are doing it makes you look silly "What CISRO dont understand is this report from CISRO, if only CISRO would read what CISRO has to say CISRO wouldnt make such bad claims"

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    2. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to John McLean

      McLean: "in denial, and with them Raupach"

      What, pray tell, is Raupach in denial of?

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  9. Ken Fabian

    Mr

    It would be good news if the paper under discussion showed that Australia hasn't experienced greater extent, intensity or geographic distribution of drought with intensifying global warming but it hasn't shown that. It doesn't predict that these won't occur in the future. It does support the not all that remarkable conclusion that there is a lot of regional difference. Severe to record rain deficiencies since 1900 have occurred in the past 15 years across the South East of Western Australia, across…

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    1. John Nicol

      logged in via email @bigpond.com

      In reply to Ken Fabian

      Ken,

      It is true that the rainfall average across Australia is not as high as it was in the middle of last century. But if you look at all of the BOM records, you will find that the lowest recorded averages occurred around the turn of the 19th century - which is epitomised by the so-called Federation Drought. The same pattern is seen in the records produced by BOM of the avearge rainfall over the Murray Darling basin.

      A plot of these records shows a clear cyclical variation of total rainfall…

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  10. Whyn Carnie

    Retired Engineer

    Articles with headers such as this have the implication that the scary bit has suffered a setback then follows the good news prefaced by 'but'. Most of the commentary that follows unfortunately polarises readers into two opposing camps: Alarmist vs Denier.
    When the two arguments are sifted, the Alarmists have relied on their premise that Deniers don't accept that Climate Change is and has occurring.Therefore anything that camp claims must be false. I have not met a single Denier who does not accept…

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    1. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to Whyn Carnie

      Is there anything new here? We have all heard:
      Pretend neutrality as if the truth lies between the two sides.
      Those who accept the science are alarmists.
      There are no deniers because they all accept that the climate has changed in the past.
      That climate change is not a threat but an inevitability.
      That we should learn to live with it.

      How much easier it would be to simply down vote this comment so that it would only be seen if someone clicked a link to expand it.

      Just think of how much…

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    2. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to Whyn Carnie

      Whyn Carnie:

      "I have not met a single Denier who does not accept that the Earth's climate has been changing"

      You're making a straw man argument. Denialists argue things like "there has been no warming for 16 years" (which is a patently false claim) and you pretend that they are only claiming that the Earth's climate has changed in the past. They are claiming a lot more than that which everyone agrees on. Please don't pretend that they're not.

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  11. James Jenkin

    EFL Teacher Trainer

    I don't think it's 'deniers' who've made a lot of normal people skeptical about climate change. How many people read Watts Up With That?

    Rather, it's advocates for climate action who are very much in the public spotlight, like Tim Flannery. They've predicted catastrophes in the short term that never happened. ('Professor Flannery says that all adds up to back-to-back droughts, and if he had a say he would ration water use' http://www.abc.net.au/news/2005-06-11/climate-change-will-prolong-drought-conditions/1590294)

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  12. Carmen Lahiff-Jenkins

    Managing Editor, International Journal of Stroke at University of Melbourne

    MWH I'm perplexed at your vehement position. There is no climate debate, science is proven, and we now need to look forward. I wouldn't bother with these arguments, more so, look for more intellectually stimulating conversation on other pages of the website. I simplify the old adage; water, horse, drink.
    I believe the readership of The Conversation are here looking for information to make up there own minds. Do not fuel this particular ignorant fire. Add your brand of fuel elsewhere where intellectuals will appreciate it. Try being smug in silence. It feels good.

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    1. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to Carmen Lahiff-Jenkins

      Why I'm passionate about this is that I want a place where those who accept the science can discuss how to move on.

      Why this is relevant now is that The Conversation are looking at how to manage the comments, and I'm urging them to implement a system such as used by Reddit. The Reddit system enables disruptive posts to be down voted and they are then not shown (unless you click to see it).

      When a disruptive comment is shown, it is very hard for some to leave it unchallenged. Mark Harrigan has done amazing work correcting the deniers. But imagine how he might have contributed if instead he just down voted the denier posts, and devoted his energies to discussing the future.

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    2. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to Carmen Lahiff-Jenkins

      Carmen Lahiff-Jenkins: "There is no climate debate, science is proven, and we now need to look forward."

      Yes I'm looking forward alright. Looking forward to the result of the next federal election where the leading contender for government doesn't care what the science says and whose policy position is to dismantle any form of carbon price.

      Is that what you meant by looking forward? If not, why not?

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    3. Whyn Carnie

      Retired Engineer

      In reply to Carmen Lahiff-Jenkins

      Carmen, I was a little confused at your second sentence, not being former engineer with newly developed writing skills such as as MW-H claims. Then my schoolboy comprehension prac came to bear and I now see it as a restatement of the MW-H "passion" not your own.

      Re-reading the MW-H statements again leads me to support your admonition to him. He obviously believes that consensual science is debatable and others not of this narrow view should be silenced.
      I'm old enough to have seen the morphosis of the original Global Warming claims but unfortunately too old to hope to be around when these collapse into ancient mythology. My kids will be around and that gives me good cheer.

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    4. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to Carmen Lahiff-Jenkins

      Whyn Carnie ("others not of this narrow view should be silenced"), just another denialist bearing straw men.

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  13. Dianna Arthur
    Dianna Arthur is a Friend of The Conversation.

    Environmentalist

    For a clear and succinct overview of the complexity, variable and extensive measurements that are required to understand climate change, I highly recommend Dr Jonica Newby's presentation on Catalyst.

    She demonstrates in lay-terms the immensity of data collection, processing and analysis required.

    Climate Change is far more than whether droughts are on the increase.

    I urge the all who are open to intelligent discussion on the very real events affecting our planet here and now, to watch this program:

    http://www.abc.net.au/catalyst/stories/3633447.htm

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    1. trevor prowse

      retired farmer

      In reply to Dianna Arthur

      Dianna--the statement that I highly recommend Dr Jonica Newby's presentation on Catalyst. Have you cheched the BOM data that was made here--- "So what do you think are the chances of having 330 months in a row of above-average temperatures? Because, since February 1985, we have had... 330 months in a row of above-average temperatures.--------"So there have been several years of below average temperature, and you can’t get a below average year without a number of below average months. Don’t take my word for it, search the Bureau’s web pages for yourself: there is no State or Region with 330 consecutive months of above average temperature since February 1985.
      If this programme is to believed , they should not make programmes that have not been checked.

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    2. Whyn Carnie

      Retired Engineer

      In reply to Dianna Arthur

      Dianna, my summation of the Catalyst item by Dr Jonica is that it was a cleverly produced piece of legerdemain.

      It cherry picked two sets of data on temperature that have no proven link to the mythical average Global Temperature that is imagined to be changing, moved on to the old high tide mark in Tasmania that likewise has no bearing on or proof the mythical global Sea Level Rise theory and then on to how many bottles of wine can be laid as a two dimensional triangle.

      Ask the Met Bureau and ABC who funds them and there is the answer. Continued funding trumps facts and objective reporting.

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    3. Felix MacNeill

      Environmental Manager

      In reply to Dianna Arthur

      Thanks Dianna - I thought the Catalyst show was useful.

      Despite the conspiracy theorising paranoia of Messrs Prowse and Carnie, it actually was based on solid evidence from the impartial, professional and reliable BOM who, as it turns out are not commie lesbian pinkos intent on sapping our moral fibre.

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    4. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to Dianna Arthur

      "So what do you think are the chances of having 330 months in a row of above-average temperatures?"

      The interviewee did say:

      "If it was just by random chance alone, then there's only a 1 in 100,000 chance that that would have happened in the absence of human influence"

      which is FAR less unlikely than 1 in 2^330. So they're obviously not telling us everything.

      I'll let you get back to moving the deck chairs now.

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    5. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to Dianna Arthur

      Here is an example of denial:

      Whyn Carnie: "the mythical average Global Temperature that is imagined to be changing"

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    6. Peter Sommerville

      Scientist & Technologist

      In reply to Dianna Arthur

      I watched the program Diana, but I reserve my judgement until I see the raw data. Which I will in due course

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    7. John Nicol

      logged in via email @bigpond.com

      In reply to Dianna Arthur

      Felix MacNeil,

      "Despite the conspiracy theorising paranoia of Messrs Prowse and Carnie" - I have read the comments by both Prowse and Carnie several times and can find no suggestion of a "conspiracy".

      I therefore suggest that you withdraw the remark and apologise the both of them. Thank you.

      This would help to keep the level of discussion on a more civel basis.,

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    8. Dianna Arthur
      Dianna Arthur is a Friend of The Conversation.

      Environmentalist

      In reply to Dianna Arthur

      I expected the usual denialists - not to be confused with bona fide sceptics.

      For them the world is a magic pudding from which we can continue to extract carbon, dump plastics and other pollutants into our oceans and waterways, deforest old growth forests, watch farmland decimated by fraccing, continue buying built-in obsolescent plastic stuff, consume processed foods, troll the oceans for remaining fish stock, krill to counter our weakened metabolisms, expand our cities infinitum, watch the diversity of flora and fauna decline, ignore data taken over 100 years, assume every extreme weather event is just an anomaly, and the earth will simply continue giving to we, the clever apes.

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  14. Peter Sommerville

    Scientist & Technologist

    The cautionary tale to be drawn from this research is the realisation that not all the predictions made based on climate models are necessarily substantiated by the models. Many predictions are mere speculation - as this paper confirms.

    I am intrigued by some of the commentary here. Science is about open, not closed minds.

    Now in the past such a comment would have drawn a massive number of red ticks. But that is no longer possible! Must be frustrating to some.

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    1. Mike Hansen

      Mr.

      In reply to Peter Sommerville

      So exactly where does this paper "confirm" that climate models used to examine likely changes to our future climate are providing predictions that are "mere speculation"?

      ----

      Here is a report of a discussion with the paper's lead author Justin Sheffield.
      "The finding that some models may have overestimated past drought is unlikely to affect predictions about future droughts. That's because working out how climate change might affect drought in the future is done using different - climate…

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    2. Dianna Arthur
      Dianna Arthur is a Friend of The Conversation.

      Environmentalist

      In reply to Peter Sommerville

      A Mike Hansen

      Excellent points you raised. Some denialists appear to want simple answers to everything. Climate Science is anything but simple, as we cannot even make exact predictions for the entire planet as to how weather events will manifest around the globe, science, at present, can only ascertain trends.

      Other, more troubling denialists, have vested interests such as the fossil fuel corporations for maintaining current practices rather than transition to clean renewables. These people have employed the sublime (scientists on the payroll of fossil fuel corporations) to the completely absurd, Lord Monkton, Andrew Bolt et al. Anything and everything to confuse and obfuscate an already difficult science.

      Meanwhile more extreme weather events are occurring. It is going to be interesting watching how the human race adapts.

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    3. Peter Sommerville

      Scientist & Technologist

      In reply to Peter Sommerville

      Mike,

      As always you offer lots of googled references, which I doubt you have actually read, let alone understood, whilst missing the point.

      Your references are entirely speculative. Climate models do not predict climate or weather. They simply predict temperature based on various scenarios. The commentary on the effects of temperature on future climate are speculative. Hence any comments about future rainfall are speculative. The problem is that some of the commentary uses the models to justify their speculations in a context that implies the models justify their speculations. It is very bad science.

      Frankly, I do not expect you to understand this.

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    4. Peter Sommerville

      Scientist & Technologist

      In reply to Peter Sommerville

      Mike,

      I rest my case. You constantly cite references that you obviously do not understand or otherwise misinterpret. Re-read the reference and try to understand it.

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    5. Mike Hansen

      Mr.

      In reply to Peter Sommerville

      @Peter Sommerville.

      You say "I rest my case. You constantly cite references that you obviously do not understand or otherwise misinterpret. Re-read the reference and try to understand it."

      Peter - there are other people who read the comments on this thread. Are you hoping that they will not notice that your claim is all hand waving and no substance.

      Here is the only substantive point you have made in the last half dozen comments - "Climate models ... simply predict temperature based on…

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  15. Mark Harrigan

    PhD Physicist

    World according to climate change speudo-skeptics:
    --------------------------------------

    Because sometimes climate scientists and other scientists with public roles in science communciation sometimes get certain details wrong and because massive reports with thousands of points of data and conclusions, evidence etc are sometimes wrong in minor detail and GASP SHOCK HORROR - sometimes new evidence arrives that leads scientists to change certain aspects of their conclusions therefore all of climate…

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  16. John Nicol

    logged in via email @bigpond.com

    Chris,

    Dams are 81% full, No new dams have been built. Inner Melbourne population grew by 18% - from the bureau of statistics:

    ""POPULATION CHANGE IN GREATER MELBOURNE

    At June 2011 there were an estimated 4.17 million people resident in Greater Melbourne, an increase of 647,200 since June 2001. The capital city grew by 18% over the decade, which was faster than the average of Australia's capital cities (17%).

    Greater Melbourne accounted for 75% of Victoria's population at June 2011, compared with 73% at June 2001. Population growth in Greater Melbourne equated to 89% of Victoria's total growth between 2001 and 2011.

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  17. Whyn Carnie

    Retired Engineer

    So Megan, look what you have turned up.

    Plenty of human reaction and behaviour to study here. Young inexperienced philosophers with textbook comments on logic, deep scientific insight and environmentalism defending the Church of Climatology against the heresy of Devil Deniers and layman conservatism.

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    1. Whyn Carnie

      Retired Engineer

      In reply to Whyn Carnie

      Oops, Chris. Unsure why you ask. My mistake. I did not envisage old "inexperienced philosopers with textbook comments on logic" when noting the three groups. Hope you are not offended.
      Final facts and proof will still trump debate and consens one day.

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    2. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to Whyn Carnie

      Whyn Carnie: "I did not envisage old "inexperienced philosopers with textbook comments on logic""

      Probably not the only thing you didn't envisage. The name calling doesn't help.

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  18. Tim Benham

    Student of Statistics

    The idea that increased average global temperature would lead to decreased global rainfall was always obviously a non-starter. How it will change the distribution of rainfall in Australia is the more (parochially) relevant question.

    The longest rainfall anomaly map I could find on the BoM site is 36 months.
    http://www.bom.gov.au/web03/ncc/www/awap/rainfall/anomaly/36month/colour/latest.gif
    It shows a distinct SW-NE gradient. Is this in line with prediction models?

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    1. Mike Hansen

      Mr.

      In reply to Tim Benham

      Tim. Karl Braganza from BOM discusses the climate modelling done for Australia here.

      https://theconversation.edu.au/a-land-of-more-extreme-droughts-and-flooding-rains-5184

      The paragraphs that are relevant to your question
      "The models are in much better agreement over southern Australia, which is expected to dry, on average, as the planet warms. This indicates that something more coherent happens to the atmospheric circulation in this part of the world, as you heat up the entire climate system.

      The models also agree that individual rainfall events will be heavier over most of the continent. This includes over regions that are expected to dry."

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  19. Tim Benham

    Student of Statistics

    The catalyst program Taking Our Temperature hardly mentions drought but it seems to have become an issue in this thread so I took a look at it. I was a little shocked by the following statement

    "So the chance of one month being above-average temperature, is one in two. The chance of the next month also being above-average temperature, is one in four. The chance of the next month also being above-average temperature, is one in eight."

    This is simply wrong because the temperatures of successive…

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    1. Mike Hansen

      Mr.

      In reply to Tim Benham

      Tim. The 330 months of above average temps refers to global temps. The references to the Catalyst episode show that it is sourced from this paper.

      Kokic, P., Crimp, S. and Howden, M. (2012) How probable is the recent run of record global mean temperatures without climate change? Environmetrics (submitted).

      http://blogs.abc.net.au/catalyst/2012/11/references-taking-australias-temperture.html

      I have not been able to find a copy of it online so I cannot comment on whether they took autocorrelation…

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  20. Whyn Carnie

    Retired Engineer

    It beggars belief that Tim Benham, Student, can see some of the fallacies in the ABC/BoM production of Catalyst when so many logicians, climatologists and environmentalists, can't. Good on you Tim, you said it succinctly.
    Hope you continue in like vein with the balance of your Student life.

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    1. Mike Hansen

      Mr.

      In reply to Whyn Carnie

      Whyn Carnie read something he liked so immediately assumed that it was true without checking for himself.

      That pretty much sums up the climate denier comments on this thread.

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    2. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to Whyn Carnie

      "Whyn Carnie read something he liked so immediately assumed that it was true without checking for himself."

      Yes, it doesn't take very long for these clowns to provide proof that they're not really skeptics.

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  21. Oregon Stream

    logged in via Facebook

    Although at least so far, there is little observed change in 'global' drought, presumably 'regional' drought intensity and persistence could be something else. After all, warming (and future accelerated warming) has been expected to stoke both ends of the hydrologic cycle, with some regions getting heavier precipitation and some getting stronger droughts. So in the global average, maybe those effects have essentially canceled each other out.

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  22. Tim Benham

    Student of Statistics

    Mike Hansen,

    The name of the programme was "Taking Australia's Temperature", not "Taking the World's Temperature". The preceding context was about winemakers in Victoria, and before that heat waves in WA. The following topic was "Australia's circulation". The reasonable interpretation is that "we" referred to Australia. If it did not they should have made the change in context clear. The Kokic et al. paper has not been published in Environmetrics.

    I am glad you concede the point about auto-correlation. Maybe Jonica Newby needs to brush up on her statistics.

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    1. Mike Hansen

      Mr.

      In reply to Tim Benham

      "concede the point" ? I never argued the contrary!

      But I agree - they should have made it clear that they were referring to global temps.

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  23. Mark Harrigan

    PhD Physicist

    There is an interesting critique from Kevin Terberth of the paper that this article refers to.

    Perhaps the most telling is that the paper used a narrow definition of drought (soil moisture)

    http://thinkprogress.org/climate/2012/11/20/1194201/climate-change-droughts-nature/

    "The new paper recently published in Nature by Sheffield et al “Little change in global drought over the past 60 years” [Nature 491 15 Nov 2012 435-440] has done some impressive work. But it should not have been published…

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    1. Mike Hansen

      Mr.

      In reply to Mark Harrigan

      Thanks for the link Mark.

      When I first googled the headline of the paper "Little change in global drought over the past 60 years" to get more context and background commentary on the research, the first 2-3 pages of results were denier blogs.

      Almost none of them will check or understand the science and most of them will have forgotten about it in a week when they find the next "gotcha". But it will have achieved the desired effect of keeping their flat earth followers fired up. As much of the commentary from the deniers on this thread shows, what you will definitely not find is any skepticism being deployed.

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