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Hottest 12-month period confirmed – so what role did humans play?

It’s official, the past 12 months have been the hottest in Australia for more than a hundred years. Temperatures averaged across Australia between September 2012 and August 2013 were hotter than any year…

It was summer, and it was hot, and then it was winter, and it was warm. But was it caused by us? Flickr/island home

It’s official, the past 12 months have been the hottest in Australia for more than a hundred years. Temperatures averaged across Australia between September 2012 and August 2013 were hotter than any year since good records began in 1910. The previous record was held by the 12-month period from February 2005 to January 2006.

The new record follows a suite of broken records following last year’s “angry summer”, including the hottest summer since records began.

New weather records are being set all the time. Sometimes these are record cold temperatures, but more often in recent times these have been record hot temperatures. A common question is what is the human role, if any, in these records compared with natural variations of weather and climate?

The link between global warming and human causes has been firmly established over the last two decades. Multiple studies have shown that it is very unlikely that natural variations in climate can explain recent global climate change. While these results are clear, it is still helpful to determine the influence of global warming on regional climate extremes, since such extremes are often more influenced by natural variability.

However, attributing a single event or a record to human activities isn’t easy. But last year Hurricane Sandy put the spotlight on climate change and extreme weather.

And in late June this year, our scientific study published in the journal Geophysical Research Letters showed human-caused climate change substantially increased the likelihood of the very hot 2013 Australian summer. Human influences on the climate system increased the chances of our record hot summer by more than five times.

Using the same approach, we have now analysed the past 12-month’s temperatures across Australia. Our results show that human influences on the climate very likely increased by more than one hundred times the chances of the record 12-month Australia temperature.

We started our analysis by considering more than 20 of the latest generation of climate models. These models all participated in an international initiative that undertakes standardised climate model experiments. From these we selected the nine models that best captured the observed variability in Australian average temperature to perform our analyses.

Using these remaining nine state-of-the-art global climate models, we investigated the chances of setting a new record high 12-month average temperature across Australia. The previous record was set in 2005.

We compared temperature probabilities from a suite of model simulations of the climate including only natural climate influences (volcanoes and solar radiation changes) with a parallel set of model simulations including natural and human influences on the climate, such as increasing greenhouse gases.

The results were clear. When human influences were included in the model simulations, the probability of setting a new record, as occurred at the end of August 2013, was dramatically higher. Indeed, it was very likely (with 90% confidence) that human influences increased the odds by at least 100 times of setting a new record 12-month temperature.

Probabilities of average September-August temperatures for Australia from observations (dashed line) and climate model simulations for 1911-2005. The vertical lines show the temperature anomalies for September 1997 to August 1998 (the hottest September to August on record) and for February 2005 to January 2006 (the previous hottest 12-month period in the observational record). David Karoly & Sophie Lewis

As above, but now showing the probabilities from observations (1911-2005) and climate model simulations for 2006-2020 including human influences on the climate, such as increasing greenhouse gases. The probability of exceeding the previous 12-month record is now at least 100 times more likely than without human influences. David Karoly & Sophie Lewis

When we considered the repeated model simulations with just natural climate factors, we found only one 12-month period out of more than 5700 years that exceeded the record set in 2005. However, when we considered the model simulations including human influences on the climate, as well as natural variability, for the period 2006 to 2020, we found 41 12-month periods out of 465 years exceeded the record.

Hence, it would be nearly impossible to get such a new Australian temperature record due to natural climate variations alone. However, such records become quite common, about once every eleven years in our current climate, with increased global average temperatures due to human activity.

The recent record temperature is also notable because it occurred at a time when El Niño-Southern Oscillation (ENSO) conditions were neutral (neither El Niño nor La Niña occurring), which typically produces normal, rather than warm, temperatures across Australia.

The model experiments also show that these types of extreme Australian temperatures will become more severe and more frequent in the future, with further global warming.

Join the conversation

134 Comments sorted by

  1. Sean Lamb

    Science Denier

    "September 2012 and August 2013" - I am confused. Is the September - August the meteorological equivalent of the financial year?

    When you use 12 possible variants of "the hottest period" you multiply the probability of achieving such a milestone.

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    1. Ray Wills

      Adjunct Professor, School of Earth and Environment at University of Western Australia

      In reply to Sean Lamb

      The period selected is rationally based on the seasons: August is the last month of winter, September the first month of Spring. As you suggest a climate 'financial year' Sep-Aug. Mar to Feb is also rational using the end of summer as a start point.

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    2. Carson Holzheimer

      Engineer

      In reply to Sean Lamb

      That is a failure in thinking Sean. The probability of achieving a milestone actually, if anything, decreases if you choose any particular 12 month period. That is because, since 1910, there are ~1236 12 month periods to compare to. instead of 103.

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    3. Sean Lamb

      Science Denier

      In reply to Ray Wills

      Fair enough, Professor Wills.

      I will just content myself with pointing out that the claim that this is due to human activity is simply assertion.
      They would be able to produce exactly the same graphs if solar driven activity was the underlying factor.

      You will also be aware that Professor Karoly has a track record of making claims regarding the Australian climate and being compelled by journals to withdraw the publication.

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    4. Henry Verberne

      Former IT Professional

      In reply to Sean Lamb

      Natural variability MAY be responsible for record Australian temperatures but it is almost certain that humans are largely responsible for global temperatures rises observed. That much is clear from multiple sources of the peer-reviewed science.

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    5. Henry Verberne

      Former IT Professional

      In reply to Sean Lamb

      Sean, you make claims that are little more than an assertion of disagreement with the authors other than vague generalities about "solar driven activity".

      If you want to be treated as just another "hand waver" how about supporting your views with something just a LITTLE more substantial?

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    6. Dennis Singer

      Student

      In reply to Sean Lamb

      Yes it's simply indicative of global warming without any attribution.

      But while global warming is occurring, the upper stratosphere is cooling. Therefore the cause of the warming trend can't be due to increased solar radiation.

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    7. Sean Lamb

      Science Denier

      In reply to Henry Verberne

      I don't see why. Hand waving is in the best tradition of climate science

      "SIMON LAUDER: In January climate scientist Professor Shang-Ping Xie was on a plane to Hobart when he read an article in the Australian newspaper which said that climate figures validate the sceptics.

      Professor Xie says that was his inspiration.

      SHANG-PING XIE: I read an article in the Australia newspaper highlighting this issue, so I thought, I need to do something about it (laughs). "
      http://www.abc.net.au/worldtoday/content/2013/s3836522.htm

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    8. John Whelan

      logged in via Facebook

      In reply to Henry Verberne

      "it is almost certain that humans are largely responsible for global temperatures rises observed". If that is true, we are guilty of very little since, as I understand it, there has been no Global Warming since 1998. That inconvenient truth has given rise to a new phenomenon, Climate Change. Not so? If you don't believe it, why don't you read the release of climate temperature data published by the Met Office in London on Christmas Eve last? I put the Karoly's of this world in the same bin as the Flannery's of this world. Desperate men trying to win an audience and win more Government grants. Times up gentlemen, even James Hansen of former NASA fame, seems to have given up on the excessive claims being made by the likes of Karoly, Flannery and others.

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    9. In reply to John Whelan

      Comment removed by moderator.

    10. Sean Lamb

      Science Denier

      In reply to Dennis Singer

      "Therefore the cause of the warming trend can't be due to increased solar radiation."

      No, I don't expect is. But there are more things twix heaven and earth.

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    11. Mark Pollock

      Analyst

      In reply to Ray Wills

      Seasons are an artificial construct. I would expect an adjunct professor, what ever that is , to know that. They don't start or finish according to a man made calendar. The "scientists" are making it up again. Some parts of Australia only have two seasons.

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    12. Henry Verberne

      Former IT Professional

      In reply to Sean Lamb

      Sean it would be helpful if you could see your way clear to describing what precisely what you are referring to when you write "But there are more things twix heaven and earth".

      Do you have ANY evidence to back up those vague assertions?

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    13. Sean Lamb

      Science Denier

      In reply to Henry Verberne

      I think it is from Hamlet Henry. But I probably mis-quoted it.

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    14. David Arthur

      resistance gnome

      In reply to John Whelan

      No global warming since 1998? Try 2005; it's warmer than 1998, as is 2010.

      Looks like 2013 may be warmer than 1998 also, which is a little bit concerning since 1998 was amidst a big El Nino whereas 2013 is a neutral/La Nina year.

      How soon are you planning to leave the planet, Mr Whelan?

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    15. Henry Verberne

      Former IT Professional

      In reply to Mark McGuire

      I perused that link. That makes clear the following: "The oceans can at times soak up a lot of heat. Some goes into the deep oceans where it can stay for centuries. But heat absorbed closer to the surface can easily flow back into the air. That happened in 1998, which made it one of the hottest years on record.

      Trenberth says since then, the ocean has mostly been back in one of its soaking-up modes".

      The other links also does not support your argument. I refer you to the authors statement: "When the climate cycle that governs that ocean cooling reverses and begins warming again, the planet-wide march toward higher temperatures will resume with vigor".

      You either misunderstand the article or are actively trying to spread mis-information.

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    16. Alvin Stone

      logged in via Facebook

      In reply to Sean Lamb

      Sean, it is quite simple. This is not a date to date measurement. Quite simply it is a measure of a 12 month period.
      What the Bureau is saying is that there has never been a 12 month stretch with temperatures this high above average in the record.
      It doesn't matter that it is August to July or January to December, it is the 12 month period that is significant.
      But I'm sure you knew that.

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    17. Alvin Stone

      logged in via Facebook

      In reply to Sean Lamb

      Attack the man, typical.

      There is no way the experiment would produce the exact same graphs if it was driven by solar activity because the activity would have already have been factored into observations and models as a natural variation.

      By the way, if you are saying that if it would produce the same results then you would be agreeing that Greenhouse gases do have a forcing effect on temperature.

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    18. Alvin Stone

      logged in via Facebook

      In reply to John Whelan

      John, you might need to read the recent paper on the PDO which suggest the hiatus (although temps are still warming just a little more slowly) is being caused by a long term natural variation that is pushing more heat into the deep ocean.

      As I'm sure you understand, average global temperatures only take into account the 2 metres above the land and oceans and so are a very narrow measure that in total accounts for probably less than 5% of the total heat entering the Earth.

      That is why climate scientists use multiple measures to determine the impacts of global warming.

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    19. Alvin Stone

      logged in via Facebook

      In reply to Mark Pollock

      As is a 12 month period. But what they do is give a fixed time where we can measure and make comparisons. Calling them a man made construct doesn't change the temporal measure which is used to make the comparison.

      Farmers and many others are seeing the seasonal effects shifting with global warming, so it is a case of pointing out the obvious. Fortunately for these scientists, the months haven't shifted with them.

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    20. Alvin Stone

      logged in via Facebook

      In reply to Mark McGuire

      Mark, you misunderstand. The oceans aren't cooling, the heat is being mixed deeper into the oceans which is slowing the warming of the atmosphere.

      The paper you refer to is saying that the PDO is the likely culprit for this and that when it moves into its next cycle we may see a substantial return of some of that heat into the atmosphere, accelerating the rise in global average temperatures again.

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    21. Mark Pollock

      Analyst

      In reply to Alvin Stone

      In a very a gradually warming world a shifting of the seasons is to be expected. The author however uses fixed seasons to suit his narrative. It's very unscientific and indicates that he is doing some polemic slicing and dicing.

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    22. Sean Lamb

      Science Denier

      In reply to Alvin Stone

      "Attack the man, typical. "

      The way I see it, Alvin, is Professor Karoly only wanted to publish if he could show the last 10 years were the hottest in a thousand years.

      Let me charitable, and assume his statistical mistake was made in error, what he should have done is corrected the error and resubmitted his 1000 year reconstruction - NO MATTER WHAT THE RESULT.

      But it seems that if his conclusions didn't fit his preconceptions then he wasn't going to publish his taxpayer funded research at all. Now that is the strangest example of publication bias I have ever come across and it is, of course, poor science.

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    23. In reply to Sean Lamb

      Comment removed by moderator.

    24. In reply to Sean Lamb

      Comment removed by moderator.

    25. Alice Kelly
      Alice Kelly is a Friend of The Conversation.

      sole parent

      In reply to John Whelan

      http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/
      John Whelan, have you looked at a graph of ocean heat content , if you look at number 3 below the graph, it will show you the heat content comparison between pentadal average 0-700m through 2008-2012, and pentadal average 0-2000 m through 2008-2012. You can also look as sea level rise on the same graph. If you look at the notes below you can switch to another interactive graph by clicking onto 'mean anomaly figures', with temperatures and salt content (interactive) information. Your statement , "there has been no global warming since 1998" is completely at odds with the science, but not at odds with Andrew Bolt. Frankly I prefer a good old fashioned accurate graph from a scientific body like NODC. If you can show me a graph of ocean heat over the same years to show no cooling in the ocean, I would be flabbergasted.

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    26. Mike Stasse

      retired energy consultant

      In reply to Alice Kelly

      I'd also like to point out that it takes 80 times as much energy (heat) to melt ice that's at 0 degrees C to water at 0 degrees C than it does to raise the temperature of ice at any temperature below zero by 1 degree C. And as many cubic kilometres of ice have been melting, a huge amount of that heat has simply disappeared melting ice.....

      The 'fact' that "temperatures haven't risen since 1998" is actually VERY worrisome when you understand what is going on, because if ice continues melting, as I believe it will, at the current rate, you can kiss your arse goodbye, it will be all over Rover....

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    27. In reply to Mike Stasse

      Comment removed by moderator.

    28. In reply to Sean Lamb

      Comment removed by moderator.

    29. In reply to Sean Lamb

      Comment removed by moderator.

    30. In reply to Mike Stasse

      Comment removed by moderator.

    31. Dennis Singer

      Student

      In reply to Sean Lamb

      It's remotely possible that there is some other forcing causing the warming, but there is no evidence.

      Evidence from "fingerprint" studies essentially rule out all the usual natural forcings.

      I gather that you don't accept the conclusions of GCM simulations that show that the extra CO2 accounts for the forcing causing GW.

      CO2 comprises over 99.9% of the GHGs in the natural (dry) atmosphere; the natural ~300ppm of CO2 is the reason the global average surface temp is 15 deg C as opposed to -15 deg C. As a qualitative plausibility argument alone, if CO2 concentrations increase by say 150%, there will be a significant rise in temperature. The rise is seemingly slow, but by the time radiative equilibrium has been reached (~1000 years) it's plausible that the temp will have increased by a few degrees.

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    32. Sean Lamb

      Science Denier

      In reply to Dennis Singer

      I am agnostic about the extent of warming driven by CO2 levels (BTW I think "forcing" is an awfully poor term and certainly isn't used frequently in biological systems modelling). What I am certain is we can see a strong correlation between solar activity proxies and temperatures. Now perhaps this is of as little significance than the 20 year correlation between Republican senators and sun spot activity
      http://www.realclimate.org/index.php/archives/2007/05/fun-with-correlations/
      But if it isn't, then you will have completely omitted a fundamental input into our climate system.
      If this is so we would expect all our climate models to suddenly start falling over in unison.......

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    33. N Wilson

      Biologist

      In reply to Mark Pollock

      "Analyst", whatever that is?

      I would imagine that the calendar year is a bit of a construct as far as the climate goes. Actually, it is for people too, as not all use the same year.

      There is no reason the 12 month period has to start on January 1st. Or perhaps the lunar New Year for Chinese and Vietnamese and any other dates for anyone else.

      I don't think it matters when the year starts, but perhaps we should agree to go from solstice to solstice, but I am sure the deniers would only agree if it suited their predetermined story, rather than to enhance the search for understanding of the climate or our role in it.

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    34. In reply to John Whelan

      Comment removed by moderator.

    35. In reply to N Wilson

      Comment removed by moderator.

    36. Doug Hutcheson

      Poet

      In reply to John Whelan

      John, "there has been no Global Warming since 1998" is the tiredest of tired denialist memes. As you know, 1) 1998 was an exceptionally hot year up to that time and 2) global - that is, land, ocean and cryosphere - temperatures have been steadily increasing, although the land surface temperature increase has not been statistically significant.

      Try picking a longer period, one in which the signal of climate change can be extracted from the noise of natural variability. 30 years should be enough.

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    37. Trevor S

      Jack of all Trades

      In reply to John Whelan

      "as I understand it, there has been no Global Warming since 1998"

      Your understanding in incorrect, don't mistake the thermal inertia of the Oceans for "no warming".

      "why don't you read the release of climate temperature data published by the Met Office in London on Christmas Eve last? "

      Here's what the Metoffice said

      "The forecast of continued global warming is largely driven by increasing levels of greenhouse gases."

      http://www.skepticalscience.com/resolving-met-office-confusion.html

      Here's Professor Kevin Andrews concern

      http://www.youtube.com/watch?v=RInrvSjW90U

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    38. Dennis Singer

      Student

      In reply to Sean Lamb

      Without recourse to correlations how do you do science? That's how we show a model is consistent with observations or otherwise.

      I think you might be referring to a widespread misunderstanding: there is this pervasive belief that scientists erroneously claim CO2 is driving GW because "hockeystick" temperature graphs correlate strongly with CO2 concentration.

      The actual reasoning is a fair bit more sophisticated. As in other areas of science, all correlations are carefully analysed to try to determine the underlying causative relationships. In climate science, a large amount of research deals with the question of attribution - a good reference is the relevant chapter in the IPCC physical sciences report.

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  2. Gerard Dean

    Managing Director

    So, given that it was the hottest year in Australia, how does that accord with the plateau in world temperatures since 1998?

    If the temperature goes up and down in different places around the earth, yet the earth's average temperature remains the same, what's the problem?

    Gerard Dean

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    1. Dennis Singer

      Student

      In reply to Gerard Dean

      Well what is the probability that there has been no warming trend since 1998?

      The time period since 1998 is too short to confirm that the warming trend of the last few decades (~0.15 deg C/decade) continues - this is a statistical issue though. Natural variability is sufficiently large and the warming trend subtle that to make pronouncements of warming trends with >95% likelihood, you need 30 or so years of data.

      If the total thermal (heat) energy content is stable, there is no global warming and no problem, but graph 2 in the following indicates that although temperatures appear to have plateaued (in the short term), thermal energy in the upper ocean is increasing steadily.

      http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/index.html

      Also:
      "The heat accumulated in the air corresponds to 6.6% of global warming, while the remaining heat is stored in the ground (31.5%), melting of ice (33.4%) and sea water (28.5%). "
      http://www.inderscience.com/info/inarticle.php?artid=27100

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    2. David Arthur

      resistance gnome

      In reply to Dennis Singer

      Historic fossil fuel use and cement production data (Oak Ridge National (US) Laboratory Carbon Dioxide Information Analysis Center) shows sufficient CO2 emission from 1800 to 2007 to raise atmospheric CO2 from 280 ppm to 430 ppm. Dissolution of CO2 in oceans limited atmospheric CO2 to about 390 ppm (as at 2007; 400 ppm in 2013), and continues to acidify oceans (decreased ocean pH).

      What part did humans play? Considering the increase in atmospheric CO2 over the last two centuries is less than anthropogenic CO2 emissions, I'd say 100%.

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    3. Mark Pollock

      Analyst

      In reply to Alvin Stone

      So you agree, at least, that the surface temperature rise has paused or stopped? The heat is being absorbed in the oceans?

      It would then follow that you agree that the angry summers and the extreme weather and the ice free article stuff is nonsense. All these scary things are heat driven, supposedly. But the heat, or energy, is hiding in the Marianas trench!

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    4. Alvin Stone

      logged in via Facebook

      In reply to Mark Pollock

      No Mark, I don't agree they have stopped. I am saying the rate of rise in global temperatures has slowed but they are still rising.

      Hence the fact that 2005 and 2010 were both hotter than 1998 and that the decade from 2000-2010 was warmer than the previous decade.

      Considerably more heat is being absorbed into the oceans and yet we are still seeing a rise in average temps even when the sun's output is reduced. This is very significant.

      The angry summer is an expected consequence of this rise but what makes it concerning is that natural variation with the suns output, the PDO and a neutral ENSO year we are still seeing records broken. This is very worrisome because these cycles will come to an end and then we may see rapid acceleration of temps again.

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    5. Alice Kelly
      Alice Kelly is a Friend of The Conversation.

      sole parent

      In reply to Mark Pollock

      It's not hiding at all, very cold deep ocean areas are shrinking, I refer you to the graph I and another person posted above. Also in the last two years there has been unprecedented sea ice loss and also land ice loss as well (glaciers and height of total mass). In the antarctic Ice shelves continue to calve caused by the antarctic ocean warming. The antarctic ocean has warmed more than other oceans.
      http://www.nasa.gov/topics/earth/features/earth20130613.html#.UiUW2qnW-BI
      I sugest it is you who is hiding.

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    6. In reply to Hugh McColl

      Comment removed by moderator.

    7. Hugh McColl

      Geographer

      In reply to Mark Pollock

      Mark, I simply accept the data. You apparently do not. So what do you use for evidence when you don't accept the raw data? Why would you be alarmed (or any other emotion) when you simply don't accept the information provided - not by me but by the scientific observers?
      And what's this stuff about what "hideously expensive peer reviewed models are predicting"? You claim that "the surface temperature rise has paused or stopped". But it hasn't stopped. Your assertion is factually incorrect. You have no evidence to show anything else - because you don't accept the NASA (and other) evidence. It's not about the models because there are no models for surface temperature. It's simply observation. You are already looking for flaws in models without, seemingly, caring what the data is. Don't you see a disconnect?

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  3. Marc Hendrickx

    Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

    so what role did humans play?

    According to recent work about 50%, the rest due to natural variation.

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    1. David Arthur

      resistance gnome

      In reply to Marc Hendrickx

      Historic fossil fuel use and cement production data (Oak Ridge National (US) Laboratory Carbon Dioxide Information Analysis Center) shows sufficient CO2 emission from 1800 to 2007 to raise atmospheric CO2 from 280 ppm to 430 ppm. Dissolution of CO2 in oceans limited atmospheric CO2 to about 390 ppm (as at 2007; 400 ppm in 2013), and continues to acidify oceans (decreased ocean pH).

      What part did humans play? Considering the increase in atmospheric CO2 over the last two centuries is less than anthropogenic CO2 emissions, 100% would be closer.

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    2. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to David Arthur

      I've heard some here claim over 100% but based on the latest peer reviewed science about 50 % is about right.

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    3. Alice Kelly
      Alice Kelly is a Friend of The Conversation.

      sole parent

      In reply to Marc Hendrickx

      Marc, could you show me the literature behind the claim"50%, the rest due to natural variation"
      This statement is at odds with the science.

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    4. Account Deleted

      logged in via email @drdrb.net

      In reply to Marc Hendrickx

      Xie, one of the authors of that paper, says that Curry has misinterpreted it.
      http://www.staatvanhetklimaat.nl/2013/08/30/xie-reacts-on-curry/

      There is an interesting discussion here: http://blog.chron.com/climateabyss/2013/08/learning-from-the-hiatus/
      A take away point for me was that Kosaka and Xie force the model to match the eastern pacific temperature record in order to include El Nino and the PDO - but given that this is a forcing imposed on the model, it becomes very difficult to say how much shifts in the PDO and El Nino might themselves be consequences of greenhouse warming.

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  4. Mark K

    logged in via email @scious.com

    I am staggered that this even got onto this website. This was refuted by satellite data a while ago.
    A quick search will bring up this article - "Australia’s Angry Hot Summer was hot angry hype– satellites show it was average".

    Two issues - satellite data says no it is not the hottest.
    Second issue is the increase in surface weather station and their location creating an increase where they may be none.

    Claims like the above are why so many people are turning from being proponents to sceptics. The continual false claims by people such as Flannery do a lot of damage to the credibility of CAGW.

    Remember, the dams will never be full again - only to overflow with flood after flood.

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    1. Mark Pollock

      Analyst

      In reply to Henry Verberne

      Surely you know how to access the satellite data? Have a look for yourself. They have recently added an Australian product so it's easy to see what a fabrication these alarmist claims are.

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    2. Mark K

      logged in via email @scious.com

      In reply to Henry Verberne

      Sorry - I thought you could cut and paste for yourself as I gave your the search term.

      http://kenskingdom.wordpress.com/2013/03/19/warming-has-paused-bom-says/
      The Bureau’s brand-new, best quality dataset, ACORN-SAT (Australian Climate Observation Reference Network- Surface Air Temperatures) clearly shows the linear trend has been flat for 18 years.

      http://wattsupwiththat.com/2013/06/27/claim-humans-play-role-in-australias-angry-hot-summer/
      both satellite datasets agree that there was nothing…

      Read more
    3. Henry Verberne

      Former IT Professional

      In reply to Mark Pollock

      I want YOU to give me the links. If you cannot or will not I think we can suspect your motives.

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    4. Marc Hendrickx

      Geologist: The Con is a bad Monty Python sketch, for climate sense see: http://www.thegwpf.org/

      In reply to Henry Verberne

      I think we have established that ss is not credible. Try quoting an original source.

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    5. Mark Pollock

      Analyst

      In reply to Henry Verberne

      I don't do do links. I do thinks. Have a go with the satellite stuff. It's easy and fun and you get the satisfaction of having worked something out for yourself.

      You can get 30 or so years of unhomogenised, Un-cherry picked machine produced Australian temperature data. Pop it into a chart or a table and see in an instant that the professor's claims about the recent "angry summer" are nonsense.

      I am sure you can do this. If you aren't prepared to do it this then I will have to suspect your motives.

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    6. Alice Kelly
      Alice Kelly is a Friend of The Conversation.

      sole parent

      In reply to Mark K

      I and others are sick of refuting this claim made against Tim Flannery, could you refer me to the sentences within the paragraph, in which you quote T.F. saying this.
      Could you show the satellite data you refer to

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    7. Alice Kelly
      Alice Kelly is a Friend of The Conversation.

      sole parent

      In reply to Alice Kelly

      On the other hand David Karoly explained the satellite data you have used well. So the Tim Flannery quote and actual words please?

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  5. Mark Pollock

    Analyst

    I wonder how many of the model simulations used by the professor included oceanic currents? The professor finishes his scary story by saying that the current ENSO conditions should preclude the current climate conditions we are observing. One would like to think that ENSO was included in the models but that might have been too hard.

    Much easier to just cherry pick from the dozens of hideously expensive, grant paid models and find the few that support whatever is the latest alarmist story. Interesting too to see that Australia's climate history pre 1910 has been expunged from the narrative.

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    1. Alvin Stone

      logged in via Facebook

      In reply to Mark Pollock

      Mark, we are in ENSO neutral conditions, coming out of a La Nina.
      We have just recorded the hottest 12 months on record.
      Normally records like these occur during El Nino periods because of the outgassing of heat from the oceans.

      The professors statement is simple logic based on observation.

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    2. Mark Pollock

      Analyst

      In reply to Alvin Stone

      Do any of the models include ENSO? Simple question. Why are you changing the subject and answering a question that wasn't asked?

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  6. Alan Wiggs

    School Teacher

    The doubt cast over "The Angry Summer" originates from satellite data - to be precise Dr Roy Spencer's data from the University of Huntsville, Alabama. Spencer is a signatory to "An Evangelical Declaration on Global Warming"....he is a charming but out there guy who has been criticised in the past for presenting data that underestimates temperature. To choose satellite data from the other side of the world in preference to ground-truthed recording station data just shows the sceptics preference to search out data that assists their viewpoint. Spencer thinks that increased CO2 will be beneficial - "My long term prediction is that eventually we are going to realise that more CO2 in the atmosphere is actually a good thing". One must examine that quality of data sources - not merely trot something out from yet another sceptic's blog.

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    1. Mark Pollock

      Analyst

      In reply to Alan Wiggs

      The satellite data on Australia does not come from the other side of the world. Surely you know how satellites work?

      They fly over Australia. They are operated by NASA, not by UAH. Spencer just tabulates the data. No one has suggested they are anything but they best available source of global temperatures.

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    2. David Arthur

      resistance gnome

      In reply to Mark Pollock

      Not too sure that Roy Spencer is such a champion: he and some bloke called Braswell got a paper pertaining to climate published in a journal, Remote Sensing, whose editorial board and reviewers lacked the technical expertise to specifically review the substance of Spencer & Brawsell's paper ("On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth’s Radiant Energy Balance", Remote Sens. 2011, 3(8), 1603-1613; doi:/rs3081603").

      A correction to Spencer's (deliberate?) errors was published a few weeks later in Geophysical Review Letters (Dessler, "Cloud variations and the Earth's energy budget". Geophysical Research Letters 38 (19). Bibcode:2011GeoRL..3819701D. doi:10.1029/2011GL049236.) - a journal whose subject matter and field of technical expertise includes the subject matter of Spencer & Braswell's erroneous article.

      The victim of Spencer's activities, Remote Sensing editor Wolfgang, Wagner, resigned over the furore.

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    3. Alan Wiggs

      School Teacher

      In reply to Mark Pollock

      Yes Mark...obviously. They are NASA satellites but it is exactly Dr Roy Spencer's tabulation of the data that has been questioned in the past. His corrections were in error for a decade and he allowed his figures to continue unchecked - despite errors. His figures became the poster-child for sceptics while continually underestimating actual temperatures. There are many sources for this if you look into evaluating and checking your sources of data. What I was getting at is that the sceptical side of this argument seems to always pick and choose data that when traced back to original sources, usually emanates from said Dr, Roy Spencer. Either that or sources that present HADCRUT3 data as HADCRUT4 (either in error or deliberately - the much celebrated MET office article in the Daily Mail for instance) Do some research into Roy's Spencer's approach and you'll understand why some of us might prefer Australian recording stations over UAH satellite data.

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    4. Mark Pollock

      Analyst

      In reply to Alan Wiggs

      . I prefer machine data. It is what it is. The other sources you mention have had too many adjustments. The Australian sources are as bad as the rest. Why, for example, would you cut off the record at 1910? Someone made this arbitrary decision? Are you familiar with the grounds for it?

      The NZ debacle should be sufficient warning against trusting national meteorological institutions with these decisions.

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    5. Alvin Stone

      logged in via Facebook

      In reply to Mark Pollock

      I assume the NZ debacle you are talking about is the one that led to the deniers who launched a case against the NZ meteorological institution NIWA getting booted out of court.

      That was one of the most scientifically inept attacks on the credibility of a meteorological institution seen to date, which is why it has not returned to the courtroom.

      As for the 1910 period for measurements, that is simply because it was only in that year that the Stevenson screen had been introduced to all of the Bureau's measurement stations. From the 1880s to that point Stevenson screens did not occur at all stations.

      The decision is one of consistency.

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    6. Alan Wiggs

      School Teacher

      In reply to Mark Pollock

      Mark....lets be honest. Look into Roy Spencer's manipulation of Satellite data and you will see who 'made too many adjustments". He did Chucky - he did. He has been held accountable and finally, after a decade misleading people knowingly, he was made to review his data. Frankly, Dr Roy takes this religious view of it all being god's work with man no part of the picture. I think (and I'm not sure) that maybe the 1910 start date is nothing more sinister than when the series of reliable Australia-wide data commenced. And if you don't trust National Meteorological institutions with data...well where do you get it from? The blogs of Nova; Bolt; Bastardi and Watt (at least the latter presents some balanced data). The books of Plimer (with 150 referenced errors in science?)

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    1. Alice Kelly
      Alice Kelly is a Friend of The Conversation.

      sole parent

      In reply to David Karoly

      Thanks David, I welcome your input, and do not feel so infuriated when I read an author reply like yours.

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    2. In reply to Sean Lamb

      Comment removed by moderator.

    3. In reply to Alvin Stone

      Comment removed by moderator.

    4. In reply to Alvin Stone

      Comment removed by moderator.

    5. In reply to Alvin Stone

      Comment removed by moderator.

    6. Mark Pollock

      Analyst

      In reply to David Karoly

      Professor, is this the Gregis paper that was was given wall to wall coverage in the love media in, what, April or May 2012? The same paper that was withdrawn so you could get the sums right and was going to be re-issued in September 2012?

      Has it taken this long to torture the data so it gives you the right answer? Oh the poor data! Can someone not put it out of its misery?

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    7. Alvin Stone

      logged in via Facebook

      In reply to Mark Pollock

      And so the deniers retreat to insult.

      You will find that the PAGES paper from earlier this year ( http://www.climatescience.org.au/content/249-last-100-years-reverse-1400-years-global-cooling ) comfortably covers off the issue you were talking about and it extends to both hemispheres.

      No Medieval Warming Period worldwide, Little Ice Age not worldwide either. Temperatures tending cooler for 1400 years before suddenly doing an unexpected about face without any natural forcing.

      As an analyst I would expect you might have an explanation for that sudden turnaround. Or would prefer just to insult the author and offer nothing constructive?

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    8. In reply to Alvin Stone

      Comment removed by moderator.

  7. R. Ambrose Raven

    none

    A denialist is one to whom truth is whatever serves the needs of the moment, who exploits discussion by combining aggression with dishonesty to incite opposition to an issue despite not having any reasonable basis for doing so. That kind has four principles:
    a. avoid the real issues;
    b. white-ant any progressive, inclusive and democratic approach;
    c. truth is whatever serves the needs of the moment; and
    d. our side does no wrong, the other side does no right.

    Denialists…

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    1. Alan Wiggs

      School Teacher

      In reply to R. Ambrose Raven

      Brilliantly written and quite thorough. You've clearly studied the psyche of the sceptic in some detail. One thing to add - the sceptics need to find conspiracies. I've heard talk of "World Socialism" and the like. They imagine some conspiracy of climate scientists feathering their own nests, making themselves rich on huge government grants supporting their research. Bizarre.

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  8. Chris Harries

    logged in via Facebook

    All around the globe these futile, heated debates about climate science go on and on endlessly. Full of sound and fury, signifying nothing. No chance of agreement.

    That's because the issue has almost nothing to with the science, to which virtually all scientists around the world are in agreement. It's about whether or not humans can face up to the rather shocking prognosis that the science community is conveying to us.

    I have every empathy for those who find it too hard to face up to this…

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    1. Mike Stasse

      retired energy consultant

      In reply to Chris Harries

      I could not agree more Chris...... and yet, as I have proved to myself and my family, switching to a low Carbon lifestyle is not only feasible and affordable, it is an IMPROVEMENT on my previous effluent lifestyle...... I've certainly never been healthier (notwithstanding the fact I'm over the hill!).

      I could never go back to the stressful consumption driven life I used to have..... Were it not for the constant frustration I feel about the lack of action on climate issues, I have no doubt I would be PERFECTLY happy..... maybe all I need to do is go into denial myself, denial that nothing will be done until it's TOO LATE!

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    2. David Arthur

      resistance gnome

      In reply to Chris Harries

      You write "We have to be patient with denial, it will work through and resolve itself with time, as it always does."

      Err, I differ with you on this; I refuse to be patient with denial, for the perfectly sound reason that these Denialists, thes intellectual and moral cowards, are consigning themselves, their children, their nations and the entire world to a future of more death and more devastation than need occur.

      I can only forgive them should their demise be premature, be it by their own hands or as acts of self-defence by their own children.

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    3. Alice Kelly
      Alice Kelly is a Friend of The Conversation.

      sole parent

      In reply to Chris Harries

      Hi, Chris, I do not think argument is futile. The changes we make to the planet now benefit those with wealth based on carbon polluting industry. It's true they are not the people arguing against AGW here, but "bad things happen when good people say nothing", is how I treat this thing. We have to start reversing the damage we do now , no ifs or buts. It is war against the future planet. And I will not shut-up. There was an interesting science show yesterday. Everybody like you and I, has to mobilise in every way possible, and hip-pocket is another way also. I will not be buying shell petrol again, and will keep arguing, thanks.
      http://www.abc.net.au/radionational/programs/scienceshow/a-message-to-shell-about-its-plans-to-drill-in-the-arctic/4919730#transcript

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    4. john tons

      retired redundant

      In reply to David Arthur

      I too am impatient with the denialists. I wonder what has happened to the investment we made an education. For many the problem with the science is that it seems that there are conflicting reports - global warming can paradoxically lead to a new ice age in Britain, it an even result in an increase in the sea ice and so denialists scoff. The reality is that climate science is a fiendishly difficult discipline; understanding our climate is not unlike the blind men attempting to describe an elephant but at least the blind men all agreed that there was something there - here in the absences of a consensus regarding the precise implications of climate change people take comfort in denying that there is such a thing.

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    5. David Arthur

      resistance gnome

      In reply to john tons

      Funnily enough, I find climate science something fairly straightforward to comprehend, perhaps because I give more than two minutes' thought to the subject on any given day.

      Regarding investment in education, I understand education is improving to the extent that children are now being trained to think critically about the motivations of politicians, priests, corporate leaders and their journalistic lackeys.

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    6. Ken Swanson

      Geologist

      In reply to David Arthur

      They are also taught to think critically about the motivations and behaviours of union leaders, rent seeking academics, self serving civil rights lawyers and their journalistic lackeys on the ABC, Radio National, Fairfax and various unnamed blogs.

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    7. Alice Kelly
      Alice Kelly is a Friend of The Conversation.

      sole parent

      In reply to Ken Swanson

      "rent seeking academics"?
      You are wrong. To accuse academics of being merely rent-seekers, when years of study, research, and validated consistent conclusions you don't like is rude. Critical thinking is important, but so is reading accurate information. Reading widely is important, and so is checking the validity of material. I value articles like this one because it has been based on research which has passed peer review, unlike much which is written about the topic which has not been adequately researched in various media not mentioned by you Ken.

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    8. David Arthur

      resistance gnome

      In reply to Ken Swanson

      Thanks Ken. My name is David Arthur, and here's what I've learnt.

      Earth is warmed by absorption of short wave sunlight. Because of this, Earth's temperature can remain unchanged by returning the same amount of energy to space. That is, solar shortwave energy is balanced by the earth re-radiating to space as a 'black body' radiator with a characteristic temperature of ~255K; that is, from space the earth's spectrum is roughly that of a radiating body with an optical surface temperature of…

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    9. John Holmes

      Agronomist - semi retired consultant

      In reply to David Arthur

      This reminds me of some of the history of vaccinations and controversy in the past, where there were references to 'fool killer out breaks' . Problem is, we cannot get our selves, children or grand kids treated so that they will escape the problem.

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    10. Mark Pollock

      Analyst

      In reply to john tons

      Nobody denies that the globe is warming. Maybe you missed out on the fallacious and deceitful nature of the straw man argument when younwere having your education. Find another stick. That one's broken.

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    11. Gary Murphy

      Independent Thinker

      In reply to Mark Pollock

      "Nobody denies that the globe is warming."

      Oh - come now.

      Every day we get some turkey saying 'it hasn't warmed for 15 years' - when oceanic heat content and ice sheet mass measurements clearly demonstrate that warming has accelerated.

      And another turkey says 'it is just natural' - when a quick glance at long-term global temperatures shows a gradual cooling for the last 5000 years and then a sharp (instantaneous in geological terms) increase in the last 100 years.

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    12. Mark Pollock

      Analyst

      In reply to Gary Murphy

      Drivel. And not even independent drivel. That there has been no, or minimal or unobservable warming for the last 15, 18, 23 or whatever years is beside the point. The important thing is that the models on which the zealots rely predicted a much higher rate and are therefore all wrong. They should be junked. If observations don't match the theory get rid of the theory.

      And the latest dog ate my breakfast excuse about the extra heat that by now be frying the polar bears is laughable. Surely an independent thinker can do better than trot out these ridiculous cliches?

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    13. Alvin Stone

      logged in via Facebook

      In reply to Mark Pollock

      The hiatus in global average temperatures (but not many other indices - ocean heat, Arctic ice, energy imbalance measured by satellites, sea level rise to start with) is actually still within the margin of error forecast by climate models.

      Previous peer reviewed work on global temps has shown that on average climate models are surprisingly accurate in forecasting a range of changes. This article explains it quite nicely - http://web.archive.org/web/20100322194954/http://tamino.wordpress.com/2010/01/13/models-2/

      Models are not perfect but they do what they are designed to do quite well.

      But at the end of the day, global warming is being supported by observations. And they, as described above, continue to show consistent, strong warming.

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    14. Gary Murphy

      Independent Thinker

      In reply to Mark Pollock

      I am confused - are you denying that the earth is still heating or not?

      You don't seem to have a consistent position.

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    15. john tons

      retired redundant

      In reply to Gary Murphy

      To Mark Pollock
      the only reliable climate change model is the earth itself. If we want to know what the earth will be like in 200 years on a business as usual approach then we need to continue the way we are and in 200 years we know with absolute certainty who was right and who was wrong.

      The upside of that approach is that you can bask in the glory that your descendants will applaud your fortitude in holding firm against the alarmist.
      The downside of that approach will be....

      Now just as I make sure my insurance cover is up to date just in case one of a myriad of misfortunes that could come my way actually occurs so I would like to think that government policy is equally prudent - it may not happen but the likelihood that climate change will have a significant impact is probably far greater than my house will get burgled.

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  9. Chris Harries

    logged in via Facebook

    For the record, there are those in genuine denial and then there are those who stridently oppose climate policies for totally perverse commercial or political reasons. The latter group preys on the former and uses them as their pawns. They are easy prey.

    It is not possible to tell these people apart, but labelling all deniers as treasonable does nothing to help them out of their corner, in fact it tends to lock them in. For the most part the majority of deniers do not have a vested interest, they are simply personalities who have trouble coping.

    When faced with hard news some people rise to the occasion and choose to take a lead; some react with passive acceptance; some turn a blind eye but stay quiet; some react with anger and disbelief. These are all natural human responses.

    This is the science that is relevant.

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    1. Mark Pollock

      Analyst

      In reply to Chris Harries

      It may not be possible for a normal person to tell us apart but for a super brain like yourself it's obviously quite easy. Otherwise you wouldn't be able to make the distinction.

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    2. Chris Harries

      logged in via Facebook

      In reply to Mark Pollock

      Thank you Mark, that's very flattering!

      Actually, I suspect you are one of the innocent ones, but I honestly don't know.

      Despite opinions to the contrary, I believe the carbon industry directly funds very few advocates, most of their work is done for free.

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  10. trevor prowse

    retired farmer

    Could someone ask the BOM to report the data from the 108 sites for the maximum temperatures during the 1972-3 summer and compare the same sites of the "angry summer" of 2012-13. I have asked for the data and have been fobbed off. The data from the BOM for the 2012-13 summer was collected from over 700 sites, thus making a comparison not very fair. I suspect 1972-3 was hotter.
    What I wonder about is, what is the natural temperature rise in comparison to the man made increase. From BOM Western Australian…

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    1. Alvin Stone

      logged in via Facebook

      In reply to trevor prowse

      Selecting a single location for sea level rise tells us nothing about global sea level rise.

      I'm sure BoM has made the comparisons you request and I trust their experts far more than a retired farmer to get things right.

      The great majority of the temperature increase can be attributed to greenhouse gases as researchers already take into account natural variability.

      Trevor, maybe you should do an online course in climate change - there are plenty out there - and then you can find the answers yourself.

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    2. Doug Hutcheson

      Poet

      In reply to trevor prowse

      Trevor, you know - I am sure you do - that the current Milankovitch cycle should be slowly cooling the planet and leading us to a new glacial maximum. Clearly, instead of cooling, we are warming. What do you think is causing this contrary cycle? It's not the sun, as Sol is in a quiet phase right now. It might be magic moonbeams, I suppose, but I have yet to read a peer reviewed scientific paper on magic moonbeams, or climate fairies, or intergalactic microwave-cookers.

      CO₂ is the climate control…

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    3. trevor prowse

      retired farmer

      In reply to Doug Hutcheson

      Alvin , As you are an ex WWF person , I imagine the thought of a differing view could not be contemplated, so I`ll ask if you have noticed that the mean sea and air temperatures in the antarctic(60-85S) have been static since 1978 according to the university of Alabama. Could you tell me why the CO2 in the world has not caused the temperatures to have a rising trend in this antarctic region. On a shorter time scale ,the BOM Tidal recording stations around Australia(14) since they were established…

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    4. Mark Pollock

      Analyst

      In reply to Alvin Stone

      So much for a conversation. You have no manners and no sense. He was asking a reasonable question and has done some reasonable research and what from the true believer? Insults and sneers. Par for the course. You must be a real climate scientist.

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    5. Alvin Stone

      logged in via Facebook

      In reply to trevor prowse

      Trevor ,

      Interesting you pick WWF-Australia, not the fact I edited newspapers for News and Fairfax or that after WWF, I worked for a boutique media agency where I had three energy companies, two of them electricity generators, as my clients, or that I now work with climate scientists. I am very accepting of multiple views but I will always give way to the peer reviewed science.

      If you could link to your references that would be very much appreciated.

      As the PAGES paper indicates, the Antarctic…

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    6. Alvin Stone

      logged in via Facebook

      In reply to Mark Pollock

      The true believer religion line. I should have guessed that would crop up soon.

      Mark, I made some simple observations. Sydney sea levels tell us nothing about global sea levels. Clear and true.

      The Bureau of Meteorology are the authorities in this area.

      Work has been done on the human contribution to global warming.

      But most importantly, it was not an insult, I was suggesting that there are many, very good, online courses that are available about the science behind climate change offered for free by respected universities (Yale, for instance).

      I was merely pointing out that Trevor could avail himself of these courses and many of his questions will be answered and those answers will be based on respected peer reviewed papers.

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    7. trevor prowse

      retired farmer

      In reply to Alvin Stone

      Alvin---you said---
      "As for the BoM tidal stations (what a strange and isolated group), I don't think they take in account GLOBAL temperatures. I could be wrong. :-)."----The Climate Commission report---"The Critical Decade" reported that Fremantle had a 7.4mm/year rise from the early 1990 to 2010. according to the National Tidal Centre 2010, ---giving the impression that sea level rise was a severe concern for Western Australia, When I asked for the air temperatures at these same14 tidal stations…

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  11. Gil Hardwick

    anthropologist, historian, novelist, editor and publisher at eBooks West

    David, and Sophie, while I respect your report and find it useful, by the same token while national averages may point to generally increasing average temperatures the effect is nowhere near uniform, nor indeed by any real measure necessarily detrimental.

    Over here in Western Australia, for example, while experiencing an average decrease in annual maximum rainfall of around 11% on 1,100 mm over the long period since 1975, bandied about by environmental lawyers and politicians alike in calling…

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