RAPID REACTION: Did the IPCC get it wrong? – experts respond

Mon Sep 16, 2013

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There are media reports today that the rate of global warming in the upcoming IPCC report has been revised down since the previous report in 2007. Below Australian experts respond.  The final IPCC working group 1 report will be published on September 27th  at 18:00 AEST.

The AusSMC will be hosting an online briefing with Australian authors live from Stockholm at this time. We will also be rounding up Australian experts to comment.

 Feel free to use these quotes in your stories.   If you would like to speak to an expert, please don’t hesitate to contact us on (08) 7120 8666 or by email.

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 Professor David Karoly is Professor of Atmospheric Science at the University of Melbourne and a review editor of the IPCC Fifth Assessment Report

The Australian gets it wrong on global warming and the IPCC, again.

 Today’s Australian newspaper has major errors in its front page article with headline “We got it wrong on warming, says the IPCC”. I look forward to The Australian publishing a correction or a new article with my headline above.

 The first sentence of the article states ‘The Intergovernmental Panel on Climate Change’s latest assessment reportedly admits its computers drastically overestimated rising temperatures, and over the past 60 years the world has in fact been warming at half the rate claimed in the previous IPCC report in 2007’

 First, the latest assessment report has not been finalised, so no conclusions are final. Second, the observed global average warming of surface air temperature over the last 60 years of 0.12°C per decade is almost identical to the value reported in the IPCC report in 2007 of 0.13°C per decade (likely range 0.10 to 0.16°C per decade) for the period 1956 – 2005.

 The Australian got it wrong again on what the IPCC reported in 2007 and what is happening to global average temperatures.”

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Dr John Cook is a Research Fellow in Climate Communication at the Global Change Institute at the University of Queensland. In 2011, John received an Australian Museum Eureka Award for Advancement of Climate Change Knowledge. John also created and maintains skepticalscience.com, a website that examines the arguments of global warming scepticism.

 “The Australian article ‘We got it wrong on warming, says IPCC” demonstrates the inherent dangers in sourcing scientific information from a UK tabloid rather than climate scientists. The Australian misrepresents the IPCC, claiming “The 2007 assessment report said the planet was warming at a rate of 0.2°C every decade, but according to Britain’s The Daily Mail the draft update report says the true figure since 1951 has been 0.12°C”. In actuality, the trend reported in the IPCC report was 0.13°C per decade (http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-direct-observations.html). The Australian discusses a slowdown in surface temperature but fails to consider that the planet as a whole continues to build up heat at an accelerating rate, currently at a rate of 4 Hiroshima bombs-worth of heat every second. The Australian also fails to report the growing body of research indicating that the slowdown in surface temperature is due to more heat accumulating in the ocean, indicated by direct ocean heat measurements. Discussion of ocean heat up-take is expected to be included in the upcoming IPCC report.”

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 Professor Steven Sherwood is Professor of Physical Meteorology and Atmospheric Climate Dynamics at the University of New South Wales and is lead-author of chapter 7 of the IPCC Working Group 1 Fifth Assessment Report, “Clouds and Aerosols”.

 ”The Australian story is riddled with errors.  The IPCC does not do climate forecasts on its own “computer,” as stated in the lead paragraph of the article, but analyses forecasts submitted to them by two dozen or so research organisations worldwide, including NASA and CSIRO.  The lead paragraph also claims that the rate of observed surface warming over the previous 60 years is half that reported in 2007, when the real difference is much smaller and, according to several published studies, is balanced by stronger than expected recent warming below the ocean surface.

The article also confuses a quantity called “transient climate response” with the projected future warming.  If we continued on a business-as-usual path, the eventual global warming would be several times larger than the “transient climate response,” not equal to it as implied in the story.  The quote from Matt Ridley, that most experts believe warming of under 2°C will be beneficial, may have been stated by Mr Ridley, but is also incorrect.  Instead, 2°C is often taken to be the maximum “safe” warming before which dangerous thresholds, such as the warming needed to guarantee the eventual melting of the Greenland ice sheet, may be crossed. Past assessments have projected that business-as-usual warming must almost certainly exceed 2°C (IPCC 2007 set a range of about 3-6°C above preindustrial by 2100), and no new results have emerged that could cause a significant revision to that assessment.

Finally, the story positions a legitimate statement by Judith Curry so as to seemingly undercut IPCC conclusions about climate change, but contrary to this implication, it is possible for a report on this or any similar topic to reach firm conclusions about important questions even when some aspects of the science are well known to be “unsettled” or in a “state of flux.”  Just as it is possible to know that a cancer patient is likely to die without treatment, even if the date or particular symptoms cannot be predicted accurately.’

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