The Australian, the IPCC and Expert Response. (September 16, 2013)|
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News & Views item - September 2013 |
The Australian, the IPCC and Expert Response. (September 16, 2013)
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The Australia Graham Lloyd, Environment editor September 16, 2013 |
Professor David Karoly
Professor of Atmospheric Science at the University of Melbourne and a
review editor of the IPCC Fifth Assessment Report |
Dr John Cook
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. |
Professor Steven Sherwood 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 Intergovernmental Panel on
Climate Change's latest assessment reportedly admits its computer
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. More importantly, according to reports in British and US media, the draft report appears to suggest global temperatures were less sensitive to rising levels of atmospheric carbon dioxide than was previously thought. The 2007 assessment report said the planet was warming at a rate of 0.2C every decade, but according to Britain's The Daily Mail the draft update report says the true figure since 1951 has been 0.12C. Last week, the IPCC was forced to deny it was locked in crisis talks as reports intensified that scientists were preparing to revise down the speed at which climate change is happening and its likely impact. It is believed the IPCC draft report will still conclude there is now greater confidence that climate change is real, humans are having a major impact and that the world will continue to warm catastrophically unless drastic action is taken to curb greenhouse gas emissions. The impacts would include big rises in the sea level, floods, droughts and the disappearance of the Arctic icecap. But claimed contradictions in the report have led to calls for the IPCC report process to be scrapped. Professor Judith Curry, head of climate science at the Georgia Institute of Technology in Atlanta, told The Daily Mail the leaked summary showed "the science is clearly not settled, and is in a state of flux". The Wall Street Journal said the updated report, due out on September 27, would show "the temperature rise we can expect as a result of manmade emissions of carbon dioxide is lower than the IPCC thought in 2007". The WSJ report said the change was small but "it is significant because it points to the very real possibility that, over the next several generations, the overall effect of climate change will be positive for humankind and the planet". After several leaks and reports on how climate scientists would deal with a slowdown in the rate of average global surface temperatures over the past decade, the IPCC was last week forced to deny it had called for crisis talks. "Contrary to the articles the IPCC is not holding any crisis meeting," it said in a statement. The IPCC said more than 1800 comments had been received on the final draft of the "summary for policymakers" to be considered at a meeting in Stockholm before the release of the final report. It did not comment on the latest report, which said scientists accepted their forecast computers may have exaggerated the effect of increased carbon emissions on world temperatures and not taken enough notice of natural variability. According to The Daily Mail, the draft report recognised the global warming "pause", with average temperatures not showing any statistically significant increase since 1997. Scientists admitted large parts of the world had been as warm as they were now for decades at a time between 950 and 1250, centuries before the Industrial Revolution. And, The Daily Mail said, a forecast in the 2007 report that hurricanes would become more intense had been dropped. Writing in The Wall Street Journal, Matt Ridley said the draft report had revised downwards the "equilibrium climate sensitivity", a measure of eventual warming induced by a doubling of carbon dioxide in the atmosphere. It had also revised down the Transient Climate Response, the actual climate change expected from a doubling of atmospheric carbon dioxide about 70 years from now. Ridley said most experts believed that warming of less than 2C from pre-industrial levels would result in no net economic and ecological damage. "Therefore, the new report is effectively saying (based on the middle of the range of the IPCC's emissions scenarios) that there is a better than 50-50 chance that by 2083 the benefits of climate change will still outweigh the harm," he said. |
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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“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_ 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.” |
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 pre-industrial 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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