Ruckus over IPCC's global warming data

 
By Ritu Gupta
Last Updated: Saturday 04 July 2015

-- (Credit: Shyamal)the world's top climate scientists, part of the Intergovernmental Panel on Climate Change (ipcc), have toned down the worst possible forecast for global warming over the next 100 years, claims The Weekend Australian. But both experts and the ipcc have criticised the reportage, saying it is riddled with prejudices and that it is premature to analyse the forthcoming ipcc report, as it may undergo several changes.

The newspaper claims to have "exclusively" obtained the draft of the fourth assessment report by ipcc, which projects a scenario "less gloomy" than that offered in ipcc's third assessment report. ipcc was set up in 1988 by two un bodies, the World Meteorological Organization and the United Nations Environment Programme to assess the "risk of human-induced climate change". ipcc reports are widely cited in any debate related to climate change. Publication of its fourth assessment report is planned for early 2007.

The news report, which appeared on September 2, says that in the draft, " ipcc scientists are confident enough to project a 3 c rise in the average global daily temperature by the end of this century, if no action is taken to cut greenhouse gas emissions". The news report says the temperature increase could be contained to 2 c by 2100 if emissions are held at current levels. In 2001, the scientists predicted temperature rises from 1.4-5.8 c by 2100, but better science has led them to adjust this to a narrower 2-4.5 c band, states the newspaper, adding: "The new projections put paid to some of the more alarmist scenarios raised by previous modelling, which have suggested that sea levels could rise by almost one metre over the same period. The report projects a rise in sea levels by century's end of between 14 cm and 43 cm, with further rises expected in following centuries caused by melting polar ice."

Does the news report mean that ipcc has diluted its findings? Or, is the reportage biased? "Any reporting on the fourth assessment report at this stage would be premature, because the draft can undergo significant changes on account of the rigorous process of reviews and approval of the report before it is finalised," says ipcc chairperson R K Pachauri. ipcc deputy secretary Jian Liu adds: "We have noted that several premature reports have appeared in the media concerning findings of the ipcc. We would like to clarify that the process leading up to the 2007 release of the fourth assessment report is long, complicated and far from complete."

Other scientists also support ipcc. "Because ipcc has thousands of scientists and thousands other reviewing it (report), its findings are trustworthy," says Dilip Ahuja, a professor at the National Institute of Advanced Studies, Bangalore, who has also been involved with an ipcc working group.

Ray Wills, a research fellow at the University of Western Australia, has an interesting point to make -- the ipcc draft has long been available to those who have signed up to the ipcc review site for a wide peer review. "Therefore, its reportage is hardly exclusive as the writer of The Weekend Australian claims," says Wills, adding: "In addition, someone who signs, also, of course must have agreed that they will not distribute, cite or publish the report as it is, after all, a draft. Whoever provided this report (to the newspaper)... has ignored this."

Wills says that Matthew Warren, the author of the news report, was earlier the director of external affairs for an Australian industry association which had heavily invested in promoting coal-fired electricity and clean coal and was supportive of the Australian government's approach to climate change. "Warren is a good fit with the Australian government that has been aggressively touting the denial of climate change for several years and reacting by simply casting doubt on parts of the science. Hence, his report tries to dismiss any upper end forecasts on climate change and sea level rise," claims Wills.

The central issue is how well climate models can predict atmospheric states, says John R Christy, director, Earth System Science Centre, usa. "I do not place much confidence in the projections after examining the models' attempts to replicate 20th century climate. However, the lower projections are welcome as they are more in keeping with what has already transpired," he adds.

Another climate change expert, says instead of arguing about numbers, the success stories about efforts to mitigate human-induced climate change should be highlighted. "Let's wait for the final report and then debate the findings. Global warming and its impact need not be re-emphasised and no number games will retard the current and ongoing efforts in addressing the climate change issues in terms of mitigation and adaptation."

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