Australians in climate change row after hot year

Scientists say the world’s climate is warming faster than feared because previous predictions were too “optimistic” and overestimated the cooling impact of clouds.

As the planet marked its fourth hottest year on record, an Australianled study published in Nature found increasing levels of carbon dioxide would lead to thinner ocean clouds and reduce their cooling impact, causing temperature rises of at least 3 C over the course of the century.

The team of scientists said the findings showed some climate models had been too “optimistic” and previous estimates of a minimum temperature rise of only 1.5 C could now be discounted. The optimistic models did not properly assess the impact of water evaporation, which sometimes rose only a short distance into the atmosphere and caused updrafts that reduced cloud cover, the study found.

“These models have been predicting a lower climate sensitivity but we believe they’re incorrect,” Prof. Steven Sherwood, from the University of New South Wales, told The Sydney Morning Herald.

“The net effect of (climate change) is you have less cloud cover.”

The study comes amid a controversy in Australia over claims by Maurice Newman — the leading business adviser to Tony Abbott, the prime minister — who said the world had been taken “hostage to climate change madness.”

Newman said the climate-change establishment, led by the Intergovernmental Panel on Climate Change, remained “intent on exploiting the masses and extracting more money.”

He wrote in The Australian: “The scientific delusion, the religion behind the climate crusade, is crumbling. Global temperatures have gone nowhere for 17 years ... If the IPCC were your financial adviser, you would have sacked it long ago.”

Newman, a former chairman of the Australian Stock Exchange, was criticized by the opposition and pilloried by scientists, who said he was expressing “flat Earth” views and should be sacked.

“His piece is a mix of common climate-change myths, misinformation and ideology,” said David Karoly, from the University of Melbourne, in an article in The Sydney Morning Herald. “It is clearly not sensible to have a person who believes that climate change science is a delusion as leader of the prime minister’s Business Advisory Council.”

Abbott once claimed that climate change was “absolute crap,” although he later said he accepted that it was “real.” He has moved to scrap tax on carbon emissions, imposed by the Labor government, and instead proposes to address climate change by paying polluters to reduce emissions, although critics say the plan is underfunded and will not achieve its reduction targets.

The debate comes as Australia in 2013 marked its hottest year since reliable recordings began in 1910.