NE NEWS SERVICE
PARIS, JAN 15
New climate models show carbon dioxide is a more potent greenhouse gas than previously understood, a finding that could push the Paris treaty goals for capping global warming out of reach, scientists have told AFP.
Developed in parallel by separate teams in half-a-dozen countries, the models – which will underpin revised UN temperature projections next year – suggest scientists have for decades consistently underestimated the warming potential of CO2.
Vastly more data and computing power has become available since the current Intergovernmental Panel on Climate Change (IPCC) projections were finalised in 2013. “We have better models now,” Olivier Boucher, head of the Institute Pierre Simon Laplace Climate Modelling Centre in Paris, said, adding that they “represent current climate trends more accurately”. The most influential projections from government-backed teams in the US, Britain, France and Canada point to a future in which CO2 concentrations that have long been equated with a 3 degrees Celsius world would more likely heat the planet’s surface by four or five degrees.
“If you think the new models give a more realistic picture, then it will, of course, be harder to achieve the Paris targets, whether it is 1.5 or two degrees Celsius,” scientist Mark Zelinka said.
Zelinka, from the Lawrence Livermore National Laboratory in California, is the lead author of the first peerreviewed assessment of the new generation of models, published earlier this month in Geophysical Research Letters. For more than a century, scientists have puzzled over a deceptively simple question: if the amount of CO2 in the atmosphere doubles, how much will Earth’s surface warm over time? The resulting temperature increase is known as Earth’s “climate sensitivity”.
Courtesy: AFP
