Scientists find carbon dioxide is more potent than thought, meaning the Paris climate goals on cutting greenhouse gases may be unattainable.
LONDON, 23 January, 2020 − The fevered arguments about how the world can reach the Paris climate goals on cutting the greenhouse gases which are driving global heating may be a waste of time. An international team of scientists has learned more about the main greenhouse gas, carbon dioxide (CO2) − and it’s not good news.
Teams in six countries, using new climate models, say the warming potential of CO2 has been underestimated for years. The new models will be used in revised UN temperature projections next year. If they are accurate, the Paris targets of keeping temperature rise below 2°C − or preferably 1.5°C − will belong to a fantasy world.
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 Institut Pierre Simon Laplace Climate Modelling Centre in Paris, told the French news agency AFP, and they “represent current climate trends more accurately”.
Projections from government-backed teams using the models in the US, UK, France and Canada suggest a much warmer future unless the world acts fast: CO2 concentrations which have till now been expected to produce a world only 3°C warmer than pre-industrial levels would more probably heat the Earth’s surface by four or five degrees Celsius.
“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°C or two degrees Celsius,” Mark Zelinka told AFP. Dr Zelinka, from the Lawrence Livermore National Laboratory in California, is the lead author of the first peer-reviewed assessment of the new generation of models, published earlier this month in the journal Geophysical Research Letters.
“Climate sensitivity has been in the range of 1.5°C to 4.5°C for more than 30 years. If it is now moving to between 3°C and 7°C, that would be tremendously dangerous”