Climate warming by 2050 is likely to be between 1.4 and 3 °C under a mid-range, no-mitigation scenario of greenhouse gas emissions, reports a study published online this week in Nature Geoscience. This range is broadly consistent with the expert assessment of the Intergovernmental Panel on Climate Change, but is based on simulations with several thousand distinct climate models that are consistent with observed temperature changes.
Daniel Rowlands and colleagues filter simulations of past and present climate change with a large ensemble of climate models according to their ability to match regional temperature changes over the past 50 years. On the assumption that models that simulate past warming realistically are the best candidates for future warming predictions, the authors conclude that a warming of 3 °C by 2050, compared with the 1960-1990 average, marks the upper end of the “likely range” of climate warming.
In an accompanying News and Views article, Isaac Held says that Rowlands and colleagues’ “massive perturbed physics ensemble is a valuable resource for further analysis of climate change.”