Global warming this century could exceed previous estimates, according to models that accurately account for energy flow at the top of Earth’s atmosphere.
Climate models generally agree that greenhouse-gas emissions will continue to raise global temperatures, but the amount of warming predicted varies considerably. Patrick Brown and Ken Caldeira at the Carnegie Institution for Science in Stanford, California, assessed a plethora of current climate models. They found that some models more accurately simulate the amount of radiation entering and leaving the atmosphere, a flow known as Earth’s energy budget, than others.
The team combined a number of models but reduced the influence of those that less realistically represent the energy budget. Their calculations reveal that, under the worst-case emissions scenario, by 2100 the planet will warm by 15% more — or about 0.5 °C — than predicted by the previous best estimate.
The researchers say that their findings strengthen the urgency of global efforts to mitigate and adapt to climate change.