E&E News discusses a groundbreaking study: Earth will warm 4.9 to 7 degrees F. How much warming will greenhouse gas emissions cause in the coming years? It’s one of the most fundamental questions about climate change — and also one of the trickiest to answer.
Now, a major study claims to have narrowed down the range of possible estimates. It presents both good and bad news. The worst-case climate scenarios may be somewhat less likely than previous studies suggested. But the best-case climate scenarios — those assuming the least amount of warming — are almost certainly not going to happen.
It’s “the most important climate science paper that’s come out in several years,” according to climate scientist Andrew Dessler of Texas A&M University, who was not involved with the study. The effort also illuminates some of the challenges of a decadeslong scientific quest to predict the strength of future climate change.
At the heart of the new study is a concept known as “climate sensitivity” — how sensitive the Earth is to greenhouse gas emissions and how much it’s likely to warm in response. In studies, scientists often focus on the amount of warming that might be expected if carbon dioxide concentrations doubled their preindustrial levels.