Energy & Science

Top Scientists Just Ruled Out Best-Case Global Warming Scenarios

A new research paper narrows a key range for future heating. We ask one of the authors what it means.

A student looks at a meltwater stream on the Glacial Ice Sheet, Greenland.Photographer: Joe Raedle/Getty Images
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A major new study of the relationship between carbon dioxide and global warming lowers the odds on worst-case climate change scenarios while also ruling out the most optimistic estimates nations have been counting on as they attempt to implement the Paris Agreement.

A group of 25 leading scientists now conclude that catastrophic warming is almost inevitable if emissions continue at their current rate, even if there’s less reason to anticipate a totally uninhabitable Earth in coming centuries. The research, published Wednesday in the journal Reviews of Geophysics, narrows the answer to a question that’s as old as climate science itself: How much would the planet warm if humanity doubled the amount of CO₂ in the atmosphere?