Want climate news in your inbox? Sign up here for Climate Fwd:, our email newsletter.



WASHINGTON — In the summer, when heat waves scorch cities or heavy rains flood the coasts, some climate scientists and environmentalists will point out any plausible connections to global warming, hoping today’s weather will help people understand tomorrow’s danger from climate change.

Then winter comes. And, like clockwork, those who want to deny the established science that humans are warming the planet will try to flip the script. In January, when large swaths of the country were gripped by bitter cold, President Trump took to Twitter to mock climate fears: “Wouldn’t be bad to have a little of that good old fashioned Global Warming right now!”

Welcome to the weather wars. As battle lines harden between supporters and opponents of climate action, both are increasingly using bouts of extreme weather as a weapon to try to win people to their side. Weather, after all, is one of the easiest things for people to bond over or gripe about, a staple of small talk and shared experience that can make it a simple but powerful opportunity to discuss global warming.

But, as Mr. Trump’s words show, it’s also a framing device that can be easily abused. That raises the stakes for how scientists, who have long tried to distinguish between short-term weather fluctuations and long-term climate shifts, draw out and discuss the links between the two.