Global warming may get Americans off the couch

WASHINGTON — Global warming’s milder winters will likely nudge Americans off the couch more in the future, a rare, small benefit of climate change, a new study finds.

With less-chilly winters, Americans will be more likely to get outdoors, increasing their physical activity by as much as 2.5 percent by the end of the century, according to a new study in Monday’s edition of the journal Nature Human Behaviour. Places like North Dakota, Minnesota and Maine are likely to see the most dramatic increases, usually the result of more walking.

But that good global warming side effect is not likely to extend to the Deep South and especially the desert Southwest because hotter summer days may keep people inside. Arizona, southern Nevada and southeastern California are likely to see activity drop off the most by the year 2099, the study found.

“It’s a small little tiny silver lining amid a series of very bad, very unfortunate events that are likely to occur,” said study lead author Nick Obradovich , who studies the social impacts of climate change at both Harvard’s Kennedy School of Government and MIT. Global warming “almost certainly will be very costly on net for humanity.”

Any overall benefit for Americans as a whole will probably be far outweighed by many other ways that climate change hurts health, said both Obradovich and outside health experts. For example, deaths from heat waves are expected to increase, allergies are likely to worsen and infectious diseases will be more easily spread, said Dr. Howard Frumkin, a University of Washington environmental health professor.

Obradovich said he got the idea to look about what climate change will do to people’s activities a few Octobers ago when he was living in San Diego and running regularly in the afternoon. There was a heat wave, temperatures broke 100, and he stayed home.