Cold Years in the Future Could Be Hotter Than the Hottest Years Now

http://science.time.com/2013/10/10/cold-years-in-the-future-will-be-hotter-than-the-hottest-years-now/

By Bryan Walsh @bryanrwalshOct. 10, 2013

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If we’re accustomed to handling much bigger temperature variations on an average autumn day—let alone the weather changes from summer to winter—it shouldn’t be hard to adapt to a climate in which the average temperature is just 3º F or so warmer than average, right?

Wrong. As an important new study published in Nature shows, even what seems like a small increase in the average air temperature could have a major effect on the planet—and on our well being. After crunching data from existing climate models, researchers from the University of Hawaii at Manoa, led by the geographer Camilo Mora, calculated that by 2047, plus or minus five years, the average temperatures in each year will be hotter across most of the planet than they had been at those places in any year between 1860 and 2005, the span of years for which scientists have the most reliable records. By about mid-century, the coldest year will be warmer than the hottest year in the past.

Read more: New Study Shows That Even Cold Years in the Future Will Be Hot | TIME.com http://science.time.com/2013/10/10/cold-years-in-the-future-will-be-hotter-than-the-hottest-years-now/#ixzz2kMjm3glG

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For some regions, especially in the tropics, that tipping point will come much earlier, with Mexico City experiencing the transition as early as 2031, Lagos by 2029 and Bogota by 2033. That’s because the natural variation in air and ocean temperatures in the tropics tends to be very small, so even a seemingly inconsequential change is enough to push the climate well out of the historical norm, leading to average temperatures much hotter than even these sizzling regions are accustomed to. Given that more than 3 billion disproportionately poor people live in the tropics and subtropics, we should be very worried about how they’ll manage to adapt to a climate hotter than they’ve ever experienced. “Our results suggest that the countries first impacted by unprecedented climates are the ones with the least capacity to respond,” said Ryan Longman, a study co-author and graduate student at Hawaii, in a statement. “Ironically, these are the countries that are least responsible for climate change in the first place.”

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Of course, the flip side of the possibility that climate models are overestimating global warming is that they could well be underestimating it instead. If the projections made in the Nature paper hold true, many of those of us alive today will experience the climate change tremendously. The hottest year in U.S. history was 2012, featuring brutal droughts and heat waves. By mid-century, we could look back upon that year as pleasant and cool—at least comparatively. A few degrees change can make a tremendous difference.