Plants are a highly effective carbon sink. Globally, forests absorb about 7.6 billion metric tons of carbon dioxide per year, about 1.5 times the annual emissions of the United States.
Since the 1980s, climate warming, prompted by rising levels of carbon dioxide and other greenhouse gasses in the atmosphere, has caused an increase in plant productivity in the Northern Hemisphere outside the tropics.
But new research published May 30 in Nature Climate Change estimates that summer warming in this region will begin to have the opposite effect within the next half-century, causing photosynthesis—or plant productivity—to decline. The global land carbon sink will likely take a hit as a result, the authors write.
The researchers found that generally in the Northern Hemisphere, warmer temperatures will mean less summer plant productivity by 2070 for most regions below 60° N—the approximate latitude of Oslo, Norway, and Anchorage, Alaska. Plant productivity in Arctic areas, ...
