The Arctic is one of the fastest-warming places on the planet —and scientists still aren’t completely sure why. Melting snow and ice may be speeding up the warming. Changes in atmospheric circulation could be playing a role. Many factors could be influencing the region’s temperatures, which are rising at least twice as fast as the rest of the world. Now, scientists think they may have discovered an additional piece of the puzzle. Plants, it turns out, may have an unexpected influence on global warming.
As carbon dioxide levels rise in the atmosphere, plants become more efficient at carrying out photosynthesis and other basic life functions. And they’re often able to save more water in the process. Water that plants exchange with the air helps cool local temperatures. When they lose less water, their surroundings start to warm up. A study published last month in Nature Communications suggests that this process is helping to warm the Arctic.
The models suggest that rising CO2—the result of human greenhouse gas emissions—is causing plants to lose less water throughout the Northern Hemisphere, including densely vegetated regions in the tropics and the midlatitudes. This process causes temperatures in these places to warm even more than they would from climate change alone. At the same time, large-scale atmospheric circulation patterns help transport heat between the tropics and the Arctic. The study suggests that this extra heat is warming the Arctic at an even faster rate.
Source: Scientific American
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