EARTH.COM - Planting more trees cools the planet and can help reduce fires, but the biggest climate returns per tree come from the tropics. That is the core message of new research, which shows that where we plant matters almost as much as how much we plant.
The study, led by the University of California, Riverside (UCR), found that forests help in two ways: they pull carbon dioxide from the air; and they change local physics at the surface and in the lower atmosphere.
Those physical effects are not uniform. In warm, wet regions they cool, while in some cooler, higher-latitude places they can nudge temperatures up.
Trees in the tropics work harder
“Our study found more cooling from planting in warm, wet regions, where trees grow year-round,” said study first author and UCR graduate student James Gomez. “Tropical trees not only pull carbon dioxide from the air, they also cool while releasing water vapor.”