Widespread 20th-century reforestation in the eastern United States helped counter rising temperatures due to climate change, according to new research. The authors highlight the potential of forests as regional climate adaptation tools, which are needed along with a decrease in carbon emissions. ….Before European colonization, the eastern United States was almost entirely covered in temperate forests. From the late 18th to early 20th centuries, timber harvests and clearing for agriculture led to forest losses exceeding 90% in some areas. …About 15 million hectares of forest have since grown sin these areas. …The researchers found that forests in the eastern U.S. today cool the land’s surface by 1 to 2 degrees Celsius (1.8 to 3.6 degrees Fahrenheit) annually. The strongest cooling effect occurs at midday in the summer, when trees lower temperatures by 2 to 5 degrees Celsius (3.6 to 9 degrees Fahrenheit)—providing relief when it’s needed most.