UCLA researcher Edith de Guzman highlights how trees keep cities cool among instances of extreme heat in a new video for ABC7 News. Research shows that tree canopies can reduce ground temperatures by 11 to 19 degrees compared to ground with no tree cover. “We’re entering into unprecedented extremes, longer heat waves, hotter heatwaves, more frequent heatwaves,” de Guzman said. “Trees are not just decorative but essential for keeping us cool.”