Satellite data analysis of green spaces in almost 300 cities shows that trees are one of the best safeguards against rising temperatures resulting from global warming. The study concludes green spaces with plenty of tree-covered areas have a bigger cooling effect than green spaces with few or no trees. Fulton Schools Associate Professor Zhihua Wang, an environmental engineer and co-director of climate systems research for the National Center of Excellence on SMART Innovations, says the findings provide a practical guide for cities to establish effective urban heat mitigation strategies. The cooling effect happens primarily through shading and transpiration, when water inside trees is released as water vapor through their leaves, which helps lower the surrounding temperature.