Urban trees play a role in reducing atmospheric carbon dioxide directly by storing carbon in the trunk, branches, roots, and leaves until these tree parts die and decay. Trees also reduce energy consumption by shading the sun, cooling the air, and directing wind movements to help us moderate temperatures around our homes and cities. Moderating temperatures with trees decreases the amount of energy needed to heat or cool our surroundings, which reduces the amount of carbon dioxide emissions from nearby power plants running on coal or natural gas.