Forests affect climate directly.
The earth’s climate is largely controlled by how much of the sun’s light and heat is absorbed and reflected. By absorbing the sun’s heat, trees cool the air.
The interaction of this relationship with an area’s topography, latitude, and altitude, can create microclimates, just as trees create microclimates almost anyplace they are by providing a windbreak and shade. Think about it: on a hot, sunny day, it’s always cooler beneath a shade tree. A city with a robust tree canopy is cooler in the summer than a similar city with fewer trees, which translates into less energy use and lower cooling costs. Also, in using less energy, less air pollution is created.
The most important role that rural trees and forests play is taking carbon dioxide out of the atmosphere. The living tissue of a tree is a storage vault for carbon, which would otherwise contribute to the greenhouse effect and to global climate change. Simply put, more trees can decrease the rate of climate change and help us withstand its effects, potentially resulting in less intense storms, fewer infectious diseases, a more stable water supply, and fewer wildfires.
Trees, however, aren’t immune to the effects of climate warming. Areas once too cold to support trees now can, and as forests migrate north, harmful insects that were once held at bay by winter freezes can wreak havoc on native species. Tropical vines called lianas are now growing faster than the trees they climb, causing trees in the Amazon and other rainforests to die at an alarming rate.
Trees and forests can either be the key to slowing climate change and mitigating its effects, or they can become its victims. It’s up to us.