Key questions scientists will need to address are how global reforestation might affect Earth’s surface albedo (reflectivity) and evapotranspiration. In the near term and locally, says Saatchi, forest restoration may actually have a warming effect. As the trees mature, the new forest canopy cover would presumably make Earth’s surface albedo darker, particularly in the Northern Hemisphere during periods of snow cover, causing it to absorb more heat. Increasing forest cover, particularly in the tropics, will increase evapotranspiration, causing a cooling effect. With Earth already warming significantly due to greenhouse gas emissions, will forest reforestation on a global scale have a net warming or cooling effect on our planet, and will the benefits of reforested areas absorbing more carbon outweigh their increased heat absorption?