Britannica Sources used in this answer

How can clearing forests for farmland change albedo and local climate?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Grinnell Glacier shrinkage — Global warming A series of photographs of the Grinnell Glacier taken from the summit of Mount Gould in Glacier National Park, Montana, in (from left) 1938, 1981, 1998, and 2006. In 1938 the Grinnell Glacier filled the entire area at the bottom of the image. By 2006 it had largely disappeared from this view.

Clearing forests for farmland significantly alters the local climate by changing the Earth’s albedo—the surface's ability to reflect solar radiation—and disrupting heat exchange processes.12

Albedo Changes

Forests typically have a low albedo (0.08 to 0.15), meaning they absorb more solar energy. When replaced by cropland or pasture, the regional albedo often increases, as agricultural land is generally more reflective than dense forest. This increased reflectivity leads to greater reflection of incoming solar radiation, which can exert a cooling effect on the surface. However, this change also creates a "patchy" landscape that alters the distribution of sensible and latent heat fluxes, which can influence the timing, intensity, and frequency of local weather events, such as summer thunderstorms.21

Local Climate Impacts

Beyond albedo, deforestation disrupts evapotranspiration, the process by which plants release water vapor into the atmosphere. Forests facilitate this cooling process; removing them reduces the release of latent heat, which can lead to surface warming. In many regions, this reduction in moisture recycling leads to decreased rainfall and an increased risk of drought. The dominance of either the cooling albedo effect or the warming evapotranspiration effect depends on the specific region and season.123