Scientists from Princeton University, based on satellite images, assessed the positive effect of forests on the cooling of the Earth and found that previous estimates of this indicator were underestimated.
The researchers used satellite imagery to understand how cloud cover affects different types of vegetation. The authors found that clouds are more likely to form over wooded areas and thereby cool the Earth’s atmosphere more.
Planting trees and reforestation is the easiest way to combat climate change, but the effects of trees on atmospheric temperature are more complex than meets the eye.
One of the scientists’ questions is whether reforestation in mid-latitude places like North America or Europe can really make the planet hotter. Forests absorb large amounts of solar radiation as a result of their low albedo, a measure of a surface’s ability to reflect sunlight. In the tropics, low albedo is offset by higher carbon dioxide uptake and dense year-round vegetation. But in temperate climates, the problem is that the heat absorbed by the sun can counteract any cooling effect that forests might provide.
But a new study by researchers at Princeton University has shown that these fears may be due to the fact that one important factor has been left out – clouds.
Considering that clouds tend to form more often over wooded areas, planting trees in large areas is beneficial and should be done for climatic purposes.
Amilkare Porporato, Princeton Professor of Environmental Protection
In addition to blocking light directly, clouds have a high albedo similar to ice and snow. However, clouds are difficult to study, and therefore their impact is often excluded from many studies of climate change.
The team found that for mid-latitude regions, the cooling effect of clouds, along with carbon sequestration, outweighed solar radiation.