Scientists have long debated the impact on global climate of water evaporated from vegetation. New research from Carnegie’s Global Ecology department concludes that evaporated water helps cool the earth as a whole, not just the local area of evaporation, demonstrating that evaporation of water from trees and lakes could have a cooling effect on the entire atmosphere. These findings, published on 14 September in Environmental Research Letters, have major implications for land-use decision making.
The researchers even thought it was possible that evaporation could have a warming effect on global climate, because water vapour acts as a greenhouse gas in the atmosphere.
Using a climate model, they found that increased evaporation actually had an overall cooling effect on the global climate. Read more… »