By prioritizing targeted increases in rainfall, forestation programs may not only mitigate global climate change itself but also reduce its concrete negative effects such as droughts. That is the conclusion of a new study by a team of researchers from the Copernicus institute of sustainable development, Wetsus, the Potsdam Institute for Climate Impact Research (PIK) and the Stockholm Resilience centre.
“As climate change is creating or intensifying droughts across the globe, targeted ecosystem restoration is an effective countermeasure through planting trees that generate their own rainfall” says Nico Wunderling, scientist at PIK and one of the authors of the study published in the journal Global Change Biology. As such, forestation promotes rainfall by enhancing evapotranspiration which in turn increases the moisture in the atmosphere. If done wisely, forestation could be used to reduce climate change-induced drying over downwind regions that are in need of water, the authors find.
Researcher from University Utrecht and Wetsus – Jolanda Theeuwen adds: “Besides that, trees promote carbon capture for climate change mitigation. The regional climate can benefit from forestation through an increase in freshwater availability. And targeted rainfall enhancement through planting trees can be used to promote moisture recycling over land.”
Focus areas for forestation with targeted rainfall enhancement could be the southern Amazon, Mexico, eastern China and Mediterranean Europe – as these regions are projected to become drier due to global climate change.
Regardless of their positive hydrological effects, massive increases in forest growth should not come at the expense of native well-functioning ecosystems such as natural grasslands nor should they endanger local water resources, the authors of the study stress.
Staal, A., Theeuwen, J. J. E., Wang-Erlandsson, L., Wunderling, N., & Dekker, S. C. (2024). Targeted rainfall enhancement as an objective of forestation. Global Change Biology, 30(1). https://doi.org/10.1111/gcb.17096