Planting new forests does not always benefit nature, French scientists have found. Trees grown in Europe after 1750 have actually intensified global warming. The new study is featured in the journal Science.
In 1750-1850, the area of European forests declined sharply - by about 190 thousand square kilometers. However, the industrial revolution stalled this process. Thanks to the transformation of coal, oil and gas into the main sources of energy from 1850 to 2013, the forest area in Europe increased by 386 thousand square kilometers.
In addition, all these territories have ceased to be wild: now foresters regulate up to 85 percent of forests in Europe. Green spaces are scientifically managed. In particular, this means that fast-growing, economically valuable tree species (pine and spruce) are planted there.
However, this policy actually contributes to global warming. First, clearing the forest releases carbon into the atmosphere that was previously stored in foliage, dead trees and soil. Second, the predominance of conifers over broadleaf species significantly affects albedo - the amount of solar radiation that is reflected into space. Pines and spruces absorb more heat than oaks and beech trees.
“Modern forests store less carbon than their 18th century predecessors. The shift towards conifers gave a warming of Europe by almost 0.12 degrees. This increase is roughly equal to six percent of the effect that burning fossil fuels has on global warming,”said lead author Kim Naudts.
Scientists urge not to consider planting new forests as a panacea for climate shifts and to be careful about what tree species are planted by foresters.