Forests are increasing around the world because of rising incomes and an improved sense of national wellbeing say researchers.
The authors refute the idea that increasing levels of CO2 in the atmosphere are the key cause of the spread of trees.
As countries become better off, farmers focus on good quality soils and abandon marginal lands, the authors say.
As a result, trees are able to rapidly reforest these deserted areas.
The study highlights the fact that between 1990 and 2015 forest growing stock increased annually by 1.31% in high income countries and by 0.5% in middle income nations, while falling by 0.72% in 22 low income countries.
Several global climate models have attributed this change to what’s termed CO2 fertilisation – where higher levels of carbon dioxide in the atmosphere boost the growing abilities of plants and trees.
But the authors say that this greening process has been going on since the 1800s in Western Europe when CO2 in the atmosphere was just starting to rise. [Continue reading…]