The scenarios of the UN’s Intergovernmental Panel on Climate Change propose that limiting climate change to 1.5°C and 2°C will require up to an extra billion hectares of forest by 2050, even while radically reducing emissions from energy, transport and so on.
The map above, part of landmark research+ by the Crowther Lab, published in the journal Science, shows where these trees could be restored and how much carbon they can capture. It confirms that restoring the Earth’s forests is the world’s most effective solution to climate change available today and has the potential to capture two thirds of man-made carbon emissions.
It finds that there is potential to increase the world’s forest land by a third without affecting existing cities or agriculture, regrowing trees over an area the size of the United States or larger than Brazil. Once mature, these new forests could store 205 billion tonnes of carbon, about two thirds of the 300 billion tonnes of extra carbon that exists in atmosphere as a result of human activity since the Industrial Revolution.
The study warns that the need for action is urgent: the climate is already changing and every year reduces the area of land that can support new forests.
The Crowther Lab finds that forests could be regrown on 1.7-1.8 billion hectares of land in areas with low human activity that are not currently used as urban or agricultural land, adding 0.9 billion hectares of tree canopy. Importantly, these are not areas that would naturally be grasslands or wetlands, but degraded ecosystems that would naturally support some level of tree cover.