Tree planting is a popular strategy for reducing carbon in the atmosphere to help combat global warming. But is it being thought through sufficiently? I think not. In recent years, the neighborly act of planting a tree in the backyard has morphed into major geoengineering projects marketed as key interventions for managing global carbon. Important examples are the Bonn Challenge, started in 2011, which set out to plant 3.5 million square kilometres (1.4 million square miles) of trees by 2030, and the United Nations’ Billion Tree Campaign. Africa has been targeted by the Bonn Challenge as a key area for “forest restoration.” It has vast areas of grasslands and savannas where the climate could grow forests. AFR100, an offshoot of the Bonn Challenge, plans to plant at least 1 million square kilometers (400,000 square miles) of trees in Africa by 2030. Already, 28 countries have signed up, each required to pledge its own target area, with some countries setting aside as much as one-third to three-quarters of their total land area for trees. It is surely time to pause and ask questions of tree planting and its consequences. The assumption underlying all this is that Africa’s grassy ecosystems are degraded and deforested landscapes “that deliver limited benefits to both humans and nature.” But we know that African savannas are ancient — much older than the human societies that cut down forests. They support the continent’s spectacular grass-dependent wildlife along with thousands of other plant and animal species that prefer sunlight. And they support human societies. The tree-planting plans ignore the fate of the savanna’s current inhabitants. And they bring the risk of raging megafires as well as adversely altering stream flows. By fixing set targets by a set period, they are forcing rapid land use change on a massive scale. It is surely time to pause and ask questions of tree planting and its consequences. Climate Benefits One motivation for global tree-planting plans is to reduce atmospheric carbon by storing emissions from industrial nations in the ecosystems of the less industrialized nations. But how effective will it be? Current emissions … Continue reading Opinion: Current proposals to plant trees to fight climate change are badly misguided