As a growing number of world governments declare climate emergencies and cities around the world experience record-smashing deadly heatwaves, more thought is being given to concrete actions that will limit global warming and avert the transformation of our planet into a “hothouse” state. In addition to reducing greenhouse gas emissions, it will likely be necessary to invest in carbon capture – reducing the amount of carbon dioxide in the atmosphere by storing the carbon in other forms. Photosynthetic organisms naturally convert atmospheric carbon dioxide into biomass as they grow, so one straightforward strategy is to increase forest cover.

A recent study published in Science analyzed satellite photographs of the Earth and determined that our planet could theoretically support just under a billion new hectares of forest cover without impinging on existing urban and agricultural land, potentially enough to allow us to meet climate goals. However, this estimate assumes current environmental conditions, and the actual potential forest cover could be much lower due to climate change itself. 

While a global reforestation effort would likely require international collaboration, over half of the estimated potential forest is in one of six countries: Russia, the United States, Canada, Australia, Brazil, or China. Tree planting is considered the cheapest and simplest solution to climate change, but it will certainly have to be mixed with emission reduction and other carbon capture strategies to represent a clear path forward.