A worker plants a sapling of Mongolian Scots pine

A worker in China plants a pine sapling as part of the country’s ambitious plan to reforest its landscape. Credit: Xinhua/ZUMA Wire

Environmental sciences

Earth’s green patches become greener — and China is leading the way

Tree-planting campaigns and crop expansion in the planet’s most populous nation are driving an expansion in leaf coverage.

Despite the loss of vast tracts of tropical forest, Earth has grown markedly greener since the turn of the millennium — with the most profound changes seen in China and India.

Chi Chen at Boston University in Massachusetts and his colleagues used satellite data to track the total surface area covered by leaves in the planet’s vegetated zones. They found that between 2000 and 2017, this area gained a number of hectares roughly equal in size to the Amazon rainforest. One-third of vegetated lands are greening, whereas only 5% are getting browner.

Greening is most pronounced in China, thanks mainly to forest conservation and tree planting, as well as intense crop cultivation. In India, irrigation and fertilizer use seem to be driving the greening of cropland vegetation.

Globally, rising carbon dioxide concentrations also seem to be playing a part, but that part is probably smaller than previously assumed, the scientists say. They add that although greening farmlands are becoming more productive, the gains do not make up for environmental damage resulting from tropical deforestation.