Greening in China and India reshapes climate both locally and far away

China and India are getting greener during recent decade. Together, the two regions account for nearly one-third of the global increase in leaf area. The two regions lie in different climate regimes. Does greening in these two regions produce similar climate effects? And how different are the simultaneous greening produce compared to their individual greening?

A new study published in Advances in Atmospheric Sciences tried to explore these problems using a land-atmosphere climate model. Their results show that greening in China generally cools the local climate with more rainfall over southern and northeastern China, while greening in India tends to produce warming and less rainfall. The Co-occurring greening in China and India yields uniform climate feedbacks across over half global lands, producing cooler and wetter southern China, cooler western Eurasia, and warmer northern North America.

“Greening does not necessarily produce the same climate response everywhere,” said corresponding author Miao Yu, Professor at Nanjing University of Information Science and Technology. “What matters is not only how much water vegetation releases into the atmosphere, but also where that moisture goes and how it changes clouds and surface heating.”

In China, increased vegetation enhances the transfer of water from the land to the atmosphere. Over southern China, more moisture favors cloud formation. The additional clouds reduce the energy reaching the surface, helping cool the air while also supporting more rainfall.

India follows a different pathway. Although vegetation also releases more moisture there, much of it is transported away instead of forming clouds and rain locally. With fewer clouds and more energy reaching the surface, temperatures rise and rainfall decreases.

The researchers found an even more intriguing response when China and India green simultaneously. Southern China becomes more consistently cooler and wetter, while western Eurasia experiences cooling. These effects arise because vegetation changes alter not only local energy and moisture, but also large-scale atmospheric circulation.

Changes in atmospheric heating can reshape winds high above the surface and influence large atmospheric waves that carry climate signals across continents. In the simulations, simultaneous greening changed the East Asian and Central Asian jet streams and favored the movement of colder polar air toward Eurasia.

“The atmosphere connects regions that may appear far apart,” said lead author Min Xiao, a graduate student working with Prof. Miao Yu at Nanjing University of Information Science and Technology. “Vegetation change in one region can reinforce, weaken, or even reverse the climate effects caused by vegetation change elsewhere.”This means that simultaneous greening is not simply the sum of two independent effects. Moisture transport, cloud feedbacks and atmospheric circulation can interact in nonlinear ways, producing climate responses that differ from those expected from either region alone.

The findings highlight a broader lesson for large-scale ecological restoration and land management. Greening can influence more than carbon storage or the climate directly above the restored land. Its effects can travel through the atmosphere and reshape climate far beyond the original greening region. The authors note that the study relies mainly on one land-atmosphere model, so further studies using multiple models will be important for testing the remote climate responses.