China planted billions of trees … and accidentally moved its rain
Jenn Jordan, The Weather Channel, 1/27/26
China’s massive tree-planting push has long been hailed as a climate win. But new research shows the country’s ambitious effort to slow land degradation, and fight climate change, has also reshaped its water supply in surprising, and sometimes uneven, ways.
When China dramatically expanded forests and restored grasslands under its “Great Green Wall” initiative, it didn’t just change what the land looked like, it changed how water moves between the ground and the atmosphere.
One key factor is evapotranspiration, a term you should become familiar with says meteorologist Jennifer Gray.
“This is basically where moisture is released into the atmosphere by tiny holes in leaves. Think of water being pulled up by the roots and then released through the leaves, almost like sweat,” she said. “It’s basically like Earth’s natural pumps.”
Those “pumps” multiplied as China planted billions more trees, a decades-long effort to stop desertification across its arid north.
“They’ve actually increased forest cover by 15% over the last five decades,” Gray explained. “If you think about the amount of moisture that those forests are releasing into the atmosphere, it is just an incredible amount.”
According to a new study published in Earth’s Future, between 2001 and 2020, freshwater availability dropped in China’s eastern monsoon region and northwestern arid region, but increased over the Tibetan Plateau.
That uneven outcome highlights how powerful, and unpredictable, trees can be. “Trees can grab water from much deeper into the earth, and so it’s going to release all of that moisture into the atmosphere, even in places where it is not raining,” Gray said.
What surprised researchers most wasn’t that water moved, it was where it ended up. “What’s so remarkable about this study is the scale of it and the unintended consequences,” Gray said. “The rain was distributed in completely different ways and in completely different places.”
The reason lies in the atmosphere itself.
“The atmosphere and the winds can actually transport moisture more than 4,000 miles,” Gray explained. “So if you plant trees in one area that doesn’t mean that that’s exactly where it’s going to rain.”
As a result, some regions where trees were planted became drier, while others far away grew wetter. “It really created an uneven distribution of water,” Gray said.
Those shifts matter most at the local level. “While re-greening an area has tremendous amounts of benefits for the environment and the entire planet, it’s the local people that actually are going to see the consequences, whether that’s pro or con,” Gray said.
Farmers, small communities and city infrastructure can all be affected by unexpected changes in rainfall, whether it’s drought in some places or flooding in others.
That’s why Gray says climate solutions can’t stop at planting trees. “It puts an exclamation mark on the importance of having city planners get involved, water management folks get involved as well,” she said, “so this can be carefully thought out as to where the water is going to be distributed once you do something like this.”
In the end, the research offers both hope and a warning. “This study is both encouraging and cautionary,” Gray said.
“On one hand, it shows the impact that we can have when we’re trying to benefit the climate and the planet. On the other hand, it also shows how this isn’t always evenly distributed.”
The takeaway, she says, is simple but essential: “The key lesson is balance, so the benefits aren’t gained in one area at the expense of another.”
Weather.com lead editor Jenn Jordan explores how weather and climate weave through our daily lives, shape our routines and leave lasting impacts on our communities.