China and India are responsible for one-third of the world’s new plants and trees during the past two decades, according to a recent study using NASA satellite data.

Though the two rapidly growing countries only contain 9 percent of Earth’s land area covered in vegetation, they are leading the way in making the planet greener thanks to intensive agriculture and tree planting programs.

“This is a surprising finding, considering the general notion of land degradation in populous countries from overexploitation,” said Chi Chen, a doctoral student at Boston University in a statement released by NASA and who led the study that was published in Nature Sustainability.

The authors stressed that this growth still doesn’t offset damage from the loss of natural vegetation in tropical regions, such as the Amazon rainforest.

China ranked No. 20 in U.S. News’ 2019 Best Countries for Green Living ranking, a perception-based survey that asks respondents how much countries care about the environment, as well as how innovative and health conscious they believe nations are. India is No. 40 in the ranking.

The researchers noted that climate change and CO2 fertilization, both natural processes, are the top drivers of the world’s increased greening. But the data revealed that human activity also plays a major role in expanding the world’s vegetation.

China accounted for one-fourth of the globe’s net increase in leaf vegetation between 2000 and 2017, with forest expansion and conservation programs accounting for 42 percent of that growth, according to the study. Another 32 percent of the growth was a result of cultivated farmlands.

In India, agricultural activity played a larger role, accounting for more than 80 percent of the country’s new green space, while forests were only responsible for 4 percent of the expansion.

The researchers also said that the study’s findings are important because they indicate that human land-use practices play a much larger role than was once thought.

Rama Nemani, a research scientist at NASA’s Ames Research Center in California, said in a press release that the findings will help researchers develop future climate models.

“This will help scientists make better predictions about the behavior of different Earth systems, which will help countries make better decisions about how and when to take action,” Nemani said.