NASA satellite data show that about a quarter of the world's new greening area from 2000 to 2017 comes from China, with the contribution ranking first in the world. Researchers believe that the reason is China's outstanding performance in afforestation and intensive agriculture.
In a paper published in the new issue of the British Journal Nature Sustainable Development, researchers from NASA and other institutions said that they analyzed the observation data of the satellites Tra and Aka and found that the global greening area increased by 5% between 2000 and 2017. China and India contributed about one-third of the global greening increment when the land vegetation area only accounted for 9% of the global total.
Among them, China's contribution accounts for about a quarter of the global green increment. The analysis shows that 42% of China's contribution comes from afforestation, 32% from intensive agriculture, and 82% from intensive agriculture in India. Intensive agriculture enables people to grow more crops on the same area of land.
Rama Nemani of NASA Ames Research Center, one of the authors of the paper, said that after observing the increase in the greening area of the earth, researchers initially thought that the main reason was that environmental factors such as climate warming promoted plant growth, but the analysis of satellite data showed that human greening activities also contributed greatly.
Researchers say that China and India are both populous countries, and there are often concerns about land degradation caused by overuse by populous countries, so the findings are surprising. The analysis shows that the land area used for crop cultivation in China and India has not changed significantly in the past decade, but the greening area and food production in both countries have increased significantly.
Although global greening has increased in recent years, researchers caution against being overly optimistic. On the one hand, the change of greening area in the future is also affected by many factors, such as the depletion of groundwater in some places, which may lead to the reduction of greening area; on the other hand, there are still many places where the tropical rainforest is disappearing, and its ecological impact can hardly be compensated by the increase of greening area in other places. Therefore, people still need to pay attention to protecting the environment.