The world is literally a greener place than it was 20 years ago, and the data from NASA satellites has revealed a counterintuitive source for much of this new foliage: China and India.
This surprising new study shows that the two emerging countries with the world’s biggest populations are leading the improvement in greening on land. The effect stems mainly from ambitious tree planting programs in China and intensive agriculture in both countries. In 2017 alone, India broke its own world record for the most trees planted after volunteers gathered to plant 66 million saplings in just 12 hours.
The greening phenomenon was first detected by researchers using satellite data in the mid-1990s, but they did not know whether human activity was one of its chief, direct causes.
Findings of the study
1. The study published in the journal ‘Nature Sustainability’ said that recent satellite data reveal a greening pattern that is strikingly prominent in China and India and overlaps with croplands worldwide.
2. China alone accounts for 25 per cent of the global net increase in leaf area with only 6.6 per cent of global vegetated area.
3. The greening in China is from forests (42 per cent) and croplands (32 per cent), but in India, it is mostly from croplands (82 per cent) with minor contribution from forests (4.4 per cent).
4. Overall, one-third of Earth’s vegetated lands are greening, while 5 per cent are growing browner.
“China and India account for one-third of the greening, but contain only 9 per cent of the planet’s land area covered in vegetation,” said lead author Chi Chen of Boston University.”
“That is a surprising finding, considering the general notion of land degradation in populous countries from overexploitation,” added Chen.
How the study was made possible ?
When the greening of the Earth was first observed, we thought it was due to a warmer, wetter climate and fertilization from the added carbon dioxide in the atmosphere, said Rama Nemani, a research scientist at NASA’s Ames Research Center and a co-author of the study. This study was made possible thanks to a two-decade-long data record from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA’s Terra and Aqua satellites. Now with the MODIS data, we see that humans are also contributing, she said.