From UPSC perspective, the following things are important :
Prelims level : MODIS
Mains level : Afforestation in India
- A new satellite-based study shows that China and India are leading the increase in “greening efforts” across the world.
The findings of MODIS
- The research team set out to track the total amount of Earth’s land area covered by vegetation and how it changed over time (2000-17).
- Through NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) data, the team found that the global green leaf area has increased by 5% since the early 2000s.
- This translates to a net increase in leaf area of 2.3% per decade, which is equivalent to adding 5.4 × 106 sq km new leaf area over the 18-year period of the record (2000 to 2017).
- This is equivalent to the area of the Amazon.
- China alone accounts for 25% of the global net increase in leaf area. India has contributed a further 6.8%.
- The greening in China is from forests (42%) and croplands (32%) but in India is mostly from croplands (82%) with minor contribution from forests (4.4%).
What is MODIS?
- MODIS is a key instrument aboard the Terra and Aqua satellites of NASA.
- With its low spatial resolution but high temporal resolution, MODIS data is useful to track changes in the landscape over time
- MODIS is playing a vital role in the development of validated, global, interactive Earth system models able to predict global change accurately enough to assist policy makers in making sound decisions concerning the protection of our environment.
- Its data helps improve our understanding of global dynamics and processes occurring on the land, in the oceans, and in the lower atmosphere.
Highlights of the study
- The study was entirely based on satellite data with access to forest inventory data.
- There were no physical checks carried out in either China or India to assess what kind of trees or vegetation was preferred.
- The quality of trees is good in view of leaf abundance.
- Satellite data do not have the ability to accurately recognise the species at the global scale.
- When the greening of the Earth was first observed, it was thought due to a warmer, wetter climate and fertilization from the added carbon dioxide in the atmosphere, leading to more leaf growth in northern forests, for instance.
- Now, with the MODIS data that lets us understand the phenomenon at really small scales, we see that humans are also contributing.
- With only 2.7% of the global vegetated area, India accounts for 6.8% of the global net increase in leaf area.
- It is as expected because most of the land cover type in India is cropland (2.11×106 sq km).
- Total cereal production in India increased by 26% during the same period.
- There are only a few forests in India, and that is why their contribution is small.
- Data show that since Independence, a fifth of India’s land has consistently been under forests.
- The Forest Survey of India’s State of Forest Report 2017 had recorded that forest cover had increased by 6,600 sq km or 0.21% since 2015.