NASA: The Earth Is Greener Than 2 Decades Ago

In surprising news, NASA has happily reported that the world is greener than it was 20 years ago. There are officially more trees on earth now than two decades ago – and it’s thanks to India and China.  The two heavily populated countries have spent recent years energetically working on tree planting programs with great success. In 2017, India broke the world record for the most number of trees planted in a set period of time. 

India and China lead the way

An astounding 66 million saplings were planted in just 12 hours. The spread of green was first noticed by NASA scientists in the mid-90s but at that time, there wasn’t enough data to say if it was caused by human activity. However, this has now been confirmed thanks to the continual work of a special scientific instrument onboard two satellites.  Called the Moderate Resolution Imaging Spectroradiometer, or MODIS, the instrument provides high-level data on Earth vegetation. MODIS has been collecting info for the last two decades and can provide detail down to the level of 500 meters.

The Earth Is Greener Than Two Decades Ago Says NASA
Source: NASA

High population countries make bigger effort

Collating the data it can be seen that there is an increase in leaf area on plants and trees equivalent to the area covered by all the Amazon rainforests. NASA says there are more than two million square miles of extra green leaf area per year compared to data from the early 2000s.  That’s a significant 5% increase. “China and India account for one-third of the greening, but contain only 9% of the planet’s land area covered in vegetation – a surprising finding, considering the general notion of land degradation in populous countries from overexploitation,” said Chi Chen of the Department of Earth and Environment at Boston University and lead author of the study.  The MODIS has captured as many as four shots of every place on Earth, every day for the last 20 years.  “This long-term data lets us dig deeper,” said Rama Nemani, a research scientist at NASA’s Ames Research Center and a co-author of the new work.  “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, 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.”  China and India have contributed to the greening in different ways. China has made a concerted effort to repair and preserve existing forests as well as introduce new forested areas in an attempt to prevent soil erosion, air pollution and climate change. 

Agricultural intensity may be short-lived

India’s green has come primarily from an increase in intensive agricultural practices, necessary to keep the food supply up to its ever-expanding population. New techniques mean there are more crops grown more intensively throughout the year. This may change though if climate change affects the availability of groundwater used for this intensive agriculture.  “But, now that we know direct human influence is a key driver of the greening Earth, we need to factor this into our climate models,” Nemani said.  “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.”

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