Scientists estimate that there are about 3 trillion trees on the earth. A huge number but probably half as many as there were before people entered the picture. And we’re losing about 10 billion trees a year to toilet paper, timber, farmland expansion, and other human activity. Trees play a crucial role in taking carbon dioxide out of the atmosphere and storing it away. For this reason, trees have become an integral part of the effort to mitigate climate change.
There are major initiatives underway around the world to plant more trees. Part of this is driven by the increasing use of carbon credits by companies trying to offset their carbon emissions. These credits are earned by either planting new trees or paying farmers or other landowners not to cut down existing trees. But how many trees are actually planted and how many survive over time?
Whether these efforts are really resulting in more trees and more carbon storage is not easy to determine. Current international inventories of global tree-sequestered carbon are subject to great uncertainty.
Researchers from the University of Copenhagen and NASA have developed a method for mapping large numbers of trees and determining their carbon content. Using artificial intelligence techniques to analyze ultra-high-resolution satellite images, they can count trees, determine their individual species, and measure their carbon content.
A study of images from Africa’s Sahel region found that it is home to nearly 10 billion trees that are currently storing 840 million tons of carbon.
Now that the groundwork for this new methodology is complete, it is ready to be deployed by public agencies, NGOs, and other interested in monitoring the numbers of trees and their carbon content.
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The counting of nine billion trees could help manage climate credits and nature restoration
Photo, posted October 27, 2018, courtesy of Ian Dick via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio
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