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Forests cover a third of the earth’s land surface and are home to 80% of terrestrial species. By storing carbon, they contribute 30% of the effort needed to limit global warming to 2°C by the next century, estimates Global Forest Watch.
But for that, it is still necessary that, by then, the forests stop being razed. How ? This non-governmental organization (NGO) has found part of the solution to this problem by creating a digital tool capable of monitoring from space the state of health of forests located in the most remote corners of the planet.
Satellites and guardian angels
How many fires consume the Amazon rainforest? Are the last primary forests of Quebec threatened? What is the extent of deforestation for 20 years in Indonesia?
All this can now be known almost in real time thanks to the software developed for Global Forest Watch, underlines Mikaela Weisse, vice-president of this organization which has become the watchdog of the world’s forests. “It’s hard to manage what you can’t measure,” she says. In the mid-1990s, it was difficult, we were still working with printed cards. But since 2014, we can say that Global Forest Watch 2.0 was born! »
The advent of cloud computing and algorithms capable of analyzing the thousands of NASA and European Space Agency satellite photos captured over decades has enabled the creation of an interactive platform capable of to identify since 2001 the changes that have occurred in the global forest cover and the cause of these upheavals.
“We can see what is happening in the canopy down to a scale of a few hundred meters, find the cause of deforestation and even measure the impact of these changes on a country’s carbon emissions”, explains the GFW spokesperson.
An example ? GFW data shows that in 2021, 3.75 million hectares of primary forest — 10 football pitches per minute — were razed in the tropics. A crucial carbon storage loss that resulted in the emission of 2.5 gigatonnes of CO2, equivalent to the annual fossil fuel emissions of a country like India, according to GFW.
The organization’s data also reveal that Canada, which is home to no less than 10% of the world’s forest cover (!), has lost 11% of its forest cover in 20 years, or 46 million hectares. Same picture for Quebec (10%).
Canada thus ranks 3rd in the world, just after Brazil and Russia, in terms of lost forest cover. Over the past 20 years, however, 57% of the destruction of Canadian forests has been due to forest fires, and not to the conversion of forested land for other purposes.
From satellites to the jungle
Deep in the Peruvian Amazon, an indigenous community can now see a GFW-provided cell phone flashing an alert signaling an intrusion into the surrounding forest. Pink pixels indicate the exact location where deforestation has taken place. Community patrollers equipped with GPS are dispatched to the scene. They note and photograph the truncated trees and the thinning perpetrated in the forest. Legal proceedings may be undertaken to put an end to these illegal cuts.
More than a source of data on forests, the organization helps communities protect their own territory, explains Ms. Weisse. “The deforestation alert radars (RADD) allow them to act on the spot. »
Technological advances mean that this famous system is now capable of obtaining images up to a resolution of 10 meters, despite the presence of clouds. A major asset for safeguarding rain and tropical forests. “In Peru, researchers have measured that the communities that used this system had halved the loss of forest cover in their territory the first year, and 21% the following year,” she says.
Same picture in Madagascar, where alerts are sent to the Forest Watcher app, adopted by Malagasy protection officers to monitor threatened rainforests. When an alert is triggered, drones are dispatched to survey the damage and collect evidence.
The well is in the tree
While 97% of deforestation is perpetrated in tropical forests, the degradation of boreal forests, due to the poor practices of certain logging companies and forest fires, is also of concern to GFW. Legal logging continues in some intact primary boreal forests, the organization deplores.
However, the fight against climate change must also involve preserving the potential of northern forests to store as much carbon as possible, explains Mikaela Weisser. “We are in the process of developing a tool that will be able to know the height and the volume of trees, to know how quickly the exploited forests are reconstituted and what is the real gain linked to the plantations. »
Because not everything that looks like a tree is necessarily a forest, she explains. “After logging, we don’t talk about deforestation, but the forest cover is degraded. This changes the ability of logged areas to support species and store carbon. It’s a very big challenge ahead of us, but we are convinced that we will get there! »