Beijing, March 8 (Xinhua) -- An article published in the monthly magazine nature climate change on the 7th said that the Amazon rainforest has weakened its self-healing ability in the past 20 years, the ecosystem has been destroyed, and it is accelerating closer to a possible "tipping point". The researchers warn that without effective measures, the world's largest rainforest could degenerate into savannah, with serious consequences for biodiversity and climate change.
Researchers in the United Kingdom, Germany and other countries analyzed the data collected by satellites on the Amazon rainforest in the past 20 years, estimated the biomass, tree moisture content, vegetation cover and other indicators in the rainforest, assessed the health of the rainforest and compared it month by month, and believed that about three-quarters of the Amazon rainforest is showing signs of weakening its self-healing ability at this stage.
An indigenous village in the Amazon rainforest in the State of Roraima, Brazil, taken on June 30, 2020. (Xinhua News Agency, photo by Lucio Tavera)
Reuters quoted Chris Bolton, one of the authors of the article and a researcher at the Institute for Global Systems at the University of Exeter in the United Kingdom, as saying that rainforests' self-healing ability has declined particularly in areas with less precipitation and close to human land such as farmland and cities. Affected by climate change, the dry season in the Amazon Basin has become longer and longer in recent years, and droughts have become more frequent and destructive. As a result, "we expect forests to recover from drought much more slowly than they did 20 years ago," and increasingly arid forests are one of the reasons for "more and more fires getting worse and spreading more widely.".
A man looks at a forest of eucalyptus destroyed by a fire in the Amazon rainforest in Umaita, Brazil, on Aug. 25, 2019. (Xinhua News Agency, photo by Gabriela)
Located in the Amazon Basin of South America, the Amazon Rainforest covers a total area of about 5.5 million square kilometers, accounting for half of the world's total rainforest area and 20% of the world's forest area, making it the world's largest and most speciesed tropical rainforest, known as the "lungs of the earth" and has important carbon sink capacity. According to Timothy Renton, director of the Institute for Global Systems, one of the authors of the article, the Amazon rainforest has absorbed about 90 billion tons less carbon dioxide over the past 20 years.
According to the researchers, in the face of challenges such as climate change, human activities, and fires, if strong measures are not taken, the Amazon rainforest may cross the "tipping point" in the future and gradually degenerate into savannah. However, it is not yet possible to estimate when the "tipping point" will arrive, nor can it estimate how long it may take for the rainforest to degenerate into grasslands.
Nicholas Bols, a researcher at the Potsdam Institute for Climate Impact Research in Germany, who participated in the study, said that while the satellite data collected meant that the Amazon rainforest could be approaching a "tipping point," it also "shows that the tipping point has not yet been crossed, so there is still hope." (Wang Xinfang)