Amazon: When the green lungs of the world are no longer green

(Baonghean) - The Amazon rainforest - the green lungs of the world - is sick. This is the worst news for scientists in particular and humanity in general, published in the journal Nature on Thursday.

On Thursday, March 19, the journal Nature published the results of a massive study by 100 researchers spanning more than three decades to track the effects of global warming on the growth of the Amazon rainforest. The study revealed an alarming result: the Amazon rainforest is absorbing less and less CO2.

Although it was expected, the research data once again startled scientists. Accordingly, in the 1990s, the Amazon forest absorbed about 2 billion tons of CO2 from the atmosphere. By 2000, this number had dropped to only 1/3. Currently, the amount of CO2 absorbed by the Amazon each year is only about 1 billion tons. If at this rate, scientists estimate that in more than 2 decades, the effectiveness of the Amazon "carbon swamp" will be about 500 tons per year.

Part of the Amazon rainforest in Peru, bordering Brazil. Photo: AFP

“The first consequence is that CO2 accumulates faster in the atmosphere,” said Jérôme Chave, a biodiversity and evolution researcher and co-author of the study. “This will eventually lead to global degradation,” said Roel Brienen, a researcher at the University of Leeds in the UK. “Many people think that if CO2 levels continue to rise, the Amazon will continue to absorb CO2, but scientific studies have shown otherwise,” he said.

To test their conclusions, researchers conducted experiments at 320 sites, each measuring 1 hectare and spanning 6 million square kilometers in the Amazon basin, beginning in the 1980s. After studying the growth and mortality rates of vegetation, the scientists found that mortality rates in the Amazon region increased by an average of 30 percent.

Damien Bonal, a researcher at the Forest Ecosystems Laboratory (INRA), explained that part of the vegetation mortality in the Amazon was due to two severe droughts in 2005 and 2010. However, Bonal also emphasized that the vegetation mortality had begun before 2005. Although the mechanism of the negative impact of climate change on vegetation is not entirely clear, scientists believe that this is the main reason for the increase in mortality in the Amazon. Some scientists also do not rule out the possibility that nutrient deficiency, flooding or heat shock... also contribute to the above situation.

More alarmingly, the mortality of other major rainforest basins in South Asia and equatorial Africa is similar to the Amazon. Scientists are even more concerned about this than deforestation in these areas. “Severe droughts have also affected this region, but that does not necessarily mean that it will be similar to what is happening in the Amazon,” Bonal warned. He stressed the importance of conducting more research in tropical rainforest areas in South Asia and equatorial Africa before it is too late.

Chu Thanh(According to Le Monde March 19)