New Delhi: Another worrying trend has emerged for the Earth, according to which the Amazon rainforest's ability to absorb the greenhouse gas methane may decrease by up to 70 percent due to extreme temperatures and humidity caused by climate change. This has been revealed in a study.

Researchers said that excessive rainfall and droughts predicted for the South American Amazon due to a warmer climate could affect its greenhouse gas emissions. It is worth noting that the Amazon rainforest, called the lungs of the earth, is mainly located in Brazil. However, some parts of it are also spread in Peru, Colombia, Ecuador and other places.

20 percent of the emissions are methane

It is known as an important 'greenhouse gas sink', which absorbs these gases from the air. Their absorption is extremely necessary to keep the atmosphere clean. However, researchers from the University of Sao Paulo in Brazil said that 20 percent of the Amazon region, which remains flooded for about half the year, releases methane, which reduces its ability to absorb other greenhouse gases. Their study has been published in the journal Environmental Microbiome.

Previous studies have shown that flooded areas of the Amazon contribute to about 30 percent of methane emissions globally. "It has already been shown that factors such as air temperature and seasonal flooding can influence the composition of microbial communities that influence methane fluxes in these environments, but what should we expect in the context of climate change and predicted extreme weather?" said lead author Julia Gontizo, a postdoctoral researcher at the University of California, Davis, US.

This is how the study was done

For this study, the researchers took soil samples from two flooded areas of the Amazon and from tall forests known to absorb methane. These samples were exposed to extreme temperatures – 27 degrees Celsius and 30 degrees Celsius. They found that methane absorption decreased by 70 percent in hot and dry conditions in the soil samples from the tall forest, while methane production increased in heavy rainfall, as the soil was not used to dealing with extreme humidity.

"Within this (elevated) forest soil, an average 70 percent decrease in (methane) consumption capacity was observed with temperature increase during dry conditions. This means that the floodplain microbiome may be able to adapt to climate change, but the upland forest microbiome is vulnerable to its effects, which could lead to a shift in the balance of greenhouse gas emissions in the Amazon in the future," the authors wrote.