Considered to be our planet's biggest carbon sink for ages, the Amazon rainforest's huge ecosystem catches billions of tons of carbon dioxide (CO2) from the atmosphere and converts it into oxygen. However, with the increasing use of fossil fuels throughout the years, the tropical rainforest is under immense pressure and its current situation might be much worse than one would think.
A first-of-its-kind study by more than 30 scientists, which is the most thorough evaluation of the Amazon Basin's impact on global climate to date, shows that the Amazon is most likely now a new contributor to the warming of the Earth, suggesting the Amazon is warming Earth's atmosphere rather than cooling it as it used to do. According to scientists, this worrisome effect is "only expected to grow."
With fires, drought, and land clearing, the tropical forest is releasing more heat-trapping gases than it stores in plants and soil. The research, supported by the National Geographic Society, on the sobering findings was published in Frontiers in Forests and Global Change.
Amazon's capacity to offset emissions
"Cutting the forest is interfering with its carbon uptake; that’s a problem," said lead author Kristofer Covey, a professor of environmental studies at New York’s Skidmore College, to National Geographic. "But when you start to look at these other factors alongside CO2, it gets really hard to see how the net effect isn’t that the Amazon as a whole is really warming global climate."
For example, emissions of the greenhouse gas nitrous oxide can increase with drying wetlands and soil compaction from logging. Also, land-clearing fires set out by farmers release black carbon which consists of pure carbon in several linked forms. Consequently, deforestation alters rainfall patterns, and flooding, cattle ranching, and dam-building exercises release methane. Roughly 3.5 percent of all methane released globally comes naturally from the Amazon’s trees, National Geographic explains.
This wasn't a problem before since the Amazon’s capacity of taking up carbon could do much more than now to offset its methane emissions. With humans being the culprit of the forest's diminished capacity, all of these sources combined appear to swamp its cooling effect.
"We have this system that we have relied on to counter our mistakes, and we have really exceeded the capacity of that system to provide reliable service," said co-author Fiona Soper, an assistant professor at McGill University.
It isn't all hopeless though, per the researchers. One logical thing would be, both for the Amazon's and the planet's wellbeing, to halt global emissions from coal, oil, natural gas. This would help restore the balance. Also, Amazon deforestation should be controlled along with more efforts to replant trees, and dam building should be reduced. Continuing to clear land at the current rates won't do us, nor the planet, any good.