The tropical forests worldwide are rapidly becoming a carbon source losing their ability to absorb carbon from the atmosphere because of a significant carbon dump; scientists are worrying, according to research published Wednesday.
As per the study, the Amazon could turn into a carbon source in 15 years due to deforestation, wildfires, and the excess greenhouse gasses injected into the atmosphere, as The Guardian reported. The study was published in the journal Nature.
Over the period of 30 years, an international consortium of European and African scientists led by researchers from the University of Leeds studied more than 300,000 trees in the Amazon and the African tropics. The climate models that usually predict that tropical forests will continue serving as carbon sinks for decades found incorrect by the researchers. Instead, according to a press release from the University of Leeds, the decades-span analysis found that the uptake of carbon into the tropical forests worldwide actually peaked in the 1990s.
“Our findings show that back in the 1990s intact tropical forests were absorbing 4.6 billion tons of carbon dioxide every year,” Simon Lewis, professor of Global Change Science at University College London, and Lee White, the government of Gabon’s Minister for Water, Forests, the Sea and Environment, wrote in The Independent. “This has slumped to an estimated 2.5 billion tons each year over the last decade. To put these colossal numbers in context, the decline of 2.1 billion tons each year is equivalent to five times the annual carbon dioxide emissions of the UK. Tropical forests have been helping us, but that help is starting to wane.”
The tropical forests make up around 50% of entire land-based carbon absorption. The continuous increase in human-made emissions year after year is straining already oversaturated tropical forests. The oversaturation has threatened the ability of the forests to provide people with food, medicine, shelter, and water, as ScienceAlert reported.
“The cause of this is climate change impacts – in terms of heat stress and droughts – on these remaining intact forests,” Lewis said, as Reuters reported. “Humanity has been really lucky so far in that these forests have been mopping up our pollution, and they might not keep doing that for that much longer.”
Although many industrialized nations are restoring forests to offset their greenhouse gas emissions, that might not be enough. In the absence of cutting emissions, the preservation of forests may not be enough, the new research shows.
Data from two large research networks of forest observations in Africa and the Amazon is combined by the scientists to conduct the research. They spent years in remote field sites. The researchers tagged individual trees of forest within 565 different patches, measured them, and estimated the height of every single tree.
Every few years, the researchers repeated the process, to figure out the carbon stored in the trees both that survived and the ones that died, as The Guardian reported. As per their calculations, the African tropics have been more resilient compared to the Amazon, and now both are on a much worrying trend line.
“There is a lot of talk about offsetting, but the reality is that every country and every sector needs to reach zero emissions, with any small amount of residual emissions needing to be removed from the atmosphere,” Lewis said as The Guardian reported. “The use of forests as an offset is largely a marketing tool for companies to try to continue with business as usual.”
Lewis and White explained in The Independent yesterday, “We need to see emissions declining fast, by almost half by 2030, in order to avoid reaching that feared point where critical carbon sinks become carbon sources and climate change begins to run out of control.”
Doug Parr, chief scientist at Greenpeace UK, having the same opinion as to the scientists, said to The Guardian, “For years, we have had scientific warnings about tipping points in the Earth system, and they’ve been largely ignored by policy and decision-makers. That forests are now seemingly losing the ability to absorb pollution is alarming. What more of a wake-up call do we need?”