Close to tipping point, Amazon could collapse in 50 years
The Amazon rainforest is nearing a threshold which, once crossed, would see one of the world’s largest and richest ecosystems morph into arid savannah within half-a-century.
Tropical forests’ carbon sink is already rapidly weakening
The ability of the world’s tropical forests to remove carbon from the atmosphere is decreasing, according to a study tracking 300,000 trees over 30 years.
The global scientific collaboration, led by the University of Leeds, reveals that a feared switch of the world’s undisturbed tropical forests from a carbon sink to a carbon source has begun.
Intact tropical forests are well-known as a crucial global carbon sink, slowing climate change by removing carbon from the atmosphere and storing it in trees, a process known as carbon sequestration. Climate models typically predict that this tropical forest carbon sink will continue for decades.
Rainforests losing ability to absorb carbon
Tropical trees are dying from heat and drought, destroying the forest’s ability to pull carbon dioxide out of the atmosphere. Decades of measurements in hundreds of locations show that the uptake of carbon from the atmosphere by tropical forests has peaked — with the turning point in the early 1990s in the Amazon and around 2015 in Africa. If the trend is allowed to continue, the typical tropical forest could become a source of carbon emissions by the 2060s. “Humans have been lucky so far, as tropical forests are mopping up lots of our pollution,” says geographer Simon Lewis. “We need to curb fossil fuel emissions before the global carbon cycle starts working against us.”