![Amazon nears climate 'tipping point' faster than expected](https://www.portugalcolonial.pt/media/shared/articles/4c/3f/dc/Amazon-nears-climate--tipping-point-717616.jpg)
-
US defends law forcing sale of TikTok app
-
Messi out for defending champ Miami as Leagues Cup begins
-
Australia bans uranium mining at Indigenous site
-
Divers attempt to reach sunken Philippine oil tanker
-
Trump accuses Harris of anti-Semitism in overblown speech
-
Coughlin clings to lead at LPGA Canadian Women's Open
-
Trump offers tech sector policy flips ahead of election
-
Spacecraft to swing by Earth, Moon on path to Jupiter
-
What's the fallout of Mexican drug lords' capture?
-
Video game makers see actors as AI 'data,' says union on strike
-
Chinese qualifier Shang to face Thompson in ATP Atlanta semis
-
'Massive attack' on French rail threatens more chaos
-
'We did it!': France breathes sigh of relief after Olympics ceremony
-
Regional concern grows as Venezuela blocks vote observers
-
Historic river parade, Dion show-stopper ignite Paris Olympics
-
Rainy Paris Olympic parade dampens many spectators' spirits
-
The one of a kind Paris opening ceremony: five memorable moments
-
Justin Timberlake seeks to dismiss DUI case
-
Warner Brothers Discovery sues NBA over Amazon rights deal
-
Kobe Bryant locker, Maradona jersey up for auction in New York
-
Historic river parade launches Paris Olympics
-
New York family of Holocaust victim reclaims Nazi-looted art
-
NASA Mars rover captures rock that could hold fossilized microbes
-
Thousands evacuate season's biggest wildfire in northern California
-
Ethiopia mourns victims of landslide tragedy
-
Lady Gaga adds sparkle to star-studded Olympic show
-
Airbus and Boeing supremacy secure despite turbulence
-
Teams sail down Seine in rain-soaked Olympics opening ceremony
-
West Indies' treble strike rocks England in third Test
-
Olympic opening ceremony under way on River Seine
-
Mott's England future uncertain as ECB chief fails to offer support
-
Trump meets Israeli PM Netanyahu in Florida
-
S.African police say 95 Libyans detained at suspected military camp
-
Blinken set for talks with Chinese counterpart in Laos
-
Norris heads Piastri in McLaren one-two at Belgian GP practice
-
G20 seeks common ground on taxing super-rich
-
European medicines watchdog rejects new Alzheimer's drug
-
Habib, Ebden eye Alcaraz and Djokovic shocks at Olympics tennis
-
Long queues, ticketing problems ahead of Paris opening ceremony
-
Two Sinaloa Cartel leaders face US charges after stunning capture
-
Spain train driver jailed for 2.5 years over deadly 2013 crash
-
Paris poised for Olympic opening ceremony spectacular
-
Judoka fails doping test in first case at Paris Olympics
-
Holder and Da Silva keep England at bay after West Indies collapse
-
Alpine F1 boss Bruno Famin to leave in August
-
Ethiopia declares three days of mourning after landslide tragedy
-
Brazilian dunes dotted with dazzling pools make UNESCO heritage list
-
Rain, cooling slow huge blaze in Canada's Jasper park
-
French Rugby's Jaminet suspended 34 weeks after racist video: Federation
-
Osaka looking to turbo-charge comeback at Paris Olympics
![Amazon nears climate 'tipping point' faster than expected](https://www.portugalcolonial.pt/media/shared/articles/4c/3f/dc/Amazon-nears-climate--tipping-point-717616.jpg)
Amazon nears climate 'tipping point' faster than expected
Hammered by climate change and relentless deforestation, the Amazon rainforest is losing its capacity to recover and could irretrievably transition into savannah, with dire consequences for the region and the world, according to a study published Monday.
Researchers warned that the results mean the Amazon could be approaching a so-called "tipping point" faster than previously understood.
Analysing 25 years of satellite data, researchers measured for the first time the Amazon's resilience against shocks such as droughts and fires, a key indicator of overall health.
This has declined across more than three-quarters of the Amazon basin, home to half the world's rainforest, they reported in Nature Climate Change.
In areas hit hardest by destruction or drought, the forest's ability to bounce back was reduced by approximately half, co-author Tim Lenton, director of the University of Exeter's Global Systems Institute, told AFP.
"Our resilience measure changed by more than a factor of two in the places nearer to human activity and in places that are driest," he said in an interview.
Climate models have suggested that global heating -- which has on average warmed Earth's surface 1.1 degrees Celsius above preindustrial levels -- could by itself push the Amazon past a point of no return into a far drier savannah-like state.
If carbon pollution continues unabated, that scenario could be locked in by mid-century, according to some models.
"But of course it's not just climate change -- people are busy chopping or burning the forest down, which is a second pressure point," said Lenton.
"Those two things interact, so there are concerns the transition could happen even earlier."
Besides the Amazon, ice sheets on Greenland and the West Antarctic, Siberian permafrost loaded with CO2 and methane, monsoon rains in South Asia, coral reef ecosystems, and the Atlantic ocean current are all are vulnerable to tipping points that could radically alter the world as we know it.
- Global fallout -
Deforestation in Brazil has surged since far-right President Jair Bolsonaro took office in 2019, hitting a 15-year high last year.
Scientists reported recently that Brazil's rainforest -- 60 percent of the Amazon basin's total -- has shifted from a "sink" to a "source" of CO2, releasing 20 percent more of the greenhouse gas into the atmosphere over the last decade than it absorbed.
Terrestrial ecosystems worldwide have been a crucial ally as the world struggles to curb CO2 emissions. Vegetation and soil globally have consistently absorbed about 30 percent of carbon pollution since 1960, even as emissions increased by half.
"Savannification" of the Amazon would be hugely disruptive, in South America and across the globe.
Some 90 billion tonnes of CO2 stored in its rainforest -- twice worldwide annual emissions from all sources -- could be released into the atmosphere, pushing global temperatures up even faster.
Regionally, "it's not just the forests that take a hit", said Lenton. "If you lose the recycling of rainfall from the Amazon, you get knock-on effects in central Brazil, the country's agricultural heartland."
Ominously, the new findings marshall data pointing in the same direction.
"Many researchers have theorised that a tipping point could be reached," said co-author Niklas Boers, a professor at the Potsdam Institute for Climate Impact Research in Germany.
"Our study provides vital empirical evidence that we are approaching that threshold."
- When you're sure, it's too late -
To assess change in the resilience of the rainforest, Lenton, Boers and lead author Chris Boulton from Exeter University analysed two satellite data sets, one measuring biomass and the other the "greenness" of the canopy.
"If too much resilience is lost, dieback may become inevitable -- but that won't become obvious until the major event that tips the system is over," said Boers.
There may be a "saving grace" that could pull the Amazon back from the brink.
"The rainforest naturally has a lot of resilience -- this is a biome that weathered the ice ages, after all," said Lenton.
"If you could bring the temperature back down again even after passing the tipping point, you might be able to rescue the situation."
"But that still puts you in the realm of massive carbon dioxide removal, or geoengineering, which has its own risks."
Just under 20 percent of the Amazon rainforest -- straddling nine nations and covering more than five million square kilometres (two million square miles) -- has been destroyed or degraded since 1970, mostly for the production of lumber, soy, palm oil, biofuels and beef.
T.Batista--PC