A new study warns that the Amazon rainforest is reaching a “tipping point” where more than half of it could turn into savanna within a few decades.
Researchers say three-quarters of the world’s largest rainforests are showing declining resilience to droughts and other adverse weather events, meaning they are less able to regenerate.
The loss of the forest will mean that billions of tons of CO2 will be released into the atmosphere.
It will also reduce the planet’s ability to process greenhouse gas and lead to an acceleration of global changing of the climateaccording to experts led by the University of Exeter.
While they acknowledge that it is “highly uncertain” when the tipping point will be reached once the process begins, they predict that it could take several decades before “a significant chunk” – perhaps “well over” 50 percent – turns into savannah. .
Although the Amazon rainforest is currently lush and green, researchers predict that the Amazon rainforest will become an African-style savannah-like environment with grass and sparse tree populations.
Researchers say three-quarters of the world’s largest rainforests are showing declining resilience to droughts and other adverse weather events, meaning they are less able to regenerate.
About a fifth of the Amazon has already been lost compared to pre-industrial levels, the researchers said, largely due to human activities such as logging and planting crops.
AMAZON KEEP WARM
The data from Prodes’ system came months after a study showed that The Amazon rainforest is now ‘fueling’ global warming.
Huge areas produce more carbon than they absorb due to deforestation, researchers from Brazil’s National Institute for Space Research have said.
The combination of fires and logging, they said, has shifted large regions from major “carbon sinks” to carbon emitters.
This shift is further fueling the global warming crisis, leading to more “extreme weather events” and the team said “it’s getting worse every year.”
Extensive observations have shown that the southeastern Amazon – about a fifth of the entire territory – has become a significant source of CO₂.
The researchers said that about a fifth of the Amazon has already been lost compared to pre-industrial levels, largely due to human activities such as logging and land use for crops.
Dr Chris Boulton of the University of Exeter said: “We have found a clear loss of resilience in the Amazon rainforest over the past 20 years.
“In the Amazon, we are really finding that, especially since the early 2000s, the 75 percent coverage of the Amazon rainforest seems to be showing some sense of unsustainability.
“And what we also found is that areas that are closer to human land use, such as urban areas or farmland, tend to destabilize faster, as do areas that receive less rainfall.”
Sustainability actually increased from 1991 until around 2000, but the consistent decline since then has resulted in sustainability well below 1991 levels.
“Deforestation and climate change are likely to be the main reasons for this decline,” said Professor Niklas Burs from PIK and the Technical University of Munich.
“Resilience is lost faster in those parts of the rainforest that are closest to human activities, as well as those that receive less rainfall.
“Many researchers suggest that a tipping point may be reached, but our study provides important empirical evidence that we are approaching this threshold.”
Despite climate change, the average rainfall in the Amazon has not changed significantly in recent decades.
However, dry seasons have become longer and droughts have become more frequent and severe.
Study measurements show that the total biomass has decreased slightly, but the buckling is much more pronounced.
Researchers highlight this distinction between sustainability and the average “state” of a rainforest.
“A rainforest may look more or less the same, but it can become unstable, making it slower to recover from a major event like a drought,” said Professor Tim Lenton from the University of Exeter.
The loss of the forest will mean that billions of tons of CO2 will be released into the atmosphere.
In the photo, the first stage of forest destruction is cutting down. There is growing evidence that deforestation is affecting the regional climate, reducing rainfall and lengthening the dry season.
More than half of the Amazon rainforest could turn into savannah within a few decades, researchers have warned.
Where is terrestrial carbon stored?
Amazon rainforest: 200 billion tons
Siberian permafrost: 950 billion tons
Arctic: 1600 billion tons
Oceans: as much as 38,000 gigatons, according to the World Ocean Review.
These figures are estimates, but actual values may be higher. In contrast, humans produce approximately 36 billion tons of carbon every year.
“If too much resilience is lost, die-off may become inevitable, but this will not become apparent until a major event occurs that flips the system,” said Professor Burs.
“Many interrelated factors, including droughts, fires, deforestation, degradation and climate change, can combine to reduce resilience and cause a tipping point in the Amazon.”
Professor Lenton sharply recalled the consequences of the loss of tropical forests.
He said: “The reason we’ve focused on the Amazon rainforest is because we think it’s one part of the climate system that could be at a tipping point – by which we mean a different possible state of vegetation and land surface in this part of South America may turn into something more like a savannah, perhaps.
“Having received this evidence, consistent with the fact that the forest is approaching a tipping point, it is worth reminding ourselves that if it reaches this tipping point and we commit ourselves to losing the Amazon rainforest, then we will receive significant feedback on global climate change.
“It will lose about 90 billion tons of carbon dioxide – mainly from trees and a little from the soil – and these are emissions in a few years.
“And also past research has shown that you’re losing forest, it affects the whole circulation of the atmosphere, so it has an impact, we call it telecom, potentially on the climate in other parts of the world.”
The conclusions were drawn using satellite data from 1991 to 2016, which includes measurements of the density of life in the forest, which is closely related to water levels and vegetation greenness.
Prof Boers said: “The buckling we have seen means that we are probably close to this particular point, or this tipping point, but we also assume that we have not yet crossed that point of no return, so there is still hope.” .
Research published in the journal Springer Nature.
MAP SHOWS DEFORTESTATION RATES AROUND THE WORLD
Using Landsat imagery and cloud computing, the researchers mapped the world’s forest cover and its losses and gains. In 12 years, 888,000 square miles (2.3 million square kilometers) of forest have been lost and 309,000 square miles (800,000 square kilometers) have grown back.
The devastation caused by deforestation, wildfires and storms on our planet is revealed in unprecedented detail.
High-resolution maps released by Google show how the world’s forests lost 1.5 million square kilometers between 2000 and 2012.
By comparison, this is a loss of forest land equal in size to the entire state of Alaska.
The maps, created by a team of researchers from NASA, Google and the University of Maryland, used images from the Landsat satellite.
Each pixel in the Landsat image represents an area the size of a baseball, providing enough data to enlarge the local region.
Prior to this, comparison of forestry data between countries was not possible with this level of accuracy.
“When you combine datasets that use different methods and definitions, it’s hard to synthesize,” said Matthew Hansen of the University of Maryland.