Scientists and environmentalists have long been warning that human-compelled deforestation and climate change could thrust the Amazon rainforests towards the point of no return. It could lead to the permanent destruction of most of the lush rainforests and conversion to a semi-arid Savannah. Experts only differ only when the point will be reached.
Deforestation levels in the Amazon, especially in the Brazilian part, have surged to around 3 football fields every minute. It is rapidly pushing the rainforests nearer to the tipping point at a much faster rate than what scientists and environmentalists had earlier feared.
The sharp rise has been compounded by a year-on-year increase in both May and June. This has been largely due to the policies of right-wing politician Jair Bolsonaro, now the President of Brazil. He has given a blanket pass to land invaders, loggers, and slash-and-burn farmers.
Clearance in July 2019 alone hit 1,345 square kilometers. It is a third higher than previous records under the present system of monitoring used by the Deter B system of satellite, which went on air in 2015.
This puts the area lost in Brazil lost more than the area of Greater London; all in a month.
Steady Rainforest Erosion Causing The Loss Of A Global Climate Stabilizing Factor
The latest study has relied on observational data that measures the resilience of the forest. It measures the ability of the forest to recover from an extreme climate event such as a drought. The figures are grim and show how things have spiraled out of control in the last two-three decades.
Almost 75% of the Amazon rainforests have already gone beyond the recovery point and, in the last two decades, have lost much of its resilience. And the least resilient regions are the drier regions, the ones closest to human habitation, such as agricultural lands, and infrastructures like roads and bridges.
These findings have further strengthened concerns that we could be closer to the tipping point or the critical threshold. But experts say that it would be difficult to predict when exactly a comprehensive tipping point would be reached.
Losing The Traditional Resilience Of The Amazon Rainforests
The Amazon rainforests are the largest storehouse of carbon and other harmful gases and are home to around 10% of the biodiversity of the planet. But humans have been relentless in their negative impact on this region directly due to deforestation, and on a global level through climate change.
The rate of deforestation reached its peak in 2021, with conservative estimates showing that over 10,000 sq. km. of forest land are gone forever between August 20 and July 21. And even as the planet marches relentlessly towards a warmer climate, the moisture of the Amazon rainforests is fast drying out and making the forests extremely vulnerable to fire and drought.
And these issues are contributing to the loss of resilience of the Amazon rainforests. It has drastically slowed down the process by which the Amazon forests had earlier bounced back from devastating natural disasters.
Scientists are concerned that it is a one-way street as the rainforests will see a more drastic loss of resilience over the coming decades. But identifying the exact extent of the loss will not be possible with the existing data in hand.
Comprehending The Harm Incurred By Humanity With The Loss Of The Amazon Forest Cover
The steady erosion in tree cover and its acceleration under hostile regimes like that of President Bolsonaro has dealt a crushing blow to efforts to use the rainforests to stabilize the global climate. The transformation of the lush rainforests into savannahs will have a debilitating effect on the capacity of the planet to absorb carbon. The consequences will be far-reaching and envelope the whole planet.
Scientists have been trying to identify new ways to study the loss of resilience. And they have diverged from traditional climate models. Newer studies rely more on satellite imagery to measure the amount of resilience lost by the Amazon rainforests.
And these studies show that human-induced climate change and direct interference through the process of deforestation could further accelerate the process of resilience already lost in this century.
Identifying New Scientific Ways To Identify Loss Of Resilience Of The Amazon Rainforests
The authors of the studies have relied on VOD, ‘vegetation optical depth,’ to measure the amount of biomass present in plants, which gives a direct and true indication of the water content of the forest.
Scientists have broken up the Amazon forests into grids that use figures from the MODIS to select merely the forest-covered land that has not been the victim of deforestation.
Individual grids are studied to understand the evolution of VOD in each of the grids between 1991 and 2016. The map on the evolution of VOD is marked by red for grids that have seen a forfeiture of biomass in the intervening years and blue indicates a surge in rainforest cover.
The satellite data clearly indicates that VOD has decreased steadily over the 25 years. The most prominent decrease has been witnessed in the south-eastern part of the basin. This is the area along the Amazon River, plus also in the northern areas, all close to the dense human population.
Dr. Chris Boulton, lead author of the papers and an Exeter University researcher told Carbon Brief that the resilience of the Amazon rainforests can be best understood by visualizing a ball in a bowl.
The ball is in a state of equilibrium when it sits on the bottom floor of the bowl. That is similar to the equilibrium enjoyed by the Amazon rainforest. But as the ball is pushed up the side, it returns to the center.
Similarly, the Amazon rainforests have the ability to recover even an extreme doubt as the ball returns to its present state.
The quicker the ball rolls to the bottom, the more resilient or stable the whole system is. But the walls get shallow even as the Amazon begins to lose its resilience.
This causes the ball t roll back very slowly indicating a loss of resilience, called the ‘critical slowing down’ theory. This method allows scientists to pick signals up without showing them as a massive change in the tree cover or biomass of the Amazon rainforests.
And the decrease in resilience has affected over 76% of the grid cells in the study, starting from the 2000s.
The Amazon rainforest is a world of its own and sustains itself through recycling water from the atmosphere, and it maintains rainfall and reduces the extent of summer. Deforestation affects this self-sustained exosphere and leads to a point of no return.