Catastrophe for the Earth: scientists warn of the threat of complete destruction of tropical forests
Further climate change associated with global warming is making tropical forests too hot for photosynthesis. This could eventually lead to the complete disappearance of this important ecosystem for our planet.
This is stated in a study published in the journal Nature. The disappearance of tropical forests will mean a catastrophe for the Earth's climate systems and biodiversity.
Observations from the International Space Station (ISS) have revealed that a small but growing percentage of leaves in tropical forests are approaching the maximum temperature threshold for photosynthesis.
The average temperature critical for photosynthesis is 46.7 degrees Celsius. When the temperature reaches this level, the photosynthetic mechanisms of tropical trees simply begin to fail.
Scientists acknowledge that only 0.01% of all leaves exceed this critical temperature each year. But the temperature trends observed this year do not bode well. A 4-degree Celsius increase in air temperature could lead to massive tree mortality in the rainforest.
Scientists say this is worrying because an increase in air temperature of 2-3 degrees Celsius means that the top temperature of the leaves rises by 8 degrees Celsius.
Covering 1.2 billion hectares, or about 6% of the Earth's surface, tropical rainforests are vital regions for our planet. They are home to half of the world's species of animals and plants.
In addition, these forests serve as freshwater reservoirs. In particular, the forests in the Amazon basin alone hold a fifth of the world's water reserves.
Another important function of tropical forests is that they produce 32% of the planet's oxygen through photosynthesis, and they help stabilise the global climate by absorbing billions of tonnes of carbon dioxide from the atmosphere every year.
Although the figure of 0.01% seems insignificant, the researchers point out that it could grow rapidly.
"It's going to increase potentially much faster," said Joshua B. Fisher, an associate professor of environmental science at Chapman University in California.
The scientists also said that their study showed a cascading effect: when leaves that were exposed to too high a temperature died, it raised the temperature of neighbouring leaves. As a result, leaves died, followed by branches, and then entire trees.
"If you have 10% of your leaves die, the whole branch becomes warmer because the critical part of that branch can no longer cool the wider branch. The same can be assumed for the entire forest when a tree dies," explained the associate professor of ecoinformatics at Northern Arizona University. Doughty.
At the same time, despite the most optimistic forecasts, scientists believe that humanity still has time to limit emissions and avoid the destruction of tropical forests.
Earlier, OBOZREVATEL reported that humanity could have missed an extraordinary event that changed the Earth's climate. A millennium of heat may follow on the planet