Climate feedbacks are processes in which changes in one area of the ecosystem trigger reactions that affect the entire system, amplifying or diminishing the initial effect. For example, melting ice reduces the reflection of sunlight, leading to additional warming, while deforestation and the loss of carbon from the soil contribute to rising CO₂ levels in the atmosphere. These factors can accelerate global warming and increase the climate's sensitivity to greenhouse gas emissions.
Scientists have identified 16 critically important "tipping points" — elements of the Earth system that can sharply change their state when certain temperature thresholds are exceeded. Even a slight disturbance in one of these systems can initiate a cascade of interconnected changes that accelerate global warming.
Such tipping points include the ice sheets of Antarctica and Greenland, mountain glaciers, sea ice, boreal forests, and permafrost, as well as the tropical forests of the Amazon and the Atlantic Meridional Overturning Circulation (AMOC).
Destabilization of any of these elements can lead to intensified warming, rising sea levels, and changes in global climate patterns, including shifts in rainfall zones. For example, the melting of the Greenland ice sheet could weaken the AMOC flow, which in turn increases the risk of extinction for the Amazon rainforest.
"For millions of years, the Earth's climate has oscillated between glacial periods and warm phases; however, it stabilized over 11,000 years ago, which facilitated the development of agriculture and complex societies," explains William Ripple, a professor of ecology and the lead researcher. "Now we are moving away from this stability and may enter an era of unprecedented climate change."
The consequences of the climate crisis are already becoming evident: the Greenland and West Antarctic ice sheets are losing their stability, while mountain glaciers and permafrost are on the brink of irreversible changes.
In the past 12 months, the global temperature has exceeded pre-industrial levels by 1.5°C, and CO₂ concentration has reached 420 parts per million. This is 50% higher than pre-industrial levels and is a record for the past 2 million years.
These changes are leading to increasingly extreme and destructive natural disasters, including wildfires and floods.
Scientists are urgently calling for immediate action, including the development of renewable energy sources, the protection of carbon ecosystems, a transition away from fossil fuels, and the implementation of climate adaptation strategies. There is also an emphasis on the need to monitor tipping points and develop risk management plans to prevent an uncontrollable scenario.
