Paris (AFP)

The planet's "vital signs" are weakening under the blows of the global economy, leading scientists warned Wednesday, worrying about the possible imminence of certain climatic "breaking points".

The researchers, who are part of a group of more than 14,000 scientists who have advocated for the declaration of a global climate emergency, believe that governments have systematically failed to tackle the causes of climate change: "the overexploitation of Earth".

Since a previous assessment in 2019, they have highlighted the "unprecedented increase" in climatic disasters, from floods to heatwaves, including cyclones and fires.

Of the 31 "vital signs" of the planet, which include greenhouse gas emissions, the thickness of glaciers or deforestation, 18 are reaching records, according to this text published in the journal BioScience.

Thus, despite the drop in greenhouse gas emissions due to the Covid-19 pandemic, the concentrations of CO2 and methane in the atmosphere reached record levels in 2021.

Glaciers are melting 31% faster than fifteen years ago and deforestation in the Brazilian Amazon also hit a record in 2020, turning this crucial carbon sink into a net emitter of CO2.

With a record of more than 4 billion head of cattle, including cows and sheep, the mass of cattle now exceeds that of humans and wild animals combined, according to the study.

"We must react to the evidence that shows we are heading towards climate breaking points, taking urgent steps to decarbonize the economy and start restoring nature rather than destroying it," said one of the authors, Tim Lenton, UK University of Exeter.

The authors believe that there is indeed "growing evidence that we are approaching, if not already passed" some of the tipping points that could drag the climate system towards dramatic and irremediable change.

This includes the melting of the Greenland and Antarctic ice caps, which could be irreversible on the scale of centuries, even if CO2 emissions were reduced.

Another possible point of no return for coral reefs threatened in particular by global warming, and on which half a billion people depend.

The authors are calling for rapid radical action in several areas: eliminating fossil fuels, reducing pollution, restoring ecosystems, opting for plant-based diets, moving away from the current growth model and stabilizing the world population.

"We must stop treating the climate emergency as an independent problem, warming is not the only problem with our pressurized Earth system," insisted William Ripple of Oregon State University.

According to him, "policies to combat the climate crisis or any other symptom should tackle the source: the overexploitation of the planet by humans".

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