Climate change poses an “existential threat” to life on Earth, a group of leading scientists warned Tuesday in a report analyzing extreme weather events in 2023 and humanity’s lack of action.
The study, published in the journal BioScienceexamined 35 planetary “vital signs,” including CO pollution2, energy and meat consumption per capita, deforestation by fire or days of extreme heat. However, 20 of these indicators have reached a record level in 2023, concludes this international scientific coalition.
“In truth, we are shocked by the ferocity of extreme weather events in 2023. We have entered uncharted territory that frightens us,” they write.
With 2023 on track to become the hottest year on record, entire regions have suffered deadly heatwaves, storms, floods, sometimes one disaster after another.
On the ocean side, temperatures “have been completely out of norm” for months, without scientists yet being able to fully explain it, underlines Johan Rockström, director of the Potsdam Institute for Climate Impact Research (PIK).
For these scientists, the observation is clear: “life on planet Earth is under siege”.
But humanity has made only “minimal progress” in reducing greenhouse gas emissions: concentrations are reaching record levels and subsidies for fossil fuels have skyrocketed.
“We must change our perspective on the climate emergency, which is no longer an isolated environmental problem, but a systemic and existential threat,” says the report, one month before the 28e United Nations climate conference in Dubai.
The most ambitious objective of the Paris agreement – warming limited to 1.5°C compared to the pre-industrial era – will have to be measured over several years to be considered achieved. But this limit could now be crossed annually, warns William Ripple, co-lead author, opening the way to a vicious cycle of worsening warming: melting of ice caps at the poles, dieback of forests, thawing of permafrost carbon sinks, extinction of corals, etc.
“Once crossed, these tipping points could modify our climate in a way that is difficult, if not impossible, to reverse,” warns this professor at the University of Oregon.
“We are not going to avoid certain tipping points, it is more about slowing down the damage,” Tim Lenton of the University of Exeter told AFP, recalling the need to drastically reduce emissions. Because every fraction of a degree counts and “the game is not over”.
Three to six billion people could find themselves “beyond the habitable region” of the globe by the end of the century, the report warns.