Even if countries meet the Paris climate agreement’s more aggressive targets, global warming could still likely trigger several climate “tipping points” that drastically alter life on Earth, according to a new study published Thursday in the journal Science would.
Why it matters: “Tip points” refer to nodal points in the climate system that, if crossed, can initiate irreversible changes. The turning points include the almost complete melting of the West Antarctic ice sheet or the shutdown of the ocean currents, which include the Gulf Stream.
- The study points out that even the Paris Agreement target of limiting global warming to 1.5°C is not enough to completely avoid some of the dangerous effects of climate change.
How it works: The researchers looked at 16 of these tipping points and found that at current levels of global warming, the world is “already on the low end of five [climate tipping point] areas of uncertainty.”
- These include the massive rise in sea level due to the irreversible collapse of the Greenland and West Antarctic ice sheets, the degradation of biodiverse biomes such as the Amazon rainforest or warm-water coral reefs, and greenhouse gas emissions due to the thawing of permafrost.
- If the world meets the Paris Agreement’s goal of keeping global warming to 1.5 degrees Celsius above pre-industrial levels, four of these triggering events become likely and five more possible, according to the researchers.
- With every tenth of a degree of warming beyond 1.5°C, more trigger events become likely and possible, they said.
What you say: “The world is heading towards global warming of 2 to 3°C,” said Johan Rockström, co-author of the paper and director of the Potsdam Institute for Climate Impact Research, in a statement.
- “This puts Earth on course to cross several dangerous tipping points that will be catastrophic for people around the world. In order to maintain livable conditions on earth, protect people from increasing extremes and enable stable societies, we must do everything possible to avoid crossing tipping points. Every tenth of a degree counts,” added Rockström.
The big picture: The United Nations warned in 2021 that the earth is likely to warm by more than 2.7°C by the end of the 21st century if countries do not further reduce greenhouse gas emissions.
- A UN-sponsored report released last year predicted that global warming by the end of the century could range between about 1.3 and 5.7°C compared to pre-industrial levels.
- It also noted that the world could reach the Paris Agreement warming limit of 1.5°C between 2030 and 2035.
- The planet has already warmed by 1.1°C from pre-industrial levels.
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