- A new study warns that multiple tipping points will be triggered if global warming exceeds 1.5°C (2.7°F) above pre-industrial levels.
- The researchers say humanity is already at risk of passing five tipping points, including the melting of the Greenland and West Antarctica ice sheets and the mass die-off of coral reefs, at the current levels of warming, and that the risk will increase with each 0.1°C (0.18°F) of warming.
- While many nations have committed to the 2015 Paris Agreement, which stipulates that warming should be limited to 1.5°C, it’s unclear whether this goal will be achieved.
A new study conveys a dire warning for the future: multiple tipping points could be triggered if global warming exceeds the critical threshold of 1.5°C.
Published this week in Science, the study found that humanity is already at risk of passing five out of 16 known tipping points at current levels of global warming. As the world inches closer to warming above 1.5° Celsius (2.7° Fahrenheit) from pre-industrial levels, an additional five tipping points could be breached. The risk of setting off more tipping points will continue to increase with each 0.1°C (0.18°F) of warming, according to the research.
“The world is heading towards 2-3°C [3.6-5.4°F] of global warming,” study co-author Johan Rockström, director of the Potsdam Institute for Climate Impact Research and co-chair of the Earth Commission, a team of scientists working to help safeguard the planet, said in a statement.
“This sets Earth on course to cross multiple dangerous tipping points that will be disastrous for people across the world,” he added. “To maintain liveable conditions on Earth, protect people from rising extremes, and enable stable societies, we must do everything possible to prevent crossing tipping points. Every tenth of a degree counts.”
Nearly 200 nations have committed to reach the goals of the 2015 Paris Agreement, which stipulates that countries must reduce carbon emissions in order to limit warming to 1.5°C, or at least well below 2°C. However, it’s unclear if this goal will be met. While one study found that it could be possible to limit warming to 2°C if all nations took swift action to meet their emissions targets on time, another recent study found there’s actually a 0.1% chance of meeting the Paris Agreement goals.
In November this year, world leaders will meet in Sharm el-Sheikh, Egypt, for the COP27 climate summit to discuss further action on mitigation and on meeting the goals of the Paris Agreement.
According to the new study in Science, the five tipping points likely to be triggered by today’s temperatures are the collapse of the Greenland and West Antarctic ice sheets; mass die-offs of low-latitude coral reefs; widespread thaw of the boreal permafrost; and the halt of the convection in the Labrador Sea. If warming continues, many other tipping points would be at risk, including the loss of the Barents Sea ice and the die-back of the Amazon Rainforest.
“We can see signs of destabilisation already in parts of the West Antarctic and Greenland ice sheets, in permafrost regions, the Amazon rainforest, and potentially the Atlantic overturning circulation as well,” study lead author David Armstrong McKay of the Stockholm Resilience Centre, the University of Exeter and the Earth Commission, said in a statement. “The world is already at risk of some tipping points. As global temperatures rise further, more tipping points become possible.”
Co-author Tim Lenton, director of the Global Systems Institute at the University of Exeter and a member of the Earth Commission, said the new study provides evidence that we must “radically accelerate decarbonising the economy.”
“To achieve that we now need to trigger positive social tipping points that accelerate the transformation to a clean energy future,” Lenton said in a statement. “We may also have to adapt to cope with climate tipping points that we fail to avoid, and support those who could suffer uninsurable losses and damages.”
Banner image: Researchers say humanity is already at risk of passing five tipping points, including the mass die-off of coral reefs, at the current levels of warming. Image by Alex Mustard / Ocean Image Bank.
Citations:
Armstrong McKay, D. I., Staal, A., Abrams, J. F., Winkelmann, R., Sakschewski, B., Loriani, S., … Lenton, T. M. (2022). Exceeding 1.5°C global warming could trigger multiple climate tipping points. Science, 377(6611). doi:10.1126/science.abn7950
Meinshausen, M., Lewis, J., McGlade, C., Gütschow, J., Nicholls, Z., Burdon, R., … Hackmann, B. (2022). Realization of Paris Agreement pledges may limit warming just below 2°C. Nature. doi:10.1038/s41586-022-04553-z
Vargas Zeppetello, L. R., Raftery, A. E., & Battisti, D. S. (2022). Probabilistic projections of increased heat stress driven by climate change. Communications Earth & Environment, 3(1). doi:10.1038/s43247-022-00524-4
