Climate change is not a gradual and linear process, but one that could suddenly and irreversibly transform the planet as we know it. That is the warning of a new study that assessed the risk of climate tipping points – thresholds beyond which a localized climate system, such as an ice sheet or a rainforest, changes dramatically and permanently.
According to the research, more than a fifth of the world’s potentially catastrophic tipping points — such as the melting of the Arctic permafrost, the collapse of the Greenland ice sheet and the sudden transformation of the Amazon rainforest into savanna — could occur as soon as 2038.
In climatology, a “tipping point” is the threshold beyond which a localized climate system, or “tipping element,” irreversibly changes. For instance, if the Greenland ice sheet were to collapse, it would also reduce snowfall in the northern part of the island, making large parts of the sheet irretrievable.
Some of the tipping elements that could be triggered at or before 1.5C of warming are the Arctic permafrost, which contains huge amounts of carbon that could be released into the atmosphere if it thaws; the Amazon rainforest, which could turn into a savanna if deforestation and drought reduce its ability to absorb carbon; the Greenland ice sheet, which could melt and raise sea levels by more than six metres; the West Antarctic ice sheet, which could also collapse and add another three metres to sea levels; and coral reefs, which could bleach and die, affecting millions of people who depend on them for food and livelihoods.
“Over a fifth of ecosystems worldwide are in danger of collapsing,” co-author Simon Willcock, a professor of sustainability at Bangor University in the U.K., said in a statement. “However, ongoing stresses and extreme events interact to accelerate rapid changes that may well be out of our control. Once these reach a tipping point, it’s too late.”
Unlike the well-established link between the burning of fossil fuels and climate change, the study of tipping points is a young and contentious science.
The study also warned that tipping points could have cascading effects on other parts of the climate system, creating a “domino effect” or a “doom loop” that would lock-in devastating changes, such as sea-level rise, biodiversity loss, and extreme weather events.
Current levels of greenhouse gas emissions risk triggering climate tipping points, scientists say.
The best way to avoid tipping points is to reduce greenhouse gas emissions as quickly and as deeply as possible, and to enhance the resilience of ecosystems and societies to cope with the impacts of climate change.
The phrase “climate tipping point” describes how parts of Earth’s climate system could abruptly collapse and trigger an irreversible sequence of warming, according to Karina Collins, author of an article on climate tipping points for Medium.
“This has potentially profound implications for our perception of future ecological risks,” co-author Gregory Cooper, a climate systems researcher at the University of Sheffield in the U.K., said in the statement. “While it is not currently possible to predict how climate-induced tipping points and the effects of local human actions on ecosystems will connect, our findings show the potential for each to reinforce the other. Any increasing pressure on ecosystems will be exceedingly detrimental and could have dangerous consequences.”
Relevant articles:
- Catastrophic climate ‘doom loops’ could start in just 15 years, new study warns, Live Science, July 3, 2023
- Climate change: What are the climate tipping points?, World Economic Forum, October 18, 2022
- How Close Are We to Climate Tipping Points?, IPCC Report AR6, November 11, 2021
- Climate Tipping Points, Medium, November 9, 2021