Climate tipping points – too risky to bet against

28/11/2019 - From the Greenland and West-Antarctic ice sheets to coral reefs or the Amazon rainforest – a number of critical elements in the Earth system could be more likely to tip than was previously thought, a group of leading scientists warns in in the highly renowned journal Nature. Evidence is mounting that these events are also more interconnected, which could eventually lead to domino effects. A possible tipping cascade of irreversible changes might put the livelihoods of people around the world at risk and marks a state of planetary emergency, the authors argue in their comment.
Climate tipping points – too risky to bet against

"It is not only human pressures on Earth that continue rising to unprecedented levels. It is also that as science advances, we must admit that we have underestimated the risks of unleashing irreversible changes, where the planet self-amplifies global warming," says co-author Johan Rockström, Director of the Potsdam Institute for Climate Impact Research (PIK). "This is what we now start seeing, already at 1 Celsius global warming. Scientifically, this provides strong evidence for declaring a state of planetary emergency, to unleash world action that accelerates the path towards a world that can continue evolving on a stable planet.”

In their commentary, the authors summarize the current state of science on tipping elements and propose a formula to investigate a state of planetary emergency as a product of risk and urgency. They highlight nine of the tipping elements as particularly critical: The Arctic sea ice, the Greenland ice sheet, the boreal forests, permafrost soils, the Atlantic Meridional Overturning Circulation, the Amazon rainforest, warm-water corals, the West Antarctic ice sheet and parts of East Antarctica. "The evidence from tipping points alone suggests that we are in a state of planetary emergency: both the risk and urgency of the situation are acute," the authors argue.

“Everybody talks about ‚climate emergency‘ now, but this paper provides a concise formula for fathoming how far we have gone down the road to disaster. That road is paved by tipping points whereof some may have transgressed already,” concludes Hans Joachim Schellnhuber, Director Emeritus of PIK and co-author of the publication.


Article: Timothy M. Lenton, Johan Rockström, Owen Gaffney, Stefan Rahmstorf, Katherine Richardson, Will Steffen & Hans Joachim Schellnhuber (2019): Climate tipping points - too risky to bet against. Nature. [DOI 10.1038/d41586-019-03595-0]

Weblink to the article: https://nature.com/articles/d41586-019-03595-0

Weblink to more information about tipping elements:
https://www.pik-potsdam.de/tippingelements

Weblink to related previous research: Planet at risk of heading towards irreversible "Hothouse Earth" state (2018, Proceedings of the National Academy of Sciences) https://www.pik-potsdam.de/news/press-releases/planet-at-risk-of-heading-towards-irreversible-201chothouse-earth201d-state?set_language=en


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