CLIMATEWIRE | Unstoppable ice loss in Antarctica. Irreversible permafrost thaw in the Arctic. The shutdown of a gigantic Atlantic Ocean current.
Scientists have warned that these and other “tipping points” in the Earth’s climate system lie ahead if global temperatures continue to rise unabated. But there’s still great uncertainty about how and when the planet might cross these dangerous thresholds.
And without clearer public communication about what exactly a tipping point is — and what can be done to prevent it — the entire concept might not be that useful when it comes to promoting climate action.
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That’s the warning presented in a new perspective paper, published Tuesday by a group of scientists, policy experts and communication specialists in the journal Nature Climate Change. Tipping points have captured the public’s imagination for years now, they argue — but it’s not clear the concept is driving any meaningful policy changes.
That’s partly due to widespread confusion about what a tipping point actually is, the paper suggests.
Early scientific literature on the subject presented the idea that certain aspects of the Earth’s climate system could have physical limits — and once the point of no return is crossed, these systems fall into a death spiral of unstoppable and irreversible change.
Studies suggest, for instance, that enough warming and drought in the Amazon could cause the ecosystem to tilt into an uncontrollable transformation from lush rainforest to dry grassland.
But over the years, as the concept has grown more popular, researchers have begun to apply the tipping point framework to a variety of other scientific and social systems. Papers have begun to suggest that there are tipping points in everything from energy pricing systems to humans’ eating habits.
Uncertainty over the likelihood of climate tipping points is another source of public confusion, the authors suggest.
The Intergovernmental Panel on Climate Change, the U.N.’s leading authority on climate science, has warned of a variety of possible tipping points in the Earth’s climate system. But some are more likely than others, and many are shrouded in uncertainty — in other words, scientists don’t know how close we are to toppling them.
That makes it hard to communicate the seriousness of tipping point threats or to inspire near-term action to prevent them.
If scientists knew for certain the Antarctic ice sheet would experience rapid and uncontrollable melting with exactly 1.5 degrees of global warming, policymakers might be more inclined to implement emergency measures to keep temperatures below that threshold.
But almost all global tipping point thresholds come with a wide range of uncertainty about when they’ll actually occur — if ever.
Instead, the authors argued, more tangible and immediate climate emergencies — such as extreme weather events, which are worsening around the globe as temperatures rise — may be more likely to inspire a greater sense of urgency among policymakers and the public.
That doesn’t mean tipping points can’t still be a useful concept in public messaging about climate change, the authors added. But scientists should communicate more clearly about their definitions and uncertainties.
That's because climate tipping points are still a major threat — even if their exact thresholds are still uncertain.
A major report last year — with contributions from more than 200 scientists — warned of 26 possible tipping points around the globe, affecting systems from ice sheets to tropical cloud cover.
It’s an issue that urgently requires more research and understanding, the report warned.
“We know enough to identify that the threat of Earth system tipping points demands an urgent response. Indeed, our best models likely underestimate tipping point risks,” it stated. “The world is largely flying blind into this vast threat.”
Reprinted from E&E News with permission from POLITICO, LLC. Copyright 2024. E&E News provides essential news for energy and environment professionals.