No collapswashing

Franchir les points de bascule écologiques aurait un coût économique gigantesque, selon plusieurs études scientifiques récentes. Des données qui rappellent l’urgence d’atténuer la crise écologique avant d’être face à des conséquences irréversibles en cascade.

We're nearly halfway through the 2020s, dubbed the most decisive decade for action on climate change. Where exactly do things stand? Climate impact scholar Johan Rockström offers the most up-to-date scientific assessment of the state of the planet and explains what must be done to preserve Earth's resilience to human pressure.

For many of us the climate crisis mainly calls to mind rising global temperatures, but the crisis goes far beyond this – we are at risk of pushing our planet across climate ‘tipping points,’ critical thresholds where small changes can lead to abrupt and irreversible shifts in the Earth’s climate system. One major element in climate tipping is a huge system of ocean currents, the Atlantic Meridional Overturning Circulation (AMOC), which is responsible for Europe's relatively mild climate. Past climate patterns show that these currents can switch abruptly between today’s vigorous flow and a much weaker flow state. A future shutdown would have potentially devastating consequences in Europe and around the world.

An international team of scientists has warned against relying on nature providing straightforward 'early warning' indicators of a climate disaster, as new mathematical modeling shows new fascinating aspects of the complexity of the dynamics of climate. It suggests that the climate system could be more unpredictable than previously thought.

Cruciale kantelpunten in het klimaatsysteem van de aarde komen in sneltempo dichterbij. Dat blijkt uit het grootste onderzoek ooit naar “tipping points”. Meer dan tweehonderd wetenschappers werkten mee aan een tekst met waarschuwingen en aanbevelingen, die is gepresenteerd op de klimaattop in Dubai (COP28).

Humanity faces ‘devastating domino effects’ including mass displacement and financial ruin as planet warms

Take part in the new scientific discussion about looming abrupt changes in the Earth system. This new webinar series invites scientists interested in tipping elements and the broader public to attend.

Amazon rainforest and other ecosystems could collapse ‘very soon’, researchers warn

Vast releases of gas, along with future ‘methane bombs’, represent huge threat – but curbing emissions would rapidly reduce global heating

The Global Tipping Points Report was launched at COP28 on 6 December 2023. The report is an authoritative assessment of the risks and opportunities of both negative and positive tipping points in the Earth system and society. Global Tipping Points is led by Professor Tim Lenton from the University of Exeter’s Global Systems Institute with the support of more than 200 researchers from over 90 organisations in 26 countries.

Three “super-tipping points” for climate action could trigger a cascade of decarbonisation across the global economy, according to a report. Relatively small policy interventions on electric cars, plant-based alternatives to meat and green fertilisers would lead to unstoppable growth in those sectors, the experts said. But the boost this would give to battery and hydrogen production would mean crucial knock-on benefits for other sectors including energy storage and aviation.

A recent paper suggested damaging climate tipping points could be closer than first thought.

Giant ice sheets, ocean currents and permafrost regions may already have passed point of irreversible change

As Nobel laureate Solow said to Congress when criticizingeconomicmodelsforfailingtoanticipatethe“GreatReces-sion,” “Every proposition has to pass a smell test: Does itreally make sense?” (2). The methods and conclusions inDietzetal.(1)donotmakesense. ...

Anthropogenic activities are increasingly affecting ecosystems across the globe. Meanwhile, empirical and theoretical evidence suggest that natural systems can exhibit abrupt collapses in response to incremental increases in the stressors, sometimes with dramatic ecological and economic consequences. These catastrophic shifts are faster and larger than expected from the changes in the stressors and happen once a tipping point is crossed.

Climate tipping points in the Antarctica, the Arctic and the Amazon are at risk of being reached before or at the current level of global warming of 1.2 degrees Celsius, requiring a “major rethink” of global climate goals and the action necessary to achieve them, according to a recent report.

Emerging ice-sheet modeling suggests once initiated, retreat of the Antarctic Ice Sheet (AIS) can continue for centuries. Unfortunately, the short observational record cannot resolve the tipping points, rate of change, and timescale of responses. Iceberg-rafted debris data from Iceberg Alley identify eight retreat phases after the Last Glacial Maximum that each destabilized the AIS within a decade, contributing to global sea-level rise for centuries to a millennium, which subsequently re-stabilized equally rapidly.

Five times in the last 500m years, more than three-fourths of marine animal species perished in mass extinctions. Each of these events is associated with a major disruption of Earth’s carbon cycle. How such catastrophes occur remains mysterious. But recent research increasingly points to the possibility that the Earth system – that is, life and the environment – may experience a cascade of disruptions when stressed beyond a tipping point.

If there’s one thing we know about climate breakdown, it’s that it will not be linear, smooth or gradual. Just as one continental plate might push beneath another in sudden fits and starts, causing periodic earthquakes and tsunamis, our atmospheric systems will absorb the stress for a while, then suddenly shift. Yet, everywhere, the programmes designed to avert it are linear, smooth and gradual.

Scientists have uncovered a fascinating new insight into what caused one of the most rapid and dramatic instances of climate change in the history of the Earth.

Depuis 30 ans, la compréhension du climat terrestre dans sa globalité s’est donc terriblement améliorée, permettant le développement de nouveaux concepts. L’un d’entre eux suscite beaucoup d’intérêt auprès de la communauté scientifique : c’est celui des points de basculement (tipping point).

Clarity on Climate Tipping Points and Feedbacks

On les appelle les "tipping points" ; les points de rupture. A partir d'eux, le climat change de manière radicale et irréversible. Des événements considérés comme des points de rupture sont la fonte des glace rapide au Groenland, qui fait monter le niveau des eaux, le fait que la forêt amazonienne rejette plus de CO2 qu'elle n'en absorbe, et les canicules en Sibérie qui ont fait fondre le sol gelé (pergélisol), ce qui a fait relâcher d'énormes quantités de méthane dans l'air. Un effondrement du Gulf Stream serait également un point de rupture absolument catastrophique.

Climate scientists have detected warning signs of the collapse of the Gulf Stream, one of the planet’s main potential tipping points. The research found “an almost complete loss of stability over the last century” of the currents that researchers call the Atlantic Meridional Overturning Circulation (AMOC). The currents are already at their slowest point in at least 1,600 years, but the new analysis shows they may be nearing a shutdown.

Abrupt disruptions to Earth's climate thousands of years ago that caused extreme sea-level rise and mass ice cap melting can serve as an early warning system for today's planetary tipping points, according to new research.

Around 13,000 researchers have called for urgent action to slow down the climate emergency as extreme weather patterns shock the world. They listed three core measures.

Climate scientists are increasingly concerned that global heating will trigger tipping points in Earth’s natural systems, which will lead to widespread and possibly irrevocable disaster, unless action is taken urgently. The impacts are likely to be much closer than most people realise, a a draft report from the world’s leading climate scientists suggests, and will fundamentally reshape life in the coming decades even if greenhouse gas emissions are brought under some control.

Analysis shows significant risk of cascading events even at 2C of heating, with severe long-term effects. The new research examined the interactions between ice sheets in West Antarctica, Greenland, the warm Atlantic Gulf Stream and the Amazon rainforest. The scientists carried out 3m computer simulations and found domino effects in a third of them, even when temperature rises were below 2C, the upper limit of the Paris agreement.

Sea ice land. 7 Tipping points are analysed here. Climate tipping points, elements of the Earth system in which small changes in global temperature can kick off reinforcing loops that ‘tip’ a system into a profoundly different state, accelerating heat waves, permafrost thaw, and coastal flooding — and, in some cases, fueling more warming.

The growing threat of abrupt and irreversible climate changes must compel political and economic action on emissions.

The persistent march of a warming climate is seen across a multitude of continuous, incremental changes. CO2 levels in the atmosphere. Ocean heat content. Global sea level rise. Each creeps up year after year, fuelled by human-caused greenhouse gas emissions.

The IPCC report sets out the world’s current knowledge of the impacts of 1.5C of warming and clearly shows the dangers of breaching such a limit. However, many scientists are increasingly worried about factors about which we know much less. These “known unknowns” of climate change are tipping points, or feedback mechanisms within the climate system – thresholds that, if passed, could send the Earth into a spiral of runaway climate change.