références en Anglais

Tipping elements within the Earth system are increasingly well understood. Scientists have identified more than 25 parts of the Earth’s climate system that are likely to have “tipping points” – thresholds where a small additional change in global warming will cause them to irreversibly shift into a new state. The “tipping” of these systems – which include the Atlantic Meridional Overturning Circulation (AMOC), the Amazon rainforest and the Greenland ice sheet – would have profound consequences for both the biosphere and people. More recent research suggests that triggering one tipping element could cause subsequent changes in other tipping elements, potentially leading to a “tipping cascade”. For example, a collapsed AMOC could lead to dieback of the Amazon rainforest and hasten the melt of the Greenland ice sheet.

Thousands of Greenland's crystal-clear blue lakes have turned a murky brown thanks to global warming — and the worst part is that they've started emitting carbon dioxide. Record heat and rain in 2022 pushed the lakes of West Greenland past a tipping point, so rather than absorbing carbon dioxide (CO₂), they began to emit it into the atmosphere, according to a new study.

The year 2024 wasn’t just another chapter in the unfolding climate saga; it felt like the plot twist no one wanted to believe. For decades, climate scientists warned of ifs — if we pass this tipping…

Oceanographer Stefan Rahmstorf explains why Amoc breakdown could be catastrophic for both humans and marine life

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.

Under current emission trajectories, temporarily overshooting the Paris global warming limit of 1.5 °C is a distinct possibility. Permanently exceeding this limit would substantially increase the probability of triggering climate tipping elements. Here, we investigate the tipping risks associated with several policy-relevant future emission scenarios, using a stylised Earth system model of four interconnected climate tipping elements.

Small increase in temperature of intruding water could lead to very big increase in loss of ice, scientists say

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.

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

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.

Collapse in system of currents that helps regulate global climate would be at such speed that adaptation would be impossible

Scientists now have a better understanding of the risks ahead and a new early warning signal to watch for.

RealClimate: A new paper was published in Science Advances today. Its title says what it is about: "Physics-based early warning signal shows that AMOC is on tipping course." The study follows one by Danish colleagues which made headlines last July, likewise looking for early warning signals for approaching an AMOC tipping point (we discussed it here),

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

By replacing thousands of equations with just one, ecology modelers can more accurately assess how close fragile environments are to a disastrous “tipping point.”

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.

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.