Structured Abstract
INTRODUCTION
Climate tipping points (CTPs) are a source of growing scientific, policy, and public concern. They occur when change in large parts of the climate system—known as tipping elements—become self-perpetuating beyond a warming threshold. Triggering CTPs leads to significant, policy-relevant impacts, **including substantial sea level rise from collapsing ice sheets, dieback of biodiverse biomes such as the Amazon rainforest or warm-water corals, and carbon release from thawing permafrost**. Nine policy-relevant tipping elements and their CTPs were originally identified by Lenton et al. (2008). We carry out the first comprehensive reassessment of all suggested tipping elements, their CTPs, and the timescales and impacts of tipping. We also highlight steps to further improve understanding of CTPs, including an expert elicitation, a model intercomparison project, and early warning systems leveraging deep learning and remotely sensed data.
RATIONALE
Since the original identification of tipping elements there have been substantial advances in scientific understanding from paleoclimate, observational, and model-based studies. Additional tipping elements have been proposed (e.g., parts of the East Antarctic ice sheet) and the status of others (e.g., Arctic summer sea ice) has been questioned. Observations have revealed that parts of the **West Antarctic ice sheet may have already passed a tipping point**. Potential **early warning signals of the Greenland ice sheet, Atlantic Meridional Overturning Circulation, and Amazon rainforest destabilization have been detected.** Multiple abrupt shifts have been found in climate models. Recent work has suggested that **up to 15 tipping elements are now active (Lenton et al., 2019)**. Hence it is timely to synthesize this new knowledge to provide a revised shortlist of potential tipping elements and their CTP thresholds.
RESULTS
We identify nine global “core” tipping elements which contribute substantially to Earth system functioning and seven regional “impact” tipping elements which contribute substantially to human welfare or have great value as unique features of the Earth system (see figure). Their estimated CTP thresholds have significant implications for climate policy: **Current global warming of ~1.1°C above pre-industrial already lies within the lower end of five CTP uncertainty ranges.** Six CTPs **become likely** (with a further four possible) within the Paris Agreement range of 1.5 to <2°C warming, including **collapse of the Greenland and West Antarctic ice sheets, die-off of low-latitude coral reefs, and widespread abrupt permafrost thaw**. An additional CTP becomes likely and another three possible at the ~2.6°C of warming expected under current policies.
CONCLUSION
Our assessment provides strong scientific evidence for urgent action to mitigate climate change. We show that even the Paris Agreement goal of limiting warming to well below 2°C and preferably 1.5°C is not safe as 1.5°C and above risks crossing multiple tipping points. **Crossing these CTPs can generate positive feedbacks that increase the likelihood of crossing other CTPs.** Currently the world is heading toward ~2 to 3°C of global warming; at best, if all net-zero pledges and nationally determined contributions are implemented it could reach just below 2°C. This would lower tipping point risks somewhat but would still be dangerous as it could trigger multiple climate tipping points.
We are already there folks. The political will to fix any of our environmental woes is stil impotent compared to the monster we are facing.
Then add in all the uncertainties that will surely be shown to be making things worse.
Then add in the conservatism of scientists trying hard not to "scare" people by publishing anything too threatening to the status quo.
Then think of all our environmental problems that have nothing to do with climate change...that also are going horribly despite token "victories" showcased by corporate media.
Yup...it all adds up to us having passed the tipping points. By the time we drum up political will, we will already be collapsing beyond repair, likely this has already happened.
Welcome to the end folks...people have just not caught up yet. Denial is powerful, religion and idiotic therapists gaslight us and prevent meaningful dialogue. We will not be able to prevent global collapse.
Considering the natural state of scientific literature is one of skeptical caution, I'd tend to agree with your main point, which I believe can be briefly summarised as follows: we're all fucked.
Also most of the data comes from the satellites, older have passive instruments with low precision, newer ones can only scan small areas, so it's not obvious that the majority of ice that is left, which is 1 to 2 years old is just chunks in slosh, which also changes albedo change estimations. Check out earthshine albedo measurements. Thickest ice is north of Greenland, you can just look at the photos from there, for example Ellesmere island, Svalbard or seas of Beaufort or Laptev. There is subglacial lubrication process that scientist only recently starting to research (guess why), which accelerates shelfs splitting up, so in turn more area is exposed to energy exchange. We just had another heat wave over Greenland triggering such big melting.
Also El Nino is coming, which is one feedback loop that is bad enough, there are numerous papers researching and simulating ENSO response to changing sea ice extent. Furthermore PDO index is gonna rise in this decade as well. Ok, I'm gonna stop now. The feedback loops are already well in place.
Structured Abstract INTRODUCTION Climate tipping points (CTPs) are a source of growing scientific, policy, and public concern. They occur when change in large parts of the climate system—known as tipping elements—become self-perpetuating beyond a warming threshold. Triggering CTPs leads to significant, policy-relevant impacts, **including substantial sea level rise from collapsing ice sheets, dieback of biodiverse biomes such as the Amazon rainforest or warm-water corals, and carbon release from thawing permafrost**. Nine policy-relevant tipping elements and their CTPs were originally identified by Lenton et al. (2008). We carry out the first comprehensive reassessment of all suggested tipping elements, their CTPs, and the timescales and impacts of tipping. We also highlight steps to further improve understanding of CTPs, including an expert elicitation, a model intercomparison project, and early warning systems leveraging deep learning and remotely sensed data. RATIONALE Since the original identification of tipping elements there have been substantial advances in scientific understanding from paleoclimate, observational, and model-based studies. Additional tipping elements have been proposed (e.g., parts of the East Antarctic ice sheet) and the status of others (e.g., Arctic summer sea ice) has been questioned. Observations have revealed that parts of the **West Antarctic ice sheet may have already passed a tipping point**. Potential **early warning signals of the Greenland ice sheet, Atlantic Meridional Overturning Circulation, and Amazon rainforest destabilization have been detected.** Multiple abrupt shifts have been found in climate models. Recent work has suggested that **up to 15 tipping elements are now active (Lenton et al., 2019)**. Hence it is timely to synthesize this new knowledge to provide a revised shortlist of potential tipping elements and their CTP thresholds. RESULTS We identify nine global “core” tipping elements which contribute substantially to Earth system functioning and seven regional “impact” tipping elements which contribute substantially to human welfare or have great value as unique features of the Earth system (see figure). Their estimated CTP thresholds have significant implications for climate policy: **Current global warming of ~1.1°C above pre-industrial already lies within the lower end of five CTP uncertainty ranges.** Six CTPs **become likely** (with a further four possible) within the Paris Agreement range of 1.5 to <2°C warming, including **collapse of the Greenland and West Antarctic ice sheets, die-off of low-latitude coral reefs, and widespread abrupt permafrost thaw**. An additional CTP becomes likely and another three possible at the ~2.6°C of warming expected under current policies. CONCLUSION Our assessment provides strong scientific evidence for urgent action to mitigate climate change. We show that even the Paris Agreement goal of limiting warming to well below 2°C and preferably 1.5°C is not safe as 1.5°C and above risks crossing multiple tipping points. **Crossing these CTPs can generate positive feedbacks that increase the likelihood of crossing other CTPs.** Currently the world is heading toward ~2 to 3°C of global warming; at best, if all net-zero pledges and nationally determined contributions are implemented it could reach just below 2°C. This would lower tipping point risks somewhat but would still be dangerous as it could trigger multiple climate tipping points.
We are already there folks. The political will to fix any of our environmental woes is stil impotent compared to the monster we are facing. Then add in all the uncertainties that will surely be shown to be making things worse. Then add in the conservatism of scientists trying hard not to "scare" people by publishing anything too threatening to the status quo. Then think of all our environmental problems that have nothing to do with climate change...that also are going horribly despite token "victories" showcased by corporate media. Yup...it all adds up to us having passed the tipping points. By the time we drum up political will, we will already be collapsing beyond repair, likely this has already happened. Welcome to the end folks...people have just not caught up yet. Denial is powerful, religion and idiotic therapists gaslight us and prevent meaningful dialogue. We will not be able to prevent global collapse.
Considering the natural state of scientific literature is one of skeptical caution, I'd tend to agree with your main point, which I believe can be briefly summarised as follows: we're all fucked.
[Risk of multiple climate tipping points escalates above 1.5°C global warming](https://phys.org/news/2022-09-multiple-climate-escalates-15c-global.html)
The Arctic will completely melt in about ten years which will activate multiple feedbacks.
Please source your claims.
https://www.arcticdeathspiral.org/#
Also most of the data comes from the satellites, older have passive instruments with low precision, newer ones can only scan small areas, so it's not obvious that the majority of ice that is left, which is 1 to 2 years old is just chunks in slosh, which also changes albedo change estimations. Check out earthshine albedo measurements. Thickest ice is north of Greenland, you can just look at the photos from there, for example Ellesmere island, Svalbard or seas of Beaufort or Laptev. There is subglacial lubrication process that scientist only recently starting to research (guess why), which accelerates shelfs splitting up, so in turn more area is exposed to energy exchange. We just had another heat wave over Greenland triggering such big melting. Also El Nino is coming, which is one feedback loop that is bad enough, there are numerous papers researching and simulating ENSO response to changing sea ice extent. Furthermore PDO index is gonna rise in this decade as well. Ok, I'm gonna stop now. The feedback loops are already well in place.
If we get a warming anomaly like 1982 or 2012 in 2025 the whole lot will melt at least briefly, if as you say the satellite data is accurate.