Possible tipping elements in the climate system.
Possible tipping elements in the climate system.
Interactions of climate tipping points (bottom) with associated tipping points in the socioeconomic system (top) on different time scales.[1]
Interactions of climate tipping points (bottom) with associated tipping points in the socioeconomic system (top) on different time scales.[1]

A tipping point in the climate system is a critical threshold that, when exceeded, leads to large and often irreversible changes in the state of the system. The term 'tipping point' is used by climate scientists to identify vulnerable features of the climate system.[2][3] If they 'tip', they are likely to have severe impacts on human society.[4][5]

The Intergovernmental Panel on Climate Change (IPCC) began considering the possibility of tipping points 20 years ago. At that time the IPCC concluded they would only be likely in the event of unmitigated global warming of 4 °C or more above preindustrial times. Tipping points are now considered to have significant probability at today's warming level of just over 1 °C, with high probability above 2 °C of global warming.[6]

Large-scale components of the Earth system that may pass a tipping point are called tipping elements.[7] At least 15 different elements of the climate system, such as the Greenland ice sheet and Antarctic ice sheets have been identified as possible tipping points.[8][9] A danger is that if the tipping point in one system is crossed, this could lead to a cascade of other tipping points.[10] If a cascade occurs, this could cause a hothouse Earth in which global average temperatures would be higher than at any period in the past 1.2 million years.[11]

Tipping points are not necessarily abrupt. For example, with average temperature rise of between 1.5 and 2 °C, the Greenland ice sheet would inexorably melt over millennia.[12][13] However, a 2021 study by the American Geophysical Union states that the Thwaites ice shelf in Antarctica has the potential to shatter by 2025.[14][15]


The 2021 IPCC Sixth Assessment Report defines a tipping point as a "critical threshold beyond which a system reorganizes, often abruptly and/or irreversibly".[16] It can be brought about by a small disturbance causing a disproportionately large change in the system. One set of definitions of "tipping points" also require self-reinforcing feedbacks, which could lead to changes in the climate system irreversible on a human timescale.[9] Palaeoclimate data and global climate models suggest that the "climate system may abruptly 'tip' from one regime to another in a comparatively short time."[17] For any particular climate component, the shift from one state to a new state may take many decades or centuries.[9]

The Special Report on the Ocean and Cryosphere in a Changing Climate released by the IPCC in 2019 defines a tipping point as: "A level of change in system properties beyond which a system reorganises, often in a non-linear manner, and does not return to the initial state even if the drivers of the change are abated. For the climate system, the term refers to a critical threshold at which global or regional climate changes from one stable state to another stable state. Tipping points are also used when referring to impact: the term can imply that an impact tipping point is (about to be) reached in a natural or human system".[18]

The term 'tipping point' has become a foundational concept in climate change science discussions and is used by climate scientists and the news media as a metaphor for "drastic, irreversible and dangerous climate change".[19][20]

Geological record

The geologic record of temperature and greenhouse gas concentration allows climate scientists to gather information on climate feedbacks that lead to different climate states. A key finding is that when the concentration of carbon dioxide in the atmosphere goes up, the average global temperature goes up with it.[21] In the last 100 million years, global temperatures have peaked twice, tipping the climate into a hothouse state. During the Cretaceous period, roughly 92 million years ago, CO2 levels were around 1,000 ppm.[22] The climate was so hot that crocodile-like reptiles lived in what is now the Canadian Arctic, and forests thrived near the South Pole. The second hothouse period was the Paleocene-Eocene Thermal Maximum (PETM) 55-56 million years ago. Records suggest that during the PETM, the average global temperature rose between 5 and 8 °C; there was no ice at the poles, allowing palm trees and crocodiles to live above the Arctic Circle.[23]

The geologic record fails to provide clarity as to whether past temperature changes have taken only a few decades or many millennia. In March 2020, researchers showed that larger ecosystems can 'collapse' faster than previously thought, the Amazon rainforest for example (to a savanna) within ~50 years and the coral reefs of the Caribbean within ~15 years once a mode of 'collapse' is triggered, which in case of Amazonia they estimate could be as early as in 2021.[24][25][26]

However, as recently as three million years ago, atmospheric concentrations of CO2 matched today's levels. At that time, average global temperatures were 3C higher than they are now and sea levels were 5-to-25 metres higher.[27]

Combining this historical information with the understanding of current climate change resulted in the finding published in 2018 in Proceedings of the National Academy of Sciences that "a 2 °C warming could activate important tipping elements, raising the temperature further to activate other tipping elements in a domino-like cascade that could take the Earth System to even higher temperatures".[11][10]

Tipping elements

Scientists have identified a large set of elements in the climate system which may have a tipping point.[28][9] It is possible that some tipping points are close to being crossed or have already been crossed, like the ice sheets in West Antarctic and Greenland, warm-water coral reefs, and the Amazon rainforest.[29][30]

Shutdown of the Atlantic Meridional Overturning Circulation

See also: Shutdown of thermohaline circulation

The Atlantic Meridional Overturning Circulation (AMOC), also known as the Gulf Stream System, is a large system of ocean currents.[31][32] It is driven by differences in the density of water; colder and more salty water is heavier than warmer fresh water.[32] The AMOC acts as a conveyor belt, sending warm surface water from the tropics north, and carrying cold fresh water back south.[31] As warm water flows northwards, some evaporates which increases salinity. It also cools when it is exposed to cooler temperatures and sea ice. Cold, salty water is more dense and slowly begins to sink.[33] Several kilometres below the surface, cold, dense water begins to move south. Increased rainfall and the melting of continental ice due to global warming is diluting surface sea water and warming it up. The lighter water is less able to sink, slowing down the circulation.[34]

Theory, simplified models, and reconstructions of abrupt changes in the past suggest the AMOC has a tipping point. If freshwater input from melting glaciers reaches a certain threshold, it could collapse into a state of reduced flow. Even after melting stops, the AMOC may not return to its current state. It is unlikely that the AMOC will tip in the 21st century,[35] but it may do so before 2300 if emissions are very high. A weakening of 24% to 39% is expected depending on greenhouse emissions, even without tipping behaviour.[36] If the AMOC does shut down, a new stable state could emerge that lasts for thousands of years, possibly triggering other tipping points.[34]

A 2021 study found early-warning signals in a set of AMOC indices,[37] suggesting that the AMOC "may be nearing a shutdown".[38]

West Antarctic ice sheet disintegration

The West Antarctic Ice Sheet (WAIS) is one of three regions making up Antarctica. In places it is more than 4 kilometres thick and sits on bedrock that largely lies below sea level.[39] As such, it is in contact with ocean heat, as well as warmer air which makes it vulnerable to rapid and irreversible ice loss. A tipping point could be reached if thinning or collapse of the WAIS's ice shelves triggers a feedback loop that leads to rapid and irreversible loss of land ice into the ocean - with the potential to raise sea levels by around 3.3 metres.[40]

Ice loss from WAIS is accelerating.[41] The palaeo record suggests that during the past few hundred thousand years, the WAIS largely disappeared in response to similar levels of warming and CO2 emission scenarios projected for the next few centuries.[42] A 2021 study of ocean floor sediments in the Antarctic's iceberg alley has shown that that tipping has occurred in the past on several occasions and that tipping can be sudden and full ice sheet retreat can take as little as ten years.[14]

Greenland ice sheet disintegration

The Greenland ice sheet is the second largest mass of ice in the world, and is three times the size of Texas.[43] It holds enough water, which if it melted, could raise global sea levels by 7.2 metres.[44] Due to global warming, the ice sheet is melting at an accelerating rate adding around 0.7 mm to global sea levels every year.[45] Around half of the ice loss occurs via surface melting, and the remainder occurs at the base of the ice sheet where the ice sheet touches the sea, by the breaking off, or 'calving', of icebergs from its edge.[46]

Snowfall in Greenland is no longer able to compensate for the loss of ice due to this melting, such that the disintegration of the ice sheet may now be inevitable.[47] Melting would not occur abruptly, but would be irreversible over millennia.[48][49]

Amazon rainforest dieback

See also: Deforestation of the Amazon rainforest and Climate change in Brazil

The Amazon rainforest is the largest tropical rainforest in the world. It is twice the size of India and spans nine countries in South America.[50] It generates around half of its own rainfall by recycling moisture through evaporation and transpiration as air moves across the forest.[51]

Deforestation of the Amazon began in the 1960s when colonists established farms in the forest. They generally slashed and burned the trees in order to cultivate crops. However, soils in the Amazon are only productive for a short period after the land is cleared, so farmers would simply move and clear more land.[52] Other colonists cleared land to raise cattle, leading to further deforestation and environmental damage.[53] Heatwaves and drought have now become a factor driving additional tree deaths. This indicates that the Amazon is experiencing climatic conditions beyond its adaptive limits.[54]

In 2021, the first long-term study of greenhouse gases in the Amazon rainforest found that in the 2010s the rainforest released more carbon dioxide than it absorbed.[55] The forest had previously been a carbon sink, but is now emitting a billion tonnes of carbon dioxide a year. Deforestation has led to fewer trees which means more severe droughts and heatwaves develop leading to more tree deaths and more fires.[56][57] In 2022, a study reported that resilience of the Amazon rainforest has been waning since the early 2000s. Resiliency is measured by recovery-time from short-term perturbations. The delayed return to a state of equilibrium of the rainforest is termed a critical slowing down (CSD). The observed CSD in the 2022 study reinforces the theory that the rainforest is approaching a critical transition.[58][59]

Permafrost and methane hydrates

See also: Gas hydrate stability zone and Permafrost carbon cycle

Permafrost is ground containing soil and/or organic material bound together by ice and which has remained frozen for at least two years.[60] It covers around a quarter of the non-glaciated land in the northern hemisphere – mainly in Siberia, Alaska, northern Canada and the Tibetan plateau – and can be as much as a kilometre thick.[61] Subsea permafrost up to 100 metres thick also occurs on the sea floor under part of the Arctic Ocean.[60] This frozen ground holds vast amounts of carbon, derived from plants and animals that have died and decomposed over thousands of years. Scientists believe there is nearly twice as much carbon in permafrost than is currently in the Earth's atmosphere.[62]

As the climate warms and the permafrost begins to thaw, carbon dioxide and methane are released into the atmosphere. Research conducted by the US National Oceanic and Atmospheric Administration (NOAA) in 2019 found that thawing permafrost across the Arctic “could be releasing an estimated 300-600m tonnes of net carbon per year to the atmosphere”.[63] In a Special Report on the Ocean and Cryosphere in a Changing Climate, the IPCC says there is “high confidence” in projections of “widespread disappearance of Arctic near-surface permafrost this century" which is "projected to release 10s to 100s of billions of tonnes [or gigatonnes, GtC], up to as much as 240 GtC, of permafrost carbon as CO2 and methane into the atmosphere".[64]

Warming in the Arctic allows the frozen permafrost to thaw, releasing locked up carbon dioxide and methane into the atmosphere.[65] In June 2019, satellite images from around the Arctic showed burning fires that are farther north and of greater magnitude than at any time in the 16-year satellite record, and some of the fires appear to have ignited peat soils.[66] Peat is an accumulation of partially decayed vegetation and is an efficient carbon sink.[67] Scientists are concerned because the long-lasting peat fires release their stored carbon back to the atmosphere, contributing to further warming. The fires in June 2019, for example, released as much carbon dioxide as Sweden's annual greenhouse gas emissions.[68]

Coral reef die-off

Main article: Coral bleaching

Around 500 million people around the world depend on coral reefs for food, income, tourism and coastal protection.[69] Since the 1980s, this is being threatened by the increase in sea surface temperatures which is triggering mass bleaching of coral, especially in sub-tropical regions.[70] A sustained ocean temperature spike of 1 °C (1.8 °F) above average is enough to cause bleaching.[71] Under continued heat stress, corals expel the tiny colourful algae which live in their tissues leaving behind a white skeleton. The algae, known as zooxanthellae, have a symbiotic relationship with coral such that without them, the corals slowly die.[72]

Between 1979 - 2010, 35 coral reef bleaching events were identified at a variety of locations.[73] Some bleaching events are relatively localised, but the frequency and severity of mass-bleaching events affecting coral over hundreds and sometimes thousands of kilometres has been increasing over the last few decades.[74] Mass bleaching events occurred in 1998, 2010, and between 2014–2017. This three year event affected more than 70 percent of the world's coral reefs, leaving two thirds of the Great Barrier Reef dead or severely bleached. Scientific American reports that the world has lost around 50% of coral reefs in the past 30 years.[75] The IPCC states that by the time temperatures have risen to 1.5C above pre-industrial times, between 70% and 90% of coral reefs that exist today will have disappeared; and that if the world warms by 2 °C, "coral reefs will be vanishingly rare".[76]

West African monsoon shift

See also: Monsoon § Africa (West African and Southeast African)

The West African Monsoon (WAM) system brings rainfall to West Africa and is the main source of rainfall in the agriculturally based region of the Sahel, an area of semi-arid grassland between the Sahara desert to the north and tropical rainforests to the south. The monsoon is a complex system in which land, ocean and atmosphere are connected is such a way that the wind direction reverses with the seasons.[77]

However, the monsoon is notoriously unreliable. Between the late 1960s and 1980s, the average rainfall declined by more than 30% plunging the region into an extended drought. This led to a famine that killed tens of thousands of people and triggered an international aid effort.[78] Research has shown the drought was largely due to changes in the surface temperatures of the global oceans, in particular, warming of the tropical oceans in response to rising greenhouse gases combined with cooling in the North Atlantic as a result of air pollution from northern hemisphere countries.[79]

The El Niño–Southern Oscillation

The possibility that El Niño–Southern Oscillation (ENSO) is a tipping element has been debated, but remains uncertain.[80] Normally strong winds blow west across the South Pacific Ocean from South America to Australia. Every two to seven years, the winds weaken due to pressure changes and the air and water in the middle of the Pacific warms up, causing changes in wind movement patterns around the globe. This known as El Niño and typically leads to droughts in Indonesia, India and Brazil, and increased flooding in Peru. In 2015/2016, this caused food shortages affecting over 60 million people.[81] El Niño-induced droughts may increase the likelihood of forest fires in the Amazon.[82]

The threshold for tipping is estimated between 3.5 and 7 °C of global warming.[83] After tipping, the system would be in a more permanent El Niño state, rather than oscillating between different states. This has happened in Earth's past, in the Pliocene, but the layout of the ocean was significantly different from now.[80] So far, there is no definitive evidence indicating changes in ENSO behaviour.[84]

Arctic sea ice

The IPCC finds that Arctic sea ice loss does not represent a tipping point because “projected losses are potentially reversible”. Sea ice coverage and global temperatures are found to vary directly without the exponential increase in loss characteristic of a tipping point.[85] However, this is dependent on the time scale. Arctic sea ice has been melting rapidly for several decades, and loss of arctic sea ice during the summer months is being viewed as particularly concerning by many climate scientists. Despite the lack of a "textbook" tipping point, many researchers agree that sea ice loss will have a warming effect on global climate due to the ice-albedo feedback.[86][87][88]

Tipping point effects

See also: Effects of climate change

If the climate tips into a state where tipping points begin to cascade, crisis related to intensifying disasters and unpredictable productivity of land will become more common. Hundreds of millions of people will be displaced by rising sea levels, and coastal storms will have greater impacts on life and property. Food and water shortages associated with more severe droughts and floods will occur, and people will die from unhealthy heat levels and generally unlivable conditions.[89] Climatologist Michael E. Mann believes a global temperature increase of 3 degrees Celsius or more has the potential to trigger collapse of the current societal organization and set the stage for massive unrest and global conflict.[90][91] The IPCC however describes a high probability that tipping points will occur at temperatures above just 2 degrees C of global warming.[92]

If cascading tipping points lead to climate temperature increases of 4–5 °C, this will make swaths of the planet around the equator uninhabitable, and lead to sea levels up to 60 metres (197 ft) higher than they are today.[93] Hans Joachim Schellnhuber, Director of the Potsdam Institute for Climate Impact Research says if the world warms by this amount, it could only sustain about one billion people.[94]

A 2021 meta study, conducted by Simon Dietz, James Rising, Thomas Stoerk, and Gernot Wagner, on the potential economic impact of tipping points found that they raise global risk; the medium estimate was that they increase the social cost of carbon (SCC) by about 25%, with a 10% chance of tipping points more than doubling the SCC.[95] Effects like these have been popularized in books like The Uninhabitable Earth, The End of Nature, and Gernot Wagner & Martin L. Weitzman's Climate Shock.

Mathematical theory

Tipping point behaviour in the climate can be described in mathematical terms. Tipping points are then seen as any type of bifurcation with hysteresis,[96][97] which is the dependence of the state of a system on its history. For instance, depending on how warm or cold it was in the past, there can be differing amounts of ice on the poles at the same concentration of greenhouse gases or temperature.[98] In a 2012 study inspired by "mathematical and statistical approaches to climate modelling and prediction", the authors identify three types of tipping points in open systems such as the climate system—bifurcation, noise-induced and rate-dependent.[17]


Bifurcation-induced tipping

This occurs when a particular parameter in the climate, which is observed to be consistently moving in a given direction over a period of time, eventually passes through a critical level - at which point a dangerous bifurcation, or fork takes place - and what was a stable state loses its stability or simply disappears.[99] The Atlantic Meridional Overturning Circulation (AMOC) is like a conveyor belt driven by thermohaline circulation. Slow changes to the bifurcation parameters in this system — the salinity, temperature and density of the water - have caused circulation to slow down by about 15% in the last 70 years or so. If it reaches a critical point where it stops completely, this would be an example of bifurcation induced tipping.[100][101]

Noise-induced tipping

This refers to transitions from one state to another due to random fluctuations or internal variability of the system. Noise-induced transitions show none of the early warning signals which occur with bifurcations. This means they are fundamentally unpredictable as there is no systematic change in the underlying parameters. Because they are unpredictable, such occurrences are often described as a ‘one-in-x-year’ event.[102] An example is the Dansgaard–Oeschger events during the last glacial period, with 25 occurrences of sudden climate fluctuations over a 500 year period.[103]

Rate-induced tipping

This aspect of tipping assumes that there is a unique, stable state for any fixed aspect or parameter of the climate and that, if left undisturbed, there will only be small responses to a ‘small’ stimulus. However, when changes in one of the system parameters begin to occur more rapidly, a very large 'excitable' response may appear. In the case of peatlands, for instance, after years of relative stability, the rate-induced tipping point leads to an "explosive release of soil carbon from peatlands into the atmosphere" - sometimes known as "compost bomb instability".[104][105]

Early warning signals

For tipping points that occur because of a bifurcation, it may be possible to detect whether they are getting closer to a tipping point, as the system is getting less resilient to perturbations on approach of the tipping threshold. These systems display critical slowing down, with an increased memory (rising autocorrelation) and variance. Depending on the nature of the tipping system, changes may also be detected in the skewness and kurtosis of time series of relevant variables, with asymmetries in the distributions of anomalies indicating that tipping may be close.[106][107] Abrupt change is not an early warning signal (EWS) for tipping points, as abrupt change can also occur if the changes are reversible to the control parameter.[108][109]

These EWSs are often developed and tested using time series from the paleorecord, like sediments, ice caps, and tree rings, where past examples of tipping can be observed.[106][110] It is not always possible to say whether increased variance and autocorrelation is a precursor to tipping, or caused by internal variability, for instance in the case of the collapse of the AMOC.[110] Quality limitations of paleodata further complicate the development of EWSs.[110] They have been developed for detecting tipping due to drought in forests in California,[111] the Pine Island Glacier in West Antarctica,[109] among other systems. Using early warning signals (increased autocorrelation and variance of the melt rate time series), it has been suggested that the Greenland ice sheet is currently losing resilience, consistent with modelled early warning signals of the ice sheet.[112]

However because the temperature is increasing so quickly there may be no warning.[113]: 1–66 

Cascading tipping points

Crossing a threshold in one part of the climate system may trigger another tipping element to tip into a new state. These are called cascading tipping points.[114] Ice loss in West Antarctica and Greenland will significantly alter ocean circulation. Sustained warming of the northern high latitudes as a result of this process could activate tipping elements in that region, such as permafrost degradation, and boreal forest dieback.[3] Thawing permafrost poses a multiplier threat because it holds roughly twice as much carbon as the amount currently circulating in the atmosphere.[115] If this is released into the atmosphere, the world will have to cope with emissions generated by the planet itself as well as those generated by human use of fossil fuels.[116]

A 2021 study with three million computer simulations of a climate model showed that nearly one-third of those simulations resulted in domino effects even when temperature increases were limited to 2 °C – the upper limit set by the Paris Agreement in 2015.[117] The authors of the study said that the science of tipping points is complex such that there is great uncertainty as to how they might unfold, but nevertheless, argue that the possibility of cascading tipping points represents “an existential threat to civilisation”.[118] In July 2021, Nature Geoscience published a review illustrating how cascading interactions in the Earth system have led to abrupt changes in climate, ecological and social systems during the past 30,000 years. The authors point out that "the geological record shows that abrupt changes can occur on timescales short enough to challenge the capacity of human societies to adapt to environmental pressures".[110]

Public concern

In April and May 2021, Ipsos Mori conducted an opinion survey in the G20 nations on behalf of the Global Commons Alliance (GCA). The results, published in August 2021, found 73% of those surveyed believe "Because of human activities, the Earth is close to ‘tipping points’ in nature where climate or nature may change suddenly, or may be more difficult to stabilise in the future".[119]: 34  People in poorer countries such as Indonesia, Turkey, and Brazil were significantly more aware of the risk of triggering tipping points than those in wealthier countries such as the United States, Japan, Great Britain and Australia.[119]

Runaway greenhouse effect

Main article: Runaway greenhouse effect

The runaway greenhouse effect is used in astronomical circles to refer to a greenhouse effect that is so extreme that oceans boil away and render a planet uninhabitable, an irreversible climate state that happened on Venus. The IPCC Fifth Assessment Report states that "a 'runaway greenhouse effect' —analogous to Venus— appears to have virtually no chance of being induced by anthropogenic activities."[120] Venus-like conditions on the Earth require a large long-term forcing that is unlikely to occur until the sun brightens by a few tens of percents, which will take a few billion years.[121]

Social tipping points and climate models

Tipping points as they relate to human behavior can have both positive and negative effects, contrasting with the normally negative connotation associated with climate tipping points. Some positive tipping points in societal behavior can drive positive climate action. There is a strong link between human behavior and environmental stability, which is not easily accounted for in climate models, such as the ongoing Lake Chad crisis.[122] The interaction of the socio-economic and regional changes induced by the climate in the Lake Chad region produces behaviors in society that change the environmental course of the region. For example, a lack of sustainable resource usage creates deep societal instabilities which prevent positive climate action from being enacted. It is this type of response, which needs to be accounted for in climate models in regions across the globe if we are to improve the accuracy of climate prediction and when and where tipping points will occur.[123]

Local environmental issues have the ability to affect regions across the globe. This effect of ecosystems or social systems at a distance is called telecoupling and can be realized when crop-producing regions experience a drought that causes a food shortage elsewhere.

Climate models that allow human behavior to change the state of the system are called Integrated Assessment Models (IAM). Current models, such as DICE, FUND, and REMIND do not account for the societal changes that could be caused by social tipping points which would drastically change the results. [124] Because of the deeply intertwined relationship between the environment and humanity, accurately modeling social tipping points is necessary for predicting the future of Earth’s climate and is an active area of research.[123]

See also


  1. ^ Otto, I.M. (4 February 2020). "Social tipping elements for stabilizing climate by 2050". PNAS. 117 (5): 2354–2365. doi:10.1073/pnas.1900577117. PMC 7007533. PMID 31964839.
  2. ^ "IPCC steps up warning on climate tipping points in leaked draft report". The Guardian. 23 June 2021. Archived from the original on 22 July 2021. Retrieved 22 July 2021.
  3. ^ a b Lenton, TimothyM.; Rockström, Johan; Gaffney, Owen; Rahmstorf, Stefan; Richardson, Katherine; Steffen, Will; Schellnhuber, Hans Joachim (27 November 2019). "Climate tipping points — too risky to bet against". Nature. 575 (7784): 592–595. Bibcode:2019Natur.575..592L. doi:10.1038/d41586-019-03595-0. PMID 31776487.
  4. ^ Climate tipping points could topple like dominoes, warn scientists, The Guardian, 3 June 2021
  5. ^ Climate change driving entire planet to dangerous 'tipping point‘, National Geographic, 28 November 2019
  6. ^ Lenton, Timothy M. (2021). "Tipping points in the climate system". Weather. 76 (10): 325–326. doi:10.1002/wea.4058. ISSN 0043-1656.
  7. ^ Lenton, T.M.; Held, H.; Kriegler, E.; Hall, J.W.; Lucht, W.; Rahmstorf, S.; Schellnhuber, H.J. (2008). "Tipping elements in the Earth's climate system". Proceedings of the National Academy of Sciences. 105 (6): 1786–1793. Bibcode:2008PNAS..105.1786L. doi:10.1073/pnas.0705414105. PMC 2538841. PMID 18258748.
  8. ^ Climate scientists fear tipping points (maybe you should too) Archived 14 November 2021 at the Wayback Machine, PhysOrg, 25 October 2021.
  9. ^ a b c d Explainer: Nine ‘tipping points’ that could be triggered by climate change Archived 11 February 2020 at the Wayback Machine, Carbon Brief, 10 February 2020
  10. ^ a b Wunderling, Nico; Donges, Jonathan F.; Kurths, Jürgen; Winkelmann, Ricarda (3 June 2021). "Interacting tipping elements increase risk of climate domino effects under global warming". Earth System Dynamics. 12 (2): 601–619. Bibcode:2021ESD....12..601W. doi:10.5194/esd-12-601-2021. ISSN 2190-4979. S2CID 236247596. Archived from the original on 4 June 2021. Retrieved 4 June 2021.
  11. ^ a b Sheridan, Kerry (6 August 2018). "Earth risks tipping into 'hothouse' state: study". Phys.org. Archived from the original on 3 October 2019. Retrieved 8 August 2018. Hothouse Earth is likely to be uncontrollable and dangerous to many ... global average temperatures would exceed those of any interglacial period—meaning warmer eras that come in between Ice Ages—of the past 1.2 million years.
  12. ^ Frank Pattyn; Catherine Ritz; Edward Hanna; Xylar Asay-Davis; Rob DeConto; Gaël Durand; Lionel Favier; Xavier Fettweis; Heiko Goelzer; Nicholas R. Golledge; Peter Kuipers Munneke; Jan T. M. Lenaerts; Sophie Nowicki; Antony J. Payne; Alexander Robinson; Hélène Seroussi; Luke D. Trusel; Michiel van den Broeke (2018). "The Greenland and Antarctic ice sheets under 1.5 °C global warming". Nature Climate Change. Journal Nature. 8 (12): 1053–1061. Bibcode:2018NatCC...8.1053P. doi:10.1038/s41558-018-0305-8. S2CID 91886763.
  13. ^ "Tipping points in Antarctic and Greenland ice sheets". NESSC. 12 November 2018. Archived from the original on 26 February 2019. Retrieved 25 February 2019.
  14. ^ a b Douglas, Benn I.; Luck, Adrian; Åström, Jan A.; Crawford, Anna; Cornford, Stephen L.; Bevan, Suzanne L.; Gladstone, Rupert; Zwinger, Thomas; Alley, Karen; Pettit, Erin; Bassis, Jeremy (20 September 2021). "Rapid fragmentation of Thwaites Eastern Ice Shelf, West Antarctica". The Cryosphere Discussions: 1–25. doi:10.5194/tc-2021-288. S2CID 240588326. Retrieved 25 January 2022.
  15. ^ Pettit, Erin C.; Wild, Christian; Alley, Karen; Muto, Atsuhiro; Truffer, Martin; Bevan, Suzanne Louise; Bassis, Jeremy N.; Crawford, Anna; Scambos, Ted A.; Benn, Doug (15 December 2021). Collapse of Thwaites Eastern Ice Shelf by intersecting fractures. AGU Fall Meeting. New Orleans: American Geophysical Union. C34A-07.
  16. ^ "IPCC AR6 WG1 Ch4" (PDF). p. 95. Archived (PDF) from the original on 5 September 2021. Retrieved 14 November 2021.
  17. ^ a b Ashwin, Peter; Wieczorek, Sebastian; Vitolo, Renato; Cox, Peter (13 March 2012). "Tipping points in open systems: bifurcation, noise-induced and rate-dependent examples in the climate system". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 370 (1962): 1166–1184. arXiv:1103.0169. Bibcode:2012RSPTA.370.1166A. doi:10.1098/rsta.2011.0306. ISSN 1364-503X. PMID 22291228. S2CID 2324694.
  18. ^ "Glossary — Special Report on the Ocean and Cryosphere in a Changing Climate". Archived from the original on 16 August 2021. Retrieved 10 July 2021.
  19. ^ Van der Hel, Sandra; Hellsten, Iina; Steen, Gerard (4 July 2018). "Tipping Points and Climate Change: Metaphor Between Science and the Media". Environmental Communication. 12 (5): 605–620. doi:10.1080/17524032.2017.1410198. ISSN 1752-4032. S2CID 148622067.
  20. ^ As Arctic warms, scientists wrestle with its climate ‘tipping point’, Mongabay, 15 July 2021
  21. ^ Temperature Change and Carbon Dioxide Change Archived 9 August 2021 at the Wayback Machine, NOAA
  22. ^ Sheridan, Kerry (6 August 2018). "Earth risks tipping into 'hothouse' state: study". Phys.org. Retrieved 8 August 2018. Hothouse Earth is likely to be uncontrollable and dangerous to many ... global average temperatures would exceed those of any interglacial period—meaning warmer eras that come in between Ice Ages—of the past 1.2 million years.
  23. ^ What's the hottest Earth's ever been? Archived 19 May 2019 at the Wayback Machine NOAA, Climate.gov, June 18, 2020.
  24. ^ "Ecosystems the size of Amazon 'can collapse within decades'". The Guardian. 10 March 2020. Archived from the original on 12 April 2020. Retrieved 10 March 2020.
  25. ^ "Amazon rainforest could be gone within a lifetime". EurekAlert!. 10 March 2020. Archived from the original on 11 March 2020. Retrieved 10 March 2020.
  26. ^ Cooper, Gregory S.; Willcock, Simon; Dearing, John A. (10 March 2020). "Regime shifts occur disproportionately faster in larger ecosystems". Nature Communications. 11 (1): 1175. Bibcode:2020NatCo..11.1175C. doi:10.1038/s41467-020-15029-x. ISSN 2041-1723. PMC 7064493. PMID 32157098.
  27. ^ Climate scientists fear tipping points (maybe you should too) Archived 14 November 2021 at the Wayback Machine, PhysOrg, 25 October 2021
  28. ^ Defined in IPCC_AR6_WGI_Chapter_04 Archived 5 September 2021 at the Wayback Machine, p.95, line 34.
  29. ^ Critical measures of global heating reaching tipping point, study finds Archived 22 August 2021 at the Wayback Machine, The Guardian, 28 July 2021
  30. ^ Ripple, William J; Wolf, Christopher; Newsome, Thomas M; Gregg, Jillian W; Lenton, Timothy M; Palomo, Ignacio; Eikelboom, Jasper A J; Law, Beverly E; Huq, Saleemul; Duffy, Philip B; Rockström, Johan (28 July 2021). "World Scientists' Warning of a Climate Emergency 2021". BioScience. 71 (biab079): 894–898. doi:10.1093/biosci/biab079. hdl:1808/30278. ISSN 0006-3568.
  31. ^ a b Gulf Stream System at its weakest in over a millennium Archived 25 February 2021 at the Wayback Machine, Science Daily, February 25, 2021
  32. ^ a b "What is the Atlantic Meridional Overturning Circulation?". Met Office. Retrieved 26 November 2021.
  33. ^ Why does the ocean get colder at depth? Archived 13 July 2021 at the Wayback Machine National ocean Service
  34. ^ a b Explainer: Nine ‘tipping points’ that could be triggered by climate change Archived 11 February 2020 at the Wayback Machine, Carbon Brief, 10 Feb 2020
  35. ^ Met Office (December 2019). "Risk management of climate thresholds and feedbacks: Atlantic Meridional Overturning Circulation (AMOC)" (PDF). Retrieved 25 November 2021.
  36. ^ Fox-Kemper, Baylor; Hewitt, Helene T.; Xiao, Cunde; Aðalgeirsdóttir, Guðfinna; et al. (2021). "Chapter 9: Ocean, cryosphere, and sea level change" (PDF). IPCC AR6 WG1 2021. Section
  37. ^ Boers, N. Observation-based early-warning signals for a collapse of the Atlantic Meridional Overturning Circulation. Archived 7 August 2021 at the Wayback Machine Nat. Clim. Chang. 11, 680–688 (2021).
  38. ^ Climate crisis: Scientists spot warning signs of Gulf Stream collapse Archived 7 August 2021 at the Wayback Machine, The Guardian, 5 August 2021
  39. ^ Bedmap2: improved ice bed, surface and thickness datasets for Antarctica Archived 21 June 2021 at the Wayback Machine, The Cryosphere, 7, 375–393, 2013
  40. ^ Reassessment of the Potential Sea-Level Rise from a Collapse of the West Antarctic Ice Sheet Archived 19 June 2021 at the Wayback Machine, Science 15 May 2009: Vol. 324, Issue 5929, pp. 901-903
  41. ^ Mass balance of the Antarctic Ice Sheet from 1992 to 2017 Archived 25 July 2021 at the Wayback Machine, Nature, volume 558, pages219–222 (2018)
  42. ^ Stability of the West Antarctic ice sheet in a warming world Archived 14 June 2021 at the Wayback Machine, Nature Geoscience (2011) Volume 4, pp 506–513
  43. ^ Quick Facts on Ice Sheets Archived 28 July 2021 at the Wayback Machine, National Snow and Ice Data centre
  44. ^ New climate models suggest faster melting of the Greenland Ice Sheet Archived 28 July 2021 at the Wayback Machine, World Economic Forum, 21 December 2020
  45. ^ Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise Archived 22 October 2021 at the Wayback Machine, GEOPHYSICAL RESEARCH LETTERS, VOL. 38, L05503, doi:10.1029/2011GL046583, 2011
  46. ^ A Full-Stokes 3-D Calving Model Applied to a Large Greenlandic Glacier Archived 28 July 2021 at the Wayback Machine, AGU, 30 January 2018
  47. ^ Greenland ice melting past 'tipping point': Study. Archived 28 July 2021 at the Wayback Machine New Straits Times, 18 August 2020
  48. ^ Lee, June-Yi; Marotzke, Jochem; Bala, Govindasamy; Cao, Cao; et al. (2021). "Chapter 4: Future global climate: scenario-based projections and near-term information" (PDF). IPCC AR6 WG1. Table 4.10.
  49. ^ Ruth Mottram - The melting of Greenland's ice sheet Archived 28 July 2021 at the Wayback Machine, RNZ, 31 August 2019.
  50. ^ Inside the Amazon Archived 9 December 2020 at the Wayback Machine, WWF
  51. ^ Recycling of water in the Amazon Basin: An isotopic study Archived 18 June 2021 at the Wayback Machine, Water Resources Research
  52. ^ Watkins and Griffiths, J. (2000). Forest Destruction and Sustainable Agriculture in the Brazilian Amazon: a Literature Review (Doctoral dissertation, The University of Reading, 2000). Dissertation Abstracts International, 15-17
  53. ^ Williams, M. (2006). Deforesting the Earth: From Prehistory to Global Crisis. Chicago, IL: The University of Chicago Press.
  54. ^ Huge study reveals why trees in the Amazon die Archived 14 July 2021 at the Wayback Machine, European Scientist, 11 November 2020
  55. ^ First study of all Amazon greenhouse gases suggests the damaged forest is now worsening climate change Archived 14 July 2021 at the Wayback Machine, National Geographic, 12 March 2021
  56. ^ Amazon rainforest now emitting more CO2 than it absorbs Archived 14 July 2021 at the Wayback Machine, The Guardian, 14 July 2021
  57. ^ Preventing An Amazon Forest Dieback Archived 14 July 2021 at the Wayback Machine, Earth Innovation Institute, March 2020
  58. ^ "Climate crisis: Amazon rainforest tipping point is looming, data shows". The Guardian. 7 March 2022. Retrieved 18 April 2022.
  59. ^ Boulton, Chris A.; Lenton, Timothy M.; Boers, Niklas (March 2022). "Pronounced loss of Amazon rainforest resilience since the early 2000s". Nature Climate Change. 12 (3): 271–278. Bibcode:2022NatCC..12..271B. doi:10.1038/s41558-022-01287-8. ISSN 1758-6798. S2CID 247255222.
  60. ^ a b All About Frozen Ground Archived 17 July 2021 at the Wayback Machine, National Snow and Ice Data centre
  61. ^ Statistics and characteristics of permafrost and ground-ice distribution in the Northern Hemisphere Archived 20 October 2021 at the Wayback Machine, Polar Geography, Volume 31, 2008
  62. ^ All About Frozen Ground Archived 20 July 2021 at the Wayback Machine, National Snow and Ice Data Centre
  63. ^ A Arctic Report Card: Update for 2019 Archived 19 July 2021 at the Wayback Machine, NOAA Arctic programme
  64. ^ S Special Report on the Ocean and Cryosphere in a Changing Climate Archived 12 July 2021 at the Wayback Machine, IPCC
  65. ^ Arctic Circle sees 'highest-ever' recorded temperatures Archived 28 July 2021 at the Wayback Machine, BBC, 22 June 2020
  66. ^ Hines, Morgan (23 January 2019). "Thanks to climate change, parts of the Arctic are on fire. Scientists are concerned". USA Today. Archived from the original on 6 October 2019. Retrieved 30 August 2019.
  67. ^ Hugron, Sandrine; Bussières, Julie; Rochefort, Line (2013). Tree plantations within the context of ecological restoration of peatlands: practical guide (PDF) (Report). Laval, Québec, Canada: Peatland Ecology Research Group (PERG). Archived (PDF) from the original on 16 October 2017. Retrieved 22 February 2014.
  68. ^ Edward Helmore (26 July 2019). "'Unprecedented': more than 100 Arctic wildfires burn in worst ever season". The Guardian. Archived from the original on 27 July 2019. Retrieved 30 August 2019.
  69. ^ Scientists are trying to save coral reefs. Here's what's working. Archived 24 July 2021 at the Wayback Machine National Geographic, 5 June 2020
  70. ^ Hughes, TP, Kerry, JT, Álvarez-Noriega, M et al. (43 more authors) (2017) Global warming and recurrent mass bleaching of corals Archived 22 July 2021 at the Wayback Machine. Nature, 543 (7645). pp. 373-377.
  71. ^ A most beautiful death Archived 24 July 2021 at the Wayback Machine, Time
  72. ^ ‘Bright white skeletons’: some Western Australian reefs have the lowest coral cover on record Archived 22 July 2021 at the Wayback Machine, The Conversation
  73. ^ Impact of Global Warming on Coral Reefs Archived 8 March 2021 at the Wayback Machine, WJST 2011
  74. ^ Mass Bleaching Archived 24 July 2021 at the Wayback Machine, Reef Resilience Network
  75. ^ Scientists Are Taking Extreme Steps to Help Corals Survive Archived 24 July 2021 at the Wayback Machine, Scientific American, 1 January 2018
  76. ^ The Great Barrier Reef is a victim of climate change – but it could be part of the solution Archived 27 July 2021 at the Wayback Machine, The Guardian, 26 July 2021
  77. ^ Transport pathways across the West African Monsoon as revealed by Lagrangian Coherent Structures Archived 16 July 2021 at the Wayback Machine, Scientific Reports volume 10, Article number: 12543 (2020)
  78. ^ Sahel Drought: Understanding the Past and Projecting into the Future Archived 18 July 2021 at the Wayback Machine, Geophysical Fluid Dynamics Laboratory
  79. ^ The role of aerosols and greenhouse gases in Sahel drought and recovery Archived 31 August 2021 at the Wayback Machine, Climatic Change volume 152, pages449–466 (2019)
  80. ^ a b Wunderling, Nico; Donges, Jonathan F.; Kurths, Jürgen; Winkelmann, Ricarda (3 June 2021). "Interacting tipping elements increase risk of climate domino effects under global warming". Earth System Dynamics. 12 (2): 601–619. Bibcode:2021ESD....12..601W. doi:10.5194/esd-12-601-2021. ISSN 2190-4979. S2CID 236247596.
  81. ^ Tipping Points: Why we might not be able to reverse climate change Archived 11 August 2021 at the Wayback Machine, Climate Science, 3 June 2021
  82. ^ Tipping the ENSO into a permanent El Niño can trigger state transitions in global terrestrial ecosystems Archived 11 August 2021 at the Wayback Machine, Earth System Dynamics, 10, 631–650, 2019
  83. ^ Schellnhuber, Hans Joachim; Rahmstorf, Stefan; Winkelmann, Ricarda (2016). "Why the right climate target was agreed in Paris". Nature Climate Change. 6 (7): 649–653. Bibcode:2016NatCC...6..649S. doi:10.1038/nclimate3013. ISSN 1758-6798.
  84. ^ Tipping the ENSO into a permanent El Niño can trigger state transitions in global terrestrial ecosystems Archived 11 August 2021 at the Wayback Machine, Earth System Dynamics, 10, 631–650, 2019
  85. ^ IPCC_AR6_WGI_TS.pdf Archived 11 August 2021 at the Wayback Machine, p.43
  86. ^ Tipping elements in the Earth's climate system, PNAS, 12February 2008
  87. ^ Climate tipping points — too risky to bet against, Nature, 27 November 2019
  88. ^ Irreversible warming tipping point possibly triggered: Arctic mission chief, PhysOrg, 15 June 2021
  89. ^ Schellnhuber, Hans Joachim; Winkelmann, Ricarda; Scheffer, Marten; Lade, Steven J.; Fetzer, Ingo; Donges, Jonathan F.; Crucifix, Michel; Cornell, Sarah E.; Barnosky, Anthony D. (2018). "Trajectories of the Earth System in the Anthropocene". Proceedings of the National Academy of Sciences. 115 (33): 8252–8259. Bibcode:2018PNAS..115.8252S. doi:10.1073/pnas.1810141115. ISSN 0027-8424. PMC 6099852. PMID 30082409.
  90. ^ Pester, Patrick (30 August 2021). "Could climate change make humans go extinct?". Live Science. Archived from the original on 30 August 2021. Retrieved 31 August 2021.
  91. ^ Steffen, Will; Persson, Åsa; Deutsch, Lisa; Zalasiewicz, Jan; Williams, Mark; Richardson, Katherine; Crumley, Carole; Crutzen, Paul; Folke, Carl; Gordon, Line; Molina, Mario; Ramanathan, Veerabhadran; Rockström, Johan; Scheffer, Marten; Schellnhuber, Hans Joachim; Svedin, Uno (12 October 2011). "The Anthropocene: From Global Change to Planetary Stewardship". AMBIO. 40 (7): 739–761. doi:10.1007/s13280-011-0185-x. ISSN 1654-7209. PMC 3357752. PMID 22338713.
  92. ^ Tipping points in the climate system, Royal Meteorological Society, 18 August 2021.
  93. ^ "Earth 'just decades away from global warming tipping point which threatens future of humanity'". ITV News. 6 August 2018. Archived from the original on 26 February 2019. Retrieved 25 February 2019.
  94. ^ Earth risks tipping into 'hothouse' state: study Archived 3 October 2019 at the Wayback Machine, PhysOrg, 6 August 2018
  95. ^ Simon Dietz; James Rising; Thomas Stoerk; Gernot Wagner (24 August 2021). "Economic impacts of tipping points in the climate system". Proceedings of the National Academy of Sciences of the United States of America. 118 (34): e2103081118. Bibcode:2021PNAS..11803081D. doi:10.1073/pnas.2103081118. PMC 8403967. PMID 34400500.
  96. ^ Lenton, Timothy M.; Williams, Hywel T.P. (2013). "On the origin of planetary-scale tipping points". Trends in Ecology and Evolution. 28 (7): 380–382. doi:10.1016/j.tree.2013.06.001. PMID 23777818.
  97. ^ Smith, Adam B.; Revilla, Eloy; Mindell, David P.; Matzke, Nicholas; Marshall, Charles; Kitzes, Justin; Gillespie, Rosemary; Williams, John W.; Vermeij, Geerat (2012). "Approaching a state shift in Earth's biosphere". Nature. 486 (7401): 52–58. Bibcode:2012Natur.486...52B. doi:10.1038/nature11018. hdl:10261/55208. ISSN 1476-4687. PMID 22678279. S2CID 4788164.
  98. ^ Pollard, David; DeConto, Robert M. (2005). "Hysteresis in Cenozoic Antarctic ice-sheet variations". Global and Planetary Change. 45 (1–3): 9–12. Bibcode:2005GPC....45....9P. doi:10.1016/j.gloplacha.2004.09.011.
  99. ^ Tipping Phenomena And Points Of No Return In Ecosystems: Beyond Classical Bifurcations Archived 11 July 2021 at the Wayback Machine, 22 November 2020.
  100. ^ Boulton, Chris A.; Allison, Lesley C.; Lenton, Timothy M. (December 2014). "Early warning signals of Atlantic Meridional Overturning Circulation collapse in a fully coupled climate model". Nature Communications. 5 (1): 5752. Bibcode:2014NatCo...5.5752B. doi:10.1038/ncomms6752. ISSN 2041-1723. PMC 4268699. PMID 25482065.
  101. ^ Dijkstra, Henk A. "Characterization of the multiple equilibria regime in a global ocean model." Tellus A: Dynamic Meteorology and Oceanography 59.5 (2007): 695–705.
  102. ^ Early warning of climate tipping points Archived 9 July 2021 at the Wayback Machine, Nature Climate Change, 19 June 2011, p.203
  103. ^ Ditlevsen, Peter D.; Johnsen, Sigfus J. (2010). "Tipping points: Early warning and wishful thinking". Geophysical Research Letters. 37 (19): n/a. Bibcode:2010GeoRL..3719703D. doi:10.1029/2010GL044486. ISSN 1944-8007.
  104. ^ Wieczorek, S.; Ashwin, P.; Luke, C. M.; Cox, P. M. (8 May 2011). "Excitability in ramped systems: the compost-bomb instability". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences. 467 (2129): 1243–1269. Bibcode:2011RSPSA.467.1243W. doi:10.1098/rspa.2010.0485. ISSN 1364-5021.
  105. ^ Luke, C. M.; Cox, P. M. (2011). "Soil carbon and climate change: from the Jenkinson effect to the compost-bomb instability". European Journal of Soil Science. 62 (1): 5–12. doi:10.1111/j.1365-2389.2010.01312.x. ISSN 1365-2389. S2CID 55462001. Archived from the original on 21 November 2021. Retrieved 30 November 2019.
  106. ^ a b Thomas, Zoë A. (15 November 2016). "Using natural archives to detect climate and environmental tipping points in the Earth System". Quaternary Science Reviews. 152: 60–71. Bibcode:2016QSRv..152...60T. doi:10.1016/j.quascirev.2016.09.026. ISSN 0277-3791. Archived from the original on 21 November 2021. Retrieved 20 April 2020.
  107. ^ Lenton, Timothy .M.; Livina, V.N.; Dakos, V.; Van Nes, E.H.; Scheffer, M. (2012). "Early warning of climate tipping points from critical slowing down: comparing methods to improve robustness". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 370 (1962): 1185–1204. Bibcode:2012RSPTA.370.1185L. doi:10.1098/rsta.2011.0304. ISSN 1364-503X. PMC 3261433. PMID 22291229.
  108. ^ Rosier, Sebastian (6 April 2021). "Guest post: Identifying three 'tipping points' in Antarctica's Pine Island glacier". Carbon Brief. Archived from the original on 31 July 2021. Retrieved 1 August 2021.
  109. ^ a b Rosier, Sebastian H. R.; Reese, Ronja; Donges, Jonathan F.; De Rydt, Jan; Gudmundsson, G. Hilmar; Winkelmann, Ricarda (25 March 2021). "The tipping points and early warning indicators for Pine Island Glacier, West Antarctica". The Cryosphere. 15 (3): 1501–1516. Bibcode:2021TCry...15.1501R. doi:10.5194/tc-15-1501-2021. ISSN 1994-0416. S2CID 233738686. Archived from the original on 1 August 2021. Retrieved 1 August 2021.
  110. ^ a b c d Brovkin, Victor; Brook, Edward; Williams, John W.; Bathiany, Sebastian; et al. (29 July 2021). "Past abrupt changes, tipping points and cascading impacts in the Earth system". Nature Geoscience. 14 (8): 550–558. Bibcode:2021NatGe..14..550B. doi:10.1038/s41561-021-00790-5. S2CID 236504982. Archived from the original on 30 July 2021. Retrieved 1 August 2021.
  111. ^ Liu, Yanlan; Kumar, Mukesh; Katul, Gabriel G.; Porporato, Amilcare (November 2019). "Reduced resilience as an early warning signal of forest mortality". Nature Climate Change. 9 (11): 880–885. Bibcode:2019NatCC...9..880L. doi:10.1038/s41558-019-0583-9. ISSN 1758-6798. S2CID 203848411. Archived from the original on 1 August 2021. Retrieved 1 August 2021.
  112. ^ Boers, Niklas; Rypdal, Martin (25 May 2021). "Critical slowing down suggests that the western Greenland Ice Sheet is close to a tipping point". Proceedings of the National Academy of Sciences. 118 (21): e2024192118. Bibcode:2021PNAS..11824192B. doi:10.1073/pnas.2024192118. ISSN 0027-8424. PMC 8166178. PMID 34001613.
  113. ^ "AR6 WG1 full report" (PDF). Archived (PDF) from the original on 13 August 2021. Retrieved 18 November 2021.
  114. ^ Rocha, Juan C.; Peterson, Garry; Bodin, Örjan; Levin, Simon (2018). "Cascading regime shifts within and across scales". Science. 362 (6421): 1379–1383. Bibcode:2018Sci...362.1379R. doi:10.1126/science.aat7850. ISSN 0036-8075. PMID 30573623. S2CID 56582186.
  115. ^ The irreversible emissions of a permafrost ‘tipping point’ Archived 14 November 2021 at the Wayback Machine, World Economic Forum, 18 February 2020
  116. ^ Climate scientists fear tipping points (maybe you should too), PhysOrg, 25 October 2021
  117. ^ Climate 'tipping points' could push us past the point-of-no-return after less than 2 degrees of warming, Live Science, 13 June 2021
  118. ^ Climate emergency: world 'may have crossed tipping points’ Archived 4 January 2020 at the Wayback Machine, The Guardian, 27 November 2019
  119. ^ a b Gaffney, O., Tcholak-Antitch, Z., et al. Global Commons Survey: Attitudes to planetary stewardship and transformation among G20 countries Archived 16 October 2021 at the Wayback Machine. Global Commons Alliance (2021)
  120. ^ Scoping of the IPCC 5th Assessment Report Cross Cutting Issues (PDF). Thirty-first Session of the IPCC Bali, 26–29 October 2009 (Report). Archived (PDF) from the original on 9 November 2009. Retrieved 24 March 2019.
  121. ^ Hansen, James; Sato, Makiko; Russell, Gary; Kharecha, Pushker (2013). "Climate sensitivity, sea level and atmospheric carbon dioxide". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 371 (2001). 20120294. arXiv:1211.4846. Bibcode:2013RSPTA.37120294H. doi:10.1098/rsta.2012.0294. PMC 3785813. PMID 24043864.
  122. ^ Nagabhatla, Nidhi (1 August 2021). "Water, conflicts and migration and the role of regional diplomacy: Lake Chad, Congo Basin, and the Mbororo pastoralist". Environmental Science & Policy. 122: 35–48. doi:10.1016/j.envsci.2021.03.019. S2CID 235526305 – via ScienceDirect.
  123. ^ a b Franzke, Christian L. E. (5 January 2022). "Perspectives on tipping points in integrated models of the natural and human Earth system: cascading effects and telecoupling". Environmental Research Letters. 17 (1): 015004. Bibcode:2022ERL....17a5004F. doi:10.1088/1748-9326/ac42fd. S2CID 245154823 – via IOP Publishing.
  124. ^ Dietz, Simon (24 August 2021). "Economic impacts of tipping points in the climate system". Proceedings of the National Academy of Sciences. 118 (34): e2103081118. Bibcode:2021PNAS..11803081D. doi:10.1073/pnas.2103081118. PMC 8403967. PMID 34400500.