Where Are We On Ice Tipping Points Post COP26?

By Chien Tat Low 22 November, 2021

What state is the cryosphere in? Did COP26 help? CWR’s Dr. Low shares key takeaways from the latest report

The cryosphere is in a dire state and yet the world remains complacent even after the COP26 meeting which has sets us on track for 2.4°C warming by 2100
Already at today’s warming of 1.2°C we have triggered irreversible tipping points & locked in 2-3 meters of SLR; once 2°C is passed, we lose large chunks of mountain glaciers
To avoid permanent “cryosphere collapse” we need a decade of urgent action or risk even greater SLR, the melting of Asia’s water source & mass extinction

Our world is on track for 2.4°C warming by 2100 as our 2030 targets still fall short even after the COP26 meeting according to Climate Action Tracker (CAT). That’s still far above the 2°C limit that the world should stay well below, if not 1.5°C.

Our ‘false sense of complacency’ is pushing the cryosphere into abrupt or irreversible change…

Clearly there is still a “false sense of complacency” that we can allow temperatures to rise for just a bit longer to prioritise today’s economic growth over our future. But what many may not know is that at our snail’s pace of policy implementation we are pushing the cryosphere – Earth’s snow and ice regions – into abrupt or irreversible change that worsens sea level rise (SLR), extreme weather, permafrost thaw, marine acidification, and mass extinctions of marine species.

We cannot negotiate with the melting point of ice…

In November 2021,the International Cryosphere Climate Initiative (ICCI) released the “State of the Cryosphere 2021” report (SOC 2021) that summarises changes happening in the cryosphere as well as the potential devastating impacts that will occur once we trigger certain tipping points. The SOC 2021 report was reviewed and supported by nearly 50 leading cryosphere scientists, and over half of them are IPCC authors.

…most of these would be triggered even by 2°C so ‘we cannot negotiate with the melting point of ice’ & must remain close to 1.5°C

These cryosphere scientists warned that without more ambitious commitments or Nationally Determined Contributions (NDCs), we will trigger cryosphere changes that will be “permanent on all human timescales” in which the impacts are “global and overwhelming in scale”. Moreover, most of these permanent changes would be triggered even by 2°C. So, the key message is clear – ‘we cannot negotiate with the melting point of ice’ and must remain close to 1.5°C.

What’s more worrying is that the realisation of the dire state of the cryosphere has yet to penetrate the highest levels of government and industry, let alone the general public. During a COP26 meeting, a group of cryosphere scientists gathered at the ICCI’s Cryosphere Pavilion to present the latest findings on cryosphere changes and why it is so vulnerable to global warming. But sadly, these videos have yet to reach a wider audience with only < 50 views online at the time of writing this article. If you have missed them, you can watch them here.

The SOC 2021 clearly shows why we must act urgently to keep global temperatures below 2°C, if not 1.5°C. because if we don’t the loss and damage from losing our cryosphere are beyond our imagination. The main findings from the report have been summarised at the end of this article.

We have already triggered ice tipping points today…

We have already locked-in 2-3m of SLR at today’s temperature

Already at today’s warming of 1.2°C, we have already locked-in 2-3m of SLR and the IPCC-AR6 report warns that this level of SLR cannot be ruled out by as early as 2100. Even with today’s most optimistic scenario of 1.8°C, permafrost thaw will add CO2 and methane emissions totalling around 150-200 GT CO2 by 2100; this is similar to the emissions of Canada today. Why does this matter? Carbon emissions from permafrost thaw, which is not fully accounted for in global emission budgets, will greatly reduce our carbon budget to remain below 1.5°C or 2°C.

Once 2°C is passed we lose large chunks of mountain glaciers; ~3°C the global weather pattern will become extremely unpredictable

Once 2°C is passed, we will lose large chunks of our mountain glaciers. The highest mountains such as the Himalayas, which are the water towers of Asia that provide water supplies for 1 in 2 Asians, will only survive by 2300. When temperatures approach 3°C, the Atlantic Meridional Overturning Circulation (AMOC) – which acts as a motor for currents in the North Atlantic and is vital in regulating weather, will shut down and cause “severe and unpredictable disturbances to global weather pattern”. This level of warming is in line with a recent Nature survey, in which many living IPCC authors expect “the world to warm by at least 3°C by the end of the century”.

Our current emissions path is driving us to “cryosphere collapse”…

Allowing the temperature to pass 4°C-5°C by 2100 by following our current emissions path will result in rapid and essentially permanent “cryosphere collapse”, causing extreme losses and significant damages for many generations. West Antarctic Ice Sheet will collapse with 2m of SLR possible by 2100 and 5m by 2150. Our oceans will become extremely corrosive and cause mass extinction of marine species – we will never see wild cod, herring and salmon on our dinner plate again.

We need a decade of urgent action…

Clearly, these ice tipping points are too risky to bet against. The only way to slow and avert these negative impacts is to stay close to 1.5°C or below 2°C. However, we only have less than a decade to act – we must decarbonise deeper and faster by 2030. Otherwise, we are on track to trigger these adverse impacts as the findings in the SOC 2021 report make clear.

Below are the impacts we are locking in at different scenarios according to the SOC 2021 report. Also check out how these scenarios will be triggered by various warming projections according to the latest estimates from Climate Action Tracker (CAT) and which IPCC AR6’s SSPs they correspond to.

SOC 2021 Scenario: Very Low and Low Emissions – Peak 1.6°C and 1.8°C and declining
Corresponds to CAT’s warming projections POST-COP26: Optimistic scenario – 1.8°C
IPCC AR6 equivalence: SSP1-1.9/ SSP1-2.6

  • SLR: Global sea levels will continue to rise for centuries, but very slowly, reaching around 2-3m above today’s levels in the next 2,000 years, with about half a meter SLR occurring early in the next century
  • Mountain glaciers: Most glaciers of the northern Andes, East Africa and Indonesia, especially those close to the Equator are disappearing too rapidly to be saved; water supplies reliant on snowpack and glaciers will be affected
  • Permafrost: Permafrost thaw will add additional CO2 and methane emissions similar to the annual emissions of Canada today totalling around 150-200 GT CO2 by 2100
  • Arctic sea ice: at least one ice-free summer by 2050
  • Polar oceans: CO2 concentration peaks between 440-480ppm. Isolated marine heat waves and related die-off events are likely to occur each year. The AMOC is likely to slow further but not collapse

SOC 2021 Scenario: Fulfilment of “optimistic” NDCs – 2.1°C and rising
Corresponds to CAT’s warming projections POST-COP26: 2030 targets only – 2.4°C
IPCC AR6 equivalence: SSP1-2.6/ SSP2-4.5

  • SLR: Lock in SLR of 3-6m and even higher levels cannot be ruled out. At this higher temperature however, a steady predictable rate of SLR from ice sheets is less certain and the rates and amount of sea level rise could be unpredictable and faster.
  • Mountain glaciers: Only glaciers of substantial size in polar regions and highest mountains (Himalayas) will survive by 2300, but they may shrink to 1/2 or 1/3 of their current size.
  • Permafrost: Permafrost thaw will add additional CO2 and methane emissions similar to the annual emissions of the EU today totalling around 220-300 GT CO2 by 2100.
  • Arctic sea ice: Summer sea ice will disappear nearly every September at ~1.7°C and the autumn freeze-up process will begin later. By the 2.2°C peak, ice-free condition will occur as early as June and persist until November. Today’s Arctic ecosystem will be lost.
  • Polar oceans: CO2 concentration will be >500ppm. The impacts of multiple stressors – increased acidification, marine heat waves, and greater freshening from meltwater off both polar ice sheets – on food webs and fisheries could be significant.

SOC 2021 Scenario: Currently implemented NDCs and Policies – 2.7°-3.1°C in 2100 and rising
Corresponds to CAT’s warming projections POST-COP26: Current policies & action – 2.7°C
IPCC AR6 equivalence: SSP2-4.56/ SSP3-7.0

  • SLR: Lock in SLR of 15-20m or more. SLR of 1-2m by 2100 is possible; at 3°C, ice sheet collapse and potentially rapid SLR cannot be ruled out.
  • Mountain glaciers: Virtually no glaciers will remain anywhere on the globe outside the Arctic, Patagonia and Himalayas where only 20-35% will remain; At 3°C, 90% of Himalayan ice and snow will be lost
  • Permafrost: Permafrost thaw will add additional CO2 and methane emissions similar to the annual emission of the US today totalling around 350-400 GT CO2 by 2100
  • Arctic sea ice: The 1.7°C summer loss threshold will be reached far earlier by ~2040. Ice free condition during much of spring and fall as well as summer will further accelerate sea-level rise and permafrost emissions. The Arctic ecosystem disruption will extend farther south. At >3.1°C, recovery of Arctic sea ice will take centuries.
  • Polar oceans: CO2 concentration will be >600ppm; with acceleration of Greenland melt, severe slowing and even shutdown of AMOC (Atlantic Meridional Overturning Circulation – which acts as a motor for currents in the North Atlantic) cannot be ruled out. This will lead to severe and unpredictable disturbances to global weather patterns, which at this temperature would be more extreme from a warmer and wetter atmosphere.

SOC 2021: Current emission growth – 4°-5°C and rising
IPCC AR6 equivalence: SSP3-7.0 / SSP5-8.5

  • SLR: West Antarctic Ice Sheet collapse with 2m of SLR possible by 2100, and up to 5m by 2150. 10m SLR from all sources is likely by 2300
  • Mountain glaciers: Virtually no glaciers will remain anywhere on the globe by 2200, with mid-latitude glaciers 90% gone by 2100; snowfall by 2100 will be extremely limited outside polar regions and high altitudes
  • Permafrost: >70% of surface permafrost will thaw by 2100
  • Arctic sea ice: The conditions of ecosystem collapse will be apparent by 2030. Recovery of Arctic sea ice of today’s conditions would likely take over 1,000 years.
  • Polar oceans: CO2 concentration will be >800ppm; mass extinction of marine species – cod, herring and salmon extremely unlikely to survive in the wild; weather would likely be extreme and unpredictable

Further Reading

  • Code Red: 8 things you need to know about water in IPCC AR6 IPCC AR6 is a code red for water too! CWR’s Debra Tan shares 8 things you may have missed on water and urges to delay no more
  • Existential Coastal Threats: 8 Things You Must Know – Rapid SLR will happen sooner than we think, yet we are still driving investments to vulnerable locations. CWR’s Debra Tan shares 8 things you need to know about the existential threat from SLR – from glaciers in the mountains to ice sheets in our poles, permafrost + more
  • 8 Risks You Missed During COVID-19 – Been focused on COVID-19? You are not alone but we can’t get distracted from the climate crisis. Catch-up with CWR’s Chien Tat Low who runs through 8 latest climate & water risks
  • It’s Time To Prioritise Sea Level Rise – CWR’s Debra Tan says it’s time to be FOMO about our rising seas. From emission accelerants to accelerated impacts she runs through three reasons to rethink our attitudes towards sea level rise – it’s a big deal, sea level rise is worse than you think. This time, even she’s depressed
  • Time To Get Radical – Alarm bells are ringing for climate change but we are still wedded to the ‘norm’ and on track to miss even the 2°C target. With time running out and serious implications for Asia’s water resources, China Water Risk’s Debra Tan calls for more flashes of brilliance

More on latest

Chien Tat Low
Author: Chien Tat Low
Low has extensive inter-disciplinary research experience, which although wide-ranging, focuses on identifying hotspots to facilitate better planning. At CWR, Low uses spatial modelling and statistical analysis as well as remote sensing, cartography, and geo-statistics to map and assess water risks. In addition, he helps manage CWR’s extensive network of contributors and partners. CWR is Low’s first foray outside academia and he hopes to apply his 12 years of scientific know-how toward enhancing the understanding of water risk in Asia, including spatial temporal variabilities of anthropogenic and natural factors on water resources. Previously, Low was a postdoctoral fellow at the University of Hong Kong where he devised methodologies to measure and benchmark the quality of urban life in an Asian context. As a certified GIS Professional, he also taught GIS and spatial analysis modules there. Low’s research on urban, human and environmental health is published in 11 prominent international peer-reviewed journals; he has also written a chapter in a book on managing environmental hazards. His PhD thesis on place effect on human well-being was prize-winning. Low is currently the reviewer editor for the journal “Frontiers in Environmental Informatics” and also reviews other international journals such as “Applied Geography”.
Read more from Chien Tat Low →