Prolonging the Health of Arctic Sea Ice
Arctic sea ice is a critical component of the global climate system because of its contributions to Earth’s reflectivity (albedo) and potential influence on global weather patterns. It is also one of the fastest changing systems on the planet due to anthropogenic climate change. The significant loss of summer sea ice to date has already had profound impacts on the Arctic region, its ecosystems and people, the global climate system, and the broader ocean. For this reason, it is the first ecosystem that Ocean Visions is focusing on within our Repair program – devoted to responsible research on ideas to prolong the health of critical marine ecosystems.
How fast are we losing sea ice?
- The Arctic region has warmed three to four times faster than the global average1-4. The faster pace of warming in the Arctic relative to the global average is known as Arctic Amplification.
- Increases in air and sea temperature in the Arctic have led to at least a 50% decline in the extent of Arctic summer sea ice over the last four decades5-7. Since 1979, thicker multi-year sea ice at least five years old has decreased by 90%6. Thicker multi-year ice has a higher albedo than thinner new ice and is also less vulnerable to melting8.
- Summer sea ice is expected to disappear by the middle of this century (under all emissions trajectories9), if not earlier10-11.
What are the climate impacts?
- The loss of summer sea ice and snow has amplified warming in the Arctic due to a decrease in albedo (reflectance of incoming solar radiation)6. This causes an energy imbalance in the Arctic (and on the planet) as darker surfaces trap incoming solar energy rather than reflecting it as sea ice does.
- Excess heat in the Earth system builds up from a number of sources, including declines in sea ice albedo and greenhouse gas emissions. The excess heat resulting from the current loss of Arctic sea ice and associated decline in albedo is equal in magnitude to 25% of the excess heat associated with CO2 emissions into our atmosphere since 197912.
- Global climate models estimate that the complete loss of summer sea ice will cause additional warming in the Arctic of >1.5°C and 0.19°C13 averaged across the globe.
What are the impacts on Arctic marine ecosystems?
- Sea ice decline has led to population declines and behavioral shifts of sea ice-dependent species such as ringed seals, harp seals, and polar bears9, 15 and northward migration of non-Arctic species.
- Climate change in the Arctic is causing a shift in primary production (the base of the food web) from sea ice associated organisms to open water associated organisms9. This shift has altered Arctic marine food webs and is evident for zooplankton, fish, and marine mammals9, 15-16.
- Such changes in the Arctic sea ice scape and Arctic marine food webs have led to increased mortality of Arctic species9.
What are the impacts on coastal communities?
- Loss of sea ice has led to increased coastal erosion and higher risk of impacts of sea level rise for coastal communities9,17.
- Thinning sea ice has led to increasingly unstable conditions that pose a safety risk, causing decreased access to culturally important subsistence resources for Arctic Indigenous peoples9.
- Diminishing sea ice cover has altered the seasonal migrations of whales and walruses in ways that increase the expense and danger of hunting by Indigenous peoples17.
Is there anything we can do about it?
The only permanent way to stop the loss of Arctic sea ice, and ultimately allow it to rebuild, is to reduce global temperatures. This means drastically cutting emissions of greenhouse gases and also cleaning up and removing the legacy greenhouse gases built up in our atmosphere and oceans. Unfortunately, the best available science indicates that almost all scenarios of rapid decarbonization combined with large-scale carbon dioxide removal are still unlikely to cool the planet in time to prevent further loss of Arctic sea ice. Given the enormity of the risks associated with continued loss of sea ice, Ocean Visions believes it is necessary to responsibly investigate all possible ideas that may be able to help forestall dangerous losses.
What types of ideas are being considered?
In addition to urgent work on decarbonization and removal of legacy pollution, there are a number of ideas that have been proposed as ways to potentially prolong the health of Arctic sea ice. These include such things as marine cloud brightening, sea ice thickening, black carbon emissions reductions, and other concepts. It is important to note that most of these ideas are as yet largely untested.
What is Ocean Visions' role?
Ocean Visions has created a first-ever assessment of potential pathways to slow Arctic sea ice loss. Released as an interactive digital road map, the assessment identifies and evaluates potential approaches and is designed to mobilize efforts to advance our collective understanding. An overview of the road map is available here.
In developing this assessment, Ocean Visions engaged with an international, multidisciplinary team of experts comprised of 11 individuals from six countries and spanning climate and earth science, governance, and Arctic issues.
The road map is a living document that will be continuously updated as new information becomes available. For those interested in engaging, we invite comment or content submissions on the road map.
Potential Approaches to Slow the Loss of Arctic Sea Ice
Ocean Visions is pleased to make available a collection of illustrations depicting potential approaches to slow the loss of Arctic sea ice. We invite you to download the collection and utilize it as part of your communication efforts.
More Information
For questions about the road map or the Ocean Visions’ Repair program please contact Senior Program Officer Kerry Nickols, Ph.D.
Citations
- AMAP, 2021. AMAP Arctic Climate Change Update 2021: Key Trends and Impacts. Arctic Monitoring and Assessment Programme (AMAP), Tromsø, Norway. viii+148pp
- Chylek, P, C. Folland, J.D. Klett, M. Wang, N. Hengartner, G. Lesins, and M.K. Dubey. 2022. Annual mean arctic amplification 1970-2020: Observed and simulated by CMIP6 climate models. Geophysical Research Letters 49:e2022GL099371.
- Druckenmiller, M. L., R. L. Thoman, and T. A. Moon, Eds., 2022: Arctic Report Card, https://doi.org/10.25923/yjx6-r184.\
- Rantanen, M., A.Y. Karpechko, A. Lipponen, K. Nordling, O. Hyvärinen, K. Ruosteenjoja, T. Vihma, and A. Laaksonen. 2022. The Arctic has warmed nearly four times faster than the globe since 1979. Communications Earth and Environment 3:168.
- This is compared to the average sea ice extent from 1981-2010. Sea ice extent refers to the total region with at least 15% sea ice cover. Sea ice extent is the most commonly reported metric for sea ice cover, largely because of observational constraints. See https://nsidc.org/learn/ask-scientist/what-difference-between-sea-ice-area-and-extent#:~:text=Sea%20ice%20area%20is%20the,15%20percent%20sea%20ice%20cover. for more information.
- IPCC, 2019: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, M. Nicolai, A. Okem, J. Petzold, B. Rama, and N. Weyer (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 3–35. https://www.cambridge.org/core/books/ocean-and-cryosphere-in-a-changing-climate/summary-for-policymakers/097A895553D86981DFE6195ADFD3DDA4.
- Arctic sea ice is also melting 10-20 days earlier each decade and is freezing and forming new ice up to a month later each decade: Meier, W.M., and J. Stroeve. 2022. An updated assessment of the changing Arctic sea ice cover. Oceanography 35:10-19.
- Perovich, D.K. and C. Polashenski. 2012. Albedo evolution of seasonal Arctic sea ice. Geophysical Research Letters 39:L08501.
- Constable, A.J., S. Harper, J. Dawson, K. Holsman, T. Mustonen, D. Piepenburg, and B. Rost, 2022: Cross-Chapter Paper 6: Polar Regions. In: Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 2319–2368, doi:10.1017/9781009325844.023.
- Notz, D., and SIMIP Community. 2020. Arctic sea ice in CMIP6. Geophysical Research Letters 47:e2019GL086749.
- Kim, Y-H., S-K. Min, N.P. Gillett, D. Notz, and E. Malinina. 2023. Observationally-constrained projections of an ice-free Arctic even under a low emission scenario. Nature Communications 14:3139.
- Pistone, K., I. Eisenman, and V. Ramanathan. 2014. Observational determination of albedo decrease caused by vanishing Arctic sea ice. PNAS 111:3322-3326
- Wunderling, N., M. Willeit, J.F. Donges, and R. Winkelmann. 2020. Global warming due to loss of large ice masses and Arctic summer sea ice. Nature Communications 11:5177.
- Brandt, S., P. Wassmann, and D. Piepenburg. 2023. Revisiting the footprints of climate change in Arctic marine food webs: An assessment of knowledge gained since 2010. Frontiers in Marine Science 10:1096222.
- Routledge, J., C. Sonne, R.J. Letcher, R. Dietz, and P. Szpak. 2023. Unprecedented shift in Canadian High Arctic polar bear food web unsettles four millennia of stability. Anthropocene 43:100397.
- Meier, W.N., G.K. Hovelsrud, B.E.H. van Oort, J.R. Key, K.M. Kovacs, C. Michel, C. Haas, M.A. Granskog, S. Gerland, D.K. Perovich, A. Makshtas, and J.D. Reist. 2014. Arctic sea ice in transformation: A review of recent observed changes and impacts on biology and human activity. Reviews of Geophysics 51:185-217.