Extra polar bear habitat within the Barents Sea in mid-July 2023 than 2012, regardless of extra atmospheric CO2 • Are you updated on that?

From polar bear science

Susan Crockford

Despite more CO2 in the atmosphere (424 compared to 392 in June), there was more sea ice in the Barents Sea in mid-July this year than in 2012.

This region has lost about six times as much sea ice over the summer as any other region in the Arctic (Regehr et al. 2016): Barents fur seals now have a longer ice-free season than the famous western Hudson Bay bears we hear so much about.

However, contrary to predictions that insisted that prolonged poor summer ice conditions would inevitably lead to catastrophic starvation and death rates (Amstrup et al. 2007; Crockford 2017, 2019), no damage to the health or population size of polar bears in the Svalbard region has been documented. Indeed, field data show that bears in Svalbard are better off than they were in the late 1990s (Lippold et al. 2019), almost certainly due to documented increases in primary productivity resulting from longer ice-free summers since 2003 (Frey et al. 2022; Crockford 2023).

Longer ice-free summers = more food

More open water exposed to the summer sun means more food for fish, a benefit that boosts the food chain to ensure more seals for polar bears the following spring. Bigger bears give birth to healthier cubs that are more likely to survive their first year of life.

Ice of the Barents Sea 2023

Ice of the Barents Sea 2012

In recent years, autumn sea ice has often arrived late or not at all on Spitsbergen, and most pregnant female polar bears are unable to dig their natal dens on the eastern islands (see map below).

However, habitat and falling sea ice (see graph below) continues to be plentiful around the Franz Josef Islands in Russia until at least late November, still within the limits of the Barents Sea subpopulation. Being flexible in nature, most Barents fur seals give birth or overwinter in the far eastern part of their range (Crockford 2019) and return to the ice off Svalbard in spring to feed on newborn seals.


Amstrup, SC, Marcot, BG & Douglas, DC 2007. Predicting the status of polar bears across their range at selected times in the 21st century. US Geological Survey. Reston, VA. PDF here

Crockford, SJ 2017. To test the hypothesis that routine sea ice coverage of 3–5 mkm2 will result in a greater than 30% decline in polar bear (Ursus maritimus) population size. PeerJ Preprints 19 January 2017. Doi: 10.7287/peerj.preprints.2737v1 Open Access. https://peerj.com/preprints/2737/

Crockford, SJ 2019. The polar bear disaster that never happened. Global Warming Policy Foundation, London. Available in paperback and e-book format.

Crockford, SJ 2023. The Polar Wildlife Report 2022. Briefing 63 from the Global Warming Policy Foundation, London. pdf here.

Frey, KE, Comiso, JC, Cooper, LW, et al. 2022. Primary Productivity of the Arctic Ocean: The Response of Seaweed to Global Warming and Sea Ice Retreat. In: 2022 Arctic Report Card, NOAA. https://doi.org/10.25923/0je1-te61

Lippold A, Bud S, Aars J, et al. 2019 Temporal trends of persistent organic pollutants in Barents Sea polar bears (Ursus maritimus) associated with changes in diet and body status. Environmental Science and Technology 53(2):984-995.

Regehr, EV, Poor, KL, Akçakaya, HR, et al. 2016 Conservation status of polar bears (Ursus maritimus) in the context of projected sea ice retreat. Biology Letters 12: 20160556. http://rsbl.royalsocietypublishing.org/content/12/12/20160556

More from dr Crockford on polar bears and sea ice can be found on our ClimateTV page.

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