A global re-assessment of polar bears highlights loss of sea ice habitat due to climate warming as the single most important threat to the long-term survival of the species, according to the latest update of The IUCN Red List of Threatened Species™ released on 19 November by IUCN, International Union for Conservation of Nature.
- Increasing Arctic temperatures could also reduce habitat and increase the incidence of disease for prey species such as ice seals
- Global Polar Bear population will decline by more than 30% over the next 35 to 40 years
The re-assessment of the Polar Bear (Ursus maritimus) used the most current sea ice and sub-population data, along with computer simulation and statistical models, to project potential changes in the size of polar bear sub-populations due to changes in sea ice. It is the most comprehensive assessment of this data to date. The results show that there is a high probability that the global polar bear population will decline by more than 30% over the next 35 to 40 years. The assessment supports the current Vulnerable status of the
polar bear on The IUCN Red List.
“Based on the latest, most robust science, this assessment provides evidence that climate change will continue to seriously threaten Polar Bear survival in the future,” says Andersen. “Climate change impacts go far beyond this iconic species, and present a threat our planet has never faced before. Governments meeting at the climate summit in Paris (COP21) next month will need to go all out to strike a deal strong enough to confront this unprecedented challenge.”
Arctic sea ice decline
Recent studies show that the loss of Arctic sea ice has progressed faster than most climate models had predicted, with September sea ice extent declining at a linear rate of 14% per decade from 1979 through 2011. As polar bears rely on sea ice to access their prey, an annual ice-free period of five months or more will cause extended fasting for the species, which is likely to lead to increased reproductive failure and starvation in some areas. According to recent sea ice projections, large regions of the Canadian Arctic Archipelago will be ice free for more than five months by the late 21st century; and in other parts of the Arctic, the five-month ice-free threshold may be reached by the middle of the 21st century. Warming Arctic temperatures could also reduce habitat and increase the incidence of disease for prey species such as ice seals, placing the polar bear at further risk.
Other threats
Along with sea ice loss, other potential threats to the species include pollution, resource exploration and habitat change due to development. Oil development in the Arctic, for example, poses a wide range of threats, from oil spills to increased human-bear interaction.
Why are polar bears important
Polar bears are important to the livelihoods of Indigenous Peoples and, as apex predators, are essential to maintaining ecosystem balance in the Arctic region.
Circumpolar Action Plan
“Whilst sea ice loss is the major threat to polar bears, the full range of current and potential threats must be considered in polar bear management plans,” says Dag Vongraven, Chair of IUCN’s Species Survival Commission’s (SSC) Polar Bear Specialist Group. “It is encouraging that polar bear range states have recently agreed on a Circumpolar Action Plan — the first global conservation strategy to strive for the long-term persistence of polar bears in the wild. IUCN is actively working with those countries, providing scientific data and advice to help implement the agreed plan in the most efficient and cohesive way possible. We truly hope that the action plan will make a difference for polar bear conservation.”
To secure the long-term persistence of polar bears in the wild that represent the genetic, behavioural, life-history and ecological diversity of the species.
In order to realize the vision, the Range States have developed six key objectives:
1. Minimize threats to polar bears and their habitat through adaptive management based on coordinated research and monitoring efforts, use of predictive models and interaction with interested or affected parties;
2. Communicate to the public, policy makers, and legislators around the world the importance of mitigating GHG emissions to polar bear conservation;
3. Ensure the preservation and protection of essential habitat for polar bears;
4. Ensure responsible harvest management systems that will sustain polar bear subpopulations for future generations;
5. Manage human-bear interactions to ensure human safety and to minimize polar bear injury or mortality;
6. Ensure that international legal trade of polar bears is carried out according to conservation principles and that poaching and illegal trade are curtailed.
The recent update also highlights habitat degradation as a main threat to many fungus species and over-fishing as the key driver of decline in marine bony fish. The full news release on this update is available here. The IUCN Red List now includes 79,837 assessed species, of which 23,250 are threatened with extinction.
(Source: IUCN Red List news release, 19.11.2015; Arctic Portal news, 11.09.2015)