Climate change is having a profound impact on the Arctic, its sensitive marine ecosystem and the human communities that rely on the area’s natural wealth. The Arctic is warming at almost twice the rate of the rest of the planet. Water temperatures are also rising, melting the pack ice more rapidly than scientists predicted only a few years ago. In 2007, seasonal minimum sea ice extent reached a record low – 23 percent less than has been recorded since satellite-based measurements started in 1979. This staggering pace of sea ice melt has continued in 2008 and 2009 – with the second and third lowest recorded coverage. Some scientists estimate that the Arctic could be seasonally ice-free in 10 to 30 years.
Arctic Sea ice minimum concentration for 1979-2006
© NASA/Goddard Space Flight Center Scientific Visualization Studio
Marine mammals and other Arctic life face an uncertain future as Arctic ecosystems adapt to warming waters and receding ice. Iconic species such as the polar bear, walrus, ringed seal and bowhead whale are all highly adapted to an existence with ice. Ice-dependent species use the ice as a platform for giving birth, resting and migrating. The underside of the ice provides habitat for tiny algae that are the base of a productive food web. Other species such as the grey whale, killer whale and red fox are taking advantage of warming waters and changing habitat by shifting their ranges towards the poles. Indigenous communities depend on many marine species to sustain their culture. Traditional hunters are encountering new challenges as ice becomes less stable, travel becomes more hazardous and animals’ migratory paths change.
Warming in the Arctic will not only affect those who live there but will influence the entire planet.[See Pew Arctic Treasure Report] The Arctic helps regulate the global climate system and influences weather patterns across much of the northern hemisphere. Extensive ice-covered areas reflect large amounts of solar energy back into space, helping to cool the planet. This heat imbalance drives ocean currents and atmospheric circulation, transporting cooler waters to the tropics and influencing the jet stream and our weather patterns in North America
Worldwide deep ocean circulation
© ACIA, 2004. Impacts of a Warming Arctic: Arctic Climate Impact Assessment.
Impacts of the warming Arctic include:
- Arctic sea ice is carried southwards into the North Atlantic, where it melts. The resulting volume of relatively fresh water affects the ecology of the area and helps drive the worldwide circulation of the oceans. Changes in recent decades have had profound effects, including the transition from cod to shrimp in Greenlandic waters. Changes in freshwater inputs to the North Atlantic may alter the global ocean currents with far-reaching effects on the global climate.
- The amount of solar energy absorbed by Arctic seas increases with large areas of open water. That causes even warmer seas.
- Warming temperatures are leading to the release of methane – a powerful greenhouse gas – from the seabed and melting tundra, wetlands and lakes in the Arctic.
- These changes could potentially impact global weather patterns and ocean circulation.
Sun over ice
© Bruno Tremblay