Geology

Climate change

Ice-albedo feedback

Arctic dipole anomaly

Oceanography

Arctic sea ice decline

Antarctic sea ice

Sea ice

Climate model

Arctic geoengineering

Arctic ice pack

Cryosphere

Northern Hemisphere

Climatology

Environmental science

Arctic

Nature Geoscience

The decline of Arctic sea ice is an integral part of anthropogenic climate change. Sea-ice loss is already having a significant impact on Arctic communities and ecosystems. Its role as a cause of climate changes outside of the Arctic has also attracted much scientific interest. Evidence is mounting that Arctic sea-ice loss can affect weather and climate throughout the Northern Hemisphere. The remote impacts of Arctic sea-ice loss can only be properly represented using models that simulate interactions among the ocean, sea ice, land and atmosphere. A synthesis of six such experiments with different models shows consistent hemispheric-wide atmospheric warming, strongest in the mid-to-high-latitude lower troposphere; an intensification of the wintertime Aleutian Low and, in most cases, the Siberian High; a weakening of the Icelandic Low; and a reduction in strength and southward shift of the mid-latitude westerly winds in winter. The atmospheric circulation response seems to be sensitive to the magnitude and geographic pattern of sea-ice loss and, in some cases, to the background climate state. However, it is unclear whether current-generation climate models respond too weakly to sea-ice change. We advocate for coordinated experiments that use different models and observational constraints to quantify the climate response to Arctic sea-ice loss. Changes in Northern Hemisphere atmospheric temperature, pressure patterns and winds emerge as a consistent response to Arctic sea-ice loss in six coupled climate models.

Consistency and discrepancy in the atmospheric response to Arctic sea-ice loss across climate models