Arctic amplification is the phenomenon whereby the Arctic is warming 2-4 times faster than the global average. While the planet's mean temperature has risen ~1.2 °C since pre-industrial times, the Arctic has recorded increases of 3-5 °C, with profound consequences for the global climate.
Amplification mechanisms
The primary driver is the ice-albedo feedback: as sea ice (high reflectivity) melts, the dark ocean beneath (low reflectivity) is exposed, absorbing more solar radiation, warming the water, and melting more ice. Other mechanisms include: increased water vapour (a potent greenhouse gas), changes in cloud cover, heat transport from lower latitudes, and permafrost loss releasing methane and CO₂.
The consequences are global: the reduced pole-to-equator temperature gradient weakens the jet stream, which becomes wavier and slower, favouring atmospheric blocking patterns that cause heatwaves, droughts, or persistent rainfall at mid-latitudes. This may partly explain the increased frequency of extreme weather events in Europe and Spain.
Arctic summer sea ice has declined by 40 % since 1979 and could disappear entirely in summer before 2050. Greenland ice sheet loss contributes to sea-level rise. See also: climate change, teleconnection.