Arctic amplification
Arctic amplification is the phenomenon in which the Arctic warms faster than the global average, especially near Earth’s surface.
Ice–albedo feedback: A climate feedback in which melting reflective ice exposes darker surfaces that absorb more sunlight, causing further warming. Declining sea ice and snow expose darker ocean and land, amplifying regional warming.
Arctic sea ice decline: The long-term reduction in the extent, thickness, and age of floating sea ice in the Arctic Ocean. It is both a visible consequence of amplification and a driver of further ice–albedo feedback.
Arctic climate change: Long-term changes in Arctic temperatures, ice, snow, ecosystems, and other components of the climate system. Arctic amplification is the unusually rapid warming component of broader Arctic climate change.
Antarctic amplification: The faster-than-global-average warming of parts of Antarctica, with strong regional and seasonal variation. Unlike the Arctic, Antarctica’s warming pattern is shaped by a continent, surrounding ocean, and distinct circulation.
Planck feedback: The stabilizing climate response in which a warmer Earth emits more infrared radiation to space. It opposes Arctic warming but is weaker there than in the tropics.
Permafrost thaw: The thawing of ground that has remained frozen for at least two consecutive years. Warming destabilizes frozen soils and can release stored carbon and damage infrastructure.
Instrumental temperature record: Systematic measurements of air and ocean temperatures collected with instruments over time. These records establish that Arctic surface temperatures have risen faster than global averages.
Global warming: The long-term rise in Earth’s average surface temperature, primarily driven by human greenhouse-gas emissions. Arctic amplification describes a regional rate contrast within global warming.
Lapse-rate feedback: A climate feedback caused by changes in the vertical temperature gradient and the resulting change in infrared emission. The Arctic’s temperature profile makes this feedback contribute strongly to polar amplification.
Greenland ice sheet: A vast body of land ice covering most of Greenland and contributing to global sea-level rise as it loses mass. Arctic warming accelerates surface melting and can increase ice-sheet mass loss.