Why the poles are warming fastest (polar amplification)

Updated November 2026

The Arctic is warming much faster than the rest of the planet. A 2022 study found it warmed nearly four times as fast as the global average between 1979 and 2021. Melting ice and snow, which expose darker surfaces that soak up more sunlight, are a big part of the reason.

How much faster?

For years, scientists often said the Arctic was warming “twice as fast” as the globe. In August 2022, Mika Rantanen and colleagues published a study in Communications Earth & Environment that used several observational datasets for the area north of the Arctic Circle (66.5° N). Over 1979–2021, they found:

The Arctic warmed by about 0.73 °C per decade; the globe by about 0.19 °C per decade.
Dividing one by the other: 0.73 ÷ 0.19 ≈ 3.8, so “nearly four times” as fast.
Parts of the Eurasian Arctic Ocean, near Svalbard and Novaya Zemlya, warmed up to seven times as fast as the globe.
Climate models rarely produce a ratio this high, so either the recent value is an extremely unlikely event or models tend to underestimate Arctic amplification.

Why do other sources give other numbers? The answer depends on the years you pick and where you draw the Arctic’s southern edge. NOAA’s Arctic Report Card 2025 says Arctic annual temperatures have risen at more than twice the global rate since 2006, and the IPCC projects the Arctic will keep warming at more than twice the global rate. All of these say the same thing: the Arctic is warming far faster than the planet as a whole.

The trend continues. NOAA found that October 2024 to September 2025 was the Arctic’s warmest 12-month period recorded since 1900, and that the last 10 years are its 10 warmest. Globally, the WMO reported that 2025 was the second or third warmest year on record, about 1.43 °C above the 1850–1900 average.

The feedbacks behind it

A feedback is a chain reaction where a change causes more of the same change. Several work together in the Arctic.

Ice and snow albedo

Albedo is how much sunlight a surface reflects. According to the National Snow and Ice Data Center, bare sea ice reflects 50–70% of incoming sunlight and snow-covered sea ice up to 90%, while dark open ocean reflects only about 6%. So when ice melts and exposes water, the surface goes from reflecting most sunlight to absorbing about 94% of it. The water warms, more ice melts, and the loop continues. The IPCC says the loss of summer sea ice and spring snow cover on land has contributed to amplified Arctic warming.

Snow on land

Arctic June snow cover on land fell by about 13.4% per decade from 1967 to 2018, a loss of about 2.5 million square kilometers (IPCC). The 2025 Arctic Report Card found June snow cover is now half what it was six decades ago. Bare ground absorbs more sunlight than snow, adding more heat.

Warmer water from the south

Warmer, saltier Atlantic water now reaches the central Arctic Ocean and weakens the layering that once kept that heat away from the ice (NOAA Arctic Report Card 2025). The Rantanen study also notes that loss of winter ice in the Barents Sea and changes in winds have boosted warming in that region.

Permafrost carbon

Thawing permafrost can release carbon dioxide and methane, which add to warming everywhere. See Permafrost and tundra.

What about Antarctica?

The south is more complicated. Antarctic sea ice showed no significant overall trend from 1979 to 2020 (IPCC AR6), before falling sharply after 2016. The Antarctic Ice Sheet is still losing mass, mostly where large outlet glaciers in West Antarctica are thinning and retreating (IPCC). See Polar ice.

Sea-level rise

Polar warming reaches everyone through the ocean. Global sea level rose about 0.20 meters between 1901 and 2018 (IPCC AR6), and from 2012 to 2025 it rose 4.75 mm a year (WMO). Ice loss from Greenland and Antarctica is a growing part of that rise. The IPCC’s likely range for rise by 2100, compared with 1995–2014, is:

Projected global sea-level rise by 2100 (IPCC AR6, likely range)
Emissions scenario	Rise by 2100
Very low (SSP1-1.9)	0.28–0.55 m
Low (SSP1-2.6)	0.32–0.62 m
Intermediate (SSP2-4.5)	0.44–0.76 m
Very high (SSP5-8.5)	0.63–1.01 m

A rise approaching 2 meters by 2100 under very high emissions cannot be ruled out because of deep uncertainty about how ice sheets will behave. Over the next 2,000 years, sea level is projected to rise about 2–3 meters if warming is held to 1.5 °C and 2–6 meters if held to 2 °C.

Effects on weather

Does a warmer Arctic change weather farther south? Scientists are still working on it. The IPCC gives medium confidence that changes in Arctic sea ice could influence mid-latitude weather, but low confidence in detecting that influence for specific types of weather. Disruptions of the stratospheric polar vortex are linked to some cold-air outbreaks in the United States and Eurasia (see Ozone hole and polar vortex), but there is no clear evidence yet of a long-term trend in the vortex.

3.8×Arctic warming vs global, 1979–2021 (Rantanen et al. 2022)
0.73 °CArctic warming per decade, 1979–2021
6% vs 50–70%Sunlight reflected by open ocean vs bare sea ice
0.63–1.01 mLikely sea-level rise by 2100 under very high emissions

Check yourself

Why does melting sea ice speed up warming?

Ice reflects most sunlight, but dark open water absorbs about 94% of it. As ice melts, the ocean absorbs more heat, which melts more ice: the ice-albedo feedback.

Why do some sources say “twice as fast” and others “four times as fast”?

The ratio depends on the time period and on where the Arctic’s southern edge is drawn. Rantanen et al. used 1979–2021 and the Arctic Circle and found about 3.8 times.

Under the IPCC’s very low emissions scenario, how much could sea level rise by 2100?

The likely range is 0.28–0.55 meters above the 1995–2014 level.