There is a 47-year record of measurements on the extent of sea ice cover in the arctic, “arctic sea ice extent” (ASIE).
Since full year 1979 through 2025, mean sea ice extent (average ASIE taken over all 12 months of each year) has declined a total of 18% over the 47-year period, or about 0.39% per year (46 yoy intervals)
Last year, 2025, was the lowest observed mean sea ice extent in the 47-year record.
In two other threads (at bottom), attention was given to 1 of 12 months (September) when the arctic summer ice reaches its minimum extent.
These threads tried to infer that the decline in ASIE entered a “pause” in September for several years, perhaps implying that the effects of global warming, at least in ASIE, had paused.
That kind of inference is flawed (as noted in discussion in the second thread), first and foremost because there are 12 months in the year and observations on 1 month say little about the overall changes in ASIE, which, of course, occur in all 12 months each year.
Here is the data averaged over all 12 months each year for 1979 to 2025.
| Year | Sea Ice Extent (million km²) | YoY Change (%) | Cumulative Change (%) |
|---|---|---|---|
| 1979 | 12.32 | N/A | 0.00% |
| 1980 | 12.33 | +0.08% | +0.08% |
| 1981 | 12.13 | -1.62% | -1.54% |
| 1982 | 12.44 | +2.56% | +0.97% |
| 1983 | 12.34 | -0.80% | +0.16% |
| 1984 | 12.11 | -1.86% | -1.70% |
| 1985 | 11.93 | -1.49% | -3.17% |
| 1986 | 12.01 | +0.67% | -2.52% |
| 1989 | 11.99 | -0.17% | -2.68% |
| 1990 | 11.71 | -2.34% | -4.95% |
| 1991 | 11.78 | +0.60% | -4.38% |
| 1992 | 12.11 | +2.80% | -1.70% |
| 1993 | 11.93 | -1.49% | -3.17% |
| 1994 | 12.02 | +0.75% | -2.44% |
| 1995 | 11.44 | -4.83% | -7.14% |
| 1996 | 11.84 | +3.50% | -3.90% |
| 1997 | 11.68 | -1.35% | -5.19% |
| 1998 | 11.76 | +0.68% | -4.55% |
| 1999 | 11.70 | -0.51% | -5.03% |
| 2000 | 11.51 | -1.62% | -6.57% |
| 2001 | 11.60 | +0.78% | -5.84% |
| 2002 | 11.36 | -2.07% | -7.79% |
| 2003 | 11.40 | +0.35% | -7.47% |
| 2004 | 11.24 | -1.40% | -8.77% |
| 2005 | 10.91 | -2.94% | -11.44% |
| 2006 | 10.77 | -1.28% | -12.58% |
| 2007 | 10.47 | -2.79% | -15.02% |
| 2008 | 10.79 | +3.06% | -12.42% |
| 2009 | 10.74 | -0.46% | -12.82% |
| 2010 | 10.72 | -0.19% | -12.99% |
| 2011 | 10.51 | -1.96% | -14.69% |
| 2012 | 10.41 | -0.95% | -15.50% |
| 2013 | 10.90 | +4.71% | -11.53% |
| 2014 | 10.81 | -0.83% | -12.26% |
| 2015 | 10.58 | -2.13% | -14.12% |
| 2016 | 10.16 | -3.97% | -17.53% |
| 2017 | 10.39 | +2.26% | -15.67% |
| 2018 | 10.32 | -0.67% | -16.23% |
| 2019 | 10.23 | -0.87% | -16.96% |
| 2020 | 10.17 | -0.59% | -17.45% |
| 2021 | 10.29 | +1.18% | -16.48% |
| 2022 | 10.34 | +0.49% | -16.07% |
| 2023 | 10.21 | -1.26% | -17.13% |
| 2024 | 10.26 | +0.49% | -16.72% |
| 2025 | 10.11 | -1.46% | -17.94% |
*years 1987, 1988 are missing data for some months and are not included