Impacts of Climate Change on Arctic Sea Ice

Satellite sensors record a downward trend in Arctic sea ice extent for all months (Figure 2; Fox-Kemper et al., 2021). This trend is particularly pronounced in the summer months (June to October) in which ice extent of the most recent five years (2018–2022) has consistently remained below the 1981−2010 inter-decile range. Over the satellite period of 1979 to 2022, the September ice extent has reduced, on average, by almost 79,000 km2 each year, or around 11.5% per decade when referenced to the long-term (19812010) mean September extent of 6.88 million km2 (OSI SAF, 2020). The various satellite products all agree that Arctic sea ice extent has considerably declined over the last 43 years. However, they all report slightly different values, for example the NSIDC sea ice index reports an average decline of approx. 79,100 km2 per year over the period 1979–2022, just over 12.3% per decade relative to their 1981–2010 mean of 6.41 million km2.