Arctic sea-ice extent: No record minimum in 2023 or recent years

Arctic sea-ice extent reaches its minimum each year in September. On 11 September 2023 the minimum was 4.969 million square kilometers（mill.km2）. This was not a record low, which occurred in 2012, when the minimum was 4.175 mill.km2, 0.794 mill.km2 less than the minimum in 2023. However, the ice extent had decreased by 0.432 mill.km2 compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. In general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing CO2 in the atmosphere, where the increase of CO2 in recent decades explains about 80% of the decrease in sea ice in September, while the remainder is caused by natural variability.