ELI5: The current Antarctic Sea Ice Extent has deviated enough from the 1991-2020 average that we can confidently say that the 1991-2020 average is no longer normal (the baseline) for Antarctic Sea Ice Extent in 2023 and onward. From now until the foreseeable future, there will be less ice on average than there was in 1991-2020.
ELI5: The current Antarctic Sea Ice Extent has deviated enough from the 1991-2020 average that we can confidently say that the 1991-2020 average is no longer normal (the baseline) for Antarctic Sea Ice Extent in 2023 and onward. From now until the foreseeable future, there will be less ice on average than there was in 1991-2020.