This time series shows the Arctic sea ice extent in millions of square kilometers over the past roughly 1,500 years. The vertical axis starts at 8, not 0, to better show year-to-year variations. Taken from the 2017 issue of NOAA’s Arctic Report Card, scientists report on a body of paleoclimate research that shows that the extent and rate of sea ice decline in the Arctic is unprecedented over at least the past 1,500 years. Climate.gov image adapted from Figure 3 in “Paleoceanographic Perspectives on Arctic Ocean Change” in the 2017 Arctic Report Card. Original data from Kinnard et al., 2011.