Posted on 22 August 2016 by dana1981 skepticalscience.com
Walsh, J. E., Fetterer, F., Stewart, J. S. and Chapman, W. L. (2016) A database for depicting Arctic sea ice variations back to 1850. Geographical Review, doi:10.1111/j.1931-0846.2016.12195.x
Scientists have pieced together historical records to reconstruct Arctic sea ice extent over the past 125 years. The results are shown in the figure below. The red line, showing the extent at the end of the summer melt season, is the most critical:
Arctic sea ice extent in recent years is by far the lowest it’s been, with about half of the historical coverage gone, and the decline the fastest it’s been in recorded history. Florence Fetterer, principal investigator at the National Snow and Ice Data Center, described the data reconstruction process in a guest post at Carbon Brief….
….Most fundamentally of all, the new dataset allows us to answer the three questions we posed at the beginning of this article.
First, there is no point in the past 150 years where sea ice extent is as small as it has been in recent years. Second, the rate of sea ice retreat in recent years is also unprecedented in the historical record. And, third, the natural fluctuations in sea ice over multiple decades are generally smaller than the year-to-year variability.