A new reconstruction of Arctic sea ice (September minimum measurements, dating back to 1850), shows dramatic reductions in extent since the dawn of the Industrial Age.
Florence Fetterer, principal investigator at the National Snow and Ice Data Centre, discusses this new reconstruction here. The reconstruction is performed to answer three questions that cannot be answered by the shorter-term satellite record:
- Has Arctic sea ice cover been this small since the start of the industrial revolution?
- Has sea ice ever declined this rapidly in the historical record?
- How is sea ice affected by natural fluctuations over multiple decades?
In short, Fetterer finds that:
1. Average Arctic sea ice cover was substantially larger at the dawn of the Industrial Revolution
2. The rapid decline of Arctic sea ice extent is indeed unprecedented in the historical record.
3. Sea ice extent can fluctuate widely from year to year - but on a decadal timeframe, there are no wide fluctuations.
Arctic sea ice has been declining since humans first began using coal on an industrial scale. The impact of that use (and related fossil fuels/greenhouse gases) on Arctic sea ice is clearly accelerating.