Publication Date September 17, 2016

The Observer view on sea ice and global warming

 A Nasa image shows receding ice cover over northern Canada. Image: MODIS/Aqua/Nasa

The sea ice covering the most northerly part of our planet shrank last week to its second lowest level on record. Once stable at around 7.5m sq km in summer, the Arctic ice cap has been dwindling for several decades and dropped to an area of 4.1m sq km a few days ago, a victim of the rising fossil-fuel emissions and increasing temperatures that now beset the Earth. At the same time, the US space agency Nasa announced that August 2016 had tied with July 2016 as the hottest month globally ever recorded. Our world is heating up dramatically.

As winter returns to the far north, its ice cover will slowly return, of course, though it will certainly not be restored to its former glory. The overall trend of summer Arctic sea-ice cover has been a steadily downwards one for the past 30 years, an inexorable decline that has deeply worrying implications for the region, and for the rest of the planet, as we report today. An Arctic that is regularly free of sea ice in summer – a real prospect for the middle of the century – will open up that fragile, pristine wilderness to all sorts of potential woes: overfishing; pollution related to oil drilling and mineral extraction; the eradication of indigenous species; and the destruction of native communities. In addition, with little or no ice left to reflect solar radiation back into space, and its dark waters absorbing more and more of that radiation, the Arctic will heat up even further, enhancing the global warming that has already taken a grip on the planet. As Professor Gail Whiteman of Lancaster University remarked last week: “Forget the FTSE: Arctic sea ice is the real barometer of global risk"