Glacial Acceleration - A Sea of Troubles
Scientists know this already, but just to give you some idea of the problem, the Greenland ice cap is melting at such a fast rate it is triggering earthquakes as pieces of ice several cubic kilometres in size break up.
Scientists say the acceleration of melting and subsequent speeding up of giant glaciers could be catastrophic in terms of sea level rise and make previous predictions published this year by the Intergovernmental Panel on Climate Change (IPCC) far too low. The glacier at Ilulissat, which it is believed spawned the iceberg which sank the Titantic, is now flowing three times faster into the sea than it was 10 years ago.
Robert Correll, chairman of the Artic Climate Impact Assessment, from Washington told me:"We have seen a massive acceleration of the speed with which these glaciers are moving into the sea. The ice is moving at 2 metres an hour on a front five kilometres long and 1,500 metres deep. "That means that this one glacier puts enough fresh water into the sea in one day to provide drinking water for a city the size New York or London for a year."
Professor Correll, who is also director of the global change programme at the Heinz Centre in Washington said the estimates of sea level rise in the IPCC report in February had been "conservative" and based on data two years old. The range of rise this century had been predicted to be 20 to 60 centimetres, but would be the upper end of this range at a minimum and some now believed it could be two metres. This would have catastrophic effects for European and US coastlines.
He said newly invented ice penetrating radar showed that the melt water was pouring through to the bottom of the glacier creating a melt water lake 500 metres deep causing the glacier "to float on land. "These melt water rivers are lubricating the glacier, like applying oil to a surface and causing it to slide into the sea. It is causing a massive acceleration which could be catastrophic."
The glacier is now moving at 15 kilometres a year into the sea although in periodic surges it moves even faster. He has seen a surge, which he had measured as moving five kilometres in 90 minutes - an extraordinary event.
If all of Greenland melts, something we were previously assured would take thousands of years, but now could be hundreds, then sea level round the world would rise seven metres. That is without any contribution from the Antarctic, the glaciers of Alaska, the Rockies, the Himalayas, or the ocean water expanding as it warms.
So the talk of sea level rise should not be in centuries, it should be decades or perhaps even single years. For 10,000 years, during all of human civilisation sea level remained stable leading us to believe that coastlines remained roughly in the same place. A century ago the sea began to rise one millimetre a year, 20 years ago it had reached two millimetres and this century it has risen to 3 millimetres. This annual rise may not seem much but add hurricane storm surges and high tides and we are soon saying good bye to a lot of coastal settlements – like the Big Apple.
Climate change is the biggest threat to the earth – although the catastrophic sea level rise facing our major coastal cities does not rate a mention.
Although it may sound like it, the commentators in Europe are not singling out America for criticism, although it has to be said as often as possible that the US is the world’s most profligate nation when it comes to fossil fuel consumption, AND has rejected the only legally binding international agreement that could do something about it. But Europeans are not doing enough either. We need convincing that our own leaders have enough political will to reach the tiny Kyoto targets that are the minimum first step to tackling this problem. The public hears the latest scientists’ warnings that an 80% cut in greenhouse gas emissions is needed if we are to stave off catastrophic climate change, yet wait in vain for the policies needed to achieve them.
