Largest Arctic Ice Shelf Breaks Up

According to a Reuters story, "The largest ice shelf in the Arctic, a solid feature for 3,000 years, has broken up." The Ward Hunt Ice Shelf broke into two pieces, and a local fresh water lake poured into the ocean after "all of the fresh water poured out of the 20 mile long Disraeli Fjord."

according to the story on the BBC site :

" Last year, the 3,250-square-km Larsen B Ice Shelf on the Antarctic Peninsula shattered over a period of a month into thousands of icebergs.The peninsula is one of the three fastest-warming regions on Earth - temperatures have gone up 2.5 degrees in 50 years.

Global change

Mueller, Vincent, and Jeffries say their calculations suggest changes of a similar nature have been taking place in the Ellesmere Island area.A century ago, the entire northern coast of the island was reported to be fringed with a continuous ice shelf. About 90% of that ice area had been lost by 1982, the scientists say.The precise timing of the break-up of the remnant Ward Hunt Ice Shelf may have been influenced by freeze-thaw cycles, wind, and tides, they tell GRL.Other factors may include changes in Arctic Ocean temperature, salinity, and flow patterns, they add."Computer models show quite convincingly that global climate change would be manifested first and amplified in the polar regions and in particular in the Arctic," Dr Jeffries said"Our observations at Ward Hunt Ice Shelf fit in with a broader picture of Arctic change which fits in with our understanding of how the Arctic climate would respond to global change."

Recently an article appeared in the New York Times that described retreating ice in Northern Alaska. In this report the evidence was anecdotal (stories told by native residents of the area, tales of polar bear drownings when pack ice broke up and the bears could not reach shore, with other bears unable to get out onto the ice and instead spending their time rummaging through the town's garbage. Robins, using that uncanny sense they possess, have moved into Northern Alaska for the first time to nest, having somehow determined that it is safe to do so.)

According to the Reuters report over the last 100 years over 90 per cent of the Ellesmere ice cap has disappeared. A similar pattern of 'regional warming' is taking place in Antartica, and the warming in the North Atlantic is also responsible for the 'regional' pattern of increasing monsoons over the Sahara region since the late 90s (which in turn was responsible for pushing desert air into Europe this summer leading to the heat wave).

According to the article " Records indicate an increase of four-tenths of a degree centigrade every 10 years since 1967. The average July temperature has been 1.3 degrees Celsius or 34 degrees F -- just above the freezing point -- since 1967." Changes in climate also affect ocean currents and salinity and the warmer temperatures leave the weakened ice vulnerable to these forces.

Other reports have indicated that snow cover in general, as monitored by satellites, has decreased by 10 per cent since 1986. I would suppose that when you have regional climate change in the north, and then this extends south to reduce the area of snow cover in such places as the Northern United States, and then you have regional warming and break up in the ice of Antartica, and regional climate change in Northern Africa and Europe, the regional changes seem to be taking place globally.

I just mention this since scientists introduce caveats. They do this because it is science, and in science they would need to write a paper and provide charts and graphs and so on which can withstand scrutiny by their peers, and so they tend to be conservative. Many times they speak in terms of probability, and given the complexity of climate, they can also speak of uncertainties due to the effect of climate change. When the Bush administration ditched the Kyoto accord one of the reasons given is that scientists used the word 'uncertain' about a hundred times in the IPCC 2001 report. That 'global warming' is taking place at both poles of the globe is not 'uncertain' and where the uncertainty lies in what the effects of our gamble with climate change will be. However the word 'uncertain' is misused to give people the impression that 'global warming' is 'uncertain' when actually only its potential effects are difficult to predict (making climate change a big gamble).