More DW Blogs DW.COM


Climate Change in the Arctic & around the globe

Arctic melt worries UN and White House

Melting ice off Svalbard, pictured 2011

The UN weather agency WMO (World Meteorological Organisation) has confirmed that the Arctic’s sea ice melted at a record pace in 2012, the ninth-hottest year on record. With just 3.4 million square kilometres (1.32 million square miles) during the August to September melting season, the sea ice cover was a full 18 percent less than the previous low set in 2007. The WMO’s Secretary-General Michel Jarraud said this was a “disturbing sign of climate change”, and pointed to the link between climate change and extreme weather events.

Meanwhile, a special briefing was called at the White House to discuss the possibility of the Arctic becoming ice free in the summer within just TWO years. Nafeed Ahmed, director of the “Institute for Policy Research & Development” headlines his post for the “Guardian“: “White House warned on imminent Arctic ice death spiral”. He describes the meeting, including NASA’s acting chief scientist Gale Allen, the director of the Department of Homeland Security and the Pentagon as “the latest indication that US officials are increasingly concerned about the international and domestic security implications of climate change”.

10 Arctic specialists were called in to advise the US government, including marine scientist Professor Carlos Duarte, currently director of the Oceans Institute at the University of Western Australia. I met and interviewed Prof. Duarte back in 2011 at the Arctic Frontiers conference, when he worked with the Spanish Council for Scientific Research.  At that time, he was already calling for urgent action and warning of the danger of “climate tipping points”, including the melt of the Arctic sea ice.  His conclusions are based on research which was presented in an article in Nature Climate Change last year.

The West Australian newspaper quotes Prof. Duarte as saying the “snowballing situation would prove as hard to slow down as a runaway train”.  He told the paper the ice melt was accelerating faster than any of the models could predict, and the prospect of an Arctic Ocean free of ice had been brought forward to 2015, compared with a prediction in 2007 that at least a third of the normal sea ice extent would remain in summer in 2100. When I spoke to him in 2011, the US navy was already assuming a date of 2050 and Duarte said he expected it to be even earlier.

Professor Carlos Duarte on Arctic Tipping Points

Prof Duarte also warned of the increasing danger of melting methane. Let me quote a little from the interview:

DUARTE: “We know from the history of ice covering the planet along geological time scales that ice is strongly a non-linear element in the earth’s system. It’s one of the components that show very rapid, very abrupt changes and tipping points. So we expect that once the ice will be lost quickly from the Arctic and also from the shelves in Greenland, then other forces will be set in motion, and many forces will be set in motion by loss of ice. One of them is the release of methane hydrates from the shallow continental shelves, mostly around Siberia, and those are molecules of methane that are trapped into ice in the sediments of the continental shelves and in the permafrost on land. So if this ice melts, this methane can be released abruptly and suddenly. And deposits of methane trapped in the shallow sediments of the Arctic amount to about five times the greenhouse power that humans have set in motion through burning fossil fuels. So if this five times what we have released in 150 years is released within a few years, that would be detrimental to the climate system and it could lead to a very rapid warming, and could again set in motion other forces like increased freshwater discharge to  the Arctic, which has already increased by 30 percent. And this involves a greater export of fresh water and buoyancy to the Atlantic, which may affect global circulation and global currents, and those in turn will affect regional climates  also further south to the sub-Arctic region. Also,  warmer temperatures are leading to dieback of the boreal forest and also the peat deposits in the boreal region are drying up to the extent that they can catch fire.”

(IRENE QUAILE:  How close are we?)

DUARTE: “We very much know what the threshold and the tipping point for the release of methanes will be, because the methane is kept in the hydrates, deposits in the salty sediments by ice, frozen sediments, and we know the freezing point of salty sediments may be around  minus 1 degree. So when the temperature of water in the summer goes well above freezing point, the hydrates will defrost and the methane will be released. So what we need to monitor is the temperature of the shallow waters in the Siberian shelf and other shallow waters in the Arctic, in the Canadian region as well, and see how close they’re getting to temperatures of 3 and 4 degrees, which will be those that will lead to melting of the hydrates.

Scary? The interview, it seems, is as relevant as ever, the Professor’s warnings more urgent. I wonder what it feels like to be called in to the White House to brief the government of a country that is both a key player in the Arctic and a top emitter of the greenhouse gases that are causing the melt? On the one hand it must be satisfying for the scientists to know they are finally being heard. But there must also be some frustration about the extent of dangerous climate change that had to be set in motion first. Has the Arctic ice already reached a “tipping point”?

Let me close with another quote from that interview with Carlos Duarte:

DUARTE: “Unfortunately society is much more mobilised by opportunities than by risks. So the discourses and warnings of risks actually almost lead to inaction by society, whereas the sight of opportunities encourages society to set themselves in motion. So the opportunities for economic growth in the Arctic have dominated the discourse and the actions by society and policy makers. Those opportunities are new navigation routes across the Arctic, and the exploitation of oil, gas and fisheries, that were not accessible just a few years ago. The paradox in this is that the Arctic countries recognise that the forces that are improving access to these resources is actually climate change and that the reason for this climate change is the burning of fossil fuels by humans.  Arctic nations themselves are responsible for 26% of the release of these greenhouse gases and are taking advantage of these opportunities, which will involve greater emissions of greenhouse gases.  (…) I think there should be a balance between the economic growth these opportunities could bring about and the economic losses, they may bring about, which I don’t think have been quantified.




May 6, 2013 | 1:54 pm



Write a Comment

Leave a comment