Search Results for Tag: feedback loops
No going back for the Arctic
(No emissions from this one for a while)
Professor Jean-Claude Gascard from the Université Pierre et Marie Curie in Paris, heads the EU’s Damocles project, identifying the challenges from climate change. He gave a very sobering summary of the state of the Arctic sea ice and confirmed there is virtually no chance of reversing the current warming trend. Only several extremely severe winters could do that, and the scientific community is not expecting that.
Scientists tend to be reluctant to come out with anything they can’t prove, and Prof. Gascard summed up the main elements behind this conviction. Sea ice extent, depths, age and drift are key factors, as well as the air temperature and the number of “freezing degree days”.
By 2002 the ice was at a minimum based on some 50 years of observation. In 2005, there was no “replenishment” of older, multi-year ice exiting the Arctic ocean. This, Prof. Gascard describes as a “tipping point”.
The ice thickness has decreased over a wide area from more than 3 metres 20 or 30 years ago to around 1.5 metres. I remember my trip out on the sea ice in Barrow, Alaska, with Dr. Chris Petrich and the Climate Change College “ambassadors”. I can hear Erika Naga reading out the measurement “1 metre 40”, and the Inupiat telling us how it used to be much thicker.
The ice is melted in various ways: through warmer water from the Atlantic and Pacific underneath, heat from storms and increased radiation from above.
2007 of course was the year that really made everybody wake up. When the Alfred Wegener Institute’s Polarstern went out to set up ice platforms, there was no ice in their target area. The Tara, which has been frozen in and drifting with the ice to compare ice drift with the “Fram” expedition has been drifting three times faster than her predecessor. And the sea ice reached its minimum. 2008 saw almost the same negative record.
Sea ice reflects much more heat back into the atmosphere than water, (albedo effect) which is much darker and absorbs it, exacerbating the warming, in what’s called a “feedback loop”. Again, I was reminded of our trip on the Chukchi Sea with Chris Petrich from the University of Fairbanks, Alaska, who is collecting data on this to be put into global models.
And the number of “freezing degree days” has dropped massively in the last few years.
Professor Gascard’s summary of all this is available online on the Arctic Frontiers site.
And if you have the time and the inclination, have a(nother?) listen to the feature on my trip onto the sea ice with the Climate Change College.
Tromsö today (the days are getting lighter):
DateJanuary 23, 2009 | 4:35 pm
Lions, Giraffes and Hippos on Ice ?
So what are these African animals (I took the pictures in Tanzania) doing on the Ice Blog? Of course it’s all about biodiversity.
The Arctic is particularly sensitive to climate change and acts as a kind of early warning system. At the same time, ice melting up there will have consequences for the whole planet. I’ve gone on a lot about how melting sea ice affects the flora and fauna in Arctic regions. There’s also been a mention of how melting glaciers change the temperature, salinity and light conditions of the ocean. I’m currently working on a radio feature on my trip out onto the sea ice up in the Arctic with the “ambassadors” from the Climate Change College and scientist Chris Petrich. (Listen out for that in Living Planet). One of the main subjects of his research is the “albedo effect”. That is all about how the whiteness of ice and snow reflects solar radiation back up off the earth’s surface. When the snow cover decreases, the “melt ponds” are a much darker cover, and that absorbs warmth – exacerbating the overall warming effect. So, polar areas have a huge importance for the planet as a whole. Then there is the methane (around 23 times more powerful than c02 as a climate gas) being released from the huge areas of melting permafrost.
All this effects not only the area where it happens, but the whole planet. And of course, the sea level is rising, which will have disastrous effects for all the low-lying areas of the globe.
All our species of plants and animals are dependent on particular habitats and living conditions – from polar bears to giraffes, hippos, kangaroos or cuckoos. (Listen to Alison Hawkes on the plight of the “bird of the year” in the Black Forest. Will cuckoos exist soon only in those quaint – or exasperating – clocks?)
The Cuckoo Story
Last night the IUCN and UNEP staged an event here in Bonn to mark Biodiversity Day.
More about the IUCN
During it, I met Pavan Sukhdev,who’s heading the TEEB project,that is a study on The Economics of Ecosystems and Biodiversity. I felt very privileged to have the chance to talk to the man who’s in charge of what some people say could do for biodiversity what Nicholas Stern’s report did for climate change. The idea is to put a price on nature and make it clear, in economic terms, what it is worth to protect our biodiversity. The first part of the report will be presented in Bonn next week, but he did give me an idea of the scale of things. You can read the interview here:
Pavan Sukhdev on putting a price on nature
DateMay 23, 2008 | 8:43 am
TagsAfrica, Arctic, Biodiversity, Climate, Climate Change College, CO2, economics, feedback loops, IUCN, Living Planet, methane, permafrost, sea ice, Sea level, TEEB, UNEP, wildlife