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Rothera
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Latitude 6734' S, Longitude 6808' W

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RE: Greenhouse Gases
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Mairi Nicolson From Wick Returns To Antarctic

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Antarctic Ice
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Scientists say they have found the first direct link between melting Antarctic ice and an increase in greenhouse gases.
The British Antarctic Survey (BAS) has been studying air bubbles trapped in the ice on Adelaide Island on an Antarctic Peninsula .

BBC Science correspondent David Shukman is currently at Rothera Research Station producing a number of reports on BAS science and operations for BBC News.

Rothera Station is the BAS logistics centre for the Antarctic Peninsula and home to well-equipped biological laboratories and facilities for a wide range of research. The station is situated on a rock and raised beach promontory at the southern extremity of Wormald Ice Piedmont, south-eastern Adelaide Island. The station has a 900 m crushed rock runway, with an associated hangar and bulk fuel storage facility, and a wharf for the discharge of cargo from supply ships. There is a transitory summer population of scientists and support staff who reach Rothera either by ship or through use of an intercontinental Dash-7 aircraft flying from the Falkland Islands.


Latitude 6734' S, Longitude 6808' W

Rothera station was established in 1975 to replace Adelaide station (1961-1977) where the skiway had deteriorated. From its inception until the 1991-92 summer season BAS Twin Otter aircraft used the skiway 300 m above the station on Wormald Ice Piedmont. With the commissioning of the gravel runway and hangar in 1991-92 air operations became more reliable and access to Rothera was greatly improved through a direct airlink from the Falkland Islands.

David Shukman reports from Antarctica. (windows media player)

-- Edited by Blobrana at 03:57, 2006-01-20

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Greenhouse Gases
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Current levels of the greenhouse gases carbon dioxide and methane in the atmosphere are higher now than at any time in the last 650,000 years.

That is the conclusion of new European studies looking at ice taken from 3km below the surface of Antarctica.
The scientists say their research shows present day warming to be exceptional.
Other research, also published in the journal Science, suggests that sea levels may be rising twice as fast now as in previous centuries.
The evidence on atmospheric concentrations comes from an Antarctic region called Dome Concordia (Dome C).
Over a five year period commencing in 1999, scientists working with the European Project for Ice Coring in Antarctica (Epica) have drilled 3,270m into the Dome C ice, which equates to drilling nearly 900,000 years back in time.

Gas bubbles trapped as the ice formed yield important evidence of the mixture of gases present in the atmosphere at that time, and of temperature.

"One of the most important things is we can put current levels of carbon dioxide and methane into a long-term context. We find that CO2 is about 30% higher than at any time, and methane 130% higher than at any time; and the rates of increase are absolutely exceptional: for CO2, 200 times faster than at any time in the last 650,000 years" - project leader Thomas Stocker, University of Bern, Switzerland.

Last year, the Epica team released its first data. The latest two papers analyse gas composition and temperature dating back 650,000 years.

This extends the picture drawn by another Antarctic ice core taken near Lake Vostok which looked 440,000 years into the past.
The extra data is crucial because around 420,000 years there appears to have been a significant shift in the Earth's long-term climate patterns.
Before and after this date, the planet went through 100,000 year cycles of alternating cold glacial and warm interglacial periods.
But around the 420,000 year mark, the precise pattern changed, with the contrast between warm and cold conditions becoming much more marked.

The Dome C core gives data from six cycles of glaciation and warming; two from before this change, four from after.

"We found a very tight relationship between CO2 and temperature even before 420,000 years. The fact that the relationship holds across the transition between climatic regimes is a very strong indication of the important role of CO2 in climate regulation" - Thomas Stocker.

Epica scientists will now try to extend their analysis further back in time.
Another study reported in the same journal claims that for the last 150 years, sea levels have been rising twice as fast as in previous centuries.
Using data from tidal gauges and reviewing findings from many previous studies, US researchers have constructed a new sea level record covering the last 100 million years.
They calculate the present rate of rise at 2mm per year.

"The main thing that's changed since the 19th Century and the beginning of modern observation has been the widespread increase in fossil fuel use and more greenhouse gases" - Kenneth Miller, Rutgers University.

The Intergovernmental Panel on Climate Change, the body which collates scientific evidence for policymakers, concludes that sea level rose by 1-2cm during the last century, and will rise by anything up to 88cm by the end of this century.

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