Posted on 07/10/2007 1:42:58 PM PDT by blam
09 July 2007
Fossilised midges provide clues to future climate change
Fossilised midges have helped scientists at the University of Liverpool identify two episodes of abrupt climate change that suggest the UK climate is not as stable as previously thought.
The episodes were discovered at a study in Hawes Water in Northern Lancashire, where the team used a unique combination of isotope studies and analysis of fossilised midge heads. Together they indicated where the climate shifts occurred and the temperature of the atmosphere at the time.
The first shift detected occurred around 9,000 years ago and the second around 8,000 years ago. Evidence suggests that these shifts were due to changes in the Gulf Stream, which normally keeps the UK climate warm and wet.
During each shift the North West climate cooled with an average summer temperature fall of 1.6 degrees – approximately three times the amount of temperature change currently attributed to global warming.
Scientists found that the atmosphere cooled rapidly and cold periods lasted up to 50 years for one event and 150 years for the other. The detection of these events will allow experts to understand more clearly what can happen when the climate system is disturbed.
Professor Jim Marshall, from the University’s Department of Earth and Ocean Sciences, explains: “At Hawes Water mud has been deposited continuously without any gaps, which allows us to measure an accurate timeline of events. We have monitored the modern environment of the lake for the past eight years and this has shown us how to read the past climate record from the ancient mud in the lake.
“Isotope analysis helped us identify the episodes of climate change. We then used fossilised heads of non-biting midges, which are preserved in every spoonful of mud. They tell us the temperature at the time the mud was deposited. We compare the population of midge heads in each sediment sample with the population of midges in Scandinavian lakes, which span a wide range of modern day temperatures.”
The team found the two abrupt climate changes correlated directly with two episodes of sharp climate deterioration in areas such as Greenland, suggesting that a change in the Gulf Stream had occurred.
Professor Marshall added: “People are worried that the melting of the polar ice caps could result in a slow-down of what we call the ‘Atlantic Conveyer’. This is where cold water that sinks in the far north is replaced by warmer water from the tropics in its circulation of the North Atlantic Ocean. A number of studies suggest that the conveyer may be unstable and may be able to slow down or switch off completely, making our climate suddenly colder. Our study provides evidence that the two climate shifts we detected were directly linked to a slow-down in the conveyer.”
Scientists believe that this new data will provided a unique test for the global climate computer models that are being used to simulate future climate change.
The research - in collaboration with University of Swansea; the Open University; University of Exeter; Edge Hill University and University College London - is published in Geology.
WHAT IS A NO-SEE-UM?
"No-see-ums are tiny biting flies that often live near water. You often see many of themswarming together in a cloud. Keep your mouth shut or you might breathe some in or swallow them! (It won’t hurt you, but it will probably make you cough.) Biting midges are called no-see-ums because they’re so tiny that it is hard to see ‘um. No-see-ums are less than ¼ of an inch long."
The are small enough to go through the mesh of 'normal' screen wire.
GGG & Catastrophism Ping
I became less interested when I realised it didn’t say ‘fossilized midgets’.
Should we be talking about fossilized midgets or midget heads? Seems somewhat un-pc.
The future? Seems to me fossils would have more light to shed on the past, but that’s just me.
So if Wolf Blitzer becomes fossilised will the climate change? Oh, you said midges, not midgets? My mistake.
Wasn’t Midge a character in Archie or Sabrina comics?
Were they wrestling?
HA!! That’s what I thought it said too, at first.
This seems to support the theory that the Arctic Ocean is the driver behind glacial periods, that when the ice melts and open water becomes available to the atmosphere, precip increases and the next glacial period begins. Shutting down the Gulf Stream would sure facilitate that process.
Archaeologists have documented at least half a dozen attempts by humans or human ancestors to colonize the British Isles. All but the last failed. Britain goes under the ice during glacials. The Brits better hope "global warming" continues.
These guys were naive enough to think Britain's past climate was "stable"??? Hit in the head with a hockey stick? They should sign on to Sunken Civ's ping lists and get a real education.
This is what happens when small insects are allowed to drive SUVs, cook on out-door barbeques, and fly in private jets. Albert Gore, Jr. is working this issue very hard, and...
Oh. Never mind.
Excellent point, blam. The Gulf Stream is thought by that research to have shut down. I don”t know that these guys in their lake research could corroborate that, because isn”t the time of this comet when glaciers were still covering most of Britain during the Younger Dryas?
Yes. This may have caused the Younger Dryas.(?) The melting of the huge (fresh water) ice lakes in NA could have shut-down the conveyer-belt.(?)
It would sure be interesting if someone could figure out a way to chart the history of the gulf stream, how “turning it on” and “off” may play a role in the glacial cycles.
If I understand this, the Gulf Stream is wind-driven and therefore unlikely to "shut down" but the North Atlantic Drift, which gets the warm water to Europe, can collapse.
“Fossilised midges have helped scientists at the University of Liverpool identify two episodes of abrupt climate change that suggest the UK climate is not as stable as previously thought.” This is the funniest thing I’ve seen. Climates are never stable. The world is constantly changing, and to not understand this is to be like alogre...
 |
||
| · join · view topics · view or post blog · bookmark · post new topic · | ||
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.