Featured Research

from universities, journals, and other organizations

Fossilized Midges Provide Clues To Future Climate Change

Date:
July 11, 2007
Source:
University of Liverpool
Summary:
Fossilized 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.

Fossilized midge head.
Credit: Image courtesy of University of Liverpool

Fossilized 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 fossilized 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 fossilized 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.


Story Source:

The above story is based on materials provided by University of Liverpool. Note: Materials may be edited for content and length.


Cite This Page:

University of Liverpool. "Fossilized Midges Provide Clues To Future Climate Change." ScienceDaily. ScienceDaily, 11 July 2007. <www.sciencedaily.com/releases/2007/07/070709111430.htm>.
University of Liverpool. (2007, July 11). Fossilized Midges Provide Clues To Future Climate Change. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2007/07/070709111430.htm
University of Liverpool. "Fossilized Midges Provide Clues To Future Climate Change." ScienceDaily. www.sciencedaily.com/releases/2007/07/070709111430.htm (accessed July 24, 2014).

Share This




More Earth & Climate News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Observation Boat to Protect Cetaceans During Ship Transfer

Observation Boat to Protect Cetaceans During Ship Transfer

AFP (July 22, 2014) As part of the 14-ship convoy that will accompany the Costa Concordia from the port of Giglio to the port of Genoa, there will be a boat carrying experts to look out for dolphins and whales from crossing the path of the Concordia. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
New Orleans Plans to Recycle Cigarette Butts

New Orleans Plans to Recycle Cigarette Butts

AP (July 21, 2014) New Orleans is the first U.S. city to participate in a large-scale recycling effort for cigarette butts. The city is rolling out dozens of containers for smokers to use when they discard their butts. (July 21) Video provided by AP
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins