. 24/7 Space News .
Global Warming Could Trigger Cascade Of Climatic Changes

illustration only
by David Stauth
Corvallis - Mar 17, 2003
Global warming and the partial melting of polar ice sheets can dramatically affect not only sea levels but also Earth's climate, in ways that may be complex, rapid and difficult to adjust to, scientists say in a new study to be published Friday in the journal Science.

Sea level and climatic changes in Earth's distant past, near the end of the last Ice Age about 14,600 years ago, offer significant clues to some phenomena that Earth may experience in the near future, possibly in coming decades or centuries, the study found.

The research was done by scientists at the University of Victoria, Oregon State University, and the University of Toronto. It revealed changes in global temperature, sea level and ocean currents that can occur with surprising rapidity.

"With the advent of global warming, we're trying to identify the climatic surprises that may be in store for us, the events that we really aren't expecting," said Peter Clark, a professor of geosciences at OSU and a co-author of the study.

"The more we look at this, the more it appears there have been large and abrupt changes in climate and sea level that are interconnected. If these changes were to happen in the future, they could cause huge societal disruptions."

About a year ago, Clark and his colleagues outlined in a publication in Nature how one of the unanticipated outcomes of global warming could be disruption of a "thermohaline circulation" pattern in currents of the North Atlantic Ocean, robbing Europe of the influence of warm ocean currents and causing widespread cooling.

This could happen when additional rainfall or melting glaciers in the Northern Hemisphere inject more fresh water into the North Atlantic and make the ocean less salty.

Scientists now believe this current may have slowed or stopped altogether many times in Earth's past. The shutdown of this current was one prominent feature of the last Ice Age.

In the new study, the researchers found that an Antarctic melting event called "Meltwater Pulse 1A," which occurred near the end of the last Ice Age about 14,600 years ago, raised Earth's sea levels about 70 feet in less than 500 years.

The melting event simultaneously caused the North Atlantic circulation to turn on, causing widespread warming of the Northern Hemisphere.

The melting event occurred following a time of increasing temperature, sea level and carbon dioxide that had some similarities - and key differences - to the present day, Clark said.

"These past events provide important clues as to how the climate system may change as the Earth warms," Clark said.

"Global warming might cause a shutdown of currents in the North Atlantic and cause Europe to cool," he said.

"But just as people are trying to adjust to that event, the same warming might also help melt an Antarctic ice sheet which would tend to start the current in the North Atlantic moving again. And that might be considered a good thing, unless you live in a coastal area which is now going to be flooded by rising sea levels."

Related Links
Department of Geosciences at Oregon State University
SpaceDaily
Search SpaceDaily
Subscribe To SpaceDaily Express

Arctic Oscillation: Cold Heralds Hot
Boulder - Mar 03, 2003
Why has the Arctic warmed so dramatically in recent years? How does the Arctic's circulation keep frigid air over the poles and sometimes allow it to spill across the United States? And how might global change affect the behavior of this circulation?



Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only














The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.