"Unprecedented" Warming Driving N. Atlantic Changes At Scale, Speed Unknown Since Civilization Began

[hatrack]

ScienceDaily (Nov. 7, 2008) — While Earth has experienced numerous changes in climate over the past 65 million years, recent decades have experienced the most significant climate change since the beginning of human civilized societies about 5,000 years ago, says a new Cornell University study.

The paleo-climate record shows very rapid periods of cooling in the past, when temperatures have dropped by as much as 18 degrees Fahrenheit (10 degrees Celsius) in a matter of years to decades, "the rate of warming we are seeing is unprecedented in human history," said Cornell oceanographer Charles Greene, the lead author of the paper appearing in the November 2008 issue of the journal Ecology, which is published by the Ecological Society of America.

During the past 50 years, melting Arctic ice sheets and glaciers have periodically released cold, low-salinity slugs of water from the Arctic Ocean into the North Atlantic. This has led to dramatic ecosystem shifts as far south as North Carolina and extensive geographic range shifts of many plant and animal species. One microscopic algal species from the Pacific Ocean, not seen in the North Atlantic for over 800,000 years, has successfully crossed over the Arctic Ocean and reinvaded the North Atlantic during the past decade. By reviewing climate changes in the past, the researchers were able to more clearly observe how this influx of fresher water has led to changes in ecosystems as well as the geographic distributions of species, said Greene.

Interestingly, the study reports findings counter to the expectations of most ecologists: that the distributions of southern species will move northward and those of northern species will retreat as the climate warms. Instead, as colder, fresher Arctic waters flow south along the Northwest Atlantic shelf, from the Labrador Sea south of Greenland all the way to North Carolina, the distributions of many northern species have actually moved southward, said Greene. In addition, the periodic freshening of shelf waters can extend the growing seasons of phytoplankton and tiny drifting animals, like copepods, which together make up the base of the marine food chain. Such climate-driven changes can alter the structure of shelf ecosystems from the bottom of the food chain upwards, said Greene.

EDIT

http://www.sciencedaily.com/releases/2008/11/081106153534.htm

[mojowork_n]

1. I thought D.U.'ers, as a group, generally favor

"change... from the bottom of the food chain upwards..."

[cliffordu]

2. Tipping point.

[Submariner]

3. I read all your environment posts hatrack and this is one of the scarier ones

because this is further evidence of the changing nature of the current engine carrying the Gulf Stream north in it's circular gyro around the North Atlantic. I pity our grandchildren and their offspring from what 19th and 20th century man has done to the biosphere.

[Bigmack]

6. My thoughts

Exactly! This is scary business..... Thanks, I think, for this post, Hatrack..... Ms Bigmack

[Barrett808]

8. I'm ever so glad that my wife and I don't have children

Watching them starve to death would be such a drag...

[Delphinus]

4. Now that the election is over

(must have said that a few dozen times or more!) I can start looking into this forum again. I've not seen the Peak Oil forum for weeks ... and this one, of course this would be one of the first posts I see.

Thanks, Hatrack. You always find the 'good' ones.

[XemaSab]

5. .

[amyrose2712]

7. ...