About Us   •   Public Education   •   Species at Risk   •   Projects   •   Other Activities   •   Membership

Global warming is back in the news these days, but with consequences that most of us haven't associated with a warming problem. From the unusual weather here in the Chilcotin-Cariboo to the numbing cold of the Atlantic seaboard, climate patterns are changing. The prevailing view has been that these shifts will take place over the next century as the world's climate slowly changes to another regime. But now, the idea of slow change is being challenged by new evidence as a look at the other side of the story shows.

There are two major heat transfer sytems operating at the planetary scale which distribute energy from the hotter regions around the earth's equator to the cooler nothern and southern parts of the planet. The first of these is the atmosphere, with its global wind patterns, storms and other events.

Less obvious are the ocean currents which circumnavigate the globe. Containing 1,000 times the heat flux of the atmosphere, these ocean currents move more slowly but are even more critical to maintaining the earth's energy distribution than the air around us.

We're all familar with one such current system, the Gulf Stream. In esssence, it is a giant conveyor belt taking warm, salty water from the tropics and transporting it to the north Atlantic. This warm water, floating on top of the Atlantic waters, cools when it reaches the North Sea and gives its heat to the winds which blow across western Europe. It is for this reason that London, England has a warmer climate than New York city located several hundred miles to the south.

It's a remarkable system and it works like this: The Gulf Stream waters are saltier and therefore denser than those in the North Sea. As they cool, the combination of weight and cold causes them to start sinking. A surface vacuum is created as they sink, drawing the Gulf Stream currents north. The sinking of this cold salty water into the less dense water below is the engine that drives the system. Deep abyssal currents circulate the dense, cold water back to the tropics where it is pulled up, re-heated, and the conveyor belt continues its cycle.

Conveyor belts break down, and there is evidence that the Gulf Stream conveyor belt has malfunctioned in the past. By combining sediment samples from the deep ocean along with ice cores from Greenland, scientists have concluded that the "mini ice age" of the 1700s was a result of the stalling of the Gulf Stream. The canals in Holland froze, famine struck Europe, shipping lanes froze over, the eastern seaboard of the U.S. experienced much colder weather, and millions died of starvation and exposure.

The most startling and frightening finding is that this change happened in a period of just three to ten years! That is instantaneous in climate terms. The alarming evidence being collated now suggests that we are about to experience another shutdown of Gulf Stream. Warmer air temperatures and melting glaciers are putting more fresh water into the system. The waters in the north Atlantic are already 20 percent less salty than they were a decade ago. The rate of sink for the upper layers has slowed by 20 to 25 percent. These factors are combining to slow the Gulf current just as they did 300 years ago. But this time the causes are man-made, and scientists believe that we're looking at not a stall but a complete failure of the system.

The consequences of a shutdown of the Gulf Stream are huge. Unlike the situation in the 1700s, a full-scale shutdown of the Gulf conveyor and other ocean transfer systems could last upwards of 100,000 years.

Global warming may mean many things but paradoxically it includes the freezing of western Europe and the eastern seaboard of the United States. Frozen ports, failed crops and heating fuel crises are just the tip of the iceberg.

Now, more than ever, we need to try and control our greenhouse gas emissions, to do what we can to slow the effects that are threatening to stop the Gulf Stream and other ocean systems; threatening to plunge us into a new ice age.

- Dave Neads

More articles in the series, The Other Side of The Story

Cariboo Chilcotin Conservation Society
Unit 201, 197 2nd Ave North Williams Lake, B.C., V2G 1Z5
Phone/Fax: 250 398-7929 • ccentre@ccconserv.org • Coordinator: Marg Evans

Original material in this website may be reproduced in any form without permission on condition that it is accredited to the Cariboo Chilcotin Conservation Society, with a link back to this site or, in the case of printed material, a clear indication of the site URL. We would appreciate being notified of such use. Although care has been taken in preparing the information contained in this web site, the CCCS does not and cannot guarantee the accuracy thereof. Anyone using the information does so at their own risk and shall be deemed to indemnify CCCS from any and all injury or damage arising from such use.

About Us   •   Public Education   •   Species at Risk   •   Projects   •   Other Activities   •   Membership

---