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Failing Ocean Current Raises Fears of Mini Ice Age
Designadrug writes "This article from Newscientist paints a picture of a major climate control mechanism teetering on the brink:
"The ocean current that gives western Europe its relatively balmy climate is stuttering, raising fears that it might fail entirely and plunge the continent into a mini ice age. The dramatic finding comes from a study of ocean circulation in the North Atlantic, which found a 30% reduction in the warm currents that carry water north from the Gulf Stream.""
The temperature differential that drives that current has shrunk slightly and therefore as lost some momentum. Then Europe gets cold for a while, things even out, and everyone is happy.
Not really. Europe, and North America get colder yes (and to be honest I'm not all that happy about that, living in Canada at the moment), but the rest of the trapped heat from global warming doesn't magically vanish, it simply gets pushed elsewhere - so think more more heat (and droughts) for Africa, more energy in the Carribean to help power hurricanes etc.
This is why the term "global climate change" is preferred these days. While there is "global warming" in that there is more energy trapped and retained in the system, that doesn't mean it's going to be evenly distributed as warming, it just means more energy in the system which can result in more dramatic swings and changes in climate.
Jedidiah.
Craft Beer Programming T-shirts
Actually the movie was based on info and theories from the Woods Hole Oceanographic Institution. They just added a bunch of bad science for plot devices. Take a look at these two links: Little Ice Age and Abrupt Climate Change
*It's not what you can do for the Dark Side but what the Dark Side can do for you!*
Global warming is a bit of a misleading name. Yes, the average temperature of the planet will go up, but that does not mean all places on the planet will increase in temperature. Before this, many scientists speculated that global warming would result in far colder, harsher winters for the United Kingdom.
The one thing about global warming that people must understand is that it will throw all the climate regions into chaos, and change them, which will change the local fauna and flora.
// file: mice.h
#include "frickin_lasers.h"
http://www.wunderground.com/education/abruptclimat e.asp
Here is the part I wanted to reference: "Since the Great Ocean Conveyor belt is driven in part by differences in ocean water density, if one can pump enough fresh water into the ocean in the key areas on either side of Greenland where the Gulf Stream waters cool and sink, this will lower the ocean's salinity (and therefore its density) enough so that the waters there no longer sink. The Atlantic conveyor belt and Gulf Stream current will then shut down in just a few years, dramatically altering the climate. "
Also here is a write up specifically dealing with the "science" of "The Day After Tomorrow."
http://www.wunderground.com/education/thedayafter. asp
"I'm in it to win it, and no limit is my home." - Snoop Dog c/o PvP Online (July 12th, 2006)
If the current is pulling all that energy from the warm waters up north and dissipating it in the process, what will happen to all the excess warmth if the current stops? Will it find another way to go? Maybe create a new current or even restart the same current again? That heat has to go somewhere, it is water after all.
Well the current that pushes northward occurs due to the conveyor effect that occurs when the water reaches up north, cools, sinks, and flows back as cold water much deeper. In general the current just circles around the equatorial Atlantic, and only a portion branches north due to said conveyor. If the conveyor effect stalls the most likely outcome is simply more and warmer water circulating in the equatorial Atlantic. That, of course, is going to have significant impacts on climate in Africa and central and South America. Potentially a lot of the energy may end up providing more power for hurricanes out in the Atlantic. What exactly will happen is unclear, but I think its safe to say that assuming everything will magically right itself is betting on the long shot - there's really no evidence for such a thing. The most likely outcome is simply a lot warmer and more energetic weather for Africa and South and Central America.
Jedidiah.
Craft Beer Programming T-shirts
True, ocean currents will still move. They're definitely chaotic system and often behave "counterintuitively".
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But all that warm water goes so far north largely because of (cold) water with high salinity. This water is dense and sinks. This is called North Atlantic Deep Water formation, and possibly drives deep ocean currents around the world.
This salinity gradient is the key energy source that "pulls" warm water so far north, more than the thermal or momentum gradients.
This gradient broke down during "the Younger Dryas cold episode, which chilled the North Atlantic region from 11,000 to 10,000 yr BP." "[This] is postulated to be a turnoff [...] of the North Atlantic's conveyor-belt circulation system which currently supplies an enormous amount of heat to the atmosphere over the North Atlantic region. This turnoff is attributed to a reduction in surface-water salinity, and hence also in density, of the waters in the region where North Atlantic Deep Water (NADW) now forms." Paleoclimate claims are supported by oxygen and carbon isotope studies on plankton.
see http://www.nature.com/nature/journal/v341/n6240/a