Mq., there was a very good discussion concerning the loss of the Gulf Stream caused by melting ice caps caused, in turn, by excess co2. It started here:
Message 19860715
There is now some objective evidence that the pump that causes the conveyor effect is getting reduced by less salty, less dense water. If true and if the effect persists, it will spell the end of the Gulf Stream, plunging Europe's average temperatures. How can that possibly be a beneficial effect of more co2?
A quote from an article that deals very well with the issue:
an important paper published in 2002 in Nature, oceanographers monitoring and analyzing conditions in the North Atlantic concluded that the North Atlantic has been freshening dramatically—continuously for the past 40 years but especially in the past decade.4 The new data show that since the mid-1960s, the subpolar seas feeding the North Atlantic have steadily and noticeably become less salty to depths of 1,000 to 4,000 meters. This is the largest and most dramatic oceanic change ever measured in the era of modern instruments.
At present the influx of fresher water has been distributed throughout the water column. But at some point, fresh water may begin to pile up at the surface of the North Atlantic. When that occurs, the Conveyor could slow down or cease operating.
Signs of a possible slowdown already exist. A 2001 report in Nature indicates that the flow of cold, dense water from the Norwegian and Greenland Seas into the North Atlantic has diminished by at least 20 percent since 1950.5
whoi.edu
Excess co2 has also indirectly resulted in lessened plankton levels. Read why this is not good:
(d) Disappearing Plankton
The ability of the oceans to absorb carbon dioxide may be at risk. Presently oceans are absorbing about 2 billion tons of carbon annually [3] . A report in Nature, August 1995, suggests that the oceans may be losing fixed nitrogen, an essential fertilizer that allows phytoplankton to grow. Phytoplankton absorb and fix carbon that is then transferred to the deep ocean. If in fact the oceans are losing nitrogen as they warm, they will tend to absorb less carbon, boosting the rate of carbon dioxide buildup in the atmosphere. [24]
Watson W. Gregg, a NASA biologist at the Goddard Space Flight Center in Greenbelt, Maryland says that the greatest loss of phytoplankton has occurred where ocean temperatures have risen most significantly between the early 1980's and the late 1990's. In the North Atlantic summertime sea surface temperatures rose about 1.3 degrees Fahrenheit during that period, Gregg said, while in the North Pacific the ocean's surface temperatures rose about 7/10ths of a degree.(San Francisco Chronicle, David Perlman, Science Editor, October 6, 2003). See Ocean Plant Life Absorbing Less Carbon
Plankton are a major carbon sink in addition to the forests, other green plants, the permafrost, the earth's soil and atmosphere. Plankton take in about half of all the world's CO2, using the carbon for growth, while releasing oxygen during the process of photosythesis. During the past 20 years there has been a stark decline, more than 9%, in primary production of plankton, while in the same period plankton of the North Atlantic has decreased by 7%. Less plankton; less carbon uptake.
Research suggests a positive feedback scenario, where more intense storms roil oceans and cause the latter to release more carbon dioxide into the atmosphere. [36]
ecobridge.org
And the following is a good article indeed:
csmonitor.com |
