Ocean Currents to Shut Off in Near Future
A Huge Global Change
What if you attended a scientific meeting and heard that global changes to climate appear to be moving toward a shut down of the planet's major ocean current?
What if that were true?
This is in fact the very message given by a scientist from the Woods Hole Oceanographic Institution.
To consider the implications to this anticipated or probable event, we offer several key elements for your consideration, including:
1) What this means in terms of the Window's View,
2) A graphic illustrating the global current being discussed (see below),
3) brief abstracts from the scientific meeting, and
4) a link to an mp3 fileso you can actually hear the entire talk by the WHOI scientist!
From The Window's View
The implications to focus on are summarized as follows. First, humans are having an affect on the global climate in ways that some effects will cause yet other effects with as yet unknown 'tipping to knock over domino type' consequences.
The shut down of the ocean currents has evidently happened before over geologic time. But when that occurred the environmental system—global ecosystem stability—was unperturbed by humanity.
We are now entering a time where the currents are likely to shut off while humans further perturb the plant's ecology. The cumulative consequences are probably beyond clear prediction. The consequences loom large with uncertainty.
We have arrived at a time when global events are so complex and so interlinked that a cascade of consequences must be anticipated. If the oceans can no longer mix waters from around the planet, life in the sea will certainly be impacted, and thereafter life on land will feel the secondary and tertiary effects.
Hold on, the change is coming, and you will be here to see it happen. This is not fiction. No one can stop it. No one escapes the consequences.
Add to this all the other events that are taking place on the timeline.
In sensible terms, the scientific information cited below does not formally state when a shut down will occur, but during the discussion to follow the presentations made in 2005, a projection of "in the next ten to fifteen years" is not out of the realm of possibilities! In terms of geologic time, That IS Real Soon!
The Earth's Oceans' 'Conveyor Belt' Current
Graphic above from: Climate Change Impacts On The United States - The Potential Consequences of Climate Variability and Change. 2000. A Report of the National Assessment Synthesis Team; US Global Change Research Program, Cambridge UniversityPress.
Abstracts From Scientific Talks at AAAS 2005
In
2005 at the annual meeting of the American Association for the Advancement
of Science (AAAS), there were a series of talks introduced as follows.
Take note of what Dr. Fine is saying about the big picture!
Remember, this IS happening now.
Signatures of Anthropogenic Warming in the Oceans and Their Implications for Society
The oceans cover 71 percent of the Earth 's surface and, because of their capacity to store, transport and exchange heat, freshwater and carbon dioxide, they are a major component of the global climate system. Observed changes in the oceans are being attributed to human activities as well as to natural climate variability. Increasing amounts of anthropogenic* carbon dioxide are being taken up by the oceans, and the solubilities of carbonate minerals in the deep oceans have been affected. The amount of oxygen has been decreasing, and there are documented changes in ecosystem structures. Impacts of anthropogenic warming vary significantly between oceans and are particularly dramatic in high-latitude regions such as the Arctic Ocean. Fresh water from the melting of high-latitude ice and from increased evaporation in the tropics has been accumulating in the North Atlantic Ocean, which can alter the ocean currents, an integral part of the climate system. Scientists believe that eventually the effects of accumulating freshwater will cause a decrease in the strength of the 'meridional overturning,' or sinking of dense water, in the high latitudes of the North Atlantic. As a consequence, the northward flow of the warm Gulf Stream would slow and move southward, causing a major readjustment of our climate system. This symposium will describe changes occurring in the ocean due to anthropogenic warming and will discuss projections of possible effects and consequences for society.
(2005 AAAS Annual Meeting, 17-21 February 2005, Washington, DC, S23)
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* anthropogenic means the source is from human activity
The following abstract is the feature of this web page. The text description plus access to the sound file help to support the statements presented at the top of this page!
Overall, Dr. Curry describes the way in which changes are interlinked. The really important essence here is that our entire global environmental system is being assaulted and insulted by human activity. These are the DRIVING FORCES behind the large scale changes we are now beginning to see, document, and understand personally.
GLOBALWARMING AND OUR PLANET'S WATER CYCLE
Talk Presented by Ruth Curry - Woods Hole Oceanographic Institution
Listen
here to mp3
Sound File (entire talk 18 minutes, a
separate browser window is used to allow you to listen while
viewing this page)
As the global thermometer continues its upward climb, it is expected to affect the hydrologic engine which cycles freshwater through the climate system. This engine is fueled by evaporation from the oceans, which pumps heat and water vapor from low to high latitudes where it precipitates and is returned to the ocean either directly or by river runoff from the continents. Sea ice and glaciers are components which store and release freshwater through the processes of freezing and melting. The hydrologic response to rising temperatures will include increases in the rates of evaporation, precipitation, and melting which in turn will profoundly affect our planet 's freshwater resources, sea level, ecosystems and economies.
Signs of changes in the global water cycle are already detectable as thinning sea ice and shrinking glaciers, increased river discharges from the Eurasian and North American continents, drought in the western U.S., and global shifts in ocean salinity distributions. Over the last forty years, low latitude surface waters have become dramatically saltier in the Atlantic, Pacific, and Indian Oceans where rising upper ocean temperatures appear to be intensifying evaporation, removing extra freshwater from the surface ocean, and thus raising its salinity concentrations. That extra water vapor has been transported by the atmosphere toward the poles, especially in the northern hemisphere, where increased precipitation and river runoff have combined with melting polar ice causing ocean salinities there to plummet.
The resulting surge of freshwater into the Arctic and high latitude North Atlantic Oceans may have climate consequences of its own. These northern seas are special sites where cold, dense waters are formed, a process which drives a component of ocean circulation dubbed the thermohaline circulation (THC). If enough freshwater is added to these special sites, however, the resulting ocean density changes could alter the Atlantic THC, diminish the amount of heat delivered to the northern latitudes, and significantly affect wintertime climate in the northern hemisphere.
(2005 AAAS Annual Meeting, 17-21 February 2005, Washington, DC, S23)
