2. Atlantic "Conveyor Belt" Disrupted
If the flow of ocean
water worldwide is severely disrupted by an influx of fresh water from melting ice caps due to rising temperatures, potentially dangerous global warming may follow, according to a survey about climate change "tipping points" released in March 2009.
This part of the ocean "conveyor belt"—called the Atlantic meridional overturning circulation—transports warm water northward (above, ice ledges in the Norwegian Sea) and sends cold water south at depth.
But the potential freshwater disturbance could prevent ocean water from moving northward and may have a range of impacts on the environment, from reducing fish stocks to spawning stronger hurricanes
Little data exists about such global warming tipping points, said lead study author Elmar Kriegler of Germany's Potsdam Institute for Climate Impact Research.
For the new study, Kreigler wanted to glean experts' opinions about the likelihood that these major changes would engender dangerous global warming. The results will ideally inform policy action, Kriegler added.
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Photograph by Norbert Rosing/NGS