A new study by US scientists at the University of Massachusetts Amherst found that the amount of fresh water cycling through the Arctic is increasing due to global warming. This has raised the concern that the large volumes of ice melt from Greenland and other sources could dilute the normally salty Arctic waters to the point that the circulation of the North Atlantic, also known as the thermohaline circulation, could be slowed or even halted, with disastrous consequences for the global climate.
Explaining this immense potential tipping point in a telephone interview with Supreme Master Television was Professor Anders Levermann from Potsdam University, a senior researcher at the Potsdam Institute of Climate Impact Research in Germany and the lead author of the Sea Level Change chapter for the coming 5th report of the Intergovernmental Panel on Climate Change (IPCC).
Professor Anders Levermann – Senior researcher, Potsdam Institute of Climate Impact Research, Germany (M): If you put additional fresh water into the North Atlantic by melting Greenland or by having more discharge from Siberian rivers, then you can freshen the North Atlantic so strongly that there won’t be any sinking of water anymore, and that would disrupt this thermohaline circulation, and could make it stop. Because there’s so much heat transport associated with this thermohaline circulation, it’s going to disturb the entire climate system.
VOICE: The thermohaline circulation acts as the “conveyor belt” bringing heat from the lower to higher parts of the northern hemisphere. A collapse of this vital system could decrease North Atlantic temperatures by up to 8 degrees Celsius, severely affecting agriculture in Europe. Sea level rise and disrupted ecosystems and rainfall patterns are the other consequences that could hugely impact human life.
Professor Anders Levermann (M): The estimates are such that this kind of sea level rise that we would get from the collapse of the thermohaline circulation would be 10 times, 20 times quicker than what we see at the moment. The sea level would, more or less, instantaneously rise in the North Atlantic by up to a meter. Then, you disrupt the heat uptake of the ocean, which would further increase global warming.
Then the rain belt in the tropics would shift by a few hundreds kilometers. If you look where people live in West Africa, and also in the Amazon region, then this is where the rainfall is, and that would change enough to disturb these communities.
VOICE: We thank Professor Levermann and Potsdam Institute for Climate Impact Research colleagues as well as the University of Massachusetts Amherst scientists for alerting us to this potential catastrophe of the ocean as it affects the ecosphere. May we act swiftly to avert such disastrously large-scale changes and protect lives. During a September 2009 videoconference in Peru, as on many previous occasions, Supreme Master Ching Hai urged for direct action that effectively addresses such complex climate problems at their root.