A new study published in the scientific journal Nature by researchers at the Autonomous University of Barcelona in Spain explains a reversal in the deep water flow of the Atlantic Ocean during an ice age 20,000 years ago. The Atlantic Ocean circulation is an important component of the world’s climate system, carrying warmth from the tropics to sub-polar North Atlantic.
However, during this past ice age, due to sensitivity to salt balance changes, warm waters began to flow southward rather than northward as they do now. The scientists conducting this study stated that over the next century, similar changes in seawater salt concentration are likely to take place in the North Atlantic due to global warming and the large amounts of freshwater being added from melting land ice.
Dr. Charles Greene, Director of the Ocean Resources and Ecosystems Program at Cornell University, USA, explained.
Charles Greene – Professor of Earth and Atmospheric Sciences, Director of the Ocean Resources and Ecosystems Program at Cornell University, USA (M): We know that if we look tens, hundreds of thousands of years into the past that there have been occasions where large inputs of fresh water into the North Atlantic has shut down what we call North Atlantic Deep Water formation. So it basically dilutes the salty water of the Gulf Stream or the North Atlantic current, so that when you make it cold, it’s not cold enough to sink to the bottom of the ocean.
And that can initially slow down the conveyor belt in such a way that it reduces the Gulf Stream’s inflow and eventually it can shut down. And since the Gulf Stream is very critical in transporting heat to Europe, the consequence of that is the potential to throw us into Ice Age conditions.
If Europe’s thrown into an Ice Age, we’ll likely be thrown into one as well. And that’s kind of the basis for ‘The Day After Tomorrow” movie, which of course is science fiction, but there was some fundamental science underlying that, which is that the North Atlantic Deep Water formation can be shut down.
VOICE: Dr. Greene pointed out that changes are already occurring within the vast urgent picture of global warming.
Charles Greene (M): This tremendous amount of fresh water that’s entering the world’s oceans is having dramatic effects on the shallower circulation and is having impacts on many of our coastal ecosystems.
We’ve lived in a very stable period in Earth’s history and over the last 10,000-20,000 years, we’ve not seen anything close to the speed and magnitude of the climate change that we’ve observed in the last 30 years.
I think we’re going to start seeing fairly dramatic impacts on our civilization in the next few decades. If we don’t do something very different very soon we’re going to truly see catastrophic changes.
VOICE: Many thanks Dr. Green and Autonomous University of Barcelona scientists for sharing your findings and urgent message. May we heed the warnings to act now to avert further and unmanageable climate changes.
Having many times touched upon the dangerous climate impacts of the planet’s current course, during a September 2009 videoconference in Peru, Supreme Master Ching Hai urged for one immediately effective measure.