news: The Great Flood
NASA climate modelers have simulated the climate changes caused by a massive deluge of freshwater into the North Atlantic that occurred near the end of the last Ice Age 8,000 years ago.
At the time, retreating glaciers opened a route for two giant lakes known as Agassiz and Ojibway to rapidly and prodigiously drain into the North Atlantic ocean. Scientists believe that the tremendous influx of freshwater in the North Atlantic interfered with the ocean's thermohaline circulation, which distributes heat around the globe, and may have caused average air temperatures to drop several degrees in some areas of the Northern Hemisphere.
While the flood was catastrophic, the researchers found it had much milder effects around the globe than many people feared. According to the model, published in this week's edition of the journal Proceedings of the National Academy of Sciences (PNAS), "temperatures in the North Atlantic and Greenland showed the largest decrease, with slightly less cooling over parts of North America and Europe. The rest of the northern hemisphere, however, showed very little effect, and temperatures in the southern hemisphere remained largely unchanged. Moreover, ocean circulation, which initially dropped by half after simulated flood, appeared to rebound within 50 to 150 years".
original text:
http://news.mongabay.com/2006/0109-giss.html