Climate Change and Ocean Circulation
A new study in the journal Nature provides further evidence that climate change can have a direct and rapid impact on ocean circulation and chemistry. Sudden shifts in temperature over Greenland and tropical rainfall patterns during the last ice age have been linked for the first time to rapid changes in the salinity of the north Atlantic Ocean. As the north Atlantic becomes less salty as a result of more rainfall in the tropics, temperatures rose by five to 10 degrees Celsius over a few decades in Greenland. This is the same ocean circulation pattern that moves warm, salty water north, keeping Europe relatively temperate. It is suggested that “the salinity of the north Atlantic is the canary of the climate system”. What does it mean for now? Climate can and does shift abruptly as a startlingly complex array of factors change states, and similar rapid swings could be spawned by human caused warming.