North Atlantic current could be slowing naturally

clipped from environment.newscientist.com Global warming may not have caused sluggish Atlantic Judging the effect of climate change on ocean currents could take longer than we thought. The circulation of warm water in the North Atlantic is suspected to be slowing, and the worry is that global warming is to blame. To investigate this, Carl Wunsch of the Massachusetts Institute of Technology used observations taken from buoys to build a model of Atlantic circulation. It suggested that currents could speed up or slow down naturally by a greater amount than the suspected slowdown linked to global warming, and such changes could persist over months or even years (Nature Geoscience, DOI: 10.1038/ngeo126). It will take decades of observations to account for these effects, Wunsch warns.