Ocean currents are warming faster than expected

Writing in The Register article Ocean currents emerge as climate change hot-spots Richard Chirgwin reports that scientists have confirmed a prediction that global warming will lead to increases in temperature of major ocean currents:

A global study that assesses the temperature change in ocean currents has made two findings – one surprising, the other less so. The unsurprising outcome is that as the Earth’s temperature rises, so does the temps in a collection of major ocean currents; the surprise is that those currents are warming faster than the globe as a whole.

According to the study, published this week in Nature Climate Change, a pattern of warming in the ocean’s long-distance currents has now been identified near Australia, Japan, Africa, and North America.

Moreover, the warming is also sending the currents “polewards”, meaning that species migrations already observed in Australia (in which many species are moving southwards at as much as a degree per year) are almost certain to happen on a global scale.

It's also worth reading the comments, in particular the contributions by Trevor Pott.