Dr Marsden reckons the technique might even improve understanding of how water from melting ice caps will affect ocean currents, including the Gulf Stream.

ECONOMIST: Lagrangian coherent structures

That is both because ice is melting and because the water is warming, causing it to expand.

FORBES: What If Mike Bloomberg Is Right And A Climate Change Nightmare Is Here?

That means more melting ice in the Arctic, dumping fresh water into the salty sea and making a mess of the all-important Gulf jet stream, which makes northern U.S. habitable.

FORBES: Climate Catastrophe Nearer, Al Gore Gives Us About 90 More Years

The paradoxical phenomenon is thought to be caused by relatively cold plumes of fresh water derived from melting beneath the Antarctic ice shelves.

BBC: Melt may explain Antarctica's sea ice expansion

Since sea-ice is already in the water, its melting has little effect on sea levels.

ECONOMIST: Getting warmer

This fresh water is ultimately derived from enhanced melting at the base of the Antarctic ice shelves.

BBC: Melt may explain Antarctica's sea ice expansion