Should we be looking at geo-engineering the climate?

Has a well-meaning international effort to cut pollution from ships contributed to a sudden warming of the waters in the north Atlantic this year? That is the extraordinary claim made this week in an article in Science magazine, the journal of the American Association for the Advancement of Science. It asserts that limits on the sulphur content of fuels used by ships have helped reduce sulphur pollution from those vessels by 80 per cent – but at the inadvertent cost of reducing cloud formation over the oceans and so speeding global warming.  

Previously, well-used corridors of the Atlantic Ocean were covered with ‘ships tracks’ – yellowish, elongated clouds which followed the paths of passing ships. Now, the clouds have been diminished, and the waters are exposed to the full power of the sun, resulting in record sea surface temperatures. As Michael Diamond of Florida State University puts it, ‘It’s as if the world suddenly lost the cooling effect from a fairly large volcanic eruption each year.’