I missed this paper (Nature, subscription required) when it came out last month. It’s pretty interesting. Ruth Curry, from the Woods Hole Oceanographic Institution, and her colleagues measured changes in salt and fresh water in the Atlantic:
The oceans are a global reservoir and redistribution agent for several important constituents of the Earth’s climate system, among them heat, fresh water and carbon dioxide. Whereas these constituents are actively exchanged with the atmosphere, salt is a component that is approximately conserved in the ocean. The distribution of salinity in the ocean is widely measured, and can therefore be used to diagnose rates of surface freshwater fluxes, freshwater transport and local ocean mixing – important components of climate dynamics. Here we present a comparison of salinities on a long transect (50 S to 60 N) through the western basins of the Atlantic Ocean between the 1950s and the 1990s. We find systematic freshening at both poleward ends contrasted with large increases of salinity pervading the upper water column at low latitudes. Our results extend a growing body of evidence indicating that shifts in the oceanic distribution of fresh and saline waters are occurring worldwide in ways that suggest links to global warming and possible changes in the hydrologic cycle of the Earth.
That’s a bit dense, but there’s a “holy shit” buried in there for those of you in Britain and elsewhere in Europe. Y’all are being warmed by a big-ass current flowing up the Atlantic, bringing warm water from the tropics. The “Wally Broecker hypothesis” is that global climate change caused by greenhouse gases could cause the conveyor belt to shut down. Bingo. European ice.
Geoffrey Lean, in The Independent, gives an altogether too breathless take on Curry’s work:
Britain is likely to be plunged into an ice age within our lifetime by global warming, new research suggests.
“Likely” seems all too strong a word, if my understanding of the science is correct, but “strong possibility”, especially given Curry’s apparent empirical support for Broecker’s hypothesis, doesn’t seem far from the mark.
To be fair, I think most people in Britian with a vague notion of how our weather works know our island’s heated by the Gulf Stream. It’s why our weather is so insanely unpredictable (and wet).
And whenever there’s anything about global warming on the news, the anchors take great delight in telling us if the Gulf Stream were to change course we could be plunged into the kind of temperatures and weather we should have for our latitude anyway.
Snow next week, hurrah!
Sorry if it sounded like I was talking down. It’s an occupational hazard of being a journalist – writing with the expectation that my audience knows nothing about the subject. I least when my audience lives next door, I’ve got a little clearer idea about what they might and might not be aware of, but I’m handicapped when it’s another continent entirely.