Posted by Peter Ceresole on May 05, 2009 at 10:58:26 user PeterC.
In Reply to: Re: Daylight saving time posted by Owen Roberts on May 05, 2009 at 09:51:12:
A possible worry would be if too much ice melts the Atlantic Conveyor would stop working for a while and Britain would revert to a Hudson's Bay type of winter.
This has happened before in the Middle Ages with the little ice age.
And previous to that, it happened for worryingly long periods of time. They can tell from mud cores from the Atlantic bottom; the ones I saw were from around Newfoundland, kept at the Lamont Doherty Geophysical Observatory. They contain layers of tiny snail shells, whose original inhabitants only live in water at certain temperatures. The Gulf Stream and the Conveyor switching off is a genuinely frightening prospect, especially as all the indications are that, when it happened, it happened very quickly. And there are now observations that it's already starting to happen again. But it's complicated, so hard to predict accurately; I suppose the major indication would be if the North Atlantic trades were dying down, as it's the west wind that blows the surface water our way and it's the surface water that gets warmed by the sun. I seem to remember that some amazing proportion of the heat falling on to the Atlantic (like 60%) is delivered to the British Isles and the nearby European coast by this mechanism. The same happens in the Pacific, but there the Easterlies fail more often, and then they get an El Nino event. That is very serious too, leading to the failure of the coastal sardine fisheries near Chile and, right across the other side, failure of the Monsoons in India.
I was really gobsmacked to discover that most of the world's weather patterns are generated by winds pushing the surface of the sea about. Dead obvious, I suppose, although coriolis forces are the other major player, both for generating the winds themselves and making sure the Gulf Stream turns right and not left...
Sorry... It's a hobby horse, and I am emphatically not an authority on this stuff, but I made a programme about it and it stuck... As it does.