The fact that climate modelling is hard is not a reason to ignore it or to disregard the results.
Water vapour is the main greenhouse gas but it comes and goes (clouds, fog, etc). CO2 stays put and has increased by 50% since the Industrial Revolution (indeed about 20% in my lifetime). A warmer world might have more clouds - and hence be cooled - or it may not. Damn difficult if we get that one wrong, though. Meanwhile the CO2 is acidifying the oceans, and the oceans are slowly warming. This is far more important dangerous than the effect on the atmosphere because the oceans contain dissolved gases and those come out of suspension when they warm. Hence the CO2 they have kinds absorbed will all come back. And the permafrost may also melt and give up methane. Ditto the clathrates. This is why climate scientists worry about a tipping point, because of the runaway feedback that may occur. If the earth warms 4 degrees the seas will expand (water expands as it warms once it's above 4 deg C of course) and the ice will (eventually) melt. I'm told Greenland's ice cap is already effectively floating on a liquid base, and if that lot goes into the sea there will be a lot of consequences for the climate of the northern hemisphere - eg the currents that form the north atlantic drift will probably shut down, cooling western Europe. Also sea levels will rise somewhat - but not all at once (water can slope across large distances) so it may be more major in the N hemisphere for a while. I can't remember the figures off hand, it's obviously a lot less than the effects of the Antarctic melting, but significant even so, especially given that most major cities are near sea level. However this may be the least of our worries because there are aquifers emptying out and resources running out, and interesting times on the horizon... -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
