The Gray Monk

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November 20, 2006

Strange weather ....

Mausi's roses blooming in November put me in mind of a question I have been pondering for a little while. It certainly came back to give me some more thoughts recenetly on considering news from the Southern Hemisphere! I have never liked the term "global warming" since it doesn't actually describe effectively what is really happening. I was reminded of this recently when talking to Ozguru in Australia and he mentioned that they have recently had a bushfire extinguished by snow in the Blue Mountains. Now there are several aspects to that which are interesting. The first is that at this season in the Blue Mountains the temperatures are usually in the upper 20's Celsius, and the second is that for the temperature to drop that low - low enough for snow that is - means that some very strange weather patterns must have come into play over the continent. Coupled with an extremely long dry period this suggests that there is a major shift happening in the weather over the Southern Hemisphere which, far from bringing warming, seems to be bringing cold.

When this information is put alongside my brother's reports from the Western Cape of the winter just past, to the effect that it has been the coldest and wettest there on record for some time, and you do begin to wonder precisely what is going on. I think that there are several things happening and only one of them is human related. Sure, we can probably do something about that, but the real bottom line there comes back to overpopulation in areas where the ecosystem is particularly vulnerable to over use and to the fact that we, in our efforts to control our envirionment, actually pump heat into the system at a phenomenal rate. Think airconditioning, think central heating .... Both are heat exchange systems, and the heat always, as Flanders and Swann have famously said in a song about Boyle's Law - transfers from a hotter body to a cooler one. So if we sink heat into the ocean as a means of cooling the air in our buildings built of glass and steel in places like the Arabian Gulf, you raise the sea temperature. If you heat your home in Europe, the heat seeping into the ground, the walls and the roof heat the atmosphere around the building. Certainly one of the most amazing things you can see is a look through an infrared lens at a modern building. The microclimate around it - and the heat plume above it - is fascinating, and that in buildings which are supposed to be compliant with modern insulation requirements.

The other aspects which are likely to underlie what is happening in our atmosphere and on the surface, quite possibly lie beneath our feet and are well beyond anything we can control. I'm talking here about the planet's own evolution. Plate tectonics mean that everything is moving, albeit at an infinitely slow rate, but still moving. Even in my lifetime that distance between Europe and America has increased by a measurable amount, minute as it happens, but measurable, and the distance between the America's and Asia and the Pacific Rim has shrunk. Everytime a volcano erupts, CO and CO2 emmissions run off the scale, and even a good earthquake can release a huge amount of these gasses if it causes a surface rupture. The planet itself is changing around us, parts are cooling, other parts are warming. Changes in the 80's to the emmissions to deal with acid rain mean that we are now producing less white and fluffy cloud and more grey. Grey absorbs heat, white reflects it. We solved the acid rain, but we now absorb more heat from the sun. Anyone got a plan for losing this somehow? Big sheets of reflective foil in the upper atmosphere perhaps? Giant mirrors in orbit around the planet to cut solar radiation?

The oceans act as heat sinks for a range of natural phenomena and we add to that by using them to cool power station outfalls, steam condenser units and even for desalination treatment plants. The Northern Europe area faces an interesting future as far as I can see, because as the "Atlantic Conveyor" slows down with the melting ice cap, the warm water which flows in to replace the outflow and comes from the warm Equatorial Regions, is diverted or ceases to flow Northward. In effect it is thought that this will trigger another Ice Age - hopefully not as violently as the movie "Day after tomorrow". But this leads me back to the snow in the Blue Mountains. I have no scientific proof of this, and probably will now attract the howls of derision from those who believe it can all be solved by simplistic models and changes to human behaviour - but I find myself wondering if the Southern Hemisphere isn't about to see a return of the ice.

The Great Southern Ocean has been slowly warming for centuries, but the recent meltdown of much of the Antarctic Iceshelf has dumped billions of gallons of fresh water into the oceans there, changing the salinity and changing the ocean currents and temperatures. If this triggers a similar slowdown to that seen in the Northern Hemisphere and specifically in the Atlantic current pattern - the Southern tip of the Americas, the Southern Ocean and the southern end of Africa and even Australia could get a heck of a lot colder.

I wonder if anyone has thought of that one - after all, the last great Ice Age in that half of the world ended just a little over 450 million years ago. It may well be that they are about to have another one!

Posted by The Gray Monk at November 20, 2006 10:42 AM

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Comments

Posted by: Justin at September 16, 2007 01:50 AM