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This is not intended as a political or emotive article about what we
can do to find global warming solutions or somehow avert climate
change; it is about the direct effect global warming and climate change
will have on snow levels and ski weather up till the end of this
century.
Excuse the pun, but whether we like it or not, the world is warming up
faster than it has ever done before. Cue heavy and sinister background
music with thunderstorms, tornadoes and tsunamis with some Al Gore
thrown in, and we could easily be drawn into the final scene of an
apocalypse, but that's not my aim here. I want to know about the future
of ski weather and the global warming facts that will affect mountain
snowfall.
This century will see an enormous increase in global temperature, as
high as 6.4°C according to reliable estimates. This is roughly five
times the temperature increase during the last century. Many people
assume that snow levels will drop as rain takes over or stops
altogether, but this is not necessarily the case. Last season had some
of the biggest snowfalls ever and it looks as though this coming winter
of 2010/10 in the northern hemisphere is going to be a good one too.
Let's just take a brief and simplistic look at how the climate affects
our ski weather. For rain and snow think 'precipitation'. The major
weather systems of the earth are formed at the equator, where hot,
moist air rises as the surface of the sea is heated by the strong sun
and then gradually cools, falling back down as it is propelled north in
the northern hemisphere and south in the southern hemisphere.
Because of the earth's rotation, and for the sake of our discussion,
let's stay in the northern hemisphere. Weather systems here generally
move from west to east and precipitation occurs as these systems hit
land. And the land we are concerned with is the west coast of America
(the Rockies) and the west coast of Europe (the Alps). As we all know,
the air is pushed up over the Rockies and the Alps where it either
snows or rains .
So if it's hotter there will be more precipitation in these areas as
the sea will evaporate more readily. But will it be snow or will it be
rain? This is the question. We've said that the global temperature is
warming up at an alarming pace, perhaps 6.4°C before the end of the
century. Now the temperature
drops as we go up a mountain by roughly the same amount every 1000
metres (6.5°C) so that by the end of this century, where the rain snow
boundary during the ski season is presently 1000 metres, it will be
rain up to 2000 metres. The precipitation will be greater and the
rain/snow level will be moving up the mountain at a rate of roughly 10
metres a year.
So it looks like there are a few years left yet, and I'll sign off by
throwing this little snippet into the algorithm. As the world gets
warmer the Greenland icecap will melt at an accelerating pace. It is
not fully known what if any effect this will have on the Gulf Stream.
Known as the Atlantic conveyor this massive engine like current brings
warm water up past the western seaboard of Europe. It then curves north
and heads back towards the Gulf of Mexico past Greenland and the east
of North America. Thirteen thousand years ago it suddenly stopped. The
reason? A huge lake of freshwater, that had built up during a warming
period burst its banks on the east coast of Canada and dropped into the
North Atlantic, disrupting the flow of the Gulf Stream almost
immediately.
If the Greenland icecap carries on melting at its accelerating pace,
then it could possibly switch off the Gulf Stream too. If this happens
there would be a significant cooling of western Europe similar to the
countries on the same latitude elsewhere round the world. This could
result in the European Alps having snowfalls higher than ever, while
the Rockies, become well, just rockier...
This is just one scenario that could affect short term future snow
levels. At the other end of the scale, with nothing to stop global warming,
there will eventually be no snow left at all.
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