Thursday, April 06, 2006

Show me anything but this

This week there is news of the world's mountain glaciers receding. This article concentrates on the Alpine glaciers: according to the World Glacier Monitoring Service, the glaciated area in the Alps has been decreasing by over 8% per decade since the 1970s - compared with less than 3% in the years before this. Climatologists and geologists have known for some time that we were emerging from the so-called "Little Ice Age", which brought harsh winters and cold temperatures to much of northern Europe, Britain included. But this evidence seems to suggest that the rate of warming has increased over the last thirty years.

Also this month, in Geoscientist (magazine of the Geological Society, of which I am a member), there is an article about the recession of the
Kilimanjaro ice fields. The Furtwangler glacier, on the mountain's peak, has shrunk back as much as five metres since 2000. In Tanzania there are even greater implications: on water supply to the population living around the mountain, which could add to the already heavy drought burden faced by local people.

What, of course, isn't clear is what is causing the acceleration of ice wasting in glaciers and ice-fields. One can argue that global warming is caused by man's influence - the burning of too much fossil fuel, the releasing of carbon dioxide into the atmosphere through slash-and-burn agriculture, indutrial processes and our own activities. However, one also has to take into account the vast quantities of "greenhouse" gases and aerosols expelled into the atmosphere from only one volcanic eruption. It may be that the world's climate is a very delicate balancing act: natural sinks in the earth can cope with naturally derived carbon dioxide, but when our activities remove a large proportion of the carbon sinks (such as forests), without reducing and in fact increasing the amount of carbon dioxide being released, then that balance is upset, and global warming is the result.

Well, we've been living on Earth for such a short time, compared to the age of the planet, and compared to the time that life has been around, that whether we go or stay seems irrelevant. At least on a cosmic perspective. In some ways it's a shame that people don't live longer: if we could expect to live as long as Methuselah (over 900 years), perhaps we'd be more motivated to make changes which we would see, rather than our children, grandchildren or remoter descendants.*

Habitable planets are so rare we appear to be occupying the only one for light-years around. So it would be a shame if our activities caused the planet to be uninhabitable - either through creating another ice age, or a greenhouse effect similar to that of Venus. What can we do? Well, it would help to use less fuel - in any case, petrol and gas reserves are not likely to last for much longer, and will become more and more expensive as stocks get lower. But everyone has to recognise that there may be a problem before means of slowing down the rate of warming become impractical or impossible.

* This thought isn't original (sorry) - see Good Omens, by Terry Pratchett and Neil Gaiman.


At Thu Apr 06, 07:40:00 pm, Blogger Who is this Dave? said...

That wass the first Terry Pratchett I read - someone I was visiting in hospital recommended it to me, being as how it's all about the Book of Revelation. Perhaps I ought the claim my entire collection of his works on expenses, seeing as they're mostly about religion (eg Small Gods) or the human condition.

I don't think he's written a Discworld book about global warming - yet. He will now I've mentioned it, of course.


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