Sunday, September 23, 2007

Global Warming?

No, I'm not really suggesting that global warming is a myth. In fact, the Antarctic Peninsula, where the other British base, Rothera, is situated, is the fastest warming place on the planet: 3 degrees over the past 50 years. That's why us hardcore Antarctic heroes at Halley call it the Rothera Riviera. Over there, ice shelves* that have been stable for thousands of years are breaking up, clearing the path for glaciers to flow into the sea. Warmer temperatures mean more melting on the surface of glaciers and this water flows through cracks to the base of the glacier where it acts as a lubricant, speeding up the flow. The sea is warming up too, melting the ice where it meets the sea and reducing sea ice. Soon there will be palm trees and everything. Book your winter-sun get-away to the Peninsula before it's too late!

*Ice shelves, like the one I live on, are massive sheets of thick, floating ice that's still attached to the land. In some places they act like giant plugs, preventing huge glaciers and ice streams from flowing out into the sea. Until global warming causes them to break up that is... maybe that houseboat isn't such a bad idea after all.

Anyway, here at Halley it's still pretty chilly. If you're interested in just how cold it's been this year, take a look at this temperature graph from the day I arrived here:
(you'll have to click on it to get a proper look)

You can see that I had a nice gentle introduction to this less than hospitable continent with temperatures at the start of the year not far below zero (I think there was one day when it was colder back home!). However, for the past six months or so -30 has been pretty normal and -40 has been a regular visitor. So far this is one of the 5 coldest of the past 50 years

I'm actually quite glad it's cold here this year. The colder it is, the less it snows. That means less digging to find stuff that was on the surface a few months back (and theres enough of that already, believe me)! Cold air holds less moisture which means less precipitation . That explains why Antarctica, a place which holds 90% of the world's fresh water, is technically a desert: it's too cold to snow much! The only reason we've got so much of the stuff is because it's too cold for it to melt either, so it builds up year after year.

4 comments:

Anonymous said...

isn't that graph just seasonal changes? you need a year-on-year graph to see the trend really.

anyway, i don't think many disagree that global warming is happening. the question is whether it is man-made or not.

Tamsin Gray said...

Hi,

Yes, you're right. I didn't intend it to illustrate any trends, it was more for interest to show what kind of temperatures I've been living in. I've edited the post to make that more clear. Thanks for pointing it our and sorry if I caused any confusion.

On the question of whether global warming is man-made or not, a close correlation between rising greenhouse gas levels and rising temperatures is becoming more and more apparent. A recent report by the IPCC (Intergovernmental Panel on Climate Change) said that it was likely that recent climate change was man made. I'm not trying to convince anyone either way, just present what I see as compelling evidence.

Anonymous said...

Your site was referred to me by the author of "75 Degrees South". I am hoping you wouldn't mind helping a science teacher who is also in a dry, high place? Although our lat creates less of a climactic extreme experience, we are just dry, windy (mucho sand), and hot.

My students in preparation for a science fair were wondering if we could get someone to measure their shadow length at solar noon somewhere on the continent to compare to. We know the light is returning and were interested in the angle and length of shadow it would create, especially if you are able to measure close to equinox or solstice.

Thank you!
haste@aps.edu

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