Saturday, 15 January 2011

Going, going....

Well, after having built my snowman friend at the end of November, he finally decided to leave me today. This was him this morning as I went out for work, and by the time I got home he was gone completely.

I know for many people it's been a complete pain having had snow since 27th November until now, but I confess to being sad that it's gone and the milder (wetter) weather has replaced it. I love the quiet insulated feeling you get when the world is blanketed in snow, and crisp sunny winter days are my all time favourite.

Over the past year as part of my work, I've been spending time talking to staff about the implications of climate change, what's causing it, how it might affect us and what we can and should do about it. One of the things I've been saying is that as the climate warms we can expect our winters to get shorter, milder and wetter with much less snow and frost. Last winter, of course, was exceptionally cold and snowy over Christmas and New Year (which I missed when I was in Canada) but I spent my year telling people that it had been exceptional and that our winters would indeed change as predicted.

So when this winter's extreme weather started, I was very surprised. Surely if the climate is changing and global temperatures are increasing, we shouldn't get 2 such extreme winters in a row?

Well, there's a couple of things to say - firstly, yes you can get 2 freak events consecutively - just because they're rare doesn't mean they can't happen close to each other. A 100 year flood doesn't mean it only happens every 100 years, it's the likelihood that is 1 in 100. Just as the likelihood of flipping a coin and getting heads is 1 in 2, it doesn't mean that if you get heads one toss, you'll definitely get tails the next.

Secondly, it's important to recognise that what happened in Scotland and the UK this winter and last wasn't what happened across the rest of the Northern Hemisphere. While we've been having extreme cold weather, many parts of the North that are normally cold have been having pretty warm times, at least comparative to what they normally have. This in itself is a worry. The parts that are warmer than normal are those that are meant to be cold - the ones with the tundra and the arctic ice, the ones that sequester carbon/methane and reflect back heat. When they fail, the result is to exacerbate the warming effect. In other words, not good news.

Now, it's all really a bit hard to say exactly what's going on. Climate is a complex thing, and global climate even more so. All the projections are based on models with many thousands of variables, each with their own set of interreactions. But a post recently on George Monbiot's blog did suggest that far from being freak random events, the arctic oscillation that we've experienced for the past 2 years may in itself be a result of climate change. As a commentator at a conference I attended in 2009 said, there is no longer any such thing as natural weather, it's now all man-made. 

By the way, weather and climate are not the same. Global warming is to do with climate, weather is something else entirely - it derives from climate but is not the same thing. (Even if you're bored with the rest of this post, by the way, I'd advise you click this link! Trust me, it's fun)

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