This being World Environment Day (which you'll no doubt have noticed by now, not least because of that hairy great logo about halfway down this column), I have been asked to write something appropriate.

But as this column is generally full of ill-informed rants, toilet humour and downright cheap jibes, I've been sitting here drumming my fingers on the head of the polar bear's head I have stuffed and mounted on my desk for some time now, wondering how to marry up this most worthy of topics with my trademark so-called humour.

I have come to the conclusion that it would be entirely within the spirit of the day for me to recycle some old jokes that have a vaguely environmental slant, thus giving you, the reader, something to think about and something to laugh about at the same time.

It's also a really easy way to fill this column, because it simply involves me cutting and pasting stuff from the internet, leaving me with more time to go out and crush some aluminium cans or something.

So let's kick off with something from American talk show host Jay Leno: "According to a new UN report, the global warming outlook is much worse than originally predicted. Which is pretty bad when they originally predicted it would destroy the planet."

Hmm, okay, not laugh-out-loud, I'll grant you, but not a bad start. What else can we find? Ah, here's a pithy one liner: "Keep Earth clean, it's not Uranus." Not sure I understand that one. Let's move on. Here's another one from an American talk show host, Conan O'Brien: "Scientists say because of global warming they expect the world's oceans to rise four and a half feet. The scientists say this can mean only one thing: Gary Coleman is going to drown."

Why are all these jokes from Americans? And that's not particularly nice, is it? Gary Coleman is the little guy from Diff'rent Strokes. All round politically incorrect, that one. See, the problem with these cracks is that the whole pickle we're in is largely America's fault, what with their insistence on driving their kids to school in huge tanks and burning barrels of oil at weekend barbecues.

In fact, the best environment gag to come out of the States is this one: "We are taking positive steps to confront the important challenge of climate change. Our work is not done. We also have a responsibility to pass on to future generations our commitment to the environment." That was George W Bush, if you were wondering.

This hasn't proven as easy as I was hoping, nor as funny. I think I'm going to have to fall back on my own tried and tested favourite gag with an environmental slant, and it goes something like this: "Why should you never wear Russian underpants?"

Thinking about it, though, the answer's probably not that suitable for a family newspaper. Buy me a pint of organic beer and I'll tell you the punchline.