The Royal Society (UK) has made available a short little booklet utterly debunking most of the pseudo-scientific claims skeptics use to torpedo climate change arguments.
Here's one example (over the fold):
The Earth’s climate is always changing and this is nothing to do with
humans. Even before the industrial revolution, when humans began
pumping carbon dioxide into the atmosphere on a large scale, the
earth experienced warmer periods.
The (partial) answer:
...We know from looking at gases found trapped
in cores of polar ice that the levels of carbon dioxide in the atmosphere are
now 35 per cent greater than they have been for at least the last 650,000
years. From the radioactivity and chemical composition of the gas we
know that this is mainly due to the burning of fossil fuels, as well as the
production of cement and the widespread burning of the world’s forests....
After reading this beautifully crafted PDF I thought, I have to share this information with anyone who has ever wanted a nice, concise document to hand to any climate change skeptics (aka head-in-sanders). In any event, the original PDF can be downloaded here, or you can go to the Royal Society's home page and click on "Is Global Warming A Swindle" (half-way down, centre page) to see the original context and some other links. It's definitely worth a look.
Credit where it's due (though I have to wonder sometimes) to the Vancouver Sun for printing a short summary. It hardly goes far enough to "balance" the inane smears and opinions masquerading as logical argument that they normally print (for instance, take this letter from Prince George), but it's a good piece.