I'm no expert on climate. I do not have the earth's entire eco-system in mind, with all its interactions, and how they evolved over the past millions of years. But probably not many people have.

Now I'm puzzled with the media or the blogosphere, where every weather event, glacier retreat or decline of a polar bear population is  interpreted as a sign of pending doom. 

We could read the IPCC reports for clarity, but a consensus of 1,500 scientists doesn't provide light reading. So here's 3 lean resources, 2 with a bird's view (including the IPCC briefing), 1 with a worm's view, that summarise the issue in less than an hour:

The first is an interesting Primer on Climate Change from the National Center for Policy Analysis (NCPA) that reads in 10 minutes and makes you think. Warning: the primer may be a bit leading in its selection of messages.

It's interesting to contrast this with the second resource, the IPCC briefing on the scientific basis of climate change in its 4th assessment report. What I took from the comparison between these 2 is that 100 years is a very short time in the history of earth (the basis of many IPCC data and graphs). And the situation may look very different when we look at global or local level.

And for something completely different, the third resource from Watts Up with its series 'How not to measure temperature'. I have no clue whether these 31 measurement stations were cherry-picked for the story, or how representative these are for the 1000s of weather stations around the globe. But the stories will at least sound plausible for anybody who has experienced the workings of a large organisation.