Whilst on the subject of climate change, there's a wonderful cartoon on the XKCD site today it's really worth clicking on the link to go see. It shows a complete time-line of average temperature change from 22,000 years ago up to today, which (as an aside) is amazingly only ~10% of the time modern humans have existed on this planet.
What's interesting to note is that 22,000 years ago the average temperature was only around 4 degrees Celsius lower than today and yet the location of the current day city of Boston was pinned down below an ice sheet one mile thick. Current models show that at the current rate of warming we can expect at least this on the positive side as a result of us pumping around 1000 billion tons of Carbon dioxide into our atmosphere since 1850. What this will do is still unknown at the street by street level but never the less, at the macro level it's pretty obvious that the results won't be desirable for people living anywhere near the coast, warming at these scales will mean sea levels increasing by meters.
Next time some climate ostrich tells you that it's quite normal for temperatures to fluctuate and that there's nothing to worry about, point out that only a couple of degrees makes the difference between being crushed by a mile of ice or sleeping with the fishes, not much wiggle room there.