Skeptics are not statisticians: 1% of a data set does not disprove the whole data set.

A friend of mine likes to provoke me by sending links to posts and articles that contradict the established science on climate change. Recently he pointed me to this post that appeared in Watt's Up With That: NCDC data shows that the contiguous USA has not warmed in the past decade, summers are cooler, winters are getting colder.  My friend accompanied this link with this comment:

Well, the figures are in from the NOAA National Climate Data Center and the rest is just high school math. While US CO2 emission has gone up precipitously in the last 100 years the average temperature in the US has gone down. Of course you could look at just the last 15 years and ignore the rest. In this case CO2 has still gone up a lot and temperature was flat. Does this fit with saying the controversy is over and global warming is an established fact.

I countered with some points, but only later realized the biggest flaw with this reasoning, which I'll get to shortly.