While it's amazing to consider that there's still a huge bloc of people bending over backwards to deny the reality of global warming, there sure are - and these people have most recently latched onto a throwaway line in the contrarian-statistics anthology Super Freakonomics to bolster their pollyanna worldview.
The world isn't warming, it's cooling, goes this argument. Just look at the (temperature) numbers. Ignore the ice sheets melting, the kids swimming at the North Pole, the weather patterns and dozens of other indicators and just look at the numbers.
Well, the Associated Press took the deniers at their word and just looked at the numbers. The news organization had two independent statisticians look at only the numbers involved in global temperatures over various periods of time, from nine to ten to eleven to thirty to 130 years, without telling them what the numbers represented. In other words, a blind study, to remove the influence of any bias on the parts of the humans examining the data.
The statisticians found an upward trend to the numbers in all cases - except if you start following the data exactly in 1998, one of the hottest years, if not the hottest year, ever, in which case you can get a small downward trend. But notably, starting in either 1997 or 1999 gives you an upward trend, i.e. warming. And to reiterate, neither of the statisticians found the ten-years-after-1998 aberration to contradict the overall pattern of upward movement in the numbers.