(not commenting on the actual post, but the preceding comments)

This may sound counterintuitive, but the Y2K "bug" fix kind of was encouraging to hear. I was always a bit incredulous when I heard that seven or so of the hottest ten years this century have been in the last decade. If global warming shot up temperatures by only a degree in that time period, it seems unlikely that with such a wide range of yearly variation in average temperature (more than a few degrees) there would be so many near-record or record years so close to the end of the time period.

Global warming is subtle, it is slow, it is sneaky. The corrected stats show that better than the corrupt ones used by alarmist propagandists.

The comments above about how 1934 is the hottest year on record talks about how that was during the Great Depression and since CO2 levels (manmade) were at an all time low, manmade global warming must be busted.  However, we can't forget about the global dimming effect.  Visible pollutants like ash and sulfur dioxide create an effect called cloud seeding.  These pollutants generate more clouds in the atmosphere.  In the last 100 years we've decreased the amount of solar energy reaching the surface of the earth by 20%.  This fights against the greenhouse effect and takes energy back out from greenhouse gases.  The problem was getting very severe in the late eighties (the Ethiopian drought).  In the 1991 the amendment to the Clean Air was enacted and visible pollutants were dramatically decreased from America.  The Ethiopian drought immediately got better.  It still was there however. This was caused by the clouds not being so heavy that they drop their load before reaching inland.  Same concept in the 30s.  The cloud cover was decreased since less fossil fuels were being burned and the greenhouse gases built up since the Industrial Revolution were able to show their true power.  Since the build up of the Asian markets, cloud cover has again increased and the temperature spikes (or lack thereof) tend to reflect that.  However, of course the greenhouse effect will overtake the global dimming effect as we saw in 2005 and are now seeing today.  It's funny no one recognizes that if we immediately switch to clean sources like solar and wind that we would almost instantly see a very dramatic rise in temperatures since all of the sun's energy will be hitting us. Not to say we shouldn't switch though.  

Very old average temperature reports tended to be taken from once a day readings of a maximum/minimum thermometer.  That's not a great method.  The average score on a class' math test would only be the mean of the highest and lowest scores by lucky coincidence.  Also, outliers in data sets are by definition always maximums or minimums; so that method is what statistics calls highly "biased."  

The newer non-thermometer temperature measurements are far more reliable.  However, the new methods have not been in use for all that long, and you can't discern any long term warming trend just from them.  And there's not a scientifically principled way to negotiate any middle ground between the various methods, favoring one over others will always be a game of chance at some level.  A lot of hard working people have done their best to navigate these issues, but there's no real guarantee that their best was good enough.