Monday, June 11th 2012, 6:50 AM EDT
Proponents of global warming alarmism place heavy reliance on the temperature record of the United States, probably the world’s best data set. They say that the record shows significant warming in the 20th century. Most global warming realists have accepted this claim, but have questioned whether this particular temperature trend–the Earth has been getting either warmer or cooler, sometimes on a far greater scale, for millions of years–has much to do with human activity.
What is less well known is that the alarmists do not rely on raw temperature data collected by American weather stations. Rather, the alarmists adjust the data before they publish it.