Posted 1 August 2016
"When we measure temperature in our backyard, we really aren't that concerned if the thermometer we use is out by a degree or two. Since most people live where temperature fluctuates by many degrees every day, and the season swing can be 80oF or more, a couple of degrees doesn't matter too much. But in the case of global warming, one or two degrees is the entire change scientists are trying to measure over a period of 50 to 100 years. Since none of our temperature monitoring systems was designed to measure such a small change over such a long period of time, there is much disagreement over exactly how much warming has or will occur." A must-read paper by Dr Roy Spencer, one if the world's top experts on temperature meaurement
Download pdf [here ](a guide to understanding global temperature data--texas policy.pdf)