....consider the temperatures 70 years ago yesterday. When CO2 levels in the atmosphere were much lower than today's. 

In the 1990's, there was a great deal of controversy regarding the measurement of temperature in the United States. The National Weather Service switched to electronic thermometers with limited cable lengths. So, too many weather stations looked like this. Of course, an air conditioner blows hot air. Critics, including me, were pointing out that the "warming" may have been an artifact of these poor quality temperature measuring stations. I participated in a survey of these stations and found one in southeast Kansas on a patio with a built-in bar-b-que.  So, NOAA obtained funds from Congress to install a U.S. Climate Reference Network (USCRN) that was intended to demonstrate that temperatures were, indeed, rising. Only one problem: they are not. Below is the entire record of the USCRN since it was installed in 2005. The result is no warming.  Has the world warmed in the past 50 years? Clearly, the answer is yes. But the fact that U.S. temperatures have not risen in 18 year...