The one thing constant about temperature is that it is never constant. We find it rising and falling no matter what time scale we observe, be it hundreds of years or tens of millions of years. This chart, showing the 10,000 years of temperature changes since the end of the last ice age confirms this truism. Here we see quite large temperature swings much greater than what has been observed in the last 150 or so years. Each one of those moves up or down were caused entirely by natural forces. Those promoting the notion that man’s actions are the primary driver of recent temperature changes require that you believe that these natural forces suddenly and inexplicably ceased functioning at the beginning of the 20th century and that human emissions are now responsible.

This temperature data is derived from Greenland ice cores.