Well, given how the written temperature record going back to 1880 has been "adjusted" no less than five times with arbitrary changes to make it appear to have been cooler back in the 30's than it actually was, and the cooling period between the late 1930's and about 1965 (while the CO2 level continued to rise) was before they were born, there may or may not be some truth to that.  There's considerable skepitcism about where they place their thermometers, mostly in the urban centers were buildings and pavement are "heat sinks" that raise the temperature up to ten degrees and give a distorted picture of what the actual "global" temperature is.  If you don't have honest data, you can't make an honest claim.

Meanwhile, the climate is getting better!  The Earth is greening and the crop yields are up due to improving CO2 levels, which are at levels 1/25th of what NASA and the Navy consider acceptable for astronauts and submariners who are in close quarters for long periods of time.