In 1974 NCAR told us there was almost no global warming from 1880 to 1974 , following 0.3 degrees C. of global cooling from 1940 to 1974 ------ but in 2018, NASA told us there was +0.3 degrees C. of global warming from 1880 to 1974, and no global cooling from 1940 to 1974 -- past historical temperatures keep changing, with "adjustments" almost always causing more "global warming" ... with no rational explanations for the "adjustments", we know this is junk science !