I bet they also can’t come up with scientific data that shows that CO2, a clean, non-polluting gas, at 420 PPM in the atmosphere, is any more dangerous than it was in the late 1800s, at 280 PPM
How did "they" know in the 1800's what the PPM was????
How did "they" know in the 1800's what the PPM was???? Probably a LOT higher than now with all of the coal fired industrial boilers, railroad locomotives, steamboats and home heating boilers and furnaces belching black smoke.