re: #200 Buck

No, I think you can not read. Try again.

Before the industrial era, circa 1800, atmospheric CO2 concentration was between 275 and 280 ppmv for several thousand of years (that is, between 275 and 280 molecules of CO2 for every one million molecules in the air); this we know from the composition of ancient air trapped in polar ice. Carbon dioxide has risen continuously since then, and the average value when Dr. Keeling ted his measurements in 1958 was near 315 ppmv. By the year 2000 it has risen to about 367 ppmv (that is 367 molecules of CO2 for every one million molecules in the air). Thus, it is higher than pre-industrial values by one third of the pre-industrial era. (You can check the math on your calculator.)