Angus King actually said...
But the real point is that in about 1860 that variation that you see was always between about 200 and 300 parts per million of CO2. In 1860, it took off, and this summer, for the first time in 3 million years, it reached 400 parts per million.
Context
Highlighting the significant increase in CO2 levels since 1860.
03/31/2014