John Adams observed, and Ronald Reagan was fond of quoting, “Facts are stubborn things . . .”
Here are the facts on atmospheric carbon dioxide (CO2):
As described at the Scripps Institution of Oceanography site:
Monthly average atmospheric carbon dioxide concentration versus time at Mauna Loa Observatory, Hawaii (20°N, 156°W) where CO2 concentration is in parts per million in the mole fraction (p.p.m.). The curve is a fit to the data based on a stiff spline plus a 4 harmonic fit to the seasonal cycle with a linear gain factor.
Data from Scripps CO2 Program.
For perspective, here’s a chart from Scripps that shows why there is concern over current levels of CO2:
- More graphs from Mauna Loa Observatory, with slightly different assumptions, here
- Scripps CO2 Program home (“Home of the Keeling Curve”)
- CO2 data from six different observing stations, on one chart
- “Keeling Curve Lessons”
- FAQ at the CO2 Program:
- How do we know that CO2 is increasing in the atmosphere?
- How fast is CO2 increasing in the atmosphere and is this changing?
- How do we know that the CO2 increase is caused by human activities?
- Isn’t the Mauna Loa record influenced by CO2 emitted by the volcano?
- How much has atmospheric CO2 increased since the industrial and agricultural revolutions?
- What are stable isotopes in atmospheric CO2 and why are these measured as well as its concentration?