Another way to illustrate the power of continuous time series is to address the "what if" question of where we'd stand if the measurements were only intermittent, say based on field campaigns every decade or two. The curve loses its simple message as well as raising questions of quality and integrity. Are the points after 1980 really more consistent than the points before 1980? Could the rise simply be a random fluctuation? These questions, which seem legitimate in the context of a sparse record, don't even come to mind in the context of the complete record, with its relentless rise.

But while the rise may seem unstoppable, there was nothing inevitable about obtaining the record itself. The Scripps Institution of Oceanography program was actually shut down for a period in 1964 following congressionally mandated budget cuts, and would have been discontinued at that time had Charles David Keeling not pushed hard to keep it going. The program had to endure a series of threats through the 1970's and 1980's associated with a coordinated effort by program officers at NSF and NOAA to transfer full responsibility for global CO₂ observations to NOAA. The program was rescued by DOE, but was never on a very secure footing and was subject to occasionally bizarre requirements, such as a "mandated convergence" with NOAA and a requirement that new discoveries be made based on the records at a pace of 2 per year.