(3) The shifting priorities of federal agencies is also a serious challenge to any long-term measurement program. This problem is not, however, necessarily any more serious in a university setting than in a government agency. In fact, the flexibility to draw support from many directions allowed in a university setting actually helps buffer against short-term policy changes.

(4) Better coordination between federal agencies doesn't necessarily improve the environment for supporting university programs. For example, the most serious threat to Charles David Keeling's program came in the early 1980's — a period when NSF, NOAA, and DOE worked together to consolidate all CO₂ measurements under NOAA's control. 

(5) The normal peer review system of handling proposals is not necessarily incompatible with sustaining a long-term measurement program in a university setting. In the case of Charles David Keeling's program, securing favorable reviews did not prove as challenging as maintaining a funding stream in the face of the shifting priorities and doctrines of the agencies. 

Our understanding of how the earth had changed and is changing draw heavily on a small number of variables that have been measured very carefully over long periods of time. These time series are the cornerstone of our understanding and provide the icons with which to communicate that understanding to the wider public. As we contemplate a future in which measurements can be made with much higher density based on deploying sensors in situ and using space-based platforms, one might easily imagine that the earth science of the future will take a rather different form. This will only be the case if these expanded efforts can also be sustained at high quality over long periods of time.  That remains to be seen.