Folks, Robock et al and Fleming have both asserted that "geoengineering cannot be tested".
Robock et al (Science, 2010): *"We argue that geoengineering cannot be tested without full-scale implementation."* Fleming (Slate): "*Global climate engineering is untested and untestable...* " These statements seem either trivially true or patently false, depending on interpretation. *Trivially true:* *If the only thing that you are willing to consider a test is the thing itself, then trivially there is no test other than the thing itself.* *Patently false:* *There are many tests that can be done that can help us understand possible consequences of a geoengineering deployment.* One could imagine someone saying in the United States in the 1950's, "There is no way you can test the proposed interstate highway system, because you will not understand all its effects until it has been deployed." This is true, in the sense that you could not predict in advance detailed effects that the interstate highway system would have on the spread of suburbia, traffic jams, the rise of the SUV, and so on. But, in the 1950's they could have tested the concrete, built a small stretch of road and learned about its construction and use etc. Would we say "*The interstate highway system cannot be tested without full-scale implementation?*" Would we say "T*he interstate highway system is untested and untestable?*" I think we would say, "There are plenty of tests we can do, but of course we will not understand the full consequences of our implementation until the implementation is complete." We perform tests to improve our understanding. We never have full understanding of consequences of our actions before we act. We hopefully act in ways that will have the greatest rational expectation of positive outcomes. We do research to avoid having rational expectations that do not accord with facts on the ground. Many people have regarded Mt Pinatubo as performing a natural experiment of geoengineering -- a test of the idea of solar radiation management. Like all tests, Mt Pinatubo was not a perfect test (e.g., the aersols were not maintained in the stratosphere, etc). Nevertheless, Mt Pinatubo has functioned as a natural test of some of the concepts underlying solar radiation management. In 2003, Alan Robock wrote a paper called "Introduction: Mt. Pinatubo as a test of climate feedback mechanisms". ( http://climate.envsci.rutgers.edu/pdf/VEAChapter1_Robocknew.pdf). How is it logically possible that Mt Pinatubo could function as a test of climate feedback mechanisms, but not of geoengineering (ie SRM), when those climate feedback mechanisms are central to the climate system response to any geoengineering effort? Furthermore, hasn't Alan claimed to have tested geoengineering concepts in his climate models and found them wanting? How can you have it both ways: testing geoengineering concepts and claiming the concepts are untestable? The list of possible useful geoengineering tests could be a long one, and includes tests of small scale physics, climate model simulations, observations of climate variability, ecosystem experiments, observations of behavior of natural or introduced particles on stratospheric transport and chemistry, small scale or short-term deployments, etc. (I am not advocating all of these, just listing them.) It seems odd, when there are a number of people eager to perform a wide range of tests on geoengineering concepts, to have a small minority claiming that these concepts simply can't be tested (especially when members of that minority have themselves been involved in testing geoengineering concepts). So, do the people who say that "geoengineering can't be tested" mean something that is both true and substantive (i.e., couldn't also have been said of, for example, the development of the US interstate highway system)? If so, it would be interesting to hear what this non-trivial interpretation might be. Best, Ken ___________________________________________________ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 [email protected] http://dge.stanford.edu/labs/caldeiralab @kencaldeira -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
