Fred (2:26)
My claim that “many factors impact climate change and any given change has so many different effects geographically” is not based on climate science so much as simple observation of history. Isn’t there plenty of evidence, in just the historical era (i.e. since we have had written records) of climate changes of substantial magnitude in the absence of large changes in CO2?
With regard to my “third argument” you comment “Is this truly an either/or proposition”. That really gets to the heart of my comment in the original piece that to an economist these are either/or propositions. For policy to be efficient, we want to do the lowest cost things first (normalized for their expected benefits). It is a waste of resources to pursue a less efficient alternative.
As regards the issue of whether China, India, Brazil, Indonesia and other high population countries will impose effective controls on growth of CO2 emissions in the foreseeable future, I again simply point to the evidence of emissions growth and observe that a very good explanation for it is that, to the leaders of these countries, raising the standard of living of their people is a far more important issue than climate change. For that matter, dealing with more conventional environmental issues and with disasters happening today are far more pressing than reducing the chance of an adverse change in climates.