Pros no.1: The problem of climate change is orders of magnitude more complex and difficult than the problem of ozone depletion it is not necessary to embrace the skeptical position about uncertainty in climate science to suggest that the same kind of policy dynamic found in the problem of the ozone layers the scientist evidence was straight wards the time scale was relatively short and most importantly there were scale substitutes for CFCs available at a reasonable cost .By contrast the climate science is much more complex and even if the complexities wash out ,the focus on near term reductions in greenhouse gas emissions is unlike the near term reduction in CFCs under the Montreal protocol for a blindingly simple reason there are no economically