I am not a climate scientist, but I trust those who are to be experts in their own field, and so I think that any reasonable person who doesn’t have his head up his ass can agree that global warming is happening, and that it is a serious threat to Human civilization. Reasonable people can also agree that it is being caused (or at least exacerbated) to some extent by Human activities–namely, the addition of billions of tonnes of greenhouse gases to the upper atmosphere, trapping the radiative heat from the sun.
So the question, once we have freed ourselves of right-wing denialism, becomes: what do we do about it? Can we just find ways to cut back on our production of greenhouse gases by, for example, overhauling our agricultural practices, switching to ‘clean’ energy sources, imposing greater fuel-efficiency standards on industry and so forth? Are these feasible? I admit, I have not studied the engineering aspects in any great detail.
What I do know, however, is that I’m not in favour of so-called ‘geo-engineering‘ schemes to mitigate the damage. And the reason for this is very simple: namely, the Earth’s climate is a non-linear system. Anyone remotely familiar with the mathematics of non-linear systems understands that even small perturbations can result in enormous and unpredictable side-effects. Neither do I believe that testing these effects locally (say for example, over a patch of New Mexico desert) is going to be at all useful, because the interactions that will be coming into play will depend upon the entire state of the atmosphere (the whole ‘butterfly effect,’ and so forth).
Geo-engineering reminds me of nothing so much as a man who, having been judged to be unhealthily overweight, demands that his doctor perform a liposuction on him so that he doesn’t need to change his diet or exercise habits. Only it would be even worse than that, because he’s living in a time before Doctors even know how to perform liposuction.