If Al Gore is to be believed, global climactic change caused by human activity is an inconvenient truth. Mr. Gore has spent the last couple of decades claiming that we are just ten years away from the point of no return. I recall claims of environmental devastation, just ten years away, dating back to the 1970s.
Let's suppose for a moment that carbon dioxide emissions are causing global warming. What is to be done about it? There was that Kyoto thing that levied carbon taxes on the countries that create wealth (while burning fossil fuels) and didn't do anything to poorer countries that also emit as much or more carbon dioxide. (I am uncertain where carbon tax money would be spent, but I suppose Mr. Gore has an idea.)
The whole idea underlying this is that since CO2 emissions cause global warming and reduced CO2 emissions will undo the badness. I think such a notion of causality is simplistic. Life is full of effects that are not negated when you negate their causes. A divorce can be caused by unfaithfulness, but subsequent faithfulness will not necessarily cause reconciliation. Is restricting CO2 emissions the most effective way to counter global warming? Are there ways to reflect more solar energy into space? For instance, clouds are white and provide shade. It's fairly easy to create clouds. Don't like clouds? OK, there are other ways. Let's treat global warming as an engineering problem.
"But, but, but," the environmentalist says, "we don't understand atmosphere dynamics well enough to 'engineer' climate." Is that so? Then how can you pontificate about global warming with such certainty?
My complaint is that Mr. Gore has his legion of Lysenkos who chant impending doom. The impending doom is too dire to wait until they understand the problem well enough to prove it. They say that emitting CO2 causes global warming and offer nothing more substantial than to stop emitting CO2. That wouldn't be a problem, except for the fact that we're talking about committing trillions of dollars to unproven hypotheses.