There are a lot of people around the country, some of them even actually pretty well-educated in traditional terms, who obstinately resist the teachings and predictions of science regarding the global environment, and equally stubbornly insist it's either unnecessary or too costly to do anything about it.
I think the evidence is pretty clear, but my thinking has always been, even if you seriously believe that the burgeoning amounts of carbon dioxide around the globe are not due to human activity, why would you NOT want to keep known pollutants to a minimum anyway? Do you pour gasoline on your garden? Do you add cleaning fluid to your mac'n'cheese? Do you drain your washing machine into the fishpond behind your house?
Well, regardless: Before the air gets too cloudy for the doubters to see what's right in front of their noses, President Obama is promulgating some new rules by executive order. These rules may have their shortcomings and loopholes, but some progress surely is better than none. Political opponents, of course, have vowed to oppose these rules, and roll them back if the Republican Party reclaims the Senate.
That's why I think it's worth noting that politically, Obama's timing makes a lot of sense. Going public now, with midterm elections looming, serves to highlight the urgency of the problem, may help to kick off a useful discussion, and should force opponents out in the open, where they will have to be public about the expressed and actual reasons for their opposition.
This may or may not succeed in moving the matter forward. There are, after all, a lot of people to whom GOP arguments about short-term negatives versus long-term positives (e.g., minor upticks in fossil fuels short term, against air we can breathe and a climate in which we can physically exist, long term). But it will certainly help to highlight some of the key differences between the parties.