I am amused at the number of analysts, politicians and people in general who equate these two topics as being significantly related. First of all, the boondoggle of ethanol as fuel somehow having a significant impact on either of these problems is highly suspect.
As background, a little chemistry lesson. Any fuel containing carbon if completely oxidized results in carbon dioxide and water. This addition of oxygen to carbon is what results in energy production. Ethanol, containing two carbons and one oxygen, is already partially oxidized prior to its use as a fuel, as compared to a hydrocarbon that has no oxygen. Therefore, the oxidation of ethanol to carbon dioxide requires only three oxygens. To a rough approximation then, the amount of energy derived from ethanol is reduced by about one-fourth as compared to a hydrocarbon containing an equal number of carbon atoms. This is why the miles per gallon obtained using ethanol as a fuel is substantially less than from gasoline, meaning that you have to burn more ethanol to go the same distance--and you are producing roughly the same amount of carbon dioxide in the process.
The idea of energy "independence" is also a non-starter--perhaps we can have less dependence on foreign oil, but there is no reason to believe that we can ever be independent of our need for foreign oil anymore than we can be independent of toys made in China, furniture made in third world countries, or fruit from South America.
Assuming we can do something (e.g., increased use of nuclear power) to reduce our energy dependence on foreign oil, there is little evidence that to do so will have any impact on global warming. The fact is that global warming is here to stay and we need to embrace it rather than try to control it. As long as China, India etc continue to grow, anything the U.S. does is for all practical purposes inconsequential.--kind of like wetting your pants while wearing a tuxedo--you get a nice warm feeling, but no one notices that you have done anything.
If global warming is occurring, it is not going to happen over night--there is time to prepare for it and better use our scarce resources to deal with it rather than wrong-headed attempts to prevent it. We need to exploit some of the positives, such as increased crop production in northern climates, while at the same time doing what is necessary to keep coastal cities from flooding (although I can think of a couple of such spots that if flooded, arguably are not worth protecting!)
The take away points are that we need to concentrate our resources on mitigating the effects of global warming, not on preventing it; we will never become "energy independent;" and these two topics have very little to do with each other.
And as a final point which I may discuss in a future blog, the most logical action that could be taken to mitigate global warming in the long haul would be to reduce the world's population--you haven't heard any politician suggesting that have you?
