vegan, vegetarianism and livestock

Consider this additional Case Study information:

As he decided what to do, Andy studied and considered an ecological argument for vegetarianism. Although the sources he consulted all cited different figures, they did agree that producing vegetables to support vegetarian diets requires significantly less energy and resource consumption than producing livestock to support carnivorous diets. Many of the sources also argued that livestock production is a significant cause of top soil erosion, deforestation, water depletion, fossil fuel consumption, and pollution in the form of livestock manure. Others argued that ecologically and economically inefficient meat-based diets contribute to global famine.

Note: Although these assertions are not universally accepted, Andy's research has convinced him that they are credible and he accepts them as true. For the purposes of this assignment, you should use these claims as starting points for ethical discussion. (If you wish to conduct additional research about this topic in order to become better informed, you may do so. This additional research, however, is not required.)

In this discussion thread, the entire class will discuss the issues surrounding the following questions:

How, and to what extent, should ecological concerns about energy and resource consumption influence Andy Stewart's choice?

If it could be shown that vegetarian diets are ecologically preferable to meat-based diets or demonstrated that meat-based diets contributed to American Dependency on foreign oil products or contributed to global famine, would that mean that a vegetarian diet is necessarily morally preferable?

If it is established that vegetarianism is "morally preferable" for any or all of these reasons, do we have a moral duty to abstain from eating meat? What ethical principles or ideals help you to understand the ethical significance of the scientific, political, and humanitarian concerns these issues raise?