Forget the floating pigs (I know you are eager to forget the floating pigs). Perhaps the most compelling planet-saving rationale for giving up meat is the massive carbon footprint generated by the global meat industry. When people think about reducing their personal carbon footprint (if they think about it), they usually turn their thermostats down, buy fuel-efficient cars, and shut off lights when they are not using them. All good things to do.
But a choice that people don’t usually think about–and that has an outsized impact on their personal carbon footprint–is meat-eating. Numbers are inherently slippery, but one recent study concluded that the contribution to greenhouse gas (GHG) emissions to global warming contributed by a vegan are about 40% less than the GHG contributions of a meat-lover:

So in some ways, choosing to eat meat is like choosing to have a few Hummers in your garage, cranking your heat and AC up, and leaving all your lights on. Most environmentally conscious people would be appalled by a neighbor that lived like that. But somehow meat doesn’t enter into the carbon equation when people are thinking about their personal impact on the planet. And it should because it is such a major factor.
So think about getting rid of those Hummers on your plate. And if you are worried that your friends and family will scorn you for going vegetarian or vegan, I’ve got good news for you. America, despite it’s meat-celebrating culture, is warming up to the meatless:
About half of American voters view vegetarians favorably, and less than a quarter view them unfavorably. Vegans are viewed less positively, but still have significantly more than a third of American voters seeing them favorably. Generally, women, Democrats, and younger respondents have a more positive opinion of vegetarians and vegans. These are among the results of a poll of 500 registered American voters conducted by Public Policy Polling (PPP), a North Carolina-based firm, from February 21st to 24th. The survey asked what respondents like to eat, what they think of fast-food, which chain restaurants they like most, and a number of other food-related issues, as well as key demographic information.
So you can be healthy, planet-friendly, AND popular (though apparently you’ll need to go easy on the vegan righteousness). And there will be fewer dead pigs floating in the rivers.