How many people know a cow has to have a calf in order to produce milk? In other words, milking cows are also calf-making cows  and around half of all calves are male that go to veal... I am not subcribing to a vegan screed but many people don't know this.

Samuel Fromartz Author Organic Inc.

Fat Knowledge has been running some interesting posts along the food/fuels them.  One is Ecological Footprint of Food Items.

There are some things you might not expect there, like chicken being lower in greenhouse gas (and energy) impact than eggs.  There is also reinforcement for the better chicken than beef thing.

That said, I can only think that the poll was a reading comprehension problem, or people answering what they really thought was being asked ... surely they know farms are "upstream" for all foods (but those wild caught, and that one amusing exception to every rule - salt, the only food mined from the earth).

How many people think about the fact that the animals killed for their meat typically get transported thousands of miles by truck without food or water to slaughterhouses, where they are sometimes not even stunned properly and are processed while still conscious.  And most people don't even realize that the federal Humane Methods of Slaughter Act of 1958 which requires that livestock be rendered insensible to pain prior to slaughter exempts poultry and rabbits. So because the USDA does not consider poultry and rabbits to be "livestock," they are routinely killed under cruel conditions in slaughter plants.  

So before everybody rushes to go buy chicken instead of other meats because chickens release fewer greenhouse gases, folks should consider the conditions that these animals were raised and killed in. And also consider that greenhouse gases are only part of the environmental equation.  Chicken factory farms put tons of manure into local waterways. And lets not forget about avian influenza, which is the result of the intensification of the poultry industry around the world.  Though if we do have deadly bird flu outbreak that kills millions or billions of people, that may help the climate change problem somewhat.  But we shouldn't have to choose between supporting climate change or bird flu.  Try some organic, local legumes, nuts, veggies and whole grains for your protein sources.  

If you need more inspiration, read the study by University of Chicago researchers, which found that eating vegetarian fare is more effective in reducing harmful greenhouse gas emissions than replacing a gas-guzzler with a hybrid car.  
http://geosci.uchicago.edu/~gidon/papers/nutri/nutriEI.pd ...