Happy Earth Day! It's cheesy but true to say that every day is Earth day. It's Earth Day if you're on Earth and getting anything - e.g. food, water, air, a place to live - from her. If you live on Earth, you have an obligation to take care of her as she cares for you. And there is simply no way that eating animals fits into that. According to New Scientist and researchers at the University of Chicago,going from an omnivorous diet to a vegan one does more for the environment than going from a gas-guzzler to a Prius. "The typical US diet, about 28 per cent of which comes from animal sources, generates the equivalent of nearly 1.5 tonnes more carbon dioxide per person per year than a vegan diet with the same number of calories." 3000 pounds per year! The bottom line is that the animal agriculture industry is wasteful and inefficient. The majority of grain grown in the US is not fed to humans but to animals, and because it takes around 16 pounds of grain to produce one pound of meat, this is a really wasteful use of land, water, and fossil fuel. Think about it: you could grow plants, send them to a processor (if you must), and then to the grocery. Or you could grow plants, send them to feed mills, send the feed to factory farms, send the animals from the factory farms to slaughter, send the slaughtered animals to processing plants, and then send the meat to the grocery. Each of those additional steps requires enormously more amounts of fossil fuel, land, and water, not to mention the fact that animals produce methane and "the number one source of methane worldwide is animal agriculture. Methane is responsible for nearly as much global warming as all other non-CO2 greenhouse gases put together. Methane is 21 times more powerful a greenhouse gas than CO2." (source)
If you are serious about climate change and protecting the Earth, you have to stop eating animal products. This is not about superiority. I am a vegan and I am not the savior of all the earth. But the science is there. To ignore it is selfishness. Yeah, you want to eat meat. But don't you also want to take long showers? And wouldn't it be more convenient to drive somewhere than bike or walk? Local food is sometimes harder to find than non-local, right? If you're reading this, chances are you're already making other sacrifices in your life to protect the Earth. Giving up meat is no different.
If you want more info, I encourage you to check out the UN's report "Livestock's Long Shadow."