Environmental Implications from Animal Consumption
I will prelude this topic with my own ignorance. I used to believe that the world had too many people—it is very easy for someone to think that; over a billion people live on less than $1.25 a day, and our natural resources are diminishing at an unparalleled rate. This is scary for someone who wants to live to the year 2090! My only comforting thought was that someone—some government or worldly body—would find a solution. But "The greatest threat to our planet is the belief that someone else will save it,” and I happen to agree with Robert Swan. We all have the power to save our planet and we can start now, by choosing what foods we put in our mouths.
Currently we are producing more than enough calories to feed all the humans on earth, except we are not singularly feeding humans; we are also feeding animals. If we shifted the total calories being produced, it is estimated that we could feed an additional 4 billion people! . So it is not so much as a quantity issue as an allocation issue. Yes, the meat being produced is being fed to humans, however it takes 28 calories of fossil fuels to produce 1 calorie of beef. Whereas it takes 3.3 calories of fossil fuels to produce 1 calorie of plant foods. So eating meat is extremely inefficient.
The amount of water that is needed to produce a kilogram of beef varies from source to source, however most seem to land onthe conservative figure of 20,000 litres of water per kilogram of red meat (I have converted these numbers from imperial to metric) . Plant foods can range from 200 litres per kilogram (cabbage) to 3,300 litres per kilogram (rice) . I would be remiss to mention that certain plant foods do use more water such as almonds and legumes, and some sources will indicate that they use more water than chicken or lamb. However, we need to pull back and look at the whole picture. This is not just a water issue; it is a planet issue.
Cows and other livestock poo, plants do not. It is estimated that cattle raised for beef produce more than 9,500Kg of waste per cow per year . Humans, on average produce 83Kg of waste per year. Where is all that poo going? Our soil? The ocean?. Still want to eat fish? It is estimated that for every kilogram of fish caught, five kilograms are killed and discarded . Not only are we polluting our oceans but we are sucking all the life from it as well.
Animal agriculture is responsible for 18% of greenhouse gases, which is more than then the transportation industry . That is a lot of cow farts and burps. This means that you can actually conserve more energy by removing meat from your diet than by not driving, and chapeau to those who do both!
We are adding more gas by raising animals to eat, subsequently we are cutting down the Amazon Rainforest to make space to graze or grow feed for animals. This is like a triple negative. Destroying 1-2 acres of rainforest every second  is killing our planets biodiversity, and it is removing an exorbitant amount of trees and plant life that reduce carbon emissions and oxygenate our planet. And in substitute of this we make room for cows to graze which then adds more gas to environment. It is a vicious cycle.
Globally over 70 billion land animals are killed to produce food, annually,  and aquatic causalities are in the trillions. That means we would have to kill every single human ten times over to equate the amount of land animals we kill each year.
By adopting a whole-food, plant-based lifestyle we can drastically reduce carbon emissions, we can start to restore our oceans and rainforest, and we can start to properly feed the entire planet. According to Richard Oppenlander 1.5 acres will yield nearly 17,000Kg of plant-based foods, whereas the same land will only produce 170Kg of meat . We can save our planet, we must save it! For at the end of the day Mother Earth does not need humans, but we do need her. It is time to give her the respect she deserves.
For more on these topics please check out the sources below. I also urge you to watch Cowspiracy. Cowspiracy is not only the best documentary I have seen on topics relating to the environment, it is one of the best documentaries I have even seen, period.
If you are interested in adopting a whole-food, plant-based lifestyle, please check out my resources.
 United Nations Development Programme. "Sustaining Human Progress: Reducing Vulnerabilities and Building Resilience." Human Development Report, 2014. Web Accessed February 25, 2015
 IOP Science “Redefining agricultural yields: from tonnes to people nourished per hectare” 1 August 2013
 World Watch “Meat Now, It’s Personal!” http://www.worldwatch.org/system/files/EP174A.pdf
 Earth Save. “2500 Gallons All Wet?” John Robbins
 treehugger.com “From Lettuce to Beef, What’s the Water Footprint of Your Food?” Matt McDermott
 “Risk Assessment Evaluation for Concentrated Animal Feeding Operations.” U.S. Environmental Protection Agency – Office of Research and Development. 2004.
 “Discards and Bycatch in Shrimp Trawl Fisheries.” UNITED NATIONS FOOD AND AGRICULTURE ORGANIZATION (FAO).
 Fao.org. "Spotlight: Livestock impacts on the environment."
 rain-tree.com "Rainforest Facts."
 Oppenlander, Richard. "Food Choice and Sustainability: Why Buying Local, Less Meat, and Taking Baby Steps Won’t Work." Minneapolis, MN : Langdon Street, 2013. Print.