Global veganism has the potential to reduce global greenhouse gas emissions, but there is no evidence of how much it cuts carbon footprint globally.
Each household in the United States emits 48 tons of greenhouse gases. One would have to drive 63 miles to produce the same emissions as eating one kilogram of beef. Meat, cheese, and eggs have the highest carbon footprint than Fruit, vegetables, beans, and nuts.
Feeding massive amounts of grain and water to farmed animals and processing, transporting, and storing their meat is extremely energy-intensive. Forests that absorb greenhouse gases are cut down to supply pastureland and grow crops for farmed animals. The animals themselves and all the manure that they produce release even more greenhouse gases into our atmosphere.
A University of Chicago study showed that carbon footprint could be reduced more effectively by going vegan than switching from a conventional car to a hybrid. The burning of fossil fuels during food production and non-carbon dioxide emissions associated with livestock and animal waste contribute to it. It shows that energy used for food production accounted for 17 percent of all fossil fuel use in the United States. The burning of fossil fuels emitted three-quarters of a ton of carbon dioxide per person.
The summer barbecue study conducted by the University of Manchester states that a typical summer barbecue for four people releases more greenhouse gases into the atmosphere than an 80-mile car journey. Professor Sarah Bridle said that a 100g medium-sized beef burger's production releases enough greenhouses gases to fill more than 60 balloons. Also, the World Resource Institute suggests that resource management will require Americans to cut their average beef consumption by about 40% to save the planet.
International affairs think tank Chatham House has called for a carbon tax on meat to combat climate change. It suggests eating vegan foods rather than animal-based ones as the best way to reduce carbon footprint.
Currently, there is no conclusive evidence to prove whether veganism reduces the human carbon footprint by half, even though it has proven to play a good hand in reducing the carbon footprint.