Food is a large source of the Carbon we create through our consumption. It is around 20% of the total in our Shropshire county. Part of the problem comes from the methods of farming used to manage the food (for example with cows for those that eat meat). Part of the problem comes from the fact that we import much of our food, and the planes, ships and lorries emit carbon in the transport of the food.
There is a great book by Mike Berners-Lee called “How bad are bananas?.” This sets out the carbon footprint of almost everything you might eat.
A research study (by P Scarborough et al. in 2014) compared the amount of Carbon Dioxide emitted due to the diets of different types of “eaters”. Thus it broadly compared meat-eaters with vegans. A simple graphic illustrates the difference.
Thus by switching to being vegan, then you will be more than halving your emission of consumption from (some of your) food.
In schools, Local Authorities can change the diet served to make sure it is nutritious but better for carbon dioxide emissions. For instance, since 2009, Bristol City Council has moved to a situation where 45 % of the food is made from locally sourced food, and 30 % prepared with organic produce.