Vegetarian eco-warriors

About a month ago, I watched an invitation video on the youtube channel of my university, to an event which will propagate the effort to reduce CO2 emissions of the participants by I can't remember how much. A large part of the video featured a student explaining how being vegetarian reduces your harm on the environment because animals produce methane (not exactly CO2 but who cares). I commented on the video provocatively, somewhat like this:

Why does this video make me want to fly to Istanbul and have a tasty Kebab upon arrival?

One bloke went all militant against me for this comment and accused me of not keeping up with the vegetarian revolution and humanity's progress. He wrote other silly things which I ridiculed. My trolling activities were terminated by the administrator who wrote me a message asking me to stop or he would have to block me. He also said that my actions could affect the number of people participating in the event. Whatever that is supposed to mean.

The vegetarian revolution and its benefits to reducing CO2 are certainly worth examining in the detail because I believe there are those out there who think how revolutionary, hip, trendy and God knows what else they are. I have my own issues with meat industry, such as, I don't like my chicken to be injected with growth hormone but that does not make me give up on eateing and enjoying Chicken altogether. But if I ever decided to become a vegetarian, let's look at the options I have:

I might buy some of that genetically modified soy from the America's to use as a meat and dairy substitute; might also make use of some of that rice from warm and humid corners of the world; spices from the Indies, East and West, so that it tastes better; maybe some vinegar and olive oil from the Mediterranean; and when we are at it, some more traditionally North West European crops grown in the sunny South Africa look real juicy. 

What do all these items have in common? They are not local. They need to be transported from thousands of miles away by means of trucks, ships and cargo planes. In contemporary world these vehicles of transport will probably be powered by fossil fuels, the days of galleons laden with spices are long overdue. It doesn't prevent me from becoming a vegetarian of course, I am well supplied, but what if I try to link that to my concern for CO2 emissions? To reduce the impact my diet has on the CO2 emissions I would have to limit my food supply by geography. I would not be so harsh on myself and allow my food to come from regions in close proximity to my current location. Because I reside in East London, the regions are as follows:

South East England (Kent and East Anglia); Channel Islands; Normandy; Calais and Dunkirk communes of France; and West Flanders.  

I wonder how long my vegetarianism would last, or if I would be able to properly feed myself. I bet within a week I would have dreams about Guernsey cows and Tartar Steaks...