There are, of course, quite a few debates going on about how to eat sustainably. By this, of course, I am only speaking of the actual impact on the environment, not taking animal justice into consideration. As much as this is important as well, I chose to deal stricly with the effect a diet can have on the environment by taking the time to make a few searches over the internet. Not all are for vegetarian or vegan diets, but here is what you can tell people about the impact their diets have on the planet, all the while not scaring them into thinking that you want them to become vegan (even though we hope that will be the end result!).
We know that eating meat is very high on the no-no list, and although I always encourage a vegan diet first, this study that was done in the UK states that if meat is eaten in very small quantities three times per week - or more if the person eats less than a portion per meal - they reduce their carbon footprint by 36%. Quite a sizeable number, considering that these people can also have coffee and tea (which are high on the water footprint mark as well, though, since these crops require quite a lot of water to produce). And, if everyone in the UK eats this way from this day on, by 2050 that country's carbon footprint will have been reduced by 14% WITH THE DIET ALONE. Impressive, right? Now imagine if they all go vegan!
Meatless Monday has existed in Canada for decades, but now it takes on a whole new meaning and is known on an international level. Once a war-support initiative, it has taken on the 'war against pollution' role and although it does not ask people to become vegetarians, it strongly suggests it. Since the meat industry is responsible for a higher degree of pollution than all forms of transportation combined, cutting out meat for even just a day per week is enough to greatly reduce everyone's footprint. Click here for a few statistics on how this helps, and here for the stats on the US.
Even scientists that are attempting to create a sustainable and healthy lifestyle for space agree that a vegan diet is the best. The Biosphere project, detailed part of the way through this document, indicates that if in a small space we need to realise that we have limited ressources, why is it any different for our planet? It has limited ressources as well!
And this information goes beyond just the amount of ressources needed and the wasted created by the producers of meat. In this document, they state also statistics such as the number of wild animals that are killed every year because they are a nuisance to farmers, and other such details. Read on.
Please add more information in the comments as this is needed to have arguments whenever we end up in a discussion with people!