Of course vegetarianism is not the ultimate answer to life, universe and everything. A vegetarian diet still damages environment. Human life in general is not good for the environment. Living in total harmony with nature is not possible (supposing that we don't want to drastically reduce the world population and dissolve all the cities around the world). So, in my opinion, we should reduce the damage we do.
It is not possible to cover our requirements for meat without deforestation and factory farming. Just imagine the idea to supply e.g. new york with meat by raising in animals on meadows around the city. It's ludicrous. I think we all agree that factory farming is not what we want. So we have to lower our requirements.
The reason why vegetarianism is more sustainable than eating meat (talking about the average meat consumption) and less sustainable than veganism is a question of calculation. You need about ten times more food if you feed plants to animals and eat the animals. That would not be a problem if it was about grass, but we eat to much meat for feeding all the animals with grass. Lots soy an grain are imported from third world countries. It sounds paradox, but this means that you eat more plants if you eat meat.
I think that reducing meat consumption is necessary if we want to decentralize food production. And the best way to reduce our meat consumption is going vegetarian.
Edited by Man, 07 April 2012 - 09:07 AM.