I am sure that you are right @hussnain, everything I see about environmental arguments shows that animal agriculture accounts for more greenhouse gasses than all the planes, trains and automobiles. The amount of grain we feed our food and dairy animals could feed the world easily so add resolving world hunger to the list of benefits to veganism.
Switching to a vegan diet for me cured type 2 diabetes, allowed me to stop all medications and nearly eliminated all symptoms of severe hardening of arteries/stroke/heart disease. I also spend about 50.00$ less on my food bill.