Methane gas is at least 23 times more potent than CO2 over a 100-year period.
Methane gas is at least 72 times more potent than CO2 over a 20-year period.Dr. Jouni Raisanen, Climatologist, Helsinki University, Finland, Member of UN Intergovernmental Panel for Climate Change (IPCC):
 Agriculture is important, particularly for methane. If this can be 
reduced, it would be quite an efficient and cheap way to mitigate the 
global warming. Unfortunately it has been urgent for quite some time, 
and we have woken up, a little bit too late. But really this is an issue
 that will require big efforts from mankind and without any additional 
delay.
Dr. James Hansen Leading climate scientist
Director of NASA’s Goddard Institute for Space Studies (GISS)
Recipient of the Shining World Hero Award from Supreme Master Ching Hai
Dr. James Hansen (m):
 The things that individuals can do are helpful. And one of the most 
helpful is actually a vegetarian diet, that produces much less 
greenhouse gases than a meat diet.
Videoconference with Supreme Master Ching Hai with London Center, UK – June 13, 2008
Supreme Master Ching Hai: Because
 if you don’t keep breeding more animals, and then there is less 
methane. And if we don’t eat meat, then there is no transportation 
necessary and less fuel needed. And all these people can be trained to 
do something else. And there will be less hunger because we will use the
 agriculture products, cereals, to feed humans instead of feeding more 
bred animals in the future. So we don’t have hunger anymore and there 
will be no more war because of hunger. So the effect is immense.