Canwest News Service: When all aspects are taken into account — from deforestation for pasture to methane from dung, our addiction to meat accounts for 18 per cent of greenhouse gas emissions. Want to lead a greener life? We all know the mantra: Drive a fuel-efficient car, insulate your house, change your light bulbs, reuse those grocery bags. How about this: Eat less meat? It’s a message we hardly ever hear. Yet according to the United Nations Food and Agriculture Organization, livestock …