save the world!

How is it that a driver of an enormous 4 wheeler which eats petrol at an astonishing rate, who has the air conditioning on, can proudly display a sticker proclaiming he is an advocate of sustainable living and all things environmental.
Now I know you have to break eggs to make an omelette, but, lets just say I think turning a light bulb off and giving yourself a pat on the back while driving a guzzler with the air-con on is a bit...over the top.
I do my bit for the environment. I cycle to work, use solar and wind power, and conserve water, but I don't profess to be anything more than a wise consumer who uses common sense.