Braindrainer

So- How much must we do to save our environment?
Some say- that we have to sacrifice just about all to achieve this.
Of course, this is the same people that would never, ever change their own lifestyle. Take Al Gore for an example!
In my hometown, they have ordered us to sorter out foodstuff from ordinary garbage to be fermented in to bio gas.
The thing is that you can only get out about 5% of the energy when making gas. If you burn it for electricity you get about 30% energy effiecency and if you burn it for heat, you get about 85% effiecency.
So what would be the smartest thing to do?