The science on recycling and the impacts for greenhouse gases is fairly clear. Yes, you're right, if I go and pick something up with a truck, the truck is burning diesel. It puts something into the atmosphere. But the net benefit still exists because you're avoiding the landfill. It's the net benefit. But it is true that recycling activities consume energy. It's an industrial process. It consumes energy. But the net benefit is still quite significant.
On July 26th, 2012. See this statement in context.