1) This can be a difficult topic. How do we put a cost on clean air and water. When someone is only interested in immediate profits then it usually takes the government issuing a new building code to force that person to do the right thing.

In the US the government cannot require everyone to build to LEED so they tried to lead by example and many new government buildings are LEED certified. Both State and Federal. This has gained a lot of attention for LEED and probably encouraged others to follow with certifying their own buildings.

Profit has motivated many business to get their buildings certified. I've heard of some studies that showed LEED buildings were able to gain 10% higher rents in the US. If the public is very interested in being green then give them a choice and they'll choose living or working in a LEED building over a non-LEED building.