I dont know exactly how the 3di is calculated, but I do know that it is a fairly good idea badly presented or implemented. The leaflets that were published at the time had several obvious numerical errors in it, which makes me suspicious that those behind it actually know what they are talking about! Similar to when there was the claim of saving 10% CO2 on flights, by saving 2.5% in each of taxi/climb/cruise/approach....
Zooker - I agree entirely, but the secondary benefit of flooded undergrounds might be more people taking flights...?!!
