What's the matter DutChy?
I had you pegged as a tree hugging environmentalist.
Are you not pleased that SpaceX is attempting to keep waste and costs down by RECYCLING components from their launches?
I know this isn't the solid rocket booster recovery system, but I'm going to mention it anyway because they've made such a big about it, and it bothers me slightly.
It looks cool and everything, but the space shuttle SRBs were actually recovered and reused. Only the big orange liquid fuel tank was expendable. The ESA's Ariane-5 uses the same system now for it's SRBs (there may be others). Both with a far simpler and more fuel efficient system - parachutes.
The main problem is splashing down in the ocean isn't particularly good for the engines, which have to be completely stripped, cleaned and inspected before they can be reused.
So as far as I can tell, there's no actual environmental benefit to Space X's fancy system, it's just more efficient in terms of time and manpower. Although maybe Space X's engines are more prone to damage from landing in the sea?
Anyway the whole thing seems a bit mis-sold to the public to me.