A lot of green initiatives have excellent ROI's.
Myth. Maybe .01% have "excellent ROI". Most are only tacitly feasible because of PR benefits. You know, the PR that means you hear all about the ones with excellent ROI then are duped into believing that's a fairly common thing.
I can think of 10 off the top of my head that we utilize in most of our hotels. The bulk of them are based around energy efficiency. Now, 10 may not be a lot in the grand scheme, but in the reality of what someone or some business may be willing to do, 10 is a good chunk and has a rather significant effect.
The problem is, I suspect, how one looks at "green initiatives". Assuming we're talking about the set of things which our government has to get involved in to force people to adopt, the idea that there's a positive ROI on them is pretty much absurd. If you could save money doing X, Y, or Z, and you are in a business which desires to make money, then you will do X, Y, and Z whether the government tells you to or not.
It's pretty absurd to point to those things and use them as a justification for all the stuff the government *is* having to force people/businesses to do. Because those things are almost certainly *not* going to be better ROI than what they're doing now. It's nearly axiomatic to the issue itself that this is the case.