It's hard to say in today's environment, where a lot of trade discussions have stalled given the current political positioning of the U.S. I have heard from folks who are closer to the negotiations than us that when the administration changed in the U.S., there was less of an interest in pursuing it because there was a perception that it would not go far.
I've also heard that the mechanism they used to identify environmental goods was one of the problems, as it allowed it to become a negotiation on each item. The thought was that if there was a different approach to identifying an environmental good...because I understand there was no definition either for an environmental good.
If you either had a definition that you could assess against or you had a process where you could have a group of engineers and scientists who would identify what an environmental good was and then put that recommendation to a negotiating group, then you would have something that maybe is a little less of a negotiation between parties who are trying to simply seek trade advantages. I think there are ways to improve the process.
Of course, one of the techniques one can use in international diplomacy is that if you can't get a broad group of folks to agree to something, then you can make your group smaller. You will find your environmental like-minded groups who want to talk about clean tech and environmental groups, and try to establish some sort of agreement with that group as a start, hopefully, and then you can expand it either to WTO or others.