The AGW scam is a technology for social control. If indeed it really is dead in the water, what we need to be looking for is the next "global problem requiring global solutions."
In your opinion who is responsible for producing these quests?
There's been a movement for World Government, essentially socialist in nature, since the 19th century. It's one of those concepts which seems to make sense - until you look at it and attempt to reconcile it with human nature. It's the Star Trek view of politics; politics on Earth was a done deal and there was a World Government, the workings of which could be glossed over; everyone was happy and no one was sad, and so the script writers could move on to the more interesting questions of galactic politics. Even earlier there was the notion of The Noble Savage and a genteel view of poverty as a romantic abstract. There's a trend toward globalisation which can't be stopped but could be steered toward their view of globalisation.
Politicians rather like the idea of a nebulous threat to focus their electorates on something harmless (to them). In the UK, we've seen the emergence of a political class, that is politicians of the main parties have far more in common with themselves than with the electorate, and many have never known any career outside politics.
Bureaucracies naturally warm to the idea of anything which gives them more to administer and extend their power and scope. Politicians in turn find it very easy to allow bureaucracies to grow and almost impossible to cut them back.
Evil bankers are rubbing their hands together at the prospect of trading nothing for vast profit.
It's not so much a plot so much as natural trends of thought from diverse groups becoming aligned through an agenda which suits them.