The Paris Agreement’s goal to reduce the risk of dangerous climate change can be achieved if greenhouse gas emissions peak by 2020, halve by 2030 and then halve again by 2040 and 2050. This is now technologically feasible and economically attractive but the world is not on this path...What should you do if you read, and indeed if you write, this kind of stuff? That's right: you should wonder "if this is economically attractive, why isn't it just happening of itself? Why do people feel the need to write reports pushing it, and trying to make it happen faster?" So you'd expect a substantial portion of the report to be dedicated to this puzzle, because it is obviously rather important. And note that this isn't some minor element tucked away in an appendix; it is literally the first words in the report, the overall most-important-thing that they want you to see.
When I say "expect", I don't mean expect-in-the-real-world of course. I mean expect in a mythical "sensible" world. What you'd expect-in-the-real-world is that they'd totally ignore the point I mention, and that's exactly what they do.
One possibility is that they are simply lying, or being somewhat more polite, being a little economical with the truth. "economically attractive" is a vague phrase as it has to be to cover such a wide area. Another is that they're just being over optimistic, or rather bad at evaluating things: of their eight or so talking heads, only one - CEO of Ericsson - is actually in bizniz. Another is that if it really was economically attractive, and just going to happen anyway, well, where's the fun in that? Who would need nice reports like this if the evil capitalists were going to do it anyway just to make money?
My image, from the report, illustrates another problem. There's a nice graph, projecting "energy use" sources. We see solar increasing nicely. What problem could there possibly be here? The answer is "we estimate that solar needs to continue growing exponentially at a pace of 23% per year... less than half of historical growth rates". Less that half of historical rates should be easy to achieve, yes? But suppose instead you assume historical growth rates. In which case, more than 100% of power will be solar by 2030. That's even better, you can stop pratting around with wind. Oops, but that would make the wind people very unhappy indeed, so assuming that would be a Bad Idea. My point, which my sarcasm badly obscures, is that the projections are quasi-arbitrary, and it isn't obvious that's its a good idea to try to "manage" them.
* Economics, Law and Ethics
* Hothouse tipping elements of no return
* The Great Persuasion: Reinventing Free Markets since the Depression
* FT: The Big Green Bang: how renewable energy became unstoppable