Please keep in mind that the Limits to Growth studies never predicted anything. They extrapolate trends to indicate what will likely happen should BAU continue along its trajectories measured at the time of the studies.
The reason they have hit the trends so precisely is that their warnings of what the extrapolations of BAU would lead to were ignored. BAU is suicide is what the studies indicated was likely and after 40 years of BAU it sure looks accurate.
The biggest thing to keep in mind about discussions related to the Limits to Growth works and our current emphasis on climate change is that they are two different mechanisms and processes. The Limits to Growth works
do not take climate change into account. This is a huge point. The Limits to Growth work is almost totally related to the global carrying capacity issues and subjects. Leaving climate change completely out of the analysis those studies which are now seen as incredibly accurate point to a civilizational collapse.
Thus we are left in this situation.
Civilization will collapse over the next few decades due to our exceeding the globes carrying capacity if we continue to pursue BAU scenarios (black or green does not matter) detailed in LTG.
Civilization will collapse over the next 30-40 years due to climate change
regardless of whether we pursue BAU or not (that is ignoring carrying capacity realities).
In combination the effects of exceeding the globes carrying capacity and worsening climate change present a death sentence to our complex civilization but they also present an existential threat to the survival of large numbers of our species.
The only path forward which satisfies a rational risk/benefit analysis is to pursue a vigorous program of global degrowth (or managed collapse for those who prefer frank language). And let's get started immediately...like in 2005 at the latest.
There is an interesting quote in the paper that is almost identical to one I have made many times ..and got beat up for making.
This suggests, from a rational risk based perspective, that we have squandered the past decades, and that preparing for a collapsing global system could be even more important than trying to avoid collapse.
BAU won't work. Get over it.
As to the 2015 projected peak in per capita industrial production being the prime metric for determining when collapse starts I an not sure I agree with using that metric. I think one can make a good argument collapse started some time ago or one could make a fair argument that we are on sort of a plateau at peak and have not really started measurable decline. But those arguments are not really important as we can clearly see the freight train coming at us at this point. You can jump in the river and try and swim for it, or you can stay on the tracks and try and stop the train. Your choice.