So, my original response got eaten by reddit's spam filter (probably because I included the same link twice, but you'll never know with these things) and I'm going to have to try again, for posterity.

By now, many of the points I made in that comment were already made by others, like Spratt & Dunlop possessing very limited credibility, or that feedbacks are both slow enough relative to human emissions to operate over many centuries and are already accounted for in the IPCC reports to a great extent. In fact, even IPCC report #4 - which was first published in 2007 - already had a whole chapter on carbon cycle and other feedbacks.

https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg1-chapter7-1.pdf

The feedbacks which are more difficult to account for, like permafrost, still have an impact that's a fraction of human emissions.

I would simply like to reiterate the points around "crippled agriculture, food shortages", etc. It would appear true if you just look at the climate projections and assume that they'll apply to the current amount of land used to grow food. What that assumption misses is that the amount of land won't stay the same: the IPCC assumes that as the population grows and climate change accelerate, people will simply clear-cut down more, more and more forest to the tune of hundreds of millions of hectares and grow crops on that land. Compare the population/GDP graph from my earlier comment (not linking it again in case it also triggers the bot) with the land use graph, where cropland extent and forested land extent simply go in opposite directions in each scenario - to the point where a scenario with 12 billion people cuts down nearly 600 million hectares. This is also why food supply projections for 2050 look like this and like this, and not like what most people assume when only looking at yield reduction projections or the talk of instability.

And finally, yes, we should move to a non-growth and sustainable system. The thing is, it looks like we may well get away with not doing that in this century, even if the cost will simply be paid by the ecosystems and future generation. That is the position of the scientists who collectively wrote the "ghastly future" paper, and at this point, the counterarguments (whether optimistic or the opposite) appear increasingly strained.