Yeah it's the "tech curve" being exponential that I don't see happening. The Haber-Bosch process (after the end of the 19th century, but only by a few years) was revolutionary, and a fine example of the kind of rapid increase in our ability to exploit the hell out of everything that hasn't been happening so much lately. The increase in technologically-enabled power may have started looking exponential at a certain point, but I don't believe it has continued like that all the way to the present. The gains today are more incremental, less momentous. The rise and fall of Moore's law shows a similar pattern in microcosm: Great new invention, rapid improvement, exponential growth that people assume will last forever, then its limits are approached and further progress in that direction is slow and complicated. When I try to imagine how the total curve of technological power has gone I can't avoid the impression that its rate of growth topped out somewhere mid 20th century at the latest.
Sure it'd be disastrous if we somehow kept up for any great length of time the exponential growth in energy use, production, and population even without fossil fuels, but the idea that this might actually happen starting from this level seems more like a techno-optimist fantasy than any kind of realistic scenario worth considering. Like some other ideas of the Consilience Project it seems to me as if it might be more relevant to some future post-collapse civilisation that needs to avoid making the same mistakes that will bring down ours.