> Mitigating it requires a commitment to what any reasonable person considers a significant drop in living standards in both the developed world
Nope, unless you consider living in cities not suburbs intrinsically worse.
GDP has some flaws as a metric, but the "real good thing" so-far correlates with it simply because we aren't doing shit about the environment. There's no reason we can ramp up electrifying everything and live nice lives. Hell, if the population actually goes down as expected, maybe we can reduce total land devoted to agriculture too which would be really nice.
The best way to do it and feel rich is to not be so obsessed with expensive electric-battery cars, and do more public transit, which I why partly I say it's the suburbs that drag us down.