Consumption habits will need to change, people will need to start eating less meat. Factory farming of cattle and other animals is a large contributor of global emissions. So less consumption is definitely part of the answer.

On the other hand, any plan that doesn't call for less consumption is simply going to be inadequate.

Societies of the past had to deal with this. We still deal with this in wealthy societies actually. When the US west coast is hot and dry, authorities ration water usage.

I can imagine governements doing a more serious job and limiting more things for the common good (aka we don't kill ourselves by destroying our environment)

exponential growth is a fantasy until fusion power and asteroid mining become real

I never understood this line of thought. Economic growth is not a growth of raw material consumption. There has been some correlation but you could imagine a forever growing GDP with shrinking raw material usage without any major problem as long as there is technological or organisational progress.

You can imagine it, but it doesn't track with reality. Economic growth has been synonymous with fast fashion, planned obsolescence, new cars every few years, a new phone every year, more and more meat in our diets, cheap plastic crap and so on - conspicuous consumption.