Most of the damage comes from unsustainable production. The amount of production happening per capita is increasing worldwide, and if we want to save the environment we have to enforce that production is sustainable.
It definitely is. It drives demands for food, housing, and industrial development, which in turn put massive pressure on the environment. Displacement of bats because of human expansion, for example, is likely a factor in the appearance of covid19. The western way of life is destructive over the environment and will not scale easily if we are not careful.
We certainly can (and must) do much, much better at operating sustainable economies and reducing our per-capita environmental footprint. But it is unhelpful that the global population is still growing rapidly, consuming ever more land and resources.
Thankfully, as economies develop and standards of living increase, birth rates tend to decline. Current trends suggest the rate of population growth is slowing, and we will eventually reach a stable population some time between 2050 and 2100.
I'm certainly not suggesting we should be telling people they can't have children, but anything we can do to encourage sustainable family sizes and bring forward the date when we reach stability is generally a good thing.
But, they didn’t account for technological takeoff, which allowed us to escape that linear production growth. Nearly half the nitrogen in your body came from the Haber–Bosch process.
Protecting nature is not a market force so you need some other mechanism for that.
And this is assuming people on average are responsible for equal amounts of emissions. But the rich are overwhelmingly bigger contributors on a per capita basis, and as automation continues it gets easier and easier for a small number of people to be responsible for a large amount of consumption.
Some of this process seems to be somewhat natural, since fertility has historically fallen in line with economic and social development, but we still need to ensure this remains true. South America, Africa and Asia are slowly "coming online" and if we're not careful we'll be fighting over scarce resources before everyone has had a chance to experience wealth.