Or you could try to affect the things that do matter in the grand scheme of things: E.g , demand more regulation for CO2-heavy industries, find ways to support CO2-neutral energy production, demand anti-deforestation clauses in trade agreements, etc.

Having one less child has far more of an impact than all of those lifestyle changes combined.

Yeah, but then you are probably reducing the frequency of people who care about the environment in future populations, which may be a net loss.

Extrapolating that out environmentally concerned people should have as many children as possible and outbreed those not concerned about greenhouse emissions?

Such a statement seems to assume that the mind is an immutable object only created in childhood.

While it certainly causes cognitive dissonance for some, an SUV driving redneck carnivore with no children has created far less emissions than a public transport using vegan environmentalist with 2 kids.

http://iopscience.iop.org/article/10.1088/1748-9326/aa7541

Mostly I’m just saying that, given that most aspects of personality are 30-80% heritable, I think people should really think twice before contributing to a future with less long-term thinkers in it.

Certainly do understand the motivation, it just seems like a race environmentalists can't win.

There are better ways to change minds.

And providing education for and/or adopting other children so that they learn how to live responsibly.

I think this advice can be simplified greatly: reduce your expenditures. If you're spending less money, then you are consuming a smaller share of the world's bounty.

Reducing energy use doesn’t necessarily mean reducing expenditures. I mean, reducing expenditures can be good if you’re saving for something else, but you don’t have to.

Instead of buying and fueling the car, you can buy the luxury bicycle.

Instead of flying to Venice, you can rent a sailing yacht. Or whatever is local to your area.

It’s like dieting. The impulse is to reduce, naturally because you’re cutting things out, but eventually you figure out that you can fill your life with other experiences.

If you save that money instead it goes into a pool that is invested in things that then go and spend it elsewhere.

So your position is that personal consumption does not result in additional resource usage?

I'm not completely sure. I just know how modern economies work. If I don't use it, the economy optimizes so that someone else will.