No it isn't. We should strife to zero carbon emissions. No amount of insulation or reduction of consumption will achieve this. The best these reductions do is delay the onset of the negative consequences of climate change.

The solution is to replace carbon emission based energy sources and there are plenty of basically infinite energy sources out there. Solar energy, geothermal energy, tidal energy, nuclear fission, possibly nuclear fusion.

Until we've scaled those up we should be reducing our energy consumption. But it's just a stopgap, not a solution.

A solution has to be possible for it to be a viable solution. There is no way the world's population is just going to decide to live an ascetic life suddenly, and there is no world organization nor will to force that to happen. Not only that, but I don't want to live in a world where we have to sacrifice the gains we have made in living conditions just to survive. We need to use our innovative powers to come up with a way we can continue to progress while maintaining the livability of our planet.

Interesting research question: how much did the fear of air travel resulting from 9/11 reduce the rate of CO2 being released into the atmosphere?

Yes, voluntary poverty is one possible solution, at least in theory.

But even if it can be implemented, it's a pretty bleak future.

And I have very serious doubt that the whole world can unite behind such selfless sacrifice. The free rider problem is obviously gigantic.

So I'd keep looking many other solutions.

We don't need to get to poverty levels to be carbon neutral. But we need to stop consuming for consumption's sake, and reduce some important bad habits. The structure of pricing must also change. People don't feel poor for not being able to eat caviar daily today, they don't have to feel poor for not affording beef daily tomorrow either.

Reducing energy impact, if anything, is the opposite of poverty.

Living below you means, avoiding unnecessary purchases and trips and saving money makes you more financially stable.

and don't procreate

Procreation is irrelevant. The USA is a bigger problem to climate than India, despite being a fifth the size or less.

And you think Americans would consume less if only they procreated more?

No, how did you get that? I'm saying that the number of people is pretty distantly related to climate impact.