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.

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.

and don't procreate