I don't think that disposable consumerism poses any risk whatsoever to the future of the species. And the normal consumer good we purchases make up only a tiny fraction of humanity's impact on the environment.

I think being defined by not owning anything at all is a serious risk, and one that I myself has fallen into. A sort of semi-hipster attitude about having the cheapest furniture. But I think it's probably more healthy to err on that side. And I agree, you need to have something more.