Well then I guess I'm a bit lost. What exactly is being suggested here?
We seem to have established that, for 'many', there's no relationship between material wealth and spirituality (although the people replying to you appear to disagree, but I'm going with your notion). And I think the original post was suggesting that climate change is a consequence of a lack of spirituality.
If we take all the above as true, wouldn't this all logically suggest:
(a) We're doomed regardless of how many solar panels / wind farms we build, because the root cause (lack of spirituality) remains unaddressed; and
(b) To avoid being doomed, we should devote the bulk of our finite efforts and resources towards general public achievement of spiritual enlightenment? And only after this has been achieved, only then might we be able to stave of climate change?
Or is something else being suggested?
Just my opinion, but I'm not so certain that there's either (a) no relationship between 'spirituality' and material circumstances, or (b) that there's an inverse relationship, as is suggested below (i.e. poor people are more spiritual). I can't see how either of these propositions are self-evidently true. The latter is a nice thought, I guess ("oh, he said the meek! oh isn't that nice!"). It's a similar idea to that of the 'noble savage' I suppose.
Going with your notion (i.e. no relationship): I think catastrophic climate change would significantly diminish material resources, in practically every respect. Even 'empty space' will be in shorter supply, due to mass migrations towards relatively unaffected geographies. IMHO, these sorts of 'material privations' (and I don't mean your voluntary weekend fast, here) would bring out the worst, most desperate behaviour in most people, particularly if experienced en masse. I don't think these would be people freed from petty material concerns, and therefore able to pursue 'spirituality'. I suspect they'll instead be people doing whatever it is they need to do to increase the chances of their family's survival.
IMHO, the social dislocation caused by catastrophic climate change is one of the few things I could see leading to a violent breakdown of social order, or to the next global scale war. I tend to think these sorts of adversities would lead one away from spiritual enlightenment (unless dying counts as spiritual enlightenment).
Would you contend that people were generally more 'spiritual' during the Great Depression? Were they more spiritually enlightened during the world war that followed? Or does one thing have nothing to do with the other?