There are currently a few rich and many poor on this planet. For the rich to maintain their current standard of living the poor must be systematically oppressed and their ability to live sustainably must be destroyed. Similarly for the rich to maintain their current standard of living the environment must be systematically destroyed.
The planet has limits, we cannot continue destroying it forever, we cannot extract non – renewable forever. The rich will not be able to maintain their current standard of life forever. Indeed I think they will not be able to maintain their current standard of living for long.
To build a world based on equality and a fair share of resources we cannot consume as we currently do in the west. Furthermore for a fair distribution of resources which does not preclude any future generations survival we must consume sustainably.
To continue our current standard of lifestyle it to preclude any future generation from a chance to live a healthy, rich life. Continuing to strip mine our oceans and land bases, toxify our environment and destroy our climate is fundamentally immoral, both due to the effects these have on humans currently living hose yet to live and the other inhabitants that share this planet.
There is no distinction in the long term struggle for human rights and the rights of the planet. We cannot have one without the other. To focus solely on increasing material standards of living with no regard to the environmental effects of those actions on the planet is a narrow minded self defeating path. Humans can only have a free and humane existence while living sustainably.