"The importance of detachment from things,
the importance of poverty,
is that we are supposed to be free from things that we might prefer to people.
Wherever things have become more important than people, we are in trouble.
That is the crux of the whole matter."
~ Thomas Merton
And wherever things have become more important than the other living things which we share this Earth with, and with the Earth itself, which sustains our lives.
It isn't the materiality of the Earth that is important as such (in terms of ownership of parts of it) -- it is our inextricable connection to it and that we are its trusted stewards. It is the water in which we swim like fish, we don't know we utterly depend on it until we are flopping gasping on dry land.
And so, we must protect the earth and in so doing we are protecting all the others on the earth.
Instead of competing with them for parts of it, we must protect it in spite of our personal interests which, in the end is our personal interest.
The material world is like a baby that two women brought to the wise man to settle a dispute. Both claimed the child as their own. The wise man, after deliberation, said to have his helpers to cut the child in half and give half to each woman. The real mother gave up the child to save its life.
If we tear this world apart, fighting for it, we might end up with a dead world.
When our standing in this world, our ego's position, becomes more important than the principles and people we are standing up for, then the position, whether it is attained or not, will mean nothing. The ego cannot judge what is important. It is impossible for it to both exist as a separate identity from all others, and also truly understand the meaning of, and maintain its position amongst those others.