If we are not doing things sustainably (as with renewable energy), there must be something else wrong that needs fixing too, and perhaps first.
Other things that need fixing:
I see these all of a piece, in one word, Capitalism. What we need is:
1. Democracy (unlimited, the economic is political, there are no individual rights to property that transcend the needs of society, and transparency is essential)
2. Equality. The first aim of every society should be to ensure the needs of every person to reach their greatest potential are met with the greatest degree of equality possible. It is not surprising on many levels that greater equality leads to a progressive society (as from 1933-1968 in USA), greater inequality leads to a regressive falangism. And there is no such thing as "equal opportunity", either you have equality or you don't.