We saw what happens when over-leveraged economies like the U.S. and Europe failed to anticipate the threats posed by unsustainable debt loads; we don't want to see what happens if we ignore signs that we are over-leveraging the planet's resources.
Like many things, there may be a time and a place for using subsidies. But they need to be better targeted. And, often, there will be better alternatives. Alternatives that do a better job of protecting the poor.