BBC World Service Radio has been mulling the question: "Is capitalism killing our planet, or is it our only hope?".
No mention by the panelists of Socialist China and Soviet Russia. I visited both and lived in the former.
They were horrid for the environment. Socialism is worse for the environment than is capitalism, by a long way.
As countries become richer, which they will best do if they follow capitalism, they tend to use less energy per unit of GNP. See the Energy Intensity index.