China will (and does to a certain extent) care about the environment because they know it will eventually be a massive problem for them. Their single-party state has only managed to stay in power because it's been very good at driving up the standards of living. And you can only pollute so much before those standards stop going up and people start to get displeased, which is why they've been trying so hard to move up the value chain and export their pollution to other countries (via cheap loans).