China does have climate policy and it’s and issue that they do not ignore. They plant trees at the interface of deserts to prevent their expansion, they produce 80% of the worlds solar panels. China is the world's leading country in electricity production from renewable energy sources, with over double the generation of the second-ranking country, the United States.
China has a lot to lose from climate change. They will see reduced agricultural production from prairie land, in a country of over a billion people. A starving population will not allow the current regime to continue and the Chinese government has every reason to come to the table.