You impose tariffs on their exported goods to compensate for their failure to impose carbon taxes, and maybe even impose an export tax on goods shipped to them.

You impose tariffs on their exported goods to compensate for their failure to impose carbon taxes, and maybe even impose an export tax on goods shipped to them. China needs trade with other countries and will get on board with a carbon tax if enough of the world is on board with such a plan, no war needed. Of course if things are truly implemented fairly, the US will also likely be subject to such taxes due to our own apparent inability to reduce our per capita carbon emissions...