> The excuse is usually that if you tax carbon all you do is move the polluters offshore, and since CO2 is a global problem it doesn't solve anything. Global problems need global solutions, but our international treaty systems are insufficient to make progress on this pressing issue.
Which is, of course, ridiculous.
They bought a coal power plant in New York, because it already existed. They're not going to disassemble it and transport it to China because that wouldn't be cost effective, so the alternative is that it would remain offline.
Likewise, if people buy electric cars or high MPG hybrids in the US because there is a carbon tax, that reduces the CO2 emitted by the US independent of what anybody else does. It doesn't require any international agreement; you can just do it on your own.
"What about global effects," you say. But that goes the other way.
Africa doesn't buy new cars by and large, they buy used cars exported from America and Europe. If the new cars people buy in America or Europe become electric then they'll still be electric when they're the used cars sold to Africa.
Oil is a global commodity. If America burns less then the price goes down. Which makes it cheaper for other countries to independently enact a carbon tax. Which they have the incentive to do because they get brownie points, and their domestic population doesn't rebel against a change that only keeps the price the same, and it generates revenue at the expense of the (foreign) oil companies. The more countries do this, the easier it is for the others to do it, at the expense of oil net exporters like Saudi Arabia and Russia.
Nothing about this requires an international agreement or any kind of cooperation from anyone. Just enact a carbon tax and pay the revenue back to the population as a dividend. It will be extremely popular as soon as everybody gets the first check and realizes that they get back more than they paid because some of the money comes from oil companies and other corporations (who receive none of the dividend).