Only about 5% of the US oil supply is Russian, and we are a small client for them. Germany is unlikely to stop purchasing Russian oil and gas, and is a major client. So I am sure you are opposed to the Russian oil embargo just announced, right? Same logic.
We should be a leader, and show the world what is possible on this front. Not throw up our hands and say, "Oh well, China says no so I guess we'll just not even try"
I do agree that we are unlikely to avoid a major climate upheaval of some type, but it will have to be addressed at some point, even if it is 50 years from now. No reason not to start now.
And yes, also work on mitigation strategies and coping strategies.