That's not to say we won't need treaties and supranational entities for some aspects of decarbonization. Methane emissions outside of agriculture are notably a problem of enforcement.
We're badly in need of a collective update to our priors regarding renewables. In the US, a hostile policy toward renewables is not only shooting ourselves in the foot environmentally, we are now actively impoverishing ourselves due to entrenched economic interests across the fossil fuel industry and the cultural inertia they actively worked to develop.