Yes, of course we'd still want to stop it. It would be much riskier though, as the consequences would be harder to know - messing with the environment is always risky. This is also why geo-engineering solutions to climate change are suspect - stopping CO2 production is just going back to a state of the world that we know worked. Seeding the ocean with iron or changing the color of the sky are radically different from any previous state of the Earth, so their impact is unknown.