Considering SpaceX's Raptor engine currently in development is going to use methane as a fuel source (produced by cow farts and rotting garbage among other thin

Considering SpaceX's Raptor engine currently in development is going to use methane as a fuel source (produced by cow farts and rotting garbage among other things), I don't think this particular issue is something to place at the top of your worries about global warming. I'd be more worried about conflicts breaking out due to mass migration due to parts of the world becoming harder and harder to eek out an exsistance in.