Methane is a far, far worse greenhouse gas than CO2, even accounting for the fact that it eventually decays back to CO2.
https://www.noaa.gov/news-release/increase-in-atmospheric-me...
So the net effect of all the methane is about 50 ppm. About 30% comes from fossil fuels. This leaves a big burp relative to preindustrial levels (comparable to 20 ppm CO2), likely from the expansion of human agriculture, more cows, maybe forest removal.
We're locked into it now due to permafrost melt and increased rainfall in to the tropical belt, swapping out one strain of rice for another will have marginal effects at best.
> "NOAA scientists are concerned that the increase in biological methane may be the first signal of a feedback loop caused in part by more rain over tropical wetlands that would largely be beyond humans’ ability to control."
The tipping point has come and gone, we're heading for the Pliocene. Plan accordingly.
No, this is incorrect. The number you cite (25x) is a 100-year global warming potential (GWP) figure. That is, if I release 1 ton of methane into the atmosphere today, over the next hundred years it will contribute to global warming about as much as if I'd released 25 tons of CO2.
But this is not an appropriate way to analyze the composition of the atmosphere at a point in time. We're not releasing 1.9 tons of methane and 420 tons of CO2 and looking at how that will effect global warming over the next 100 years. Instead we're looking at the CO2 that has built up over the past few hundred years, and the methane that has built up over the past few decades, and looking at how that affects global warming now. We want to integrate over past contributions and look at the resulting warming at a point in time rather than look at emissions at a point of time and integrate over future warming.
The effect of methane when you look at it this way is much higher. The IPCC estimates[1] that methane radiative forcing (i.e contribution to global warming at a point in time, based on current atmospheric concentration) is about 0.48 W/m^2, vs. 1.82 W/m^2 for CO2. That is, the ratio of (warming due to methane) to (warming due to CO2) is about 1:3.8, not 1:8.4 (50 ppm:420 ppm from your calculation). More than twice as bad as the calculation based on GWP!
The good news is that since methane has a short half life, if we can cut methane emissions that portion of the total radiative forcing will respond quickly (1-2 decades). Cutting CO2 emissions takes much longer to show effects.
[1] https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_Chapt...
That's really all there is to it, you have to eliminate fossil fuels from the system if you believe climate change is a real issue.
Of course, at this point, even that won't stop the climate from steadily warming for the rest of your life, i.e. for the next 100 years at least. The trigger has been pulled.
I advise against buying property on the coasts, in flood plains, etc.