> 1. Methane emissions capture heat energy in the atmosphere, and that heat energy doesn't just disappear after the methane is gone.
No, that's completely wrong. Methane does not "capture" the heat. Earth is constantly radiating energy out to the rest of the universe. What methane, CO2 and other greenhouse gases do is to change the radiation properties of the atmosphere, resulting in reflecting some of the energy back to earth. This energy ultimately gets radiated out, but more greenhouse gases means more time before it does, which, assuming constant external irradiation from sun, results in higher steady state temperature. When the methane is gone, its effect on warming is gone.
No, that's completely wrong. Methane does not "capture" the heat. Earth is constantly radiating energy out to the rest of the universe. What methane, CO2 and other greenhouse gases do is to change the radiation properties of the atmosphere, resulting in reflecting some of the energy back to earth. This energy ultimately gets radiated out, but more greenhouse gases means more time before it does, which, assuming constant external irradiation from sun, results in higher steady state temperature. When the methane is gone, its effect on warming is gone.