Earth temperature and Solar activity have always been in lock-step. Until 1975. Now they are out of step, and increasingly so. A strong argument for anthropogenic climate change *not* driven by the sun. I put the link above, but I suspect that many in the discussion did not read it. I will repost later.
And yes, methane is a more effective greenhouse gas than C02, but the CO2 is where we have leverage. If we slightly increase CO2, and it slightly increases warming at the poles which releases methane which causes huge warming, it seems very smart to attack the trigger over which we have control - CO2. It's not the whole story, but it is *something* we can do.