[Rastafarian]

You seem to be forgetting about the billion or so human-made combustion engines, that are easily capable of altering the global climate in a few years.

Or about the tens of thousands of nukes, that can strip the poles of ice caps if properly deployed and again completely change the climate.

Or the probably achievable proposed projects of building solar mirrors or seeding the south oceans with iron.

One can look at the amount of energy humankind was commanding 300 years ago and now, and than extrapolate that to the next 300 years. That power would be enough to move stars around, not talking about a single planet surface fluctuations in gas pressure.