Sorry if I seem a little paranoid, but I have been baited by other people with the same similar approaches. Probably just gun shy. I have no interest in fighting anyone.
My takes
Yes the world does heat and cool on its own, since we have had glacial ice ages that have covered North America at times with no human help.
Burning coal, car exhaust emissions all add Co2 to the environment. I think every bit we do to help , helps slow down the process. China is doing away with coal burning power plants, putting in solar arrays and trying to reduce emissions. To just give up and say China will screw it up anyways shouldn't matter. We have to do our part. Now that the permafrost is warming up even more gases go into the atmosphere. It's like a boulder rolling down hill gaining momentum.
If you want to be a fatalist the human race will eventually screw up the environment so bad that there will be a global extinction event, and then mother nature will start over with bugs and small mammals. Who know, maybe its like the matrix and we are on version 15 of an extinction event.