Actually most climate scientists have said that about 1.5 to 2 degrees has been the result of human activity due to the industrial era over the last 200 years. If we really work hard over the next 200 years we might be able to get it to 1.5 to 2 degrees above this as we pump the last of the fossil fuels. This 3 to 4 degree difference is less than the difference between breakfast and lunch. 200 years from now they estimate that 5% of the economy will need to go to counteract the effects of this 2 degree warming. However 200 years from now our economic wealth estimated to be 450% of today but it will only seem like 430% of today with the climate adjustment. Oh no. Also in the carbon cycle long before humans were around the co2 was 5x what it is now, with minimal harmful effects. Mostly what you are saying is correct, but if human climate change is a thing, other than what I said above, it isn't a thing really. It's mostly other than humans causing climate change. Either way the best solution is to adapt to it as it changes, costing around 5% of our economic growth.