If the benefit of burning carbon exceeds the costs associated with burning carbon then people will burn CO2 and society will get wealthier.
If the costs exceed the benefits, then society will get wealthier simply from stopping self destructive behaviour.
Amazing right?
Except we don't charge the full cost of the negative externalities so oil companies cause a lot of damage because they are under the mistaken impression that their current extraction rates are useful to society.
The reason why we care about the negative externalities of fossil fuels is that they are most likely permanent but the benefit is temporary. So the cost benefit analysis tells us we are burning too much and this ends up harming us actually and it is just that we haven't experienced most of the harm yet.