[chr1]

There is a social penalty. If you try to burn garbage in your yard your neighbours will not allow it. But the price cannot be larger than life, so when it is freezing outside and there is nothing else to burn, they won't mind the smoke, and will come to the warmth of fire instead.

Even if we stopped all unnecessary consumption, and kept only the minimum necessary for life, we would not make significant impact on climate change, because with the current number of people CO2 will still accumulate, and would become problem some time later.

If energy is clean, it simply will not cause global warming, independently of demand, but we do not even need to make it clean, we simply need to use the CO2 (e.g. by creating forests in deserts) or to use some other technology to gain fine grained control over the climate.