> You cannot address climate change without drastic long term reduction in human activity/population.

Of course you can. You must change activities to be carbon neutral, but you can maintain the same level of comfort you have today. More than "can maintain", you "must".

If you rely on sacrifice from the whole planetary population in order to tackle climate change, we are doomed. It will never happen, as it goes against the competitive nature of humans.

The correct path is forward: innovate, so that carbon neutral forms of energy and materials are better than carbon-emitting versions. Energy is an almost solved problem, using this vector. Let's attack materials now.