The main problem with your assertion is that you are assuming negative consequences are only attached to the option of doing nothing.
In order to "save energy and do less damage to the environment" changes will have to be made. These changes will have negative repercussions which may, or may not outweigh the benefits. No-one knows if the changes we are expected to make will actually make any difference in the long term.
If catastrophic destruction by AGW is simply postponed by a few years / decades / centuries / millennia then it makes no real difference*, the planet is still gone**. It might be a different bunch of people that get to see the end of the world but it is still the end of the world.
But, assume that we can prevent global warming by cutting emissions etc. etc. then there are a few important factors that need to be taken into consideration:
(1) we still need power. You might want to go back to living in a cave but I don't. More importantly I like to have power in things like hospitals.
(2) we still need transport. Especially those people in hard to reach places
(3) research focussed into reducing emissions will necessarily deprive research from other areas, arguably including healthcare / disease prevention etc.
(4) We would all have to go Nuclear. This has its own problems, not least the atomic bomb making possibilities It would be ironic if the steps taken to save the planet allowed a fundamentalist religious nutjob to make a bomb and destroy the world.
So, if we did as the AGW doomsayers are telling us (and remember they don't actually _know_ that doing what they say will help) people will die because of it, by diseases that haven't been cured, lack of hospital care because there are fewer hospitals further away with less transport and poorer roads, through hypothermia in winter and hyperthermia in summer and many other causes.
So what number do we put on the additional deaths? 1? 100? 1000? 2 billion? 20 billion? I certainly have absolutely no idea, but surely the most important question regarding climate change is "will more people suffer and die by doing what is necessary than by doing nothing?"
*unless it is staved off until after we can all leave and go terraform someplace else. But this is not really a resolution, if it was we would be better off putting resources into space travel and planet forming rather than being green.
**Your assumption that AGW will destroy the planet is flawed. It might destroy all the higher orders of life, but in that case, once the environment stabilised evolution would just re-populate the planet with Humans 2.0 to start over again.