What if carbon isn't the actual problem? By this, I mean to say that humans are acting in ways that are useless to the future of the places (environment) they need to survive.
We keep hearing words like "economics", "energy", "sustainable" and "civilization as we know it" , but we don't see the words "net useful", "contributory" or even "intentional" when it comes to human leadership and plans. Only "It's the Economy of Stupid!" That's all we have been protecting.
So what if we change our sources of energy? Our species still acts as though it can take without paying the planet for our existence. Civilization (city-based extraction) is well lost.
Spoiled rotten Humanity to Mother Earth:
"Thanks for life, Mom. Here's the key to your nursing home room. The bill will go to your estate. Been nice sucking you dry."