Mr. Johnson, my concern is not based on physical impossibility.  Humans could completely abandon fossil fuels and live in a manner that preserves vegetation, forest, etc.  But the commitment is lacking.  People like their comfort.  I am replanting 160 acres of timber land with my own hands and money.  I have 4 kW of money losing photovoltaic on my roof.  I see very few houses with the same.  Many sit in their chairs and complain about the forestry industry, few will go out in the awful blackberries and poison oak to clear and plant trees.  No, the lifeboat is not a realistic comparison because a life boat is a horrible environment which many are motivated to escape.  No the comparison is a group at a luxury resort enjoying all manner of good stuff being asked to give it up so as to make life sustainable on a small planet.  How many takers you expect?  How about you yourself?  Luxury is addicting.