[ricardo81]

I'm not sure if there's such a thing as a 100% renewable economy, perhaps if you mean energy inputs yes, but there's always(?) going to be processes that involve emissions through 'work' as well as any emissions to create those renewable energy sources.

We can always offset. I mean, burning fossil fuels in itself is not a bad thing, but we know they're a finite resource and we simply have to offset those emissions with carbon sequestration.

[pfdietz]

Why shouldn't there be a 100% renewable economy? What energy inputs cannot even in principle be substituted for with renewable energy?

The reduction in fossil fuel usage needed to get to a climate-sustainable level is so large that any tolerable residuum could instead be handled by biomass.