> And here the question is: why would you want a single goal? Why 100% renewable?

Overlapping goals can coexist on varying time frames.

Setting aside nuclear (technically not "renewable", but also not carbon-based, and very energy dense) the goal is to stop releasing CO2 into the air from energy generation and return to pre-industrial levels.

This is because the surplus of CO2 generated so far has already caused clear and undeniable problems (not all of which are yet fully realized), and continued excess will only make things worse.

> What drives us should be: save where it makes sense, don't where it doesn't. Iterate every 10 years and recheck.

Solar is already economically competitive in many places and is expected to improve further.