Triggering civil unrest and such is not really required to reduce population sizes: as we seem to be tracking ca. +3.5 C increase in average temperatures by 210

Triggering civil unrest and such is not really required to reduce population sizes: as we seem to be tracking ca. +3.5 C increase in average temperatures by 2100, the reduction in population levels will happen automatically by extinctions of animals, disease, extreme weather, flooding of coastal areas, loss in crop productivity, droughts, melting ice cover, societal unrest, and so on. Renewable energy will have a hard time winning globally unless cheap dirty stuff like coal and oil is made much more expensive through taxes or other means. There is also active resistance from the fossil fuel industry too.