> When oil got cheap and plentiful after World War II, humans didn’t enjoy the savings. They built more cars.
In the same way cheap solar will induce massive demand for all kinds of stuff, which is still made by emitting CO2. Like, yes, your car has lower carbon footprint than ICE car. But it has some, and far from negligible. And when billions of newly minted middle class buy their own first car, it will add up, even if these are all solar powered BEVs.
Maybe it will turn into a nonproblem, idk(that happens rarely)...but our predictions and projections ough to be fixed in any case.