ASILurker, if you’re surprised that solar capacity has been growing exponentially for decades, and doing so globally, perhaps you should ramp down your tone of extreme superiority.
In order to limit to 1.5 C (or even 2 C) without negative emissions, it’s too late. The second half of this century will have to work with that. That’s been clear a while already; RCP2.6 goes negative, and we’re above its curve already. The fast we go, the less catch-up we need later.
Currently, and this is new, we’ve hit the spot where the cheapest energy is renewables in many situations. As prices continue to fall quickly, while prices for the fossil fuel competition are expected to rise, the number of situations increases. That’s what’s fueling the worldwide exponential growth in solar and wind deployment, and it’s why it’s reasonable to expect the exponential growth to continue a while longer.