The Oil Drum

That should be Impact = Population X Affluence / Technology.
Concentrating solar can reduce natural gas consumption for peaking power within a timespan of months. Solar energy could be 25% of our power production in one years time, since our hundreds of megawatts of production would turn into hundreds of gigawatts at 1000 sun levels. More practically, we will just go to 100 sun levels and only produce an additional 25 gigawatts a year each year, substituting for gas at first, then for coal, then for nuclear, as we go from photovoltaic to thermal generation while our manufacturing capacity ramps up.
Concentrating solar ramps up within months, concentrating thermal takes years. Say, ten years to ramp up to the point of replacing all natural gas, and another ten years to replacing all coal.