But your estimate is demonstrably off by at least a factor of ten thousand. The thrust of this paper is that it takes 90 tons of ancient biomass to result in 1

But your estimate is demonstrably off by at least a factor of ten thousand. The thrust of this paper is that it takes 90 tons of ancient biomass to result in 1 gallon of gasoline. This is a reduction of 30,000 to 1. This is the opposite of an efficient system. The vast majority of solar input and related carbon captured from the atmosphere by ancient plant matter is not being utilized by modern fossil fuel systems. The point of this paper is that the ancient photosynthesis to fossil fuels process is incredibly inefficient. The "400 years" isn't indicative of the energy we're consuming today -- it's indicative of the extremely low percentage of solar energy that ends up captured inside fossil fuels. We absolutely can carbon capture our way out of this. Again, you can do some pretty basic math on known sequestration techniques to disprove your conclusion.