If we wanted to remove enough CO2 to get back to the preindustrial level of 280 ppm, it would take 2.39 x 10^20 joules of energy. For a reality check, that's almost as much as the world's total annual energy consumption (5.8 x 10^21 joules every year).
Isn't that over an order of magnitude difference? What am I missing? How is that "almost as much"?