Define efficient. We have ways that take about as much electricity to remove the CO2 from the air as we get from burning the fossil fuels today. If we got to a

Define efficient. We have ways that take about as much electricity to remove the CO2 from the air as we get from burning the fossil fuels today. If we got to a point where we have an extreme energy surplus, we could do it. But as long as we're burning fossil fuels to generate electricity, we can't really pull the CO2 out of the atmosphere more efficiently than we can put it here. It does allow a type of location arbitrage, where places that are good at producing clean energy could pull gas out of the air for places that don't have any options besides fossil fuels. You'd have to convince the places burning fossil fuels that it's worth paying the clean energy rich places for that service though. Then after you have it out of the air, storage becomes another hard issue. At the moment there's the low hanging fruit of carbon capture at plants that burn the fuels, which can be done many times more efficiently.