The award for net negative carbon removal can’t be accomplished without achieving carbon neutral first. Capturing and sequestration of air or from ocean surface is wasted time. The power plant next door is putting out 2 tons of CO2 per hour. Spending the energy to get CO2 directly from air when the atmosphere has only 6% CO2 is wasted time. By the time gigatons is achieved we will be past the point of no return. We must achieve carbon neutral to even consider carbon negative.
Technically, we are past the point of no return. The artic tundra is melting and those big holes in Siberia - that’s the methane escaping from the decaying tundra. And, just for kicks, if CO2 emission worldwide are reducing, why is the CO2 concentration in the atmosphere accellerating ? That’s because the carbon sinks are full. Want proof? Do you have a soda stream at home? Put warm tap water into it and try to carbonate it. It wont. CO2 doesn’t dissolve in warm water. Now try it with cold water. As the oceans warm, they absorb less CO2. As for ‘sucking CO2 out of the air and sticking it in the ground’ that is laughable. Gold is economical at 6 ppm - that’s 6 grams / tonne of SOLID material. To get anywhere with CO2 from air, you need a whopping great fan and to power that…you need a volcano (or a lot of geothermal energy). Now, we can spend a lot of time (which we don’t have) reinventing the wheel, or look around us. Sugar is the largest capture industry on the planet, and it is profitable. Sugar is C12H22O11 and all the C comes from the atmosphere. OK, so we rerelease it into the atmosphere, but that’s where my XPRIZE submission comes in…
The solution is superconductor motors that require 80% less energy to run compression systems to liquefy the CO2 and inject it into abandoned oil wells. These wells are between 8 to 12 thousand feet deep and the added benefit of stopping the emission of methane leaking from the 3.2 million abandoned oil wells in the US.
The solution is to get fusion working. Then we wont need to wait for superconductor motors to become commercially available because we will have unlimited power. And you are still stuck with trying to mine CO2 at 400ppm. Even flue gas is only 1200 ppm, but if we are on fusion power then you don’t have 1200ppm. And which charity is going to pay for it?