How much energy is require to remove a small amount of CO2 from the atmosphere?

mooneyes

1. The problem statement, all variables and given/known data

Estimate how much energy is required to remove a small amount of CO₂ from the atmosphere if we were to do a clean-up operation to take back greenhouse gas released into the atmosphere by human activity. Give the estimate in energy per molecule of CO₂. Compare this with the energy released by burning one atom of carbon to form one molecule of CO₂. Assume the concentration of CO2 in the atmosphere is 400 ppm. The heat of combustion of carbon is 30 kJg^-1

2. Relevant equations

(Carbon 12) + 2(Oxygen 16) → (Carbon dioxide)

3. The attempt at a solution

• It says to remove a small amount, so I assume this to be 1 kg.
  I then want to work out how much energy is in a CO₂ molecule.
  Then compare this to the energy in individual C and 2 O atoms.
  The difference is the energy required to remove one CO₂ molecule.
  Work out the mass of CO₂ and scale up the energy difference

This was my general train of thought but I doesn't involve either of the given quantities; the 400 ppm or the heat of combustion! Should I be using the 400 ppm as the "small amount" I want to remove? Any help is appreciated.
1. The problem statement, all variables and given/known data



2. Relevant equations



3. The attempt at a solution