We could get to net negative, just with carbon capture, for less than Iran is costing us. (Atmospheric carbon capture, if scaled, would cost ~ $1-2 to capture a gallon of gasoline's CO2 emissions).

Of course, that's one of the dumbest ways to get to carbon neutral. Solar and wind + batteries cost less than internal combustion engines, yet they're somehow "too expensive" and would cripple the economy.