Burning ancient sunlight is expensive.
In, like, setting up petawatts of nuclear electrolysing plants that will split seawater into H2 and O2, where the gases will dilute the atmosphere enough that CO2 levels drop.
This harebrained idea is on par with those CCS projects, but has the nice side effect that the nukes can sometime later be repurposed to more useful things.
From Wikipedia:
"Misuse of watts per hour
Many compound units for various kinds of rates explicitly mention units of time to indicate a change over time. For example: miles per hour, kilometres per hour, dollars per hour. Power units, such as kW, already measure the rate of energy per unit time (kW=kJ/s). Kilowatt-hours are a product of power and time, not a rate of change of power with time.
Watts per hour (W/h) is a unit of a change of power per hour, i.e. an acceleration in the delivery of energy. It is used to measure the daily variation of demand (e.g. the slope of the duck curve), or ramp-up behavior of power plants. For example, a power plant that reaches a power output of 1 MW from 0 MW in 15 minutes has a ramp-up rate of 4 MW/h.
Other uses of terms such as watts per hour are likely to be errors."