It would save you a lot of work, and humanity a lot of death, to just accept "overshoot", when referring to population, just means the same as it means in plants, when they themselves are "Shoots", until leaves are formed, then the leaves form, and the plant moves on to growing to thousands of times the size it was as a shoot. paying back it's energy debt to the planet, which it ran up until it first formed leaves.
We just formed our first leaves in the form of the solar farms big and small, all over the planet. Now we have to start issuing our equivalent of nutrients in the plant - money, paid to all representing the energy absorbed by those leaves, in order to conduct the energy needed by all, to do our natural function of creating, reversal of entropy, which will quickly reverse the damage we've done to get to the stage of forming leaves.
That is the most natural outcome.
The death you imply has to happen, will only happen if nobody understands what we need to do next - issue the solar indexed stimulus necessary to sustain us through this next stage of human development, enabling us to pay back our energy debt owed to the planet as a species.
Failure to do that, is failure to pay back a debt that the planet can't afford to have unpaid.