And even if such a miracle drug did exist, if seems like the better solution is to simply lead a healthier lifestyle to begin with.
We should be pursuing fusion as if the survival of the planet depends on it…because it is likely that it does.
People can hardly be trusted with a dangerous nuclear power.
400 years to boil the oceans, but that kind of timescale means we can have 300 years of business as usual followed by using a von Neumann probe to rearrange Mercury into a Dyson swarm, at which point the Earth's temperature is under total external control because we can switch the sun off when we don't like the heat.
OK, so more like "hiding" the sun — switching it off is still possible with a Dyson swarm but I don't know how long that takes — but from the point of view of Earth it might as well be switching it off.
Starship can carry 2 per trip. Inflatable, polymer hardening, weigh-shift controlled kites gliding just beyond L1 on the solar wind. We would have to launch 3 a day indefinitely, so we would still be encouraged to sort out our CO2 situation.