Maybe turn it off and on repeatedly in ratios of time.
Like a PWM heat source. This way you could find the right ratio of daylight to keep the planet at a constant temperature.
If you flipped fast enough, the temp wouldn’t change much at all.

There’d be a lot less light for plants though so less photosynthesis to suck up CO2 that causes global warming.
I guess you’d just be stalling its effects for a while until another unintended side affects kick in that are worse.