The only thing that will make any difference is systemic change. It's fine to take shorter showers or turn off your PC, but a handful of companies are causing most of this. Coca-Cola should quit using plastics for instance. That would make a dent. It's not likely to happen.
The rich folks in power want us to feel like we are responsible for their mess. This has been going on for years. Turn off lights, recycle (lol), or do whatever... but feeling guilty or seeing it as actually making a difference doesn't effect a damn thing... unfortunately.
Serious question, does that make a difference if you heat your house using a thermostat anyway? The furnace should just run for less time to compensate.
I have the same question about incandescent lightbulbs that seem to have been banned in many places.
For computers with discrete GPU's this could save a lot of power!
When you aren't using lights, turn them off.