Yeah the scale of thermal energy contained in the earth makes this fear (prematurely cooling the earth) irrelevant. The entire global consumption of energy is less than 2% of earth's thermal heat flow from the core.
Whoops, thanks for the correction. I was looking at end-user electricity consumption so it didn't include all the losses involved.
That's staggering at first glance. So much energy!
But then, I wonder how much it would really matter if we were harvesting that energy to move objects around on earth and turn on LEDs vs letting it dissipate into space. So I'm still skeptical of the concern.
https://en.wikipedia.org/wiki/Watt#Terawatt