In many places it makes sense to heat the earth (yes) in summer using the heat pump (using electricity from photovoltaics) so that efficiency in winter is better.

This sounds rather dismissive that anyone could have thought about this. I never looked up what effect this has either (in my defense, I'm not a user of this type of energy), but that doesn't make me conclude conservation of energy is hard to comprehend

Hacker News is always the first to think of things, because nobody else ever thinks about things or has ideas, especially not the scientists studying renewable energy.

Also. What are the effects of brining that heat up to the atmosphere?

One day humans will realize that their existence and energy use will always have an environmental impact.

Not guaranteeing I got these conversions correct, but I believe the rough estimate for the thermal energy of the Earth is on the order of 10^31 Joules.[0] while the rough estimate for human energy use is 10^20 Joules per year.[0]

So if we switched to 100% geothermal (a few orders of magnitude more than we're actually discussing using), we'd be using on the order of a hundred trillionth of the energy per year?

[0] https://physics.stackexchange.com/questions/51920/amount-of-...

[1] https://ourworldindata.org/energy-production-consumption

This also ignores that the Earth already has a flux of 50TW per year, so it's only an increase of about 40% (and even less, when you consider that intentional extraction would slow the flux of all surface area above it).

Not only that, but Earth's internal heat is being renewed constantly via things like radioactive isotopes and tidal forces.

So what happens if we slow that flux? That's spread across the globe. What's the impact if those numbers are localized?

Radioactivity and tidal forces create a fixed amount a heat and that heat dissipates at a given rate, right? So what happens if we change that rate of dissipation/extraction?

The point is, it's all handwavy. Seems familiar to just about everything we've done before - fossil fuels, plastics, PFAS...

You do know we actively use geothermal plants right now, right? It has almost no effect? Let alone compared to the effect of climate change.

The biggest concerns are specific techniques for pumping water, which (sometimes) can cause small earthquakes.

You seem to be missing the point.