I always wondered if anybody has calculated how much of our global heating could be attributed, if any at all, to every electronic device, server, and engine outputting heat as a byproduct.

▲

hetspookjee 2 days ago | parent | next [-]

I have the feeling that particular energy output does not so much, really. For example this plant in the image is about 700x400m and when multiplied with the suns peak output you already get a potential energy of 280MW. And this site almost triples that. The sun shines practically everywhere, though.

Humans produce about 20TW globally at this time (ChatGPT), while the sun adds about 174000TW of energy to the earth.

I guess you could argue that our waste heat does something, but I think the greenhouse gases that trap this enormous energy more effectively have a far bigger effect.

	▲	dehrmann 2 days ago \| parent [-]
		I think that works out to 0.01%? There's some hand-waving around solar radiation in the atmosphere vs. on the surface and double counting some that goes to solar power, but the number looks smaller than the variation in solar output over the solar cycle.

▲

csomar 2 days ago | parent | prev | next [-]

Negligible, almost invisible. Now the emissions (CO2) coming from the gas/oil/coal energy generation so you can run your device in the first place, that's very high.

▲

quickthrowman a day ago | parent | prev | next [-]

It’s 0%. Solar radiation is about 1.4kW per square meter.

We use a fraction of the sun’s total energy output each year, orders of magnitude more energy are in sunlight radiating onto the Earth than in the heat rejected from buildings with air conditioning.

▲

TGower 2 days ago | parent | prev [-]

I did a quick alalysis and it actually matched the ~1.5 degree celcius rise pretty accurately. It required a bunch of incorrect simplifying assumptions, but it was still interesting how close it comes.

Estimated energy production from all combustion and nuclear from the industrial revolution onwards, assumed that heat was dumped into the atmosphere evenly at once, calculate temperature rise based on atmosphere makeup. Ignores the impact of some of that heat getting sinked into the ground and ocean, and the increased thermal radiation out to space over that period. In general, heat flows from the ground and ocean into the atmosphere instead of the other way around, and the rise in thermal radiation isn't that large.

On the other hand, this isn't something that the smart professionals ever talk about when discussing climate change, so I'm sure that the napkin math working out so close to explaining the whole effect has to be missing something.

▲

marcosdumay 2 days ago | parent [-]

Your math is completely wrong.

We use ~20 TW, while solar radiation is ~500 PW and just the heating from global warming alone is 460TW (that is, how much heat is being accumulated as increased Earth temperature).

▲

TGower 2 days ago | parent [-]

Well the math is correct, the methodology has obvious flaws some of which I pointed out. If you took all the energy that has been released by humanity burning things since the industrial revolution and dumped it into a closed system consisting of just the atmosphere, it would rise by about 1.5 C.

	▲	quickthrowman a day ago \| parent [-]
		The discussion thread (and original question) you are participating in is about heat being rejected to the atmosphere through vapor-compression refrigeration or evaporative cooling, not CO2 or emissions from combustion. Reread the top level comment. The amount of heat rejected to the atmosphere from electronic devices is negligible.