We often talk about the climate impact based on greenhouse gases, but extracting fuel from the ground and using it in exothermal processes of course also releases energy as heat.
This is mostly¹ in contrast with renewables, which make use of energy that’s not long-term contained to begin with, so would end up as heat in our atmosphere anyways.
So, my question is: Does the amount of energy released by non-renewables have any notable impact on our global temperature? Or would it easily radiate into space, if we solved the greenhouse gas problem?
¹) In the case of solar, putting up black surfaces does mean that less sunlight gets reflected, so more heat ultimately gets trapped in our atmosphere. There’s probably other such cases, too.
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Let me borrow an image to put some numbers around it:
So, in one hour, the Earth receives more energy from the sun than us humans generate in an entire year. If we took all of the energy we generated over a year (and not just the waste heat) and converted it into heat, we wouldn’t even be adding half of one percent to the system. Our direct contributions to the system are minuscule. The problem is we’re pumping out green house gasses like there’s no tomorrow. And those directly increase the amount of solar energy the Earth retains. And when we start keeping 1 or 2 more percent of that insane amount of solar energy, it adds up really, really fast.
Not that it changes things much, but pretty much that entire 163,000 TWh ends up as heat, not just the waste. Pretty much the only energy that doesn’t is light and other transmissions that get radiated into space.
Thanks.
Source for that image: https://explainingscience.org/2021/10/18/opportunities-for-solar-energy/
Humans generate 4,000 terawatt hours of electricity in a year. The sun dumps nearly that much on earth in 1 minute. That’s a 6 order of magnitude difference. So I’m going to assume that human heat generation is probably negligible.
Its not the question you asked, but Nuclear plants can raise the temperature of the bodies of water they use for cooling nuclear plants. Additionally climate change is reducing water availability needed for nuke plants which is something I don’t hear the nuclear advocates talk about when we’re facing a dryer and hotter future. We’ll have to start turning off nuclear plants right when we need them.
This is already happening occasionally in the last decade:
Lochbaum analyzes reports from the NRC showing when nuclear plants scale back generation because of warm water.
In June, nuclear plants in Georgia, South Carolina and Pennsylvania scaled back their generation multiple times because of hot temperatures warming their cooling water. The Limerick power plant on the Schuylkill River near Philadelphia has scaled back because of high temperatures frequently over the past decade, according to the reports.
The Dresden and Quad Cities plants in Illinois had to scale back because of high water temperatures multiple times over the past five years. The Duane Arnold plant in Iowa and the Monticello plant in Minnesota also reported scaling back generation because of temperatures.
Yeah, I’m from Germany and we experienced this second-hand in 2022, when lots of French reactors were either in reparation or had not enough cooling water during the drought, so France imported tons of power from us and drove up prices.
This all happened on top of inflation and the Russian conflict, so hard to say how much it actually influenced prices, but those were quite high in the end, so presumably not nothing.Without this happening, I probably wouldn’t have been acutely aware of nuclear producing much heat. Obviously, they do have those massive cooling towers and I have read before that it’s just another form of steam power, but you know, never properly thought about it.
That heat is kinda overshadowed by the giant ass ball of fusion shitting metric shit tons of energy at us.
It got a bit technical in the middle. Hit me up if you need that ELI:5.
The greenhouse gas “problem” is necessary to survive. If the greenhouse effect didn’t exist, neither would life as we know it.
The issue with combusting non-renewables is that that energy used to be sequestered away from the carbon cycle, effectively allowing for a balance without too much overall disruption (certain natural events notwithstanding).
So now, with all this stored away, not-part-of-the-carbon-cycle carbon being burned up, we’re adding more to the carbon cycle, disrupting it, and causing a new higher thermal equilibrium (which has yet to be reached due to geological time scales). Side note: water is a better greenhouse gas than methane or carbon, but it’s accounted for.
Because the greenhouse effect still exists, and we’re adding more greenhouse gasses, the greenhouse effect will not allow heat to transfer to space as easily.
With solar being “captured” by a black roof, that would be mostly negligible, as a portion of that energy will potentially radiate away during the capture process. However, with more greenhouse gasses being dumped into the atmosphere, that radiative cooling will become less viable as time goes on, as it too will stay largely captured.
We need to reduce greenhouse gas emissions, otherwise it’ll cause a runaway effect. That part might be too late.
I’m not exactly sure of the context of the question.
Electricity plants use the excess heat for district heating. It isn’t just wasted. If we could suddenly stop using coal or other combustibles for electricity production, we’d still need to produce energy for heating.
Transport is different though. Gasoline engines are highly inefficient and produces a lot of excess heat that isn’t used even when the heater is on full blast. It’s not much in comparison to power production though, so while it will be more efficient to drive and heat a car by electricity, excess heat from cars isn’t really an issue in itself. It’s the pollution that is the main issue.
Well, my thinking was that if the produced heat was not negligible, then it would be cooler (literally) to use energy for heating which is being pushed into our atmosphere already anyways, rather than actively unearthing additional energy.
As for solar panels I think the word you’re looking for is “albedo”
Off the top of my head I think it’s close to earth’s natural albedo anyway. Or even if it is a lower number and more energy/heat is absorbed it’s so negligible. Only the tiniest fraction of the earth’s surface would be/are covered in panels
Given a radiative forcing coefficient of
ln(new ppm/old ppm)/ln(2)*3.7 W/m**2I have previously calculated that for every 1kWh of electricity generated from natural gas, an additional 2.2 kWh of heat is dumped into the atmosphere due to greenhouse effect in every year thereafter (for at least 1000 years that the resulting carbon dioxide remains in the air). So while the initial numbers are similar, you have to remember that the heat you generate is a one-time release (that dissipates into space as infrared radiation), but the greenhouse effect remains around in perpetuity, accumulating from year to year. If you are consuming 1kW of fossil electricity on average, after 100 years you are still only generating 1.67kW of heat (1kW from your devices and .67kW from 60% efficient power plant), but you also get an extra 220kW of heat from accumulated greenhouse gas.I have wondered this question myself, and it does appear that the heat from the fossil/nuclear power itself is negligible over long term compared to the greenhouse effect. At least until you reach a Kardashev type I civilization level and have so many nuclear/fusion reactors that they noticeably raise the global temperature and necessitate special radiators.
