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Comment by imnotreallynew | Hacker News Reader

Yes, and that’s been the line of thinking taught in schools and every discussion I’ve read on this topic for at least 20 years. Yet, there never seems to be any concrete proof that heating is being caused by excess energy being trapped inside the atmosphere because “emissions”. Again, it’s all very hand wavy.

I’m not saying that’s NOT the method of action, it totally could be, but I would think there would be more evidence nowadays compared to 20 years ago but there doesn’t seem to be. Everyone just parrots everyone else.

I’m just thinking of Occam’s razor. Perhaps the planet is getting hotter because were just producing a fuckload of heat. It doesn’t need to be anywhere near the energy the planet captures from the sun. But day after day, over decades, surely the minuscule amount of heat being generated by activity on the surface has SOME cumulative effect. Or maybe not, i dont know.

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Your top level comment got flagged but:

some napkin math suggests the additional heat can’t solely be from those sources.

According to https://www.climate.gov/news-features/understanding-climate/...

The ocean gained heat at a rate of 0.83 watts per square meter from 1993-2022.

The same article also says there are more than 360 million square kilometers.

This gives us 0.83 * 1e6 * 360e6 = 2.988e+14 watts heating in the ocean in that time period.

A watt of electricity ends up becoming a watt of heat, and according to https://www.iea.org/reports/electricity-information-overview... the world used 22,000 TWh in 2022. Converted to power, thats 22e3 * 1e12 / 24 / 365 = 2.5e12 watts.

It’s not right to use power here and energy should be used instead because that wattage will be lower each previous year, but, even at that peak, it’s not enough (by two orders of magnitude) to account for even just the ocean warming, let alone land or atmospheric heating.

The mechanism for CO2 trapping heat is well understood: https://youtu.be/sTvqIijqvTg?si=M_5uZwjNCThm3swH

Using total energy consumption (not just electricity) and redoing the calculation using entire incident solar flux, I get that they are within a factor of 4 of each other. I agree that the sun currently dominates and the co2 capture is the dominant mechanism. It's also interesting that our consumption is so close to the same order of magnitude. It suggests that if we were to heavily invest in e.g. nuclear to solve our carbon issue that the heat alone would be on the same scale of excess energy and heating would continue. It also says that for solar to solve the problem we would need to cover something like 5-10% of the land mass in solar cells!

> But day after day, over decades, surely the minuscule amount of heat being generated by activity on the surface has SOME cumulative effect. Or maybe not, i dont know.

What if you apply the same logic to the sun? Shouldn't we be getting hotter and hotter every day from the cumulative heat from the sun until we all cook? The reason we don't is that the earth is constantly radiating heat out into space. [1]

This is connected to why carbon dioxide is the primary driver of the current warming trend: it absorbs some of the infrared that would go back into space and sends it back down again. We know that this happens, we know that carbon dioxide concentrations are increasing due to fossil fuels, we know that temperatures are increasing.

[1]: https://en.wikipedia.org/wiki/Earth%27s_energy_budget#/media...

>But day after day, over decades, surely the minuscule amount of heat being generated by activity on the surface has SOME cumulative effect.

No it doesn't, because the heat escapes out into space, so the minuscule effect is only an immediate one, not a cumulative one. That's why the greenhouse effect, being cumulative, is much stronger. If I put on an extra coat every day, it's not the heat output from my muscles in putting the coats on that is making me feel hot, it's the increasing number of coats that I'm wearing. Likewise, if I burn a tonne of coal, then that heat will have essentially disappeared overnight, but the global warming-causing CO2 will stick around in the atmosphere for another [very big number] years.

To address the cumulative effect, this is the same as the sun. There is a balance of heat radiant on the earth and then earth radiates to space. The amount coming to earth is set by the distance to the sun and how reflective the earth is. The amount leaving the earth is set by its temperature (blackbody) and how much is trapped by various mechanisms (reflecting back to the earth again). Therefore, one way to think about it is the excess energy on top of the ones accounted for, like the sun.

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