Comment by brabel | Hacker News Reader

Comment by brabel | Hacker News Reader

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> So what can possibly cause warming is only the effect of the difference in temperatures between the CO2 gas and the surface.

This shows you have a complete misunderstanding of the basic physics going on.

If you have a source of radiation directly hitting a surface, some of the radiation will warm the surface by being absorbed by the surface material, but some of that radiation will be reflected back into space. When you add air on top of such surface, the air will capture both some of the direct radiation, as well as some of the reflected radiation. That's what causes extra warming of the surface compared to the situation without air. Now, air is a mix of several gases... different gases absorb very different amounts of radiation in the sunlight spectrum... what we're saying when we say methane is much more powerful as a greenhouse gas than CO2, is that methane can absorb much more radiation, which makes it warm up much more than CO2, and that heat stays around until dissipated back into space, which takes quite a long time!

Now that you understand the process at play, I hope it's obvious that your comment above is incredibly wrong on so many levels. IT's ok to be wrong, but I hope you're able to look for what's real and try to understand things better to avoid making such comments that may lead innocent people into a complete misunderstanding of the situation.

> That's what causes extra warming of the surface compared to the situation without air.

While this effect may be real, it's not what people are referring to as the "greenhouse effect". This requires the absorption and re-emission as IR. Methane and CO2 are considered greenhouse gases because they absorb thermal IR, not because they absorb reflected light from the surface.

In addition to the Wikipedia article machina_ex_deus linked, this might be a good intro: http://forecast.uchicago.edu/archer.ch4.greenhouse_gases.pdf. I'm not sure if I buy all of machina_ex_deus's conclusions, but I think his description of the effect is much closer to accurate than yours.

No, you're the one misunderstanding the physics. The reflected radiation is in a different spectrum than greenhouse gas absorption spectrum. The greenhouse effect is supposed to be about the difference in thermal radiation absorption frequencies, not sunlight absorption frequencies. You can read again about greenhouse effect to see that you misunderstood it. CO2 is the same as air in sunlight spectrum, which is the reflected radiation. Both are negligible. The entire argument rests on thermal radiation absorption, not sunlight absorption.

Do you have any background in physics at all? Seems like you don't really understand physics.

Here, wikipedia's entry:

https://en.m.wikipedia.org/wiki/Greenhouse_effect

The warm surface emits thermal radiation in IR, which is what is absorbed by greenhouse gases.

That's not your fault, their explanation is extremely misleading, like I have said.

You seem to be looking for a slightly misleading representation of what the "greenhouse effect" actually means to go on an irrelevant tangent about whether or not CO2 and methane cause global warming. If you ignore the term "greenhouse" and just think about the physical process by which the Earth's temperature changes, you will see that what I said is much more accurate than your silly interjection about what greenhouse means. I am sure you understand that the Earth is not in any sort of thermal equilibrium, but you keep saying that. It's like you just ignore the Sun, which is what drives the whole process, and only consider what would happen if you had a solid and a gas under thermal equilibrium, and then changed the gas, which is completely irrelevant to how atmospheric temperature changes depending on the contents of the atmosphere (and assuming changes in Sun radiation are neglibigle). I really think you're intentionally trying to murk the waters to troll us all.

I'd recommend watching this video if you'd like to know the more nuanced story behind climate change: https://youtu.be/oqu5DjzOBF8 I am not qualified at all to really comment on it but this did open my eyes to how confusing the entire thing is.

I know that video. The thing is, when you get to this point, it should've been pretty clear for any honest scientists that you shouldn't trust the narrative / story, you should do the full calculation, and be honest about how trustworthy the calculation is.

The picture presented is as if the story is already enough (it definitely isn't), and the shortcomings of the calculations are not important, while the truth is that the story was heavily biased, and the calculations are very important. And the calculations really are dumpster fire.

I have to agree, when money and interests like with the situation around climate change are involved its hard to do actual science, it just turns into a fucked up manipulation game.

https://en.wikipedia.org/wiki/Berkeley_Earth was funded by the Charles A. Koch Foundation, which hoped to get a contrarian result backed by real science. The study lead was a climate science skeptic at the time. It reached the same conclusion as everyone else.

Decades earlier, ExxonMobil spent millions to do its own science and came to the same conclusion. https://www.scientificamerican.com/article/exxon-knew-about-...

It's not hard to do the science. It's hard to be truthful about the results when they affect your bottom line.

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