Yes and no. It has been proven (for more than 200 years) that CO2 increases heat retention, even when present in small amounts.
It has also been proven that CO2 is not the only one doing that (methane has an effect even far greater than CO2, for the same amount).
Could you share some scientific facts that you believe to be 100% proven?
Would help to determine what your yard stick is here...
In 01988 Jacques Benveniste did some experiments which seemed to show some sort of chemical alteration of water in the presence of antibodies, though it didn't show up with the usual spectroscopic techniques: https://en.wikipedia.org/wiki/Water_memory which were published in Nature. Replication attempts were made by several teams. They failed, so Benveniste was wrong.
So I wouldn't say it's "settled science" that water is H2O. When contrary evidence pops up, chemists investigate it and find out what's wrong with it; they don't just dismiss it. That would be unscientific.
We could also quibble about the meaning of "H2O", though perhaps this is less interesting. For example, although it's only about 0.1 ppm, a part of any sample of water exists in the form of free hydronium (H3O+) and hydroxyl (OH-) ions, not H2O. Because this is an equilibrium, you can't just remove the ions to get pure H2O; they come right back. This self-ionization is responsible for significant aspects of water's behavior, including the formation of streamers that limit the storage time of water-dielectric capacitors, and the particular way acid-base chemistry works in water.
Natural water also contains about 155 ppm DOH and D2O, though this can be removed, and it's arguable that this is within the meaning of "H2O" anyway.
And the water molecules in liquid water or ice form a continuous hydrogen-bonded network, though this was not known until 01920; to some extent it's just a matter of convention rather than objective fact that we consider those bonds to be "intermolecular", making water H2O rather than an (H2O)n polymer; we consider the weaker hydrogen bonds between DNA strands to make DNA a single molecule rather than two intertwined molecules. (The polywater affair, however, posited the formation of a covalent water polymer.)
The list of things "conclusively prove[n] with 100% certainty" is vanishingly small and not a burden of proof that anyone applies to something unless they are looking for literally any reason to dismiss it out of hand. Other folks have already mentioned the difference between "carbon" in climate science parlance and "CO2" which you appear to have ignored in subsequent comments.
Assuming your question is indeed in good faith (I don't believe it is, but others may have the same question with a little more honesty) - anthropogenic climate change is a scientific theory that is the best answer to the evidence we currently have. No other theories taken seriously by the scientific community come close, and new data fits ACC models with more and more accuracy. So "no, but close enough."
Yes. Though that sounds like weasel words, the word change is missing.
It was 100% proven that human contribution is the main and most important culprit of (the current) climate change. Also that human released CO2 is the most important mechanism.
Literally the only thing the IPCC is virtually certain of is that the upper oceans warmed since 1970.
If you are pointing at studies that haven't been incorporated by the IPCC, then they are definitely subject to doubt. This isn't some deterministic problem you can repeat in a lab and science the shit out of. This is heuristics, fudges, and elbow grease type science where we do our best and then compare against the same type of work of others.
Since CO2 ppm nearly doubled since pre-industrial times then humans are responsible for nearly half of the CO2 in the atmosphere.
> Has it yet been absolutely proven 100% that a gas comprising 0.04% of Earth's atmosphere is the main culprit/control knob which controls climate(s) around the Earth?
Yes, for reasonable definitions of "proven 100%".
And Science doesn't work by "Absolutely 100% proving" anything. Bayesian statistics which underpins almost all of modern science lets us take highly educated guesses with communicable confidence in that guess. So stop looking for "100% absolute proof" to be convinced, you won't get it.
Aside from the hyperbole, pretty much yeah.
Oxygen and Nitrogen aren't important when considering the greenhouse effect since they're diatomic molecules with tighter absorption bands and don't have the broad bands in the IR so that 99.96% of the atmosphere just doesn't matter (Argon is monoatomic which is even more dismissable. H2O matters but gas-vs-droplets is complicated and took decades to sort out).
It is all the rest of it that matters. And for example, satellite measurements of the absorption bands in the atmosphere show that CO2 absorption has been widening which explains the satellite observed reduction in IR emission from the Earth which explains warming as an imbalance in the heat budget of the entire planet.
The increase in CO2 coming from humans is also established via analysing the isotopes of carbon in the CO2 in the atmosphere and we can see that it is coming from carbon that we dig up out of the ground (protected from cosmic ray radiation) vs. the CO2 that was in the atmosphere. We can also measure that only about half the carbon we emit stays in the atmosphere, while the other half does get captured by the natural carbon cycle. But that's enough to disturb the balance. Small deviations in the budget add up over time.
And these questions are very, very basic. We wouldn't be discussing climate change if scientists didn't have the answers more or less nailed down.
More information and a massive amount of references can be found at skepticalscience.com
I'd also recommend Ruddiman's undergraduate text on climate:
https://www.amazon.com/William-F-Ruddiman-Earths-Climate/dp/...
Although for $287 for the paperback, maybe rip it off on libgen. I think back when I bought the first edition it was $80 which seemed steep. Fuck science publishers, seriously.
Has it been proven that a gas comprising 0.04% of Earth's atmosphere is the main factor which affects Earth's climate(s)?
I'm asking, because 0.04% of something seems like a particularly small fraction to have such a dramatic effect on a whole planet's weather and climate. Especially in a non-linear dynamic and chaotic - hence very difficult to predict - system like Earth's weather and climate system.
In my opinion it is important to ask these questions because some extremely huge decisions ride on them.
If you have doubts about the scientific understanding of the greenhouse effect, study up on that. But continually bringing up that 0.04% makes it sound like you are clinging to that fact as a "gotcha" and avoiding learning anything more.
After having spent decades debating "climate change deniers", I came to to the realization that the greenhouse effect as thought in schools is vastly oversimplified, and essentially no lay person understands it.
This is not to say that climate change isn't real, but most people don't have the technical background to educate each other, and attempt to do so based on inaccurate models.
Having read hundreds of articles, I still don't understand how to reconcile the greenhouse model with the fact that infrared radiation only travels ~10m in the atmosphere in the bandwidth absorbed by CO2.
It's because it's a highly non-linear and chaotic system.
If earth's climate was a linear system, then indeed your gut feeling that 0.04% change is small would be warranted.
The effect of CO2 on the climate is old science, it goes back to the 19th century, it seems a little bit insincere to ask this kind of question, if you had actual interest you would have found the answer very easily already.
This is such a dubious statement you keep repeating. Is it the main one? No, probably not. If you took out all the Nitrogen, shit would break a lot faster than if you took out all the CO2. You could probably name a few others.
However it is proven that carbon emissions is the main thing affecting the the change we are observing in earth's climate. And I shouldn't have to, because you are who you are, I'm going to staple on "within reasonable amount of certainty"
Now, we could potentially make many more clouds. For instance, container ships could be required to have fuel additives or “salt lofters”that promote cloud seeding and marine cloud brightening.
Regarding the greenhouse effect of water vapor, I don't know whether what matters is the average relative humidity or the total amount of water vapor in the atmosphere. For our sake I hope it's the former.
2) 100% of what?
Edit: for those struggling with the irony, my comment is pro-questions and pro-heresy. Let's not attack people for asking questions
I'm really just asking an honest question, and it's always healthy to revisit the evidence especially when you're making a big claim like "sand does maths".
What if it's only 99.99% sure that CO2 is the reason for climate change? What about 90%? No need to act until we bring that up to 100%?
What's with the fixation on 0.04% as a number? Things can't have huge impact unless numbers are also big? I don't want to offend, but that's honestly third grade mentality.
There's surprise about small things having little impact, and then there's denial hidden as feigned curiosity. Especially when the answers are directly available from much more credible sources than random internet posters.
Compare with:
"Has it yet been absolutely proven 100% that the lead comprising 0.03% [hypothetically - for reference, this is 100000x the FDA limit] of our food intake is the main culprit/control knob which controls brain development?"
No, it actually isn't the "main" control knob. And our bodies are also complex with many feedback loops. And no study will ever reach p = 0. And it's a really small number. And yet we have made "extremely huge decisions" regarding what fuels we allow, what tests food have to undergo etc...
This is a loaded question ( https://en.wikipedia.org/wiki/Loaded_question ), since it implies that this question-asking is honest and straightforward.
On the contrary, it seems like OP is "jaqing off" ( https://rationalwiki.org/wiki/Just_asking_questions ); unless, of course, they can absolutely prove 100% that they're acting in good faith.
In contrast, OP's hunch about the climate emergency either not existing because the concentration of anthropogenic CO2 in the atmosphere is "small" (according to some unspecified criteria), and/or fixing itself due to plant growth, run counter to the consensus position of the world scientific community, and hence the burden of proof is on OP https://en.wikipedia.org/wiki/Burden_of_proof_(philosophy)
It was their choice to raise that burden to the unachievable height of '100% absolute proof' :)
Couple of questions because I'm curious...
What percentage of the 0.04% CO2 in Earth's atmosphere do humans contribute?
Has it yet been absolutely proven 100% that a gas comprising 0.04% of Earth's atmosphere is the main culprit/control knob which controls climate(s) around the Earth?