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A man who linked CO2 to climate change in 1895 (cloverly.com)
103 points by stevemillburg 2471 days ago
9 comments

Interesting quote from his Wikipedia page:

In 1884, based on this work, he submitted a 150-page dissertation on electrolytic conductivity to Uppsala for the doctorate. It did not impress the professors, among whom was Cleve, and he received a fourth-class degree, but upon his defense it was reclassified as third-class. Later, extensions of this very work would earn him the 1903 Nobel Prize in Chemistry.[5]

Arrhenius put forth 56 theses in his 1884 dissertation, most of which would still be accepted today unchanged or with minor modifications.

As someone who is just finishing their PhD, the above keeps me humble!

The president of the US received a very convincing and thorough report about climate change on 1965.[1]

We've known for a very long time but humanity is not taking the issue seriously because we are idiots (collectively speaking). Just yesterday someone in congress asked Greta Thunberg "Why should we listen to science?" [2]

[1] https://www.documentcloud.org/documents/3227654-PSAC-1965-Re...

[2] https://twitter.com/Jumpsteady/status/1174407565876310016

You just created fake news. You took the context, the facial expression and the exact wording out of that quote and ignored it. When I listened to EXACTLY what he said and watched EXACTLY how he said, it doesn't look like he's suggesting we shouldn't listen to the science, it doesn't look like he doesn't know why we should listen to the science.

The nuance of the way he said what he said is important. The guy could still be a complete idiot, I don't know him, but you seem to have not been too honest with your quote.

He's asking the girl to expand upon why it is SO important to listen to the science, it almost sounds like an exploratory question rather than him trying to say we should not listen to the science.

I ask questions at work that test basic assumptions all the time because when someone says something, they may not mean it the way you think they mean it.

My point is not that the guy was an idiot for asking the question or if he was helping Greta in her argument. My point is that such question should not even need to be asked in 2019.
Looks like I misunderstood your point - thanks for clearing it up.
No worries, my writing wasn't great to being with :P
Perhaps we should come up with a convincing answer to that question, rather be unprepared in the moment and the act indignant after the fact.

Here, I'll start:

- Science gave us antibiotics a hundred years ago, savings hundreds of millions from certain death since then. Now would be a good time to listen to science again, or we will be facing a catastrophe of biblical proportions in the next hundred years.

Please add your ideas in the comments.

Anything that runs on electricity, the internet, wifi, computers, fiber optics, lasers, etc. Not only we use those things every day that come from science, but most are oblivious to the gigantic infrastructure that powers a single Google search.

> or we will be facing a catastrophe of biblical proportions in the next hundred years

Probably much sooner than that.

It's more complicated than that. I'd say the problem is not even scientific facts, but entirely political. The conclusions from my observations are:

1. Many ordinary people around the world only cares about living a better life, they do not care, or even are hostile to the welfare of the people faraway. If a policy inevitably affects them personally, many would boycott all actual policies and refuse the take any responsibility, e.g. "they are taking away our X", X can be an incandescent lightbulb, a car, a job, or the national economy.

You can argue how an incandescent lightbulb have better overall environmental records in its entire lifecycle, it's a matter subjected to objective data and their interpretation, but it's not what I meant - People often react strongly without doing any evaluation. Last time, I saw a post about how eBay banned shipping vacuum tubes because they don't want to spend time distinguishing the restricted mercury rectifiers and unrestricted tubes, a bad decision for the buyers. The posters in the comment section literally replied something like, "the evil liberals are banning vacuum tubes! The 100% of the RoHS regulations is bullshit!"

If such things can trigger strong reactions among a group of people, imagine what would happen if one wants to implement a policy, for, e.g. refugee settlement, or climate.

The fact that the privileges elites are not affected and not accountable by a policy makes the issue worse. First it strengthens the People vs. Establishment image that can be exploited by propagandists, Second, not being affected personally encourages bad policies or bad executions.

2. The political establishment has lost all credibility to many people. What is the reason for people to believe you when you have a government machine that has a long records of manipulating politics against foreign nations, conducting unethical human experiments, publishing media propaganda, ignoring the Constitute by setting up military base [0] in Guantanamo, establishing mass surveillance systems all over the world, and often acts in favor of private interests and other wrongdoings?

To many people, it means they would distrust the establishment entirely. If the governments spent millions of dollars on vaccination across the world, backed by WTO, to many people, why can't it be another huge conspiracy, e.g. mind control? Even if the establishment says "1 + 1 = 2", some people would see it as another huge conspiracy going on. Don't forget what I said before: You can argue rationally and even make good arguments, but people often react strongly without doing any evaluation.

And now the establishment is telling you that the global climate is in crisis and strong international efforts must be made globally. To many people, it instantly means an authoritarian or totalitarian "New World Order". It is backed by evidences from scientific findings, that are not intuitive, and not easily verified from personal experience, it would only make the people more suspicious. (Remember, in the 1920s, some high-profile physicists denied the existence of molecules, mainly because there was no "intuitive" way to see it yet. And ball lightning was not accepted until the 1970s. My point is that even the best people on evaluating evidence can reject something simply because it's not intuitive enough)

Also, "often acts in favor of private interests" is a bullet point. There are genuinely a lot of money to be made, a lot of interest to be gained, in the attempt of curbing climate change. It's entirely persuasive that a climate policy can be exploited in many malicious ways, and I'm sure at least one major corruption is not uncovered yet. Even if there isn't a huge conspiracy, smaller ones are bad enough, for example, the new-energy industry in China has a lot of bad actors, some of them only do it to get some subsidies, and others totally ignore the environmental regulations and creates highly toxic semiconductors waste, only to sell cheap solar panels.

Also, the hypocrisy of some elites - they are supposed to hold more responsibility over social issues, but some are actually the people who want to use the platform for personal benefits.

All of these don't do any good for PR. And not be mention that all of these can be weaponized by propagandists for different agendas, especially in the Internet age when information is readily available.

Finally, because of Observation No.1, "Many ordinary people do not care, or even are hostile to the welfare of the people faraway", even the "best" politicians selected by the people are likely to put the interest of one's nation above everything.

[0] Ironically, also because of Observation No.1, "Many ordinary people do not care, or even are hostile to the welfare of the people faraway", quite a few people think their government must be allowed to ignore the Constitution and continue the torture at Guantanamo.

3. Most subjects of science are not intuitive. What is being written in popular science and most textbooks is merely a caricature of the subject, far from the full picture, but is considered "correct enough" to be a useful mental model (or physical model) for public consumption. For a simple example, an electric circuit is inherently an electromagnetic phenomenon, yet the fairy tale of "the flow of electron" is commonly used, it's an incomplete and flawed model even at DC. We use it because most people, myself included, are incapable of thinking the physical picture of vector calculus and solve PDE mentally, let alone Quantum Field Theory, not to mention the "truth" is only sometimes relevant and useful.

Thus, if someone wants to engage in denialism or create FUD, one could just write something that is largely relevant but out-of-context, and say "you are being fooled, everything you know is wrong"! I suspect many pseudoscientific subjects frequently use this technique (or fell into it).

The sensationalized scientific reporting by the media is another bad offender, when you exaggerate everything and publicized inaccurate or false facts (e.g. today's weather is hot because of global warming!), it can seriously backfire. Also, to be honest, some famous people on the subject of environment (not necessarily climate) have a tendency to be alarmists that exaggerate a potential risk due to psychological biases, want public awareness, or simply due to limited data or foresight.

All of it, only give more power to the denialism campaign.

The fact that many findings heavily require interpretation doesn't help as well. Historically, there have been some instances that an interest group downplaying the harmful effect of a certain substances, highly-respected institutions creating false and unrepeatable results for power or fame, etc. So, in the eye of a suspicious citizen, the entire body of search on climate science is a huge lie. For example, the Climate Gate scandal is largely about the internal power struggle of a dozen of researchers within a institution, but many people reinterpret it and see it as the "evidence" that the entire climate science is a huge lie.

* So, what is the end-game? I suspect...

1. The result would be serious, a lot of people and places will suffer, but not as bad as the "the end of the world as we know it" painted by some sensationalized media in popular culture.

2. Superpowers and their citizens refuse to take any responsibility. Just like how Gulf War is broadcasted on TV, as long as they are doing well, it doesn't matter.

3. It's possible that the internal political corruptions do more harm than good and don't solve any real issues, but I hope not.

Currently, my belief is:

1. A huge amount of funding should go to carbon extraction projects, maybe allow private fundings. It might be the projects that would face the least public resistance. But thinking again, maybe it's not a good idea, as some people may call it the evil climate control system by the globalists that actually manufactures climate changes and must be stopped (just like how AIDS/HIV deniers said the treatment itself is the cause). Its cost-effectiveness and energy efficiency is also doubtful. I'm not sure...

2. Go nuclear. I'd love to see more AP1000 reactors. But thinking again, I'm not sure, maybe it's not a good idea. Although technically the system is sound, but the political resistance, strong pressure on safety, and mismanagement creates a lot of additional costs and safety risks. Not to mention the resistance of deep underground nuclear waste disposal repository is even higher, despite the fact that there are already thousands buckets of nuclear waste waiting for proper disposal, and without a repository, the risks for the environment is much more higher.

You nailed down the issues that surround the topic of climate change very well. I wish there were more people that would consider the points you mentioned.

About the proposed actions to take: I think we need to bet even more heavily on nuclear fusion. It seems to be the only thing that could make carbon extraction sting less.

> nuclear fusion.

Fully agree.

But the meme of nuclear fusion has been around for nearly 50 years, yet nowhere close for practical utilization due to a lot of unseen technical problems.

I can only hope that we'll be a bit more lucky this time. And that the projects won't be ruined due to political struggles.

While I would totally love to see nuclear fusion be an option, I am afraid the timeline simply does not fit the challenge. Realistically, we won't be able to have nuclear fusion production-ready under less than 20 years, and most probably ~40 years.

If we do nothing in the next 20 years, it's not 2 degrees we are looking at, but 4+ degrees. The difference will be millions vs billions of deaths.

Wasn't the issue with incandescent lightbulbs more that they were (at least for a time) not as long lasting as their older counterparts, or that they'd generate less light? In that sense, people were more interested in a better product on a quality level than they were on the eco credentials of said product.

And that sort of thinking applies in a lot of other fields too, and often explains why products which are bad for privacy, not open source, centralised, walled gardens, seemingly poorly coded, etc do well. Because for most people, privacy is seen as less important than good UX/UI design and ease of use.

That's one of the big problems both the environmentalist and open source communities have to deal with; often their alternatives are (at the moment) worse for the average user/consumer, and they're not gonna sacrifice quality/ease of use/whatever over some philosophical message.

To bad you core premise is incorrect. CO2 is not the driver of global temperature changes. If it was then ice core samples would show this. The ice cores show something completely different. The ice core data shows that CO2 levels respond to temperature changes. So temperatures go up and then hundreds of years later CO2 levels go up. Temperatures go down and then hundreds of years later CO2 levels go down.

What does drive global temperatures then? It is that huge ball of gas and fire in the sky commonly called the Sun.

So other then your core assumption being wrong your write up sounds interesting.

Citations very much needed...
First, this phenomenon is well known, and it's easy to find citations if you look at the raw data [0]. BTW, the cause of the periodic change in temperature is believed to be the periodic variation of Earth orbital eccentricity, obliquity and precession [1][2], which causes the Earth to receive more or less solar radiation.

> So temperatures go up and then hundreds of years later CO2 levels go up.

> CO2 is not the driver of global temperature changes.

Next, OP's argument is not a a good one. If you know p->q, it doesn't imply q->!p. Thus I reject OP's argument as invalid, unless more information can be added to improve the argument. In fact, q->p is entirely possible. It's how an oscillator circuit works.

And here's an interesting case: Perhaps the planet Earth is more similar to an electronic circuit than most people think. Although the idea of orbit variation can explain a lot of things, including the δ¹⁸O time sequence (an indicator of temperature) obtained from the ice core records, but some serious issues remain unsolved. If you convert the δ¹⁸O time series into the frequency domain via FFT (i.e. putting it into a "spectrum analyzer"), you expect to see a 413,000 years cycle spike which is the periodic change of Earth's eccentricity. However, this is not detected. There are many hypotheses, but the most interesting one is: perhaps Earth's climate is a nonlinear system worked like a frequency modulator. It transforms some AM "carrier" signals, such as the 413,000 years cycle, with astronomical information, to a FM signal in the δ¹⁸O time sequence. This paper attempts to demodulate it with limited success [3].

See? The climate of Earth is a complex system with a myriad of positive and negative feedback mechanisms that are still not fully understood. So if the OP wants to claim that CO2 is not important to the global temperature, he should attack the climate models instead (I really hope the model is wrong and the reality is much brighter), not presenting oversimplified statements.

It's not worth debating the issue further, per Guidelines,

> Please don't use Hacker News for political or ideological battle.

I shared the possibility that the Earth creates a FM signal that contains astronomical information, since it inspires intellectual curiosity, which is what the site exists for.

[0] https://en.wikipedia.org/wiki/File:Vostok_420ky_4curves_inso...

[1] https://en.wikipedia.org/wiki/Climate_change_feedback

[2] https://en.wikipedia.org/wiki/Milankovitch_cycles

[3] https://web.archive.org/web/20091211025437/http://www.geolab...

Arrhenius' descendant, Greta Thunberg, is leading a worldwide effort to keep global warming under 1.5 degrees. She has been nominated for the Nobel Peace Prize as well. Maybe there will be 2 Nobels in the family.
>1.5 degrees

I was under the impression that there was worldwide consensus that we will pass 1.5 -- that it's too late to realistically prevent that. More, that if you count from the late 19th and early 20th century averages we've already passed 1.5.

The number isn't that relevant, whether its 1.5 or 2C. What is relevant, that we can limit the temperature raise only if we strongly stop on the breaks with respect to CO2 emissions. If we don't do that, we will have quite different and much more unpleaseant numbers.
From what I've read, stomping on the breaks with respect to CO2 emissions would very quickly, and very dramatically increase global average temperature due to reduced aerosol masking.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/201...

Even if this was the case, and even if there was no realistic workaround to it (the article you linked mentions aerosol emission mitigation), this will happen at some point. Would you rather this happens now, or when the world has warmed 5 degrees already?
I wonder if anyone's estimated the relationship between global change in temperature and change in QUALYs.
Yes please continue to give the Nobel Peace Prize to people who have actually accomplished nothing. It will surely keep the stature of said award high.
Follow the Fridays for Future climate strikes around the world today(9/20 - already starting in Australia and New Zealand) and see what she has accomplished.
Walk with me here: What has she really accomplished? Yelling at adults that they are bad for not being pre-occupied with something that they individually have zero control over?

This girl is a show-puppy for the media points. It annoys me.

Is she really related to him ? Her dad shares the same first name, Svante, but the connection to Arrhenius I've only found mentioned on troll sites.

[EDIT] I stand corrected. There is afamily link.

The Nobel Peace prize is a joke. Obama won it despite green-lighting the Afghanistan surge.
He won it BEFORE green lighting the Afghanistan surge.
Good point - the committee must be horrible at judging people. Obama had essentially no foreign policy accomplishments at the time that they awarded him, suggesting they gave it out simply as tacit disapproval of Bush.
If the entire prize is a joke, it'd make sense if you could point to patterns rather than one anomaly.
Even more recently it’s likely that Aung San Suu Kyi will be held accountable for crimes against humanity.

https://en.m.wikipedia.org/wiki/Nobel_Prize_controversies#Pe...

After having tried to understand what made climate change skeptics skeptical, i’ve stumbled upon this graph (This is just one link, but i’ve seen it in a lot of places) :

https://faculty.ucr.edu/~legneref/bronze/climate.htm Which gives a very weird feeling about the scale of recent temperature change.

Since the planet have known huge temperature variations in the previous thousands of years ( long before humans emitted co2), and those kind of changes seem to be extremely cyclical, i must say i’m starting to wonder about the current general panic and human activity blaming.

Could anyone here more knowledgeable explain what’s the counter-argument to this « it’s cyclical and huge, and human have very little thing to do with it » skeptical argument ?

It usually happens much slower than pictured in the graph, and it is believed that humans are the cause for the acceleration.

On the other hand it also isn't the end of the world as some people would have you believe.

In terms of graphs, I think this one gives a good overview of how ridiculously precipitated everything is:

https://xkcd.com/1732/

I know this graph as well, but i've always been suscipicious of the "hockey stick with multiple lines" in the end. Seems like it has been heavily critized as well :

https://wattsupwiththat.com/2016/09/20/josh-takes-on-xkcds-c...

I'm pretty sure climate change is an extremely complex subject, but i must say the "simple" data tells a story that's so different from what seems to say the majority of professionals working in the field that it makes me a bit nervous.

Sorry, I'm tuning off. A quick browse of that site raises a ridiculous amount of "propaganda" red flags.

IME when it comes to climate change, where there's smoke, there's fire. It's tempting to let yourself go and get wrapped by a nice "it'll all work out because they're either wrong or lying" narrative. I certainly wish everyone on earth who says climate change is happening was either wrong or lying.

But the truth is hard and sucks hard. I remember even five years ago seeing an image of a French meteorologist doing the weather forecast for August 2050. high 30s / low 40s everywhere. I remember this vividly, the prospect shocked me.

Here's the image I'm talking about, alongside the real french weather forecast for the last week of July 2019: https://i.redd.it/c37bdoqu4nd31.jpg

Let it sink in that things are progressing off-the-charts rapidly.

The Wizard and the Prophet, which I highly recommend, had a good section on the history of our worries about global warming. As per the article we've understood that increasing atmospheric CO2 would cause global warming for a very long time. What people thought for many decades, though, was that the CO2 we produced would mostly be absorbed by the oceans keeping the atmospheric concentration from getting too high. Figuring out that no, secondary effects would cause the oceans to re-emit that CO2 back into the atmosphere took many decades, into the 1960s I believe.
Perchance inspired by https://news.ycombinator.com/item?id=21015826 ? ;)

(Mostly linking it because it also contains a few other interesting dates around climate change. Basically, the oil knew in the 1970's that global warming would be a problem, and we've suspected it to be an issue since Arrhenius at least)

Indeed, I was recently intrigued to learn for how long the connection between anthropogenic CO2 and global warming has been suggested. Someone recently post this short "note" in a newspaper from 1912: https://i.redd.it/iay5mutszgg31.jpg
In the excellent book The Science of Life by HG Wells, GP Wells, and Julian Huxley (published in the 1930s) the authors mention that burning carbon would eventually warm the atmosphere. Interestingly, their solution to counteract this was to add mass around the equator. I don’t remember if they said why this might work, though.
I think one thing that everyone should know with respect to climate change is how simple it is to prove that increases in co2 cause increases in temperature. You can literally put some co2 and a thermometer in a bottle and watch the temperature climb. It’s not some mysterious effect.
Your claim is that if you put CO2, a relatively easy to acquire gas, into a bottle, the temperature will keep climbing? Isn't this a violation of the laws of thermodynamics.

I'm not so sure your experiment would work unless you specify various other conditions. The main reason that CO2 is a 'greenhouse gas' is that it absorbs thermal infrared light. In other words, CO2 'reflects' infrared light. This, combined with the fact that the sun is continuously heating the earth means that -- in the context of the Earth's atmosphere -- CO2 acts like a giant blanket. Only in the context of a continuously externally heated object does CO2 cause temperature increases, which is not something that is necessarily going to be simulated by 'putting CO2 into a bottle'.

However, CO2 by itself does not cause things to heat up. That is patently ridiculous, and bad science. In fact, if you fill a jar with CO2 and water gas (also a greenhouse gas), and expose it to the air on a cloudless night, and then put some kind of insulating layer between it and the earth (like some feet of straw), it'll actually freeze: https://pazhayathu.blogspot.com/2012/02/water-cooler-air-con...

https://youtu.be/Ge0jhYDcazY

This is a video demonstration. All you need is 2 bottles under the same amount of illumination with different amounts of co2.

Sorry, I should have said, under illumination, and the temperature will reach a higher equilibrium with co2 in it, but it will not rise without limit.

I guess the previous poster was assuming the experiment taking place under a suitable light source like a halogene lamp, so the effect of CO2 in the atmosphere can be reproduced.
But there's more than that... you'd also need a body of large thermal mass opposite the halogen bulb to absorb the heat, and then re radiate it, so it could bounce off the CO2.
I was thinking of a 12" glass sphere with an 11.5" black sphere inside of it. The black sphere would be the thermal mass (maybe full of water) and it would have temperature sensors all around. Then in the space between, some air. Get a baseline temperature reading. Then pump in a tiny amount of CO2. Check temperature delta.

I wonder if something like that has been done.

The amount of change you would see from that is going to be really way too small to get an accurate reading on. You'd also need to run a control experiment with heating the ball with just plain air (rather than air + extra CO2), because the glass is also going to act like a greenhouse trap anyway.
This misses the actual mechanism, which is not as simple as you might think. CO2 at ground level is actually irrelevant. What matters is CO2 at the height in the atmosphere where an infrared photon might escape to space without further interactions with the atmosphere. Increases in CO2 matter only because with more CO2 the height where a photon might escape increases, and the air is colder at this increased height, and hence the amount of energy emitted is (temporarily) less - until the overall temperature of the earth increase so that the temperature at this increased height is back to what it was before.
I don’t think it quite works that way- infrared radiation emitted from the ground can exit directly into outer space.
That's true for infrared radiation of a frequency that isn't absorbed by CO2 (or other greenhouse gasses). But a photon at a CO2 absorbtion frequency makes it only a few feet at ground level before being absorbed again.
The central dispute is not whether CO2 causes a greenhouse effect. It's that CO2 is itself a relatively weak greenhouse gas, compared to say methane (making cow farts a valid concern), and our atmosphere is already relatively saturated. The dispute is whether increases in the amount of CO2 affect other climate systems that work together to magnify the warming, and that requires computer modelling.
So far the spherical cow model of climate change that Arrhenius used, with better numbers for absorption spectra and so forth, have historically out performed computer models without disagreeing with them by a huge amount. We can hope that the most recent computer models are more accurate but we won't know quickly. You do need to model that CO2, while weak, blocks a spectrum of infrared that isn't blocked by the much more influential water vapor. But that still doesn't require looking at feedback loops, much less cell modeling.

To be honest that uncertainty about exactly how things will turn out is what makes me most concerned about global warming. Better to play Russian roulette with 6 blanks that'll ruin the hearing in one ear than with 4 blanks, one entirely empty chamber, and one actual bullet. IPCC forecasts are bad but they're not unbearably bad. The real danger is that thing'll go far worse even if we can also plausibly hope that they'll be far better.

Cow belches. But it turns out that extractors have been massively under-reporting their own belches. Anyway when the frozen polar methane bubbles (i.e., explodes) out, and the permafrost melts and decomposes, cows will be the least of our problems.
The simple example I gave can’t give you any sort of quantitative answer as far as how much the earth will warm, as you pointed out the earth climate is a complex system with many feedbacks. But it’s an easy way to see the basic principle.
Sounds simple but it would be hard to get an accurate test. I mean, it's not a basic kitchen experiment, is it? And why is it that modifying such a small part of the atmosphere (0.04%) can cause such a huge problem?
> And why is it that modifying such a small part of the atmosphere (0.04%) can cause such a huge problem?

There's a lot of energy going by, and greenhouse gasses grab a slice of it that is otherwise poorly grabbed.

Perhaps picture a small cabin, with a big hot stove, and a window open to bitter arctic night. Without the window, you soon bake. Without the stove, you soon freeze. You tweak the window's openness to change room temperature. Keeping or killing your house plants as you prefer. The window is a patchwork, some patches overlapping, some not. The part of the window along the ceiling matters a lot, as much heat is trying to escape there. Tweak a patch over an otherwise open hole there, and it matters.

Earth is doing a BBQ roll, hanging between white hot Sun, and black cryo space. The atmosphere fluffs out during the day, and contracts at night. Lunar day is 120-ish C. If aliens umbrellaed the Earth, then vacuum would come down to ground, the atmosphere become some meters of oxygen nitrogen snow. That's a large flow of energy going by. Atmospheric water absorbs, and emits back, a lot of heat - deserts get cold at night. Different molecules have different absorption spectra. CO2 absorbs well at some frequencies water doesn't. Including in thermal infrared, where ground is radiating heat to space.

As an aside, Stanford has a fun project for more efficient refrigeration. A material engineered to preferentially emit heat, thermal infrared, at frequencies less well absorbed by the atmosphere. The "holes". So just sitting on a roof, it's cooler than the roof, because it can better "see" space than the roof can.

It's a simple lab proof of carbon dioxide causing heating. We're not discussing a scale model of the sun and earth.
The same reason an extra pinch of salt can ruin a soup.
It is indeed a basic kitchen experiment.

https://youtu.be/Ge0jhYDcazY

https://youtu.be/kwtt51gvaJQ

> And why is it that modifying such a small part of the atmosphere (0.04%) can cause such a huge problem?

The modification is invisible to you, but not invisible to the photons which are supposed to leave the atmosphere and cool off the earth a bit. It it were visible to you, it would look like this:

https://www.youtube.com/watch?v=81FHVrXgzuA

Regarding the photons of thermal frequencies leaving the Earth atmosphere, or remaining there, the simplest you can imagine is a blanket: if it's cold outside the blanket keeps the heat not leaving the area under the blanket, keeping you warm. Here, the CO2 is actually a "one-way" blanket, it doesn't block the incoming radiation:

The heat coming from Sun has other frequencies as it comes than the photons blocked that would cool off the Earth.

The key is: CO2 is an ink-black "blanket" for exactly a part of the radiation that cools off the Earth. It's not too big, but big enough to make in sum that 0.8 C degree change since 1880. Or to produce even more warming in the coming years as we burn always more and we haven't managed to change that.

A little more precise:

"Energy arrives from the sun in the form of visible light and ultraviolet radiation. The Earth then emits some of this energy as infrared radiation. Greenhouse gases in the atmosphere 'capture' some of this heat, then re-emit it in all directions - including back to the Earth's surface."

(There's of course infrared radiation coming from the Sun, but the one making problem is the radiation from the Earth)

Scientific details, like absorption spectra and the measurements, are here: https://skepticalscience.com/print.php?r=35

A little simpler explanation by American Chemical Society:

https://www.acs.org/content/acs/en/climatescience/climatesci...

Or even, for kids, "meet Mr. Sunbeam" part from Futurama:

https://www.youtube.com/watch?v=0SYpUSjSgFg

It doesn't. The atmosphere is not a closed system as upper limit varies. The global temperature strongly correlates to the sun's activity and our distance from it, and nearly not at all to anything else, other than cataclysmic events such as huge volcanoes, asteroid strikes, etc.
Not true. Very short term effects correlate to solar exposure, where CO2 effects have a built-in long-term filtering that stretches out the response time, averaging out shorter fluctuations.

Temperature is increasing not because of increased insolation, but because of increased retention.

It's almost as if CO2 is a sort of "greenhouse" gas!