"1838: Claude Pouillet, a French physicist, attributes the natural greenhouse effect to water vapor and carbon dioxide. He concludes that any change in the amount of water vapor, such as CO2, is expected to result in climate change." (google translate).
I’ve always found climate scepticism strange, because of its emphasis on refusing to accept the connection between rising temperatures and CO2. This really seems to be the least defensible position which could be chosen. The “scepticism” is disputing really basic science which has been well understood for a long time, and it’s in that sense that calling it denial is accurate. It would be much more defensible to accept a lower level of climate sensitivity, but dispute the mechanisms which cause higher sensitivity, or possible future positive feedback effects.
Sorry to hijack, but I have been curious about this for a while and have not been able to find any references from anyone working on the climate models or who has studied the forecasting methodology in detail.
If in 50 years, we find out that the predictions made by our models had been wrong (either the measures we take to reduce CO2 don't lead to the results we expected, or the warming we see is outside of the expected ranges) - in the post-mortem of the models, what would we likely say had gone wrong?
If in 50 years, we find out that the predictions made by our models had been wrong (either the measures we take to reduce CO2 don't lead to the results we expected, or the warming we see is outside of the expected ranges) - in the post-mortem of the models, what would we likely say had gone wrong?
This has already happened. Models developed in the 1990s didn't match what happened in the 21st century. The resulting controversy is called the pause. Why did temperatures stop rising when models said they should continue? We didn't stop putting CO2 in the atmosphere after all.
For better or worse, the controversy was resolved by scientists "correcting" the historical temperature datasets to erase the pause from the record. The data was brought into line with the theory. You can go read old news stories or articles about the pause and look at the temperature graphs in them, then compare to the current, up to date temperature graphs and see that they don't match.
If you like there's a talk here by a guy who started out as a skeptic because he kept spotting errors in studies, and became a peer-reviewed, published climate scientist. He's still a skeptic about the models used to predict the future (he says he thinks the basics of climatology are sound though):
That talk is quite technical but might provide some answers to how the models could be wrong. Ultimately nothing surprising: they're based on major approximations and the underlying datasets may have issues. Go read his papers for more details.
> in the post-mortem of the models, what would we likely say had gone wrong
I think it's a really interesting question, even though on a charged topic and difficult to forecast.
Balance of feedback systems? There are so many feedback systems here, positive and negative all overlapping. Even if you are 95% sure you have each one figured out, after a little over a dozen factors that error compounds and you're at around 50/50 of getting something wrong.
Of course, could be wrong in the other direction too... that's why errors are bars not arrows.
Note: Feedback systems here are not under-studied, they're just hard to model. This isn't an example of a black swan that would devastate the discipline, if that's what you were looking for. Those might be... supervolcano? Nuclear war? Atmospheric scrubbing technology breakthrough? Even those have calculable effects. If there's some radical unpredicted shift I can't imagine it being along the lines of "water vapor and CO2 don't actually warm things," that's just too well confirmed.
Climate research is one of the most politically-infused research avenues, among the likes of nuclear and genetically modified agriculture. There is money to be made, and lost, depending on public outlook of our climate, and it has a lot of power when used to enforce political ends such as sanctions, subsidies, and could lead to such events like uprisings, occupying of countries and war.
Most likely, if climate research is found to be far off the alarming predictions made by most institutions, we'll chalk it up to political meddling/statistical fubbing and move on. If the lifestyle changes for most of the polulation are already in place by then, many will believe it was "for the best, anyway", and I'm inclined to agree with this view - our response to climate change is more important than if climate change was primarily our fault to begin with. I'm not advocating for skewing research in favor of one position or the other, but it enables a public forum of such scale that at the very least, prepares us for dealing with ever-increasing scopes of global issues that impact all life on Earth, which will come in handy when we progress to the point we're dealing with the ethics of extremely advanced technology.
Surely "what would we say had gone wrong" depends entirely on .. what actually happens? This seems like a double counterfactual that's impossible to answer in advance.
Presuming we don't lose key information (e.g. deliberate erasure of the NOAA archives), we'd treat it in the same way as the current investigation; find what changes are required to the model to make it consistent with the data.
How about the rising temperatures and the decreasing number of pirates?
There is nothing "basic" in climate science unless you assume that CO2 is the only factor.
My father has been going on about cloud coverage lately. The conspiracy being that they have a cooling effect and invalidate some liberal climate change agenda.
Cloud coverage impact on global temperature is one of the last unknowns hard for us to predict. Hence it is the last defense any serious scientist for denial
We have a clearly observed and measured rapid global warming in the last decades. So whatever mechanism might counteract global warming, it obviously allowed the rapid warming to happen and unless anyone can present a plausible model why the counteraction should get stronger than any further warming, it won't prevent further warming.
You can see that most of the time, temperature rises lead increases in CO2. This implies that rising temperature increases CO2 levels, but not necessarily the other way around.
If you zoom out even further, the correlation isn't clear anymore at all:
Lastly, what's even the big issue with changes in global temperatures? Even without humans, this planet would go in and out of ice ages on semi-regular intervals. We can't really control that. Life adapts. In the interest of our descendants, we had better develop technology to deal with a tougher climate, rather than cut down on emissions so that maybe ten or twenty generations can live with a somewhat smaller fallout of manmade climate change.
> In the interest of our descendants, we had better develop technology to deal with a tougher climate, rather than cut down on emissions
Or do both. Let's make the world less hostile to live in for billions of people, whilst also providing technology & resources for them to survive.
About your graph: historical global temperature changes are not the same as anthropomorphic global temperature changes. Past periods of high CO2 do not contradict the notion that CO2 leads to higher global temperatures. Indeed, it confirms that there is a strong relationship between the two.
There are other sources of temperature change so you can't use one indicator to prove there is no effect. What climate scientists have done is look at ALL the possible drivers of climate change and ruled out all of the natural causes as contributing to the current very sharp and ongoing rise in temperature. Everything that's left is caused by human activity.
On the right of that graph, there is a vertical red line. That's not an axis or a border, that's the recent rise in CO2 levels, and it's unprecedented. The overwhelming majority of evidence shows that human activity, mainly greenhouse gases, is causing climate change. Misrepresenting one graph does not change that.
Here is a great, low emotion description that covers the "CO2 lags temperature change". Potholer54 cites his claims, and does a lot of work to run down where claims first originated, then reads that paper instead of just citing some random web blogger or popular news article.
One of the problems cited: the temperature/CO2 graph probably came from an antarctic ice core sample ... and temperature leading/lagging there is different than in non-polar locations.
Second, the climate is a complex feedback system; there isn't one independent variable and everything else is dependent. If something forces any of the variables in the feedback system it can affect the other variables. For instance, say the artificial release of CO2 by humans results in the thawing of the arctic, releasing gigatons of methane, at which point CO2 might no longer be the primary driver. Over geologic time there are different causes for these forcings, but that doesn't mean that the current forcing (human released CO2) isn't the current problem.
He covers all of that and more, much better, in 13 minutes.
[EDIT] I forgot to address "what's even the big issue with changes in global temperatures?"
That is a supremely cavalier attitude. Nobody is saying AGW is going to kill off all life. In the long term life will recover. But in the short term we humans are going to have to deal with the consequences: displacement of millions of people through crop failures and loss of coast, disruption of economic systems, and more civil unrest. The US military is gaming out these scenarios because they believe the science, not because they are pinko tree huggers who hate freedom.
> Lastly, what's even the big issue with changes in global temperatures? Even without humans, this planet would go in and out of ice ages on semi-regular intervals. We can't really control that. Life adapts.
The issue is the rate of change, which is unprecedented. The path we're currently on will devastate ecosystems and cause a huge drop in crop production.
Thankfully climate scientists don't just eyeball a single graph. And as a matter of fact, you conflate two things, one is that we know that now industrial emission is the cause for global warming and the other is, that in the past warming has lead to the release of CO2. These are two different things, and taken together only implies a positive feedback loop.
On the second question, the problem with global warming is, that everybody talks about the weather, and all our systems are well adapted to the current climate. Concretely, there are farmers at the edge of the Sahara, who are adapted to a semi-arid conditions, and when the Sahara moves south, then they have to deal with desert conditions. Similar, when the Great Barrier Reef moves south, then there are dive centers without a reef north of the new location.
So we will have to adapt to a warmer climate anyhow, but not cutting down emissions is an entirely unforced error, it makes global warming worse, without any concrete benefit. Cutting down emissions is precisely the "smaller fallout of manmade climate change" you are arguing for.
You've missed the point. It is well known that co2 is a greenhouse gas. You can do the experiment yourself with some children using a plastic water bottle, a thermometer, and a mixture of baking soda and vinegar. We understand this physics extremely well. Denying the causal effect of co2 on warming is akin to denying the causal effect of gravity towards an apple falling from a tree.
>Lastly, what's even the big issue with changes in global temperatures? Even without humans, this planet would go in and out of ice ages on semi-regular intervals. We can't really control that. Life adapts. In the interest of our descendants, we had better develop technology to deal with a tougher climate, rather than cut down on emissions so that maybe ten or twenty generations can live with a somewhat smaller fallout of manmade climate change.
There's some old German food/nutrition researcher I read who mentioned in passing that co2 acted as a blanket in the atmosphere warming the planet. I can't remember the author or title of the book, it was something from the 1800s I was skimming from archive.org.
I remember being dumbfounded at the time and pasting the excerpt to some friends on IRC. People have known atmospheric co2 warms the planet for a very long time.
This book wasn't even about climate, it was about diet and evolution. It turns out if you want to talk about the history of evolution, you have to talk about the atmosphere and how it varied going through oxygen and carbon-rich periods.
«The existence of the greenhouse effect was argued for by Joseph Fourier in 1824. The argument and the evidence were further strengthened by Claude Pouillet in 1827 and 1838 and reasoned from experimental observations by Eunice Newton Foote in 1856. John Tyndall expanded her work in 1859 by measuring radiative properties of a wider spectrum of greenhouse gases. The effect was more fully quantified by Svante Arrhenius in 1896, who made the first quantitative prediction of global warming due to a hypothetical doubling of atmospheric carbon dioxide. However, the term "greenhouse" was not used to refer to this effect by any of these scientists; the term was first used in this way by Nils Gustaf Ekholm in 1901.»
Maybe it was a common way of thinking about atmosphere back then.
I remember while reading up on the history of climate science, that Fourier found that the planet should be markedly colder than it is, purely from physics. Then calling atmosphere a blanket that keeps it warm. That must have been in the early 1800s.
So thought was moving in the right direction long ago.
"An atmosphere of [carbon dioxide] would give to our earth a high temperature; and if as some suppose, at one period of its history the air had mixed with it a larger proportion than at present, an increased temperature…must have necessarily resulted."
One may suppose, too, that a healthy smattering of works by the great Edgar Allen Poe might come in handy, disregarding, of course, their largely unscientific nature; furthermore, if one wishes to write in such a fashion, one must devote oneself to the cause of attractive semicolon usage... a largely forgotten art in these modern times.
In the Norwegian engineer paper (TU) from 1960 the main discussions of their time was that they had to get away from burning trees as energy source and use oil/coal or water fall to get the energy to supply the industry.
Lot of talks about deforestation with examples that we have not recovered from today (example Røros).
One of the tragedies of our failure to tackle GHG emissions is that now reasonable pathways to stay under 2C of warming require massive negative carbon sequestration after 2040, and at the moment the only way to do that is burning wood and capturing the CO2 emissions. The volume of wood which will have to be burnt each year is more than the volume of all international shipping. That is going to mean covering huge areas of land in industrial plantations which will probably damage wildlife further. Because we’ve delayed action, we’re entering into the teeth of a dilemma which will drive further mass extinctions whatever we do, either remove habitat for wood production for negative carbon, or accept high levels of warming.
Why does sequestration involve burning wood? Isn't it easier to leave the carbon in wood form and build e.g furniture, buildings, structures out of wood, and leave the carbon there?
I have to admit, not working at a startup or FAANG-scale company, I'm amazed to see the place I work mentioned, even just as a note, on here. Fun little double-take!
My (12 minute long) KubeCon + CloudNativeCon keynote in Barcelona this year used Foote's discovery of global warming as an example of simultaneous invention, and compared it to the creation of over a dozen container orchestrators other than Kubernetes.
Readit News
sources: https://jancovici.com/changement-climatique/croire-les-scien... https://en.wikipedia.org/wiki/Greenhouse_effect
"1838: Claude Pouillet, a French physicist, attributes the natural greenhouse effect to water vapor and carbon dioxide. He concludes that any change in the amount of water vapor, such as CO2, is expected to result in climate change." (google translate).
edit: I think it was this paper https://gallica.bnf.fr/ark:/12148/bpt6k95017r/f1.image.r=Pou... but I have not checked (cannot Ctrl-F).
If in 50 years, we find out that the predictions made by our models had been wrong (either the measures we take to reduce CO2 don't lead to the results we expected, or the warming we see is outside of the expected ranges) - in the post-mortem of the models, what would we likely say had gone wrong?
This has already happened. Models developed in the 1990s didn't match what happened in the 21st century. The resulting controversy is called the pause. Why did temperatures stop rising when models said they should continue? We didn't stop putting CO2 in the atmosphere after all.
For better or worse, the controversy was resolved by scientists "correcting" the historical temperature datasets to erase the pause from the record. The data was brought into line with the theory. You can go read old news stories or articles about the pause and look at the temperature graphs in them, then compare to the current, up to date temperature graphs and see that they don't match.
If you like there's a talk here by a guy who started out as a skeptic because he kept spotting errors in studies, and became a peer-reviewed, published climate scientist. He's still a skeptic about the models used to predict the future (he says he thinks the basics of climatology are sound though):
https://www.nicholaslewis.org/wp-content/uploads/2019/09/Lew...
That talk is quite technical but might provide some answers to how the models could be wrong. Ultimately nothing surprising: they're based on major approximations and the underlying datasets may have issues. Go read his papers for more details.
I think it's a really interesting question, even though on a charged topic and difficult to forecast.
Balance of feedback systems? There are so many feedback systems here, positive and negative all overlapping. Even if you are 95% sure you have each one figured out, after a little over a dozen factors that error compounds and you're at around 50/50 of getting something wrong.
Of course, could be wrong in the other direction too... that's why errors are bars not arrows.
Note: Feedback systems here are not under-studied, they're just hard to model. This isn't an example of a black swan that would devastate the discipline, if that's what you were looking for. Those might be... supervolcano? Nuclear war? Atmospheric scrubbing technology breakthrough? Even those have calculable effects. If there's some radical unpredicted shift I can't imagine it being along the lines of "water vapor and CO2 don't actually warm things," that's just too well confirmed.
Most likely, if climate research is found to be far off the alarming predictions made by most institutions, we'll chalk it up to political meddling/statistical fubbing and move on. If the lifestyle changes for most of the polulation are already in place by then, many will believe it was "for the best, anyway", and I'm inclined to agree with this view - our response to climate change is more important than if climate change was primarily our fault to begin with. I'm not advocating for skewing research in favor of one position or the other, but it enables a public forum of such scale that at the very least, prepares us for dealing with ever-increasing scopes of global issues that impact all life on Earth, which will come in handy when we progress to the point we're dealing with the ethics of extremely advanced technology.
Presuming we don't lose key information (e.g. deliberate erasure of the NOAA archives), we'd treat it in the same way as the current investigation; find what changes are required to the model to make it consistent with the data.
https://isccp.giss.nasa.gov/role.html#COMP_MODS
The connection isn't disputed, the causality is. Look at this graph:
https://totheleftofcentre.files.wordpress.com/2012/11/400000...
You can see that most of the time, temperature rises lead increases in CO2. This implies that rising temperature increases CO2 levels, but not necessarily the other way around.
If you zoom out even further, the correlation isn't clear anymore at all:
https://pbs.twimg.com/media/Cx5-osJUkAAPkF8.jpg
Lastly, what's even the big issue with changes in global temperatures? Even without humans, this planet would go in and out of ice ages on semi-regular intervals. We can't really control that. Life adapts. In the interest of our descendants, we had better develop technology to deal with a tougher climate, rather than cut down on emissions so that maybe ten or twenty generations can live with a somewhat smaller fallout of manmade climate change.
Or do both. Let's make the world less hostile to live in for billions of people, whilst also providing technology & resources for them to survive.
About your graph: historical global temperature changes are not the same as anthropomorphic global temperature changes. Past periods of high CO2 do not contradict the notion that CO2 leads to higher global temperatures. Indeed, it confirms that there is a strong relationship between the two.
There are other sources of temperature change so you can't use one indicator to prove there is no effect. What climate scientists have done is look at ALL the possible drivers of climate change and ruled out all of the natural causes as contributing to the current very sharp and ongoing rise in temperature. Everything that's left is caused by human activity.
On the right of that graph, there is a vertical red line. That's not an axis or a border, that's the recent rise in CO2 levels, and it's unprecedented. The overwhelming majority of evidence shows that human activity, mainly greenhouse gases, is causing climate change. Misrepresenting one graph does not change that.
https://www.youtube.com/watch?v=zQ3PzYU1N7A
One of the problems cited: the temperature/CO2 graph probably came from an antarctic ice core sample ... and temperature leading/lagging there is different than in non-polar locations.
Second, the climate is a complex feedback system; there isn't one independent variable and everything else is dependent. If something forces any of the variables in the feedback system it can affect the other variables. For instance, say the artificial release of CO2 by humans results in the thawing of the arctic, releasing gigatons of methane, at which point CO2 might no longer be the primary driver. Over geologic time there are different causes for these forcings, but that doesn't mean that the current forcing (human released CO2) isn't the current problem.
He covers all of that and more, much better, in 13 minutes.
[EDIT] I forgot to address "what's even the big issue with changes in global temperatures?"
That is a supremely cavalier attitude. Nobody is saying AGW is going to kill off all life. In the long term life will recover. But in the short term we humans are going to have to deal with the consequences: displacement of millions of people through crop failures and loss of coast, disruption of economic systems, and more civil unrest. The US military is gaming out these scenarios because they believe the science, not because they are pinko tree huggers who hate freedom.
The issue is the rate of change, which is unprecedented. The path we're currently on will devastate ecosystems and cause a huge drop in crop production.
On the second question, the problem with global warming is, that everybody talks about the weather, and all our systems are well adapted to the current climate. Concretely, there are farmers at the edge of the Sahara, who are adapted to a semi-arid conditions, and when the Sahara moves south, then they have to deal with desert conditions. Similar, when the Great Barrier Reef moves south, then there are dive centers without a reef north of the new location.
So we will have to adapt to a warmer climate anyhow, but not cutting down emissions is an entirely unforced error, it makes global warming worse, without any concrete benefit. Cutting down emissions is precisely the "smaller fallout of manmade climate change" you are arguing for.
False dichotomy. Why not do both?
Deleted Comment
I remember being dumbfounded at the time and pasting the excerpt to some friends on IRC. People have known atmospheric co2 warms the planet for a very long time.
This book wasn't even about climate, it was about diet and evolution. It turns out if you want to talk about the history of evolution, you have to talk about the atmosphere and how it varied going through oxygen and carbon-rich periods.
«The existence of the greenhouse effect was argued for by Joseph Fourier in 1824. The argument and the evidence were further strengthened by Claude Pouillet in 1827 and 1838 and reasoned from experimental observations by Eunice Newton Foote in 1856. John Tyndall expanded her work in 1859 by measuring radiative properties of a wider spectrum of greenhouse gases. The effect was more fully quantified by Svante Arrhenius in 1896, who made the first quantitative prediction of global warming due to a hypothetical doubling of atmospheric carbon dioxide. However, the term "greenhouse" was not used to refer to this effect by any of these scientists; the term was first used in this way by Nils Gustaf Ekholm in 1901.»
I remember while reading up on the history of climate science, that Fourier found that the planet should be markedly colder than it is, purely from physics. Then calling atmosphere a blanket that keeps it warm. That must have been in the early 1800s.
So thought was moving in the right direction long ago.
https://www.theguardian.com/environment/earth-insight/2013/j...
"An atmosphere of [carbon dioxide] would give to our earth a high temperature; and if as some suppose, at one period of its history the air had mixed with it a larger proportion than at present, an increased temperature…must have necessarily resulted."
https://archive.org/details/mobot31753002152491/page/382
Lot of talks about deforestation with examples that we have not recovered from today (example Røros).
https://www.youtube.com/watch?v=lmGFgZ889kYhttps://docs.google.com/presentation/d/1YkvOgnnbTqWIzQnyaUUp...