Has anyone looked into the theory that SO2 is an "anti-greenhouse" gas and that much of the greenhouse effects of CO2 have been negated by SO2. Essentially SO2 particles stay in the air for a long time and reflects a large spectrum of light so it fails to be absorbed by land or sea/converted to infrared (infrared is primarily what the CO2 reflects).
Recently (since 2010ish but moreso since 2020 in shipping) there has been a global effort to reduce SO2 emissions (eg by installing scrubbers) which has caused the CO2 increase over the last 150 years to actually "take effect" since the SO2 is no longer negating the effects.
I stumbled upon this theory recently and it sounds compelling but am curious if better informed people could shine a light about this.
“The Intergovernmental Panel on Climate Change concludes that it is the most-researched solar geoengineering method, with high agreement that it could limit warming to below 1.5 °C”
There’s a risk it’d affect the ozone layer. But Paul Crutzen, who won the Nobel Prize for his ozone research in 95, said the sulfur plan is “the only option available to rapidly reduce temp rises and counteract other climactic effects”.
We’d also need to add shockingly little SO2 to the stratosphere. We currently emit 200m tons per year (25% is humans, rest is volcanos and other natural sources). We’d need to add an extra 100k per year.
Edit: I think one of the Microsoft co-founders was looking into it, the problems of proving it would work were political - not engineering-related.
It always strikes me as odd that the geoengineering experiment that got us into the predicament (dumping boatloads of CO2 into the atmosphere), the politics were so much easier.
That's a tiny amount, relatively. But is that "just a little more" or is it "just a little more, but in a really inconvenient and difficult to reach altitude"?
What kind of infrastructure would be required to put it where it needs to go?
> To achieve a 2 °C result, the plan would inject 6.7 teragrams (6.7 billion kg/14.8 billion lb) of sulfur dioxide per year into each pole, calling for an eye-watering total of 13.4 teragrams (29.5 billion lb) of material annually.
>The study goes on to look at logistics, finding that existing aircraft can't carry enough payload to a sufficient height to get the job done... To hit the cooling target, this project would need 125 purpose-built SAIL-43Ks, flying a total of 1,458 missions per day during the four-month injection period at each pole. These planes would take off, climb for 30 minutes, vent their entire load of sulfur dioxide within two minutes, then come back down over the following 30 minutes, and spend the next hour loading up again and refueling for the next mission.
> All sulfur oxides are nasty to breathe in, harming the lungs and causing asthma and bronchitis if inhaled regularly... It notes that the effects of teragrams of sulfur dioxide and the associated acid rain deposits are risky both to humans and to the wider ecosystem, requiring lots more research. And it expects some stratospheric heating as well.
So yeah, we could. It would be expensive (but not $trillions), and the environmental effects would be horrific.
And yet its still being proposed, because that's how desperate we are.
Delivering the SO2 directly to the stratosphere needs some new tech to be developed.
Assuming that's done, the environmental side effects should be negligible, as I understand it. The stratosphere is pretty isolated from the atmosphere we live in, and the SO2 breaks down there over 1-2 years.
Probably make more sense to launch from ground. No reason to lift entire plane into the air. The launch stations can be placed in relatively remote locationst to minimize human or natural habitat impact. Possibly place launch locaitons close to So2 mining location to limit transport Co2.
Yes, this has been studied quite a bit (but not "extensively"). I am (guardedly) a fan of managing the earth's albedo, but not on a global scale and especially not with a toxic compound like SO2. Some of the most important issues:
* It's not just SO2, but soot and other particulates that reflect sunlight, in particular IR.
* SO2 (and soot etc, for that matter) have other side effects; its not that they were eliminated for no reason. And the point of any ecological activity (not just climate intervention) is to make the environment more supportive to human life and ativity. Stratospheric SO2 advocates tend to dismiss these issues.
* solar radiation adjustment has other consequences (on agriculture, for example).
In the case of SO2 the frequencies reflected by SO2 are not all ones we want to do without -- we need some UV to get through.
* Stratospheric SO2 injection (AKA "SAI") is hard to switch off, so if we are unhappy with the results (widespread reduction in agriculture, if that's what happens) we would be waiting years, possibly decades, to get things back on track.
Solar radiation can also be managed at a more local level in the troposphere through marine cloud brightening for example, and can be done with more benign chemicals than SO2 (e.g. water), and can be switched on and off quite rapidly (days). It will use more energy and activity, but also provide greater control (in some locations on the water you may not want increased shade because of microscopic marine life).
Note I am working on removal of ambient greenhouse gas (CH4) and so am quite sensitive to the safety and consequences of intervention.
I wonder if there's a way to keep the SO2 localized to a geographic area? The best bang for the buck should be over the arctic to help with the ice loss and less reflectivity due to that.
> Has anyone looked into the theory that SO2 is an "anti-greenhouse" gas
Yes.. there is an entire section in the IPCC report dedicated to this. This is also the reason they believe there is a "missing volcanic eruption," as it would explain data anomalies in their back projections. Make of that what you will.
Yes, James Hansen. His page [1] has links to his newsletter posts, but here's a recent example that looks into the shipping emissions reductions and the role they may be playing:
FWIW, I found this book to be an extremely disappointing introduction to Neal Stephenson and an extremely disappointing exploration of Sulfur-based geoengineering. The actual geoengineering is just a vehicle for a semi-political thriller IMO.
It's not a great book, but the fact that a single billionaire could decide to change the climate with a relatively small amount of SO2 was news to me until I read this!
Contrarian opinion, but given the models have been poor at predicting the catastrophes that they typically claim, I’m hesitant to support atmospheric engineering to try and cool the planet.
Let’s not kid ourselves, global cooling is FAR worse than global warming. Ice ages are no joke.
The risk/reward bet here is that we put jussst enough SO2 to drop by X degrees. I’m just not confident enough in our computational capacity to account for all the variables that could produce unintended consequences.
Tangential, but we can’t even figure out proper programs/legislation to improve education or reduce inner city poverty.
As a person from a cold country I'm not so sure about that. It's much easier to dress up on a cold day than to cool down on a hot day. It's cheaper to warm up a house than to cool it down. There are way less diseases/viruses/insects in cold climates. Granted, the food is much harder to come by, though, unless it's maritime (cold waters are much more abundant with life than warm oceans).
And in case of global warning, if it ever gets too cold, we know what to do.
As someone who went to school for this, no. Mammals evolved to survive colder conditions. Going hotter and with higher CO2 is not going to be awesome for our biology.
Sulphur dioxide. That's the thing that caused all the acid rain that was going to be the end of all life as we know it back in the 1980s when were still concerned about global cooling, right? The same thing that made it possible to practice the moon landings just downwind of Sudbury, Ontario because all vegetation was stripped by the fallout from the big stacks at the nickle smelters?
Yeah. Pump that shit into our atmosphere. What could possibly go wrong?
"The furnaces of the world are now burning about 2,000,000,000 tons of coal a year. When this is burned, uniting with oxygen, it adds about 7,000,000,000 tons of carbon dioxide to the atmosphere yearly. This tends to make the air a more effective blanket for the earth and to raise its temperature. The effect may be considerable in a few centuries."
A plot of an absolute quantity like this should really have a zigzag line at the bottom of the y-axis indicating that it does not start at zero. Or else, it should start at zero and / or be logarithmic.
Why? I think there's some intuitive idea that something is being hidden or there's cheating in the presentation, but that doesn't have to be the case if the purpose of the plot is to illustrate relative change (and the y axis is clearly labeled).
The counter-argument is that it makes it look like CO2 has 10x'd instead of doubling, but since those values aren't calibrated in units that we can intuitively understand, it's not obviously the correct choice to start at 0.
The values below 150 have little value since we have always had CO2 except for maybe when earth was created. Look at the 800k view to get a better perspective.
That said I do feel like when people do that it is not a great practice.
When I was a physics undergrad, they drilled it into us to always choose axis limits such that they just perfectly frame all measurement points (with some reasonable padding). This way, you see the most amount of detail. Like you say, having a graph that is mostly whitespace is of little value. Axes must be labeled properly anyway, so there is nothing misleading about it. If people who don't look at the axes are misled, well, that's always going to be the case.
I think the misleading aspect in this case is that when looking at the 800k view, it seems that CO2 levels have doubled (or more) compared to previous peaks, whereas it's actually a ~30% increase. It's still a very significant increase, and should be shown accurately.
The demand that every graph should start at zero is completely absurd, probably from teachers that try to enforce random demands, nobody expect CO2 levels to go to 0 and it is better to use the full space of the screen.
I don't think 0 makes sense here. Nor does "50% lower in preindustrial times" makes sense either. The correlation between temperature and co2 exists, but the absolute values involved are not intuitive.
"The co2 level is N standard deviations out of the ordinary compared to preindustrial times" feels more useful here, but reading that requires basic statistics (which general audiences probably lacks).
It's still misleading. a naive glance would make someone think co2 levels had risen to 800% of original value, when it's only 150% of original (which is obviously still terrifying)
I disagree. Clearly the absolute amount of CO2 is more important than the relative change.
It would have much more impact and be less misleading if they started at 0.
Not starting at 0 both lets people dismiss the graph because they used the stupid not-starting-at-zero trick, and it hides the fact that CO2 concentration has increased by 50% which is insane!
For those wondering why there is zig zag in the plot after 1958. The data source changed at that date [1].
* 1000 - 1958: Historical CO2 record from the Law Dome DE08, DE08-2, and DSS ice cores
* 1958 - Today: in situ air measurements at Mauna Loa, Observatory, Hawaii.
Hawaii does month by month measurement and the seasons have vastly different CO2 levels due to plant activity. Going back further was just a rough yearly average.
The zig zags are a reasonably smooth yearly wave if you zoom into them.
It's absolutely mind blowing that we as humans were able to increase a constituent part of the atmosphere from from 0.028% to 0.04%. Written like that it looks small but, each part per million of CO2 in the atmosphere represents approximately 2.13 gigatonnes of carbon, or 7.82 gigatonnes of CO2.
I don't understand how people think Carbon Capture is a solution.
Every Gigaton of carbon is roughly equivalent to covering the entirety of Texas in ~1 millimeter of carbon.
Globally, we emit about ~13x that per year.
That's about equivalent to covering the state of Massachusetts in a foot of carbon.
Per year.
The entire planet is either the ocean, in use, desert, or already covered in forests.
~33% of the earth is desert. We'd need a decent chunk of that to get ~0% fossil fuel energy. But let's pretend we don't. We'd still need to cover all of that in several feet of carbon to capture all of our emissions.
> Every Gigaton of carbon is roughly equivalent to covering the entirety of Texas in ~3 feet of carbon
That seems high. I get a lot smaller number, but maybe I've messed up some unit conversions. I'm using:
1 ton = 10^3 kg
1 g CO2 = 12/44 g of C (C == carbon, not Celsius)
Density of C is 2.2 g/cm^3
1 Texas = 6.95x10^5 km^2
Assuming those are right and I didn't botch any conversions between metric prefixes I get this:
10^9 tons CO2 x 10^3 kg/ton x 10^3 g/kg = 10^15 g CO2
10^15 g CO2 x 12/44 g C/g CO2 = 2.7x10^14 g C
2.7x10^14 g C x 1 cm^3 C/2.2 g C = 1.2x10^14 cm^3 C
6.9x10^5 km^2/Texas x 10^10 cm^2/km^2 = 6.9x10^15 cm^2/Texas
1.2x10^14 cm^3 C / (6.9x10^15 cm^2/Texas) = 1.7x10^-2 Texas cm C
Check:
1.7x10^-2 Texas cm C x 1 km / 10^5 cm = 1.7x10^-7 Texas km C
1.7x10^-7 Texas km C x 6.9x10^5 km^2/Texas = 1.2x10^-1 km^3 C
1.17x10^-1 km^3 C x 10^15 cm^3/km^3 x 2.2 gm C/cm^3 C = 2.57x10^14 gm C
2.57 gm C x 44 gm CO2/12 gm c x 1 ton/10^6 gm = 9.4 x 10^8 ton CO2 = 0.9 gigaton CO2
PS: the above is for 1 gigaton of CO2 since that is what emissions figures usually use. But if you were just talking about after capture and extraction of carbon, multiply the above by 44/12, giving 6.2x10^-2 Texas cm C.
PPS: If we took all of the CO2 out of the atmosphere, the amount of carbon would be enough to cover to Texas to about 53 cm.
> I don't understand how people think Carbon Capture is a solution.
While the current crop of carbon capture technologies are rather inefficient and useless, once we've got more of a mastery of bioengineering, it's by far the best answer to the long term greenhouse gas problem (not without its risks though).
The tens of meters deep peatlands that cover Canada, Russia, and the rainforests of the tropics hold enough biomass to more than triple the planetary CO2 ppm if they were burned. Those peatlands only started forming 18,000 years ago when the glaciers started receding so we have hard evidence that nature is capable of sequestering mind boggling amounts of carbon very quickly. That suggests that if we engineered a system we could do it even faster. It might take us a century to develop the biotech to that point, but long term the solution is on the horizon.
If we had the political will now we could get a decent head start by industrializing seaweed, algae, and other fast growing organisms for CO2 capture.
I think that you slipped some decimal places somewhere. The most common allotrope of carbon, graphite, has a density of 2.26 metric tons per cubic meter. Texas has an area of 695,663 square kilometers. Covering Texas with a 1 meter (~3 foot) layer of graphite would consume
People think its a solution because its one tool in a toolkit. You are right capture alone won’t solve everything, but I don’t think anyone is seriously suggesting as much, and are saying instead its an important complement to other strategies.
The story in many ways is even more subtle than that -- the carbon cycle (both natural and augmented by human activity) generates ~200Gt of carbon annually, and absorbs ~200Gt of carbon. Human activity yields about 6-10Gt annually. So CO2 emissions are increased by about 3% from the natural baseline, but some of this is absorbed by natural increases in carbon sinks. We don't completely understand how the budget works out.
Funny! I read your comment in exactly the reverse way: "2.13 / 7.82 gigatonnes" sounds high. 0.28% to 0.04% sounds absolutely tiny. Maybe THAT's the right way to think about it?
And the global averaged temperature was 20 degrees warmer. Also this increase has been faster by 100 fold compared to previous increases. This is about to get very chaotic and civilization crushing.
If you can remember the Jurassic Park tagline (original movie), "an adventure 65 million years in the making", then you've got a good ballpark figure for this.
Don't think 6 million would be enough, the max temp and co2 levels of the Cretaceous was 66 million years ago, and the Cretaceous period was 145-60 million years ago.
That perioid may be a somewhat large peak in a co2 graph, making the current co2 increase look negligible. However ocean levels are also estimated to have been 50-100 meters higher than today at that period, along many other side effects.
When looking over a vast time like this with a high levels of variations and varying local maximums and minimums, linear graphs become misleading. If you were going to include the Cretaceous you would have to plot it logorithmically, but at that point the graph becomes uninteresting because every peak except the current one would be just slim lines.
Edit: I saw my dead sibling pointed to a graph which is some weird logarithmic-linear hybrid, i.e. it show three distinct timeperiods in three different scales. This is indeed a rather odd way of representing data, and I don’t think it is helpful.
Seriously!! ;) The systematic monitoring of carbon dioxide levels in the Earth's atmosphere began in the 1950s. The Mauna Loa Observatory in Hawaii, established in 1958, has been continuously monitoring atmospheric carbon dioxide levels. So anything before that, I'd take with a grain of salt and maybe extra some cayenne pepper.
What's the view on the immediate impact on elevated CO2 levels on humans? I know high indoor CO2-levels correlate with poor mental performance, but as far as I know that might just be because it also correlates with reduced O2 levels. But it seems reasonable that a 25% increase of CO2 in ambient air would do something to our health.
No problems outdoors but my worry there is that being inside can easily more than double CO2. Even with a window cracked slightly. So we're ok if we have really good ventilation. A fan makes us safe. At <300PPM we would have had far less to worry about here.
As CO2 reaches over 500PPM (this is not that far away) that doubling of CO2 levels from being indoors puts us in the cognitive impairment range. Not good.
Mauna Loa is not the only source of historic CO2 levels, though it has the oldest data. You can see all the other ones that NOAA keeps track of through their data interface [1]. Most of the data sources report very similar numbers, especially in the trendlines.
Readit News
Recently (since 2010ish but moreso since 2020 in shipping) there has been a global effort to reduce SO2 emissions (eg by installing scrubbers) which has caused the CO2 increase over the last 150 years to actually "take effect" since the SO2 is no longer negating the effects.
I stumbled upon this theory recently and it sounds compelling but am curious if better informed people could shine a light about this.
https://twitter.com/hankgreen/status/1687535525169930241
https://twitter.com/LeonSimons8/status/1688145475289931776
https://www.weforum.org/agenda/2023/07/sea-surface-temperatu...
“The Intergovernmental Panel on Climate Change concludes that it is the most-researched solar geoengineering method, with high agreement that it could limit warming to below 1.5 °C”
There’s a risk it’d affect the ozone layer. But Paul Crutzen, who won the Nobel Prize for his ozone research in 95, said the sulfur plan is “the only option available to rapidly reduce temp rises and counteract other climactic effects”.
We’d also need to add shockingly little SO2 to the stratosphere. We currently emit 200m tons per year (25% is humans, rest is volcanos and other natural sources). We’d need to add an extra 100k per year.
Edit: I think one of the Microsoft co-founders was looking into it, the problems of proving it would work were political - not engineering-related.
200M + 100k = 200.1M, and I doubt the 200M figure had 4 significant figures.
What kind of infrastructure would be required to put it where it needs to go?
> To achieve a 2 °C result, the plan would inject 6.7 teragrams (6.7 billion kg/14.8 billion lb) of sulfur dioxide per year into each pole, calling for an eye-watering total of 13.4 teragrams (29.5 billion lb) of material annually.
>The study goes on to look at logistics, finding that existing aircraft can't carry enough payload to a sufficient height to get the job done... To hit the cooling target, this project would need 125 purpose-built SAIL-43Ks, flying a total of 1,458 missions per day during the four-month injection period at each pole. These planes would take off, climb for 30 minutes, vent their entire load of sulfur dioxide within two minutes, then come back down over the following 30 minutes, and spend the next hour loading up again and refueling for the next mission.
> All sulfur oxides are nasty to breathe in, harming the lungs and causing asthma and bronchitis if inhaled regularly... It notes that the effects of teragrams of sulfur dioxide and the associated acid rain deposits are risky both to humans and to the wider ecosystem, requiring lots more research. And it expects some stratospheric heating as well.
So yeah, we could. It would be expensive (but not $trillions), and the environmental effects would be horrific.
And yet its still being proposed, because that's how desperate we are.
Why can't people use normal units. If you absolutely must use imperial units then at least use tons.
Assuming that's done, the environmental side effects should be negligible, as I understand it. The stratosphere is pretty isolated from the atmosphere we live in, and the SO2 breaks down there over 1-2 years.
* It's not just SO2, but soot and other particulates that reflect sunlight, in particular IR.
* SO2 (and soot etc, for that matter) have other side effects; its not that they were eliminated for no reason. And the point of any ecological activity (not just climate intervention) is to make the environment more supportive to human life and ativity. Stratospheric SO2 advocates tend to dismiss these issues.
* solar radiation adjustment has other consequences (on agriculture, for example). In the case of SO2 the frequencies reflected by SO2 are not all ones we want to do without -- we need some UV to get through.
* Stratospheric SO2 injection (AKA "SAI") is hard to switch off, so if we are unhappy with the results (widespread reduction in agriculture, if that's what happens) we would be waiting years, possibly decades, to get things back on track.
Solar radiation can also be managed at a more local level in the troposphere through marine cloud brightening for example, and can be done with more benign chemicals than SO2 (e.g. water), and can be switched on and off quite rapidly (days). It will use more energy and activity, but also provide greater control (in some locations on the water you may not want increased shade because of microscopic marine life).
Note I am working on removal of ambient greenhouse gas (CH4) and so am quite sensitive to the safety and consequences of intervention.
Yes.. there is an entire section in the IPCC report dedicated to this. This is also the reason they believe there is a "missing volcanic eruption," as it would explain data anomalies in their back projections. Make of that what you will.
https://en.wikipedia.org/wiki/1808_mystery_eruption
http://www.columbia.edu/~jeh1/mailings/2023/FlyingBlind.14Se...
1: http://www.columbia.edu/~jeh1/mailings/
It's called Termination Shock.
https://arxiv.org/abs/2108.08393
Let’s not kid ourselves, global cooling is FAR worse than global warming. Ice ages are no joke.
The risk/reward bet here is that we put jussst enough SO2 to drop by X degrees. I’m just not confident enough in our computational capacity to account for all the variables that could produce unintended consequences.
Tangential, but we can’t even figure out proper programs/legislation to improve education or reduce inner city poverty.
As a person from a cold country I'm not so sure about that. It's much easier to dress up on a cold day than to cool down on a hot day. It's cheaper to warm up a house than to cool it down. There are way less diseases/viruses/insects in cold climates. Granted, the food is much harder to come by, though, unless it's maritime (cold waters are much more abundant with life than warm oceans).
And in case of global warning, if it ever gets too cold, we know what to do.
It's been all around twitter. Casey Handmer writes about it in depth, worth checking out.
https://www.pbs.org/wgbh/nova/sun/
Yeah. Pump that shit into our atmosphere. What could possibly go wrong?
-1912 newspaper (New Zealand) https://paperspast.natlib.govt.nz/newspapers/ROTWKG19120814....
I understand that for line graphs, where you are looking at variations rather than absolutes, this is acceptable, but in this case.
- This is an interactive graph, at least give us the option of starting at zero.
- CO2 went from 280 ppm to 420 ppm, it is significant enough to see the variations even on an absolute scale.
- Don't make the bottom line (x axis) stand out as it does now, especially considering that the y axis doesn't stand out.
Why? I think there's some intuitive idea that something is being hidden or there's cheating in the presentation, but that doesn't have to be the case if the purpose of the plot is to illustrate relative change (and the y axis is clearly labeled).
The counter-argument is that it makes it look like CO2 has 10x'd instead of doubling, but since those values aren't calibrated in units that we can intuitively understand, it's not obviously the correct choice to start at 0.
That said I do feel like when people do that it is not a great practice.
We didn't even get oxygen until 2.4 billion years ago: https://en.wikipedia.org/wiki/Great_Oxidation_Event
Offsetting zero is an annoying practice.
"The co2 level is N standard deviations out of the ordinary compared to preindustrial times" feels more useful here, but reading that requires basic statistics (which general audiences probably lacks).
It would have much more impact and be less misleading if they started at 0.
Not starting at 0 both lets people dismiss the graph because they used the stupid not-starting-at-zero trick, and it hides the fact that CO2 concentration has increased by 50% which is insane!
https://www.climate.gov/news-features/understanding-climate/....
The zig zags are a reasonably smooth yearly wave if you zoom into them.
Deleted Comment
Every Gigaton of carbon is roughly equivalent to covering the entirety of Texas in ~1 millimeter of carbon.
Globally, we emit about ~13x that per year.
That's about equivalent to covering the state of Massachusetts in a foot of carbon.
Per year.
The entire planet is either the ocean, in use, desert, or already covered in forests.
~33% of the earth is desert. We'd need a decent chunk of that to get ~0% fossil fuel energy. But let's pretend we don't. We'd still need to cover all of that in several feet of carbon to capture all of our emissions.
It is not going to happen.
That seems high. I get a lot smaller number, but maybe I've messed up some unit conversions. I'm using:
Assuming those are right and I didn't botch any conversions between metric prefixes I get this: Check: PS: the above is for 1 gigaton of CO2 since that is what emissions figures usually use. But if you were just talking about after capture and extraction of carbon, multiply the above by 44/12, giving 6.2x10^-2 Texas cm C.PPS: If we took all of the CO2 out of the atmosphere, the amount of carbon would be enough to cover to Texas to about 53 cm.
While the current crop of carbon capture technologies are rather inefficient and useless, once we've got more of a mastery of bioengineering, it's by far the best answer to the long term greenhouse gas problem (not without its risks though).
The tens of meters deep peatlands that cover Canada, Russia, and the rainforests of the tropics hold enough biomass to more than triple the planetary CO2 ppm if they were burned. Those peatlands only started forming 18,000 years ago when the glaciers started receding so we have hard evidence that nature is capable of sequestering mind boggling amounts of carbon very quickly. That suggests that if we engineered a system we could do it even faster. It might take us a century to develop the biotech to that point, but long term the solution is on the horizon.
If we had the political will now we could get a decent head start by industrializing seaweed, algae, and other fast growing organisms for CO2 capture.
That's not a complete argument.
Do you have a critique of the IPCC's stance that CCS is part of the solution and necessary to decarbonize hard to abate sectors like steel/cement? [0]
[0] https://www.catf.us/2022/04/what-does-latest-ipcc-report-say...
659663 * 1000 * 1000 * 2.6 = 1,715,123,800,000 tons (1.7 trillion tons)
of carbon. One billion tons of carbon would make a Texas-covering graphite layer about 0.58 millimeters thick.
Deleted Comment
https://bg.copernicus.org/articles/19/4431/2022/ is a great summary of some of the more recent work in the area. It's astonishing how poorly we understand this system in the macro.
https://en.wikipedia.org/wiki/Cretaceous–Paleogene_boundary
If you can remember the Jurassic Park tagline (original movie), "an adventure 65 million years in the making", then you've got a good ballpark figure for this.
That perioid may be a somewhat large peak in a co2 graph, making the current co2 increase look negligible. However ocean levels are also estimated to have been 50-100 meters higher than today at that period, along many other side effects.
Edit: I saw my dead sibling pointed to a graph which is some weird logarithmic-linear hybrid, i.e. it show three distinct timeperiods in three different scales. This is indeed a rather odd way of representing data, and I don’t think it is helpful.
https://today.tamu.edu/2021/06/14/ancient-deepsea-shells-rev...
https://ehp.niehs.nih.gov/doi/10.1289/ehp.1104789
https://ehp.niehs.nih.gov/doi/10.1289/ehp.1510037
Cognitive impairment seems to get really noticeable at ~1000 ppm.
As CO2 reaches over 500PPM (this is not that far away) that doubling of CO2 levels from being indoors puts us in the cognitive impairment range. Not good.
[1] https://gml.noaa.gov/dv/data/index.php?category=Greenhouse%2...