I really love this article because it helps us see our cumulative emissions as an object, or as a hyperobject as Tim Morton would call it. However, I want to drill down on this phrase "Human CO2 Emissions." Both humans and ancient, fully-decomposed biomass are elements in an assemblage (a system, a process, or a machine) that unburies carbon, sets it on fire, and deposits it into the atmosphere. Humans are animals -- we have bodies that need to eat and sleep and shit, but emitting CO2 is not one of our human needs, not one of our body's needs. We were human for a long time before we started emitting Co2. And therefore, we can continue to be human when we stop. This is important to me because the denialist movement has forced us/liberals to closely identify Co2 emissions with humanity -- as if "to be human is to emit/pollute" -- anthropogenic climate change. It's not really anthropogenic, its industronic: emitted by industry, which is mediated and modulated by a thing we call The Economy. That thing, The Economy, can be re-shaped by governments who are corrupt to a greater or lesser degree (right now, greater, perhaps in the future, lesser).
Because there are still some unresolved gaps in our carbon budget (the carbon budget imbalance). On average its close to zero, but not for any given year. The uncertainties are generally largest in land use emissions and the land/ocean sinks: https://essd.copernicus.org/articles/14/4811/2022/
While this is all quite exciting, I fear it's mostly hype. Which is a tragedy, because Zeke is a really, really good meteorologist. It's only when it comes to climate that he tries his best to spread fear.
In this case, he's compared human carbon emissions to everything … well, everything except natural carbon emissions. Here's a graphic showing that comparison …
Nice article Zeke. I have a question about land uptake of CO2. It's pretty well understood that in the ocean the increasing pH level prevents more of the CO2 from being converted to carbonate and bicarbonate ions. This nonlinearity in the uptake roughly cancels out the logarithmic dependence of the forcing so that the temperature increase is proportional to the cumulative emission. What is the corresponding physical mechanism in the land uptake that is responsible for a lower fraction of the CO2 uptake? Is there a good reference for this? Thanks.
As far as I know the "land" uptake is actually growth of trees and vegetation and if we see 3K temperature increase there will be precious little of that where we see it now.
Thanks for the comment. I would suggest, from Zeke's post, that the decreased land uptake is happening now, rather than something that occurs towards the end of the century. The decreasing CO2 uptake is the basis of the Transient Climate Response to Cumulative CO2 Emissions (TCRE), popularized by Myles Allen but probably dates back to Ken Caldeira. There is a statement in AR6, WG1 p. 743 that "The land carbon cycle does not appear to play a fundamental role in the origin of the linearity and path-independence of TCRE ..." that implies that the land carbon cycle is poorly understood. It's unclear to me how the land component shows up in the modeling of the total uptake of CO2. Any insight on this would be appreciated.
What it means is an awful lot of shovels in old money.
The important number is 50 - the percentage increase in atmospheric CO2 level since industrialisation. Humanity activity has increase level from 280ppm to 420ppm.
If you understood how CO2 functions in the atmosphere you would appreciate the significance of this. I'll give you a start, the atmosphere is not saturated with CO2.
Sure, that's one important number, but all the others really aren't important.
I've been thinking about this whole post for the last few hours, and I think the really shocking number is this: If Mr. Hausfather is correct, and the mass of CO2 emitted from fossil fuels is actually greater than the total living biomass on the planet, then the carbon removed from the natural carbon cycle over the last few hundred million years is greater than the total current biomass of the earth. This would imply that the earth's biomass a few hundred million years ago must have been at least twice what we have now.
Or, possibly, there was a lot more CO2 in the atmosphere and hydrosphere. Or, perhaps, there was a lot of carbon trapped in volcanic rocks that has been liberated by volcanos. Both of these things could be true. But, it seems overwhelmingly likely that most of the explanation is that the earth supported a great deal more biomass a few hundred million years ago.
I don't say this to claim that releasing lots of CO2 into the atmosphere is a great boon to life. It's still a huge uncontrolled experiment with unpredictable consequences, and we shouldn't do it if there's a good way to avoid it. But it does stagger the imagination that the earth may have lost half its biomass because the formation of fossil fuels has removed most of the carbon from the carbon cycle.
"it seems overwhelmingly likely that most of the explanation is that the earth supported a great deal more biomass a few hundred million years ago."
What you seem to be forgetting is that that ancient carbon was laid down over a period of a few hundred million years ... say, for example, 200,000,000 years ... with a fraction laid down in every thousand years perhaps. Humans have burnt through it all in about 150 years.
We haven't yet burned through it "all" - there's plenty left in the ground. But certainly, we're returning it to circulation much faster than it came out.
Though it seems reasonable to predict that, for the high emission scenarios, the continued uptake of atmospheric CO2 may degrade, at this point the global carbon budget assessments (e.g., Friedlingstein et al) over the past decades confirm that the sinks are acting much as we believe they have over at least centuries. That is, the net annual uptake continues to be directly proportional to CO2 ppm levels. If emissions are currently flattening, to be followed by declining, we should expect a subsequent flattening of atmospheric CO2 levels, with declining CO2 levels once we've reached emission reductions of around 40-60%. The rate of decline would be slow, over decades to be sure, but isn't it about time that our projections start reflecting this? We can actually target specific atmospheric values (e.g., Hansen's 350 ppm target).
Thanks for sharing that article. If one assumes that the natural sinks continue to remove atmospheric CO2 pretty much the same as they have in the past -- in direct proportion to the concentration of CO2 in the atmosphere -- and note that we seem to be 1) peaking in anthropogenic CO2 emissions, it's fairly easy to project that modest decreases (say, ~2% per year) in global emissions will lead to 2) a flattening in CO2 levels within a few decades, 3) declining to under 400 ppm (perhaps approaching 350 ppm) during this century.
The first two items (1 & 2) are explicit goals of the 2015 Paris Agreement. IMO, these are now within reach (if we try). They should be part of an upbeat narrative about the future with scenarios that confirm that, by continuing to develop and deploy affordable, clean energy infrastructure we can gain control of the greenhouse gas content of the atmosphere.
Historically CO2 has been removed from the atmosphere by weathering of rocks which takes thousands of years.
It's not clear to me why you would expect the CO2 level to drop if we keep adding CO2. If we halve the emissions we roughly halve the increase in atmospheric level.
As you know, the CO2 level has been much higher in the past, and the temperatures with it, and that state persists - in human terms - forever.
You're correct that removal of carbon through the weathering of rocks is a long-term, slow process for CO2. Currently, as the work by Friedlingstein and others has shown, and as ZH reported in the article, anthropogenic emissions are around 40 GT/year and the additional removal by sinks beyond the pre-industrial removal rate, is now over 20 GT/ year. Assuming that the sinks continue to remove CO2 in proportion to the atmospheric content (now about 420 ppm), the CO2 removal rate will remain high even as we reduce emissions, eventually falling only as atmospheric levels decline. Note: This is good news since it means that aggressive emission reductions provides even more value.
Yes, there is nothing we make more of than CO2 except maybe crushed rock - which doesn't increase the total amount of rock. Much, much more than all other waste combined, at about 40 times the number two problem waste (which is coal ash).
Yes it is rational. Much better than using China's emissions as justification and excuse for doing less than we are able to in the face of a global problem that is not helped by delay. It isn't climate activists that oppose border tariff adjustments to cover emissions made elsewhere. Wisely or not, the rest of the world agreed with China committing to peaking their emissions 10 years later than fully developed nations but it will be the rest of the world doing what they have committed to that gives a strong position to call on China to do more.
Actually, I just attended an engineering alumni event at Oxford which explained that very little change has been observed up until recently due to inertia in the system. This is accelerating and we should expect dramatic changes over very short periods of time now.
I really love this article because it helps us see our cumulative emissions as an object, or as a hyperobject as Tim Morton would call it. However, I want to drill down on this phrase "Human CO2 Emissions." Both humans and ancient, fully-decomposed biomass are elements in an assemblage (a system, a process, or a machine) that unburies carbon, sets it on fire, and deposits it into the atmosphere. Humans are animals -- we have bodies that need to eat and sleep and shit, but emitting CO2 is not one of our human needs, not one of our body's needs. We were human for a long time before we started emitting Co2. And therefore, we can continue to be human when we stop. This is important to me because the denialist movement has forced us/liberals to closely identify Co2 emissions with humanity -- as if "to be human is to emit/pollute" -- anthropogenic climate change. It's not really anthropogenic, its industronic: emitted by industry, which is mediated and modulated by a thing we call The Economy. That thing, The Economy, can be re-shaped by governments who are corrupt to a greater or lesser degree (right now, greater, perhaps in the future, lesser).
Should say 750 billion tons for land use, not 750 tons.
Thanks, will fix it!
Wait, why don't the positive and negative portions of the Global Carbon Budget chart equal each other at every instant?
Because there are still some unresolved gaps in our carbon budget (the carbon budget imbalance). On average its close to zero, but not for any given year. The uncertainties are generally largest in land use emissions and the land/ocean sinks: https://essd.copernicus.org/articles/14/4811/2022/
While this is all quite exciting, I fear it's mostly hype. Which is a tragedy, because Zeke is a really, really good meteorologist. It's only when it comes to climate that he tries his best to spread fear.
In this case, he's compared human carbon emissions to everything … well, everything except natural carbon emissions. Here's a graphic showing that comparison …
https://wattsupwiththat.com/wp-content/uploads/2023/07/Barplot-IPCC-Human-Natural-C-emissions.png
"Staggering scale"? … Hardly.
w.
Nice article Zeke. I have a question about land uptake of CO2. It's pretty well understood that in the ocean the increasing pH level prevents more of the CO2 from being converted to carbonate and bicarbonate ions. This nonlinearity in the uptake roughly cancels out the logarithmic dependence of the forcing so that the temperature increase is proportional to the cumulative emission. What is the corresponding physical mechanism in the land uptake that is responsible for a lower fraction of the CO2 uptake? Is there a good reference for this? Thanks.
The land sink is a lot more complicated, but you are really seeing CO2 fertilization competing against increased wildfires and vegetative/soil carbon loss from hotter/drier conditions. https://climate.nasa.gov/news/3057/land-ecosystems-are-becoming-less-efficient-at-absorbing-carbon-dioxide/
As far as I know the "land" uptake is actually growth of trees and vegetation and if we see 3K temperature increase there will be precious little of that where we see it now.
Thanks for the comment. I would suggest, from Zeke's post, that the decreased land uptake is happening now, rather than something that occurs towards the end of the century. The decreasing CO2 uptake is the basis of the Transient Climate Response to Cumulative CO2 Emissions (TCRE), popularized by Myles Allen but probably dates back to Ken Caldeira. There is a statement in AR6, WG1 p. 743 that "The land carbon cycle does not appear to play a fundamental role in the origin of the linearity and path-independence of TCRE ..." that implies that the land carbon cycle is poorly understood. It's unclear to me how the land component shows up in the modeling of the total uptake of CO2. Any insight on this would be appreciated.
One problem, nobody ever counts the role of fungi.
OK - it's a big number. There are lots of other big numbers:
US Federal debt: $32 Trillion (13 times the tons of CO2 emitted since 1700)
Number of potential deals in a hand of bridge: 536 trillion quadrillion
Number of potential solutions to a sudoku grid: 196 quadrillion quadrillion quadrillion
Is there a significance to the number?
What it means is an awful lot of shovels in old money.
The important number is 50 - the percentage increase in atmospheric CO2 level since industrialisation. Humanity activity has increase level from 280ppm to 420ppm.
If you understood how CO2 functions in the atmosphere you would appreciate the significance of this. I'll give you a start, the atmosphere is not saturated with CO2.
> "The important number is 50"
Sure, that's one important number, but all the others really aren't important.
I've been thinking about this whole post for the last few hours, and I think the really shocking number is this: If Mr. Hausfather is correct, and the mass of CO2 emitted from fossil fuels is actually greater than the total living biomass on the planet, then the carbon removed from the natural carbon cycle over the last few hundred million years is greater than the total current biomass of the earth. This would imply that the earth's biomass a few hundred million years ago must have been at least twice what we have now.
Or, possibly, there was a lot more CO2 in the atmosphere and hydrosphere. Or, perhaps, there was a lot of carbon trapped in volcanic rocks that has been liberated by volcanos. Both of these things could be true. But, it seems overwhelmingly likely that most of the explanation is that the earth supported a great deal more biomass a few hundred million years ago.
I don't say this to claim that releasing lots of CO2 into the atmosphere is a great boon to life. It's still a huge uncontrolled experiment with unpredictable consequences, and we shouldn't do it if there's a good way to avoid it. But it does stagger the imagination that the earth may have lost half its biomass because the formation of fossil fuels has removed most of the carbon from the carbon cycle.
"it seems overwhelmingly likely that most of the explanation is that the earth supported a great deal more biomass a few hundred million years ago."
What you seem to be forgetting is that that ancient carbon was laid down over a period of a few hundred million years ... say, for example, 200,000,000 years ... with a fraction laid down in every thousand years perhaps. Humans have burnt through it all in about 150 years.
I didn't forget that - I highlighted it.
We haven't yet burned through it "all" - there's plenty left in the ground. But certainly, we're returning it to circulation much faster than it came out.
Though it seems reasonable to predict that, for the high emission scenarios, the continued uptake of atmospheric CO2 may degrade, at this point the global carbon budget assessments (e.g., Friedlingstein et al) over the past decades confirm that the sinks are acting much as we believe they have over at least centuries. That is, the net annual uptake continues to be directly proportional to CO2 ppm levels. If emissions are currently flattening, to be followed by declining, we should expect a subsequent flattening of atmospheric CO2 levels, with declining CO2 levels once we've reached emission reductions of around 40-60%. The rate of decline would be slow, over decades to be sure, but isn't it about time that our projections start reflecting this? We can actually target specific atmospheric values (e.g., Hansen's 350 ppm target).
Our projections do reflect this! Once emissions get low enough atmospheric concentrations start declining. https://bg.copernicus.org/articles/17/2987/2020/
Thanks for sharing that article. If one assumes that the natural sinks continue to remove atmospheric CO2 pretty much the same as they have in the past -- in direct proportion to the concentration of CO2 in the atmosphere -- and note that we seem to be 1) peaking in anthropogenic CO2 emissions, it's fairly easy to project that modest decreases (say, ~2% per year) in global emissions will lead to 2) a flattening in CO2 levels within a few decades, 3) declining to under 400 ppm (perhaps approaching 350 ppm) during this century.
The first two items (1 & 2) are explicit goals of the 2015 Paris Agreement. IMO, these are now within reach (if we try). They should be part of an upbeat narrative about the future with scenarios that confirm that, by continuing to develop and deploy affordable, clean energy infrastructure we can gain control of the greenhouse gas content of the atmosphere.
Historically CO2 has been removed from the atmosphere by weathering of rocks which takes thousands of years.
It's not clear to me why you would expect the CO2 level to drop if we keep adding CO2. If we halve the emissions we roughly halve the increase in atmospheric level.
As you know, the CO2 level has been much higher in the past, and the temperatures with it, and that state persists - in human terms - forever.
You're correct that removal of carbon through the weathering of rocks is a long-term, slow process for CO2. Currently, as the work by Friedlingstein and others has shown, and as ZH reported in the article, anthropogenic emissions are around 40 GT/year and the additional removal by sinks beyond the pre-industrial removal rate, is now over 20 GT/ year. Assuming that the sinks continue to remove CO2 in proportion to the atmospheric content (now about 420 ppm), the CO2 removal rate will remain high even as we reduce emissions, eventually falling only as atmospheric levels decline. Note: This is good news since it means that aggressive emission reductions provides even more value.
Yes, there is nothing we make more of than CO2 except maybe crushed rock - which doesn't increase the total amount of rock. Much, much more than all other waste combined, at about 40 times the number two problem waste (which is coal ash).
Yes, and as the level of CO2 in the atmosphere increases from 0.03% to 0.04%, it's important that the largest emitters reduce their emissions. Is it rational for America to handcuff our economy more than we've already done when China emits far more and they're still building coal power plants left and right. https://normanjansen.substack.com/p/climate-catastrophe#%C2%A7crisis-while-massive-chinese-co-emissions-keep-increasing
Yes it is rational. Much better than using China's emissions as justification and excuse for doing less than we are able to in the face of a global problem that is not helped by delay. It isn't climate activists that oppose border tariff adjustments to cover emissions made elsewhere. Wisely or not, the rest of the world agreed with China committing to peaking their emissions 10 years later than fully developed nations but it will be the rest of the world doing what they have committed to that gives a strong position to call on China to do more.
You can find all the details on the land sink (which is mostly vegetative growth) here: https://essd.copernicus.org/articles/14/4811/2022/
Actually, I just attended an engineering alumni event at Oxford which explained that very little change has been observed up until recently due to inertia in the system. This is accelerating and we should expect dramatic changes over very short periods of time now.