The Forest Prime-Evil

Guest Post by Willis Eschenbach

There’s a new study out claiming that tropical forests are losing their ability to sequester carbon dioxide. Bad forest, no cookies for you! The study is entitled “Asynchronous carbon sink saturation in African and Amazonian tropical forests”, and is available through Sci-Hub here. In their press release it says:

In the 1990s intact tropical forests removed roughly 46 billion tonnes of carbon dioxide from the atmosphere, declining to an estimated 25 billion tonnes in the 2010s.

The lost sink capacity in the 2010s compared to the 1990s is 21 billion tonnes carbon dioxide, equivalent to a decade of fossil fuel emissions from the UK, Germany, France and Canada combined.

Overall, intact tropical forests removed 17% of human-made carbon dioxide emissions in the 1990s, reduced to just 6% in the 2010s.

Now, the first thing I noticed was that this study falls under what I modestly call “Willis’s Rule Of Authors”, which states that

Q ≈ 1/N2

Where “Q” is the quality of a scientific study, and N is the number of study authors. In English, this means that the quality of a study decreases in proportion to the inverse of the square of the number of authors … which in this case is … wait for it … no less than one hundred and six authors.

So … how did the one hundred and six authors determine that the tropical forest are no longer sequestering as much as they used to sequester?

According to the study, they used both observations and models. How much of each? Well, a clue is that the word “model” appears 158 times in their study, while “observations” appears only 44 times … here’s a typical comment.

A statistical model including carbon dioxide, temperature, drought, and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly.

Now, it turns out that we can actually measure roughly how much human-generated CO2 is sequestered each year. The calculation is not all that complex. We know how many gigatonnes (“GT”, 109 metric tonnes) of carbon are emitted each year from the burning of fossil fuels plus cement manufacture. We know that for every 2.13 GT of carbon emitted, the atmospheric carbon dioxide level increases by one part per million by volume (ppmv). We routinely measure the atmospheric carbon dioxide level at the Mauna Loa Observatory.

So we take a look at how much carbon is emitted in a given year and we calculate how much the CO2 level should have increased. We subtract from that the actual increase in CO2 during that year, and the difference is the amount sequestered in that year by various carbon sinks around the planet.

Using that calculation, Figure 1 shows the amount of CO2 sequestered by year since 1959.

Figure 1. Percentage of anthropogenic CO2 sequestered by year.

There are some interesting things about this graphic. First, the amount sequestered varies widely year by year. This depends on two factors, the amount of natural emissions of CO2, and the variations in the natural carbon sinks. These are weather-driven. Some years there’s a lot of green growth on land and at sea, and other times there’s much less, which varies the amount of the carbon sinks. On the other side of the ledger, El Nino years like 1998 show an increase in natural CO2 emissions, so the percentage sequestered is smaller. With very large El Ninos, the amount of CO2 released may actually overwhelm the sinks, as in 1967.

Next, the smoothed value (blue/black line) varies between about 40% and 50%. It has hit both 40% and 50% twice in the past and most recently is about in the middle. There is no statistically significant long-term trend in the data (a least-squares analysis shows sequestration increased by 9% over the period, but the p-value is 0.20, far from significant).

Of interest for our purposes is the average for the 1990s and the 2010s mentioned in the study. In the 1990s the average sequestered was 49.8%. In the 2010s the average was 46.0%. The difference indicates the reduction in sequestration is 3.8%, but again it is not statistically significant …

But the one hundred and six authors say that forest loss reduced the amount sequestered by 11%. Hmmm …

Ah, well, I guess we shouldn’t expect models to actually agree with reality, that would be far too boring. In any case, we’re left with several possibilities, which include:

  1. The new paper is correct, forest sequestration has decreased by 11%, and coincidentally some other unknown carbon sink has increased by 7.2%, or …
  2. The new paper is wrong, or …
  3. The uncertainty is too great to come to any conclusion.

My conclusion? I’m not taking firm sides in this question, although option 2) seems most probable, followed by option 3). In any case, there’s no indication of a long-term reduction in the sequestration rate. And finally, I find it … well … discouraging that the authors didn’t include the actual sequestration calculations and discuss the implications of reality as opposed to models.

My best to everyone from a very dry hillside near the ocean in Northern California,


As Usual: I politely request that you quote the exact words you are discussing, to avoid at least some of the misunderstandings that are the bane of the internet.

Technical Note: As you might imagine, there is a lag between when CO2 is emitted at the surface and when that surface CO2 affects the background CO2 as measured at Mauna Loa. This lag is on the order of ten months, and it has been adjusted for in Figure 1 above.

4.8 29 votes
Article Rating
Newest Most Voted
Inline Feedbacks
View all comments
June 7, 2021 10:16 am

At least 106 vitas got enhanced in the process.

Richard Page
Reply to  ResourceGuy
June 7, 2021 10:32 am

Very true. I firmly believe that to those in academia, it is no longer about publishing good, knowledgeable papers that will stand the test of time but about getting your name on the mostest, fastest – no matter what tripe it happens to be.

Reply to  Richard Page
June 7, 2021 11:26 am

I wonder if it their fault as much as it is the stupid RTP process of universities.

Reply to  ResourceGuy
June 9, 2021 11:04 am

Agree — the author list is piled on because everybody has to get their required virtue-signal in. Disgusting and pathetic.

June 7, 2021 10:24 am

Hi Willis – This paper by David Motes takes a new approach.

Guest blog by David Motes; GW driven by Plant Evapotranspiration Reduction

June 7, 2021 10:27 am

Shameless hijack. Would you please provide monthly updates on the communication between you and your reviewers about the peer reviewed paper you’re writing? If it has already been published, then my bad, and I’ll find it and read it. We would be better served if we saw ALL of the exchanges, both ways. Feel free to comment to us, but I would think that those comments would also be sent to your reviewers.

There is much written here about the perversion of the peer reviewed process to keep skeptics in subterrannea, and this might be a good example of it.

Thanks in advance

Reply to  bigoilbob
June 7, 2021 11:28 am

Willis gave this paper a lot of exposure, that fact doesn’t cross your mind?

“The study is entitled “Asynchronous carbon sink saturation in African and Amazonian tropical forests”, and is available through Sci-Hub here. In their press release it says:”

Then you fail to address the post itself which suggest that you didn’t find any errors on Willis or the 106 authors part.

Somebody is wrong, maybe that is you?


Reply to  Sunsettommy
June 7, 2021 1:00 pm

Willis gave this paper a lot of exposure, that fact doesn’t cross your mind?”

I thought the prior “exposure” was to pre-harden it for peer review. If I missed the point of his post(s) then I stand corrected. That seemed like a good idea, and I noted all of the responses.

And thanks for the Sci-Hub and Science Daily links. But is Sci-Hub a peer reviewed publication, for which Willis has passed said peer review? No diss of either of these pubs, just want to get an update on his progress towards what I understood his goal was.

AGAIN, I am only following up on Willis’s goal of producing a properly peer reviewed paper, to possibly use the back and forth to better understand the process.

“Then you fail to address the post itself which suggest that you didn’t find any errors on Willis or the 106 authors part.”

Agree, because I didn’t critique it. My interest is in examples of peer review abuse, and I thought this might be an opportunity to see some.

Jeff Alberts
Reply to  bigoilbob
June 7, 2021 5:56 pm

I thought…”

Well there’s yer problem.

Reply to  Willis Eschenbach
June 7, 2021 3:07 pm

Thanks for the update Mr. Eschenbach, and I fully understand.

Ulric Lyons
June 7, 2021 10:29 am

During low solar periods, particularly during centennial solar minima, El Nino conditions increase and the tropical forests become drier and release massive plumes of CO2. Ideally seen as a natural negative feedback.

June 7, 2021 10:38 am

If you care about too much CO2 in the atmosphere plant a tree. If it turns out that the amount of CO2 in the atmosphere doesn’t matter, we still get the tree. If you reduce the amount of fossil fuels you consume, the price goes down and someone somewhere else uses more.

Ron Long
June 7, 2021 10:42 am

Thanks, Willis. Tropical forests are jungles, and I have mentioned before they stink when you walk (or cut your way or push against stinging plants or turn around) through them. The stink is from accumulated rotting vegetation on the ground. Rotting is an oxidation process, therefore what is the balance between CO2 uptake in the green leaves, then oxygen outgassing, and finally consumption of oxygen in the rotting process?

Paul Lognonne
Reply to  Ron Long
June 7, 2021 11:52 am

Well said. Tropical rain forests are their own self contained eco-system. Relying on hydro-carbon combustion thus creating H20 + CO2 + heat. The CO2 aids in the lushness of the forest together with the H2O. Excess H2O is drawn out by the heat of the tropical sun forming the clouds above the canopy.
Both the Japanese and nassa have in the past launched satellites to measure CO2 in the atmosphere which show a n excess of CO2 over the world’s rain forests. It appears that rain forests add to the CO2 in the atmosphere. This goes against environmental thinking. Have I got something wrong?

Clyde Spencer
Reply to  Paul Lognonne
June 7, 2021 1:06 pm

The first OCO-2 map released at AGU in 2014 similarly showed high values of CO2 over both the Amazon basin and the Congo.

Trying to Play Nice
Reply to  Paul Lognonne
June 7, 2021 3:24 pm

Any good alarmist worth his salt would tell you that the rain forests are sucking the anthropogenic CO2 from other areas to use it. There’s always an explanation that fits the meme.

Reply to  Paul Lognonne
June 8, 2021 6:54 am

Both the Japanese and nassa{sic} have in the past launched satellites to measure CO2 in the atmosphere which show a n excess of CO2″

The problem isn’t in the forest process. The problem is in the measurement process.

N.B. “satellites to measure CO2”, with a failure to measure commensurate O₂ levels and likely N₂ levels, NO levels and other life process excretions/emissions.

That is, you have been given one very narrow view of the forest photosynthesis/growth/decomposition/respiration process.
Which also means that decisions made by authorities using a very narrow and tailored view of the process are invariably wrong.

Reply to  Paul Lognonne
June 9, 2021 12:40 pm

Makes sense. Hard to increase the amount of carbon-containing bio-matter in the rain-forest as it’s pretty much already maxed-out. Dead vegetation doesn’t build up on the ground as the decay-process is very rapid and the remaining decay-products immediately taken up by the vegetation. However, a re-growing forest, newly “greening” land area or increasing ocean phytoplankton would take up carbon.

Last edited 1 year ago by beng135
Pat Frank
Reply to  Ron Long
June 7, 2021 2:45 pm

Much of the stink is likely due to anaerobic fermentation going on in the anoxic wet understory of the ground litter. Anaerobic metabolism releases hydrocarbons, and worse, low molecular weight carboxylic acids.

Butyric acid (4-carbon) smells like vomit. The stink of valeric acid (5 carbon) is indescribably vile.

Then there are the amines — putrescine, cadaverine, etcetra-ine. The names reveal all. And the volatile thiols, variations on the smell of poo-poo. 🙂

Bacteria, the best friends your nose never wanted.

Reply to  Pat Frank
June 8, 2021 7:11 am

I found Ron’s statement rather vague.
Any forest or swamp allowed to grow uninhibited quickly becomes a veritable jungle. Vines, roots, deadfall, tangled undergrowth, interwoven mid level understory all combine to make off trail travel difficult.
I know of woodlands in Pennsylvania and Virginia where understory, deadfall, undergrowth coupled with dense interwoven rhododendron patches make it a truly serious effort to walk off trail.

It’s called trail breaking or bush-wacking and have been considered strenuous dangerous efforts for centuries at least.

Much of the stink is likely due to anaerobic fermentation going on in the anoxic wet understory of the ground litter. Anaerobic metabolism releases hydrocarbons, and worse, low molecular weight carboxylic acids.”

Portions along the Amazon basin are frequently inundated and remain underwater for several months. Breaking trail during the months immediately following inundated periods will smell incredibly foul as submerged often anaerobic life decomposes underwater plant and animal life remains.

Trail breaking through swamps and estuaries release the same kinds of foul smelling compounds.

Trail breaking through relatively dry upland forests, no matter how overgrown may smell musty, but rarely foul.

Reply to  ATheoK
June 9, 2021 12:52 pm

Dig under the leaf-litter into the humus of a east NA forest and you can smell the bacteria (and see the white fungal strands). Not really a foul odor, but distinctive. Now swampy areas, that’s foul….

Last edited 1 year ago by beng135
Mike Dubrasich
Reply to  Ron Long
June 7, 2021 6:14 pm

Any forest, tropical or not, features net growth, which is gross growth minus mortality. Net growth is the addition of carbon, or if you like, the net sequestration of carbon from the atmosphere.

Young forests exhibit positive net growth. As they age forests have less and less net growth until some maximum storage capacity is reached. Thereafter net growth is negative until the forest burns, at which point most of the prior growth is volatilized. Then the process begins anew.

If examined over any appreciable length of time, forest carbon storage is zero. What is reduced (fixed) must be oxidized. The only exception to this rule is certain swamp forests wherein trees fall into the water and fail to rot in the anaerobic situation — and eventually become coal.

No forest I am aware of is making coal today, but theoretically it could be happening somewhere. The forests I work in in the western US are most definitely not turning into coal.

Joao Martins
Reply to  Mike Dubrasich
June 8, 2021 10:53 am

Excellent explanation!

June 7, 2021 10:48 am

The swing in sequestration was about 80% from 1985 to 1990. Really? How does that happen globally?

Rud Istvan
June 7, 2021 10:54 am

WE, your skepticism (ridicule) of this paper is well deserved.

I went and looked at the paper in Nature. It is WORSE that you pointed out.
The paper is paywalled (and I did not waste my money), but as usual the SI is not. The alarmist tell is in SI table 5 footnote 1, explaining their final conclusion methodology.

They took two 20 year intervals and calculated the centered delta T means—1985 and 2050. Now 2050 hasn’t arrived yet. So they took the mean of 19 CMIP5 models for that interval. Then they regionally downscaled that mean to ‘match’ the regional forest plots in the study. Then they used that downscaling to project their erroneous models of African and Amazonian forest plot observations forward to 2050 to ‘prove’ it will get worse in the future.

Just three little problems. CMIP5 provably runs hot. Regional downscaling is very unreliable (discussed in essay ‘The Last Cup of Coffee’ in ebook Blowing Smoke). And as you show, their model of ‘observations’ is off by about a factor of 3 high. Not science, nonsense.

Thomas Gasloli
Reply to  Rud Istvan
June 7, 2021 12:22 pm

And yet they think they are doing science instead of creating science fiction.

Pat Frank
Reply to  Thomas Gasloli
June 7, 2021 2:53 pm

It’s video-game science, Thomas. Real science is hard, with lots of gritty attention to detail. The answers come slowly and in small bits.

Tweaking a model and then deciding what it means is easy. Big jumps in output are available, and one can make exciting and sweeping generalizations.

All physically meaningless, but the computer graphics make it all look really realistically real-like.

Glitter-glitter-strobe and all the low-attention-span reporters sit up and smile.

These people are hacks. They’re lazy. They don’t know how to do actual science.

another ian
Reply to  Pat Frank
June 8, 2021 3:04 am

As the bloke with whom I shared a post graduate office remarked as he added another print-out of output from his modelling project to a growing stack

“You know real knowledge doesn’t increase as fast as computer output”

Nicholas McGinley
Reply to  Rud Istvan
June 8, 2021 9:13 am

I would wager cash money they had their result before they ever even decided on a methodology.
Which may be one reason why they did not bother trying to do any actual scientific investigations.
After all, if they did something scientifically, they might get the “wrong” result, and then what?

Reply to  Rud Istvan
June 8, 2021 2:37 pm

Once Upon a Time some non-green non sequestering corporately irresponsible group would have had plans to harvest those senescent trees and replace them with vigorous young things who by the year 2050 would be at their peak of CO2 consumption.

But alas, such things cannot be allowed. At least in one part of our biome age is respected.

June 7, 2021 10:55 am

Mother Nature is calling for more, otherwise she wouldn’t sequester any.

Reply to  Scissor
June 7, 2021 11:58 am

That might be equivalent to believing the universe needs more diffuse heat, otherwise mechanical processes would be more efficient.

Reply to  AndyHce
June 7, 2021 12:28 pm

The second law is certainly real.

Doug S
June 7, 2021 11:21 am

The study conclusion seems counter intuitive. If the earth is indeed “greening” and increasing amounts of CO2 is being pumped into the atmosphere, wouldn’t we expect the sequestered CO2 to be increasing as well? I must be missing a piece of this cycle in my understanding.

Reply to  Doug S
June 7, 2021 11:56 am

Original Post (O.P,) neglected to write the report claims it looked at 300,000 trees over a 30 year period. The joint conclusion of those many co-authors is that the result they ascertained is (quote): “… largely driven by carbon losses from trees dying.”

As for the supposed benefit of contemporary rising CO2 it is worth understanding that in the tropics elevated CO2 augments vine growth ( and relatively more so than a tree). The woody forest vines are not benign in regards to tree stands – they (vines) contribute to tree death. I hear it’s still about survival of the fittest out in the jungle.

Doug S
Reply to  Doug S
June 7, 2021 12:18 pm

Thanks gringojay, I didn’t read the report but the detail you cite makes sense. It’s reasonable to me that as CO2 and temperature rise, the forests and other plant life on earth respond in non-linear ways; moving past one level of CO2 drives understory growth, then moving past the next level drives other competing changes. Thinking about the limits of this process and imagining the dense plant coverage in ancient earth in combination with ultra high CO2 levels and higher temperatures makes an interesting puzzle for me.

Joao Martins
Reply to  Doug S
June 8, 2021 11:21 am

My experience in orghards: if you have apple or pear trees (or other fruit trees; my remark is still more important for peach orchards) you must “train” them in a certain way (depending on the density of the orchard and the growth habits of each variety) so that all the canopy will utilize sunlight to an optimum. That is why you don’t have fruits inside the canopy (when there are some, they are smaller, less sweet, worse quality). Many young vegetative branches formed inside the canopy are actually parasites: they consume more for their growth than the amount of photosynthate they produce, because they are in the shadow. A forest tree will grow and “prune itself” of those parasitic branches: look at the quantity of dead old branches in trees of unmanned forests, the tree did stop feeding them because they were growing in a place where they would be inefficient and become parasitic. Eventually, dead branches will fall — but not as quickly as we prune them in orchards (every year). The size of the tree/species, the habit of growth of the species, all the events that make dead branches fall (from histologic characteristics of their tissues to exposition to wind, type of forest and geography, etc.), all these are factors for a solid “non-linearity” of the global processes like those that this paper claims to elucidate…

Last edited 1 year ago by Joao Martins
June 7, 2021 11:25 am

Hi Willis, thank you for this very interesting post. Hope you are enjoying the very dry hillside near the ocean in Northern California.

June 7, 2021 11:32 am

Willis, the post reads, “With very large El Ninos, the amount of CO2 released may actually overwhelm the sinks, as in 1967.”

Is 1967 a typo?

1967 was the ebb year of the 1966/1967 La Nina and the start year of the 1967/1968 La Nina. In other words, it was in the middle of back-to-back La Ninas. It was not an El Nino year, according to NOAA’s Oceanic NINO Index (ONI):
Climate Prediction Center – ONI (


Dean skallman
June 7, 2021 11:47 am

I recall a paper from long ago that contended that tropic forests hold all of their nutrients and carbon in the living biomass. Little to none is in the soil. They based the conclusion on how poor the soil was for growing crops after clearing.

Rud Istvan
Reply to  Dean skallman
June 7, 2021 12:25 pm

I know that it true for the Amazon; because of the high rainfall the low lying basin soils are leached out. Less true for the fringes where agriculture has been encroaching. Wrote about it for different reasons in essay Pseudo Precision in ebook Blowing Smoke.
Dunno about Africa generally. Is probably not true for the Congo basin, also covered in the same essay.

Frank from NoVA
Reply to  Dean skallman
June 7, 2021 3:05 pm

Hence the traditional practice of slash and burn agriculture.

Nicholas McGinley
Reply to  Dean skallman
June 8, 2021 9:25 am

What you say is exactly correct for tropical soils and biomes in general.
The soil is virtually devoid of nutrients due to excessive leaching from the high rates of rainfall.
Any vegetation which falls to the ground is quickly decomposed and absorbed by nutrient hungry plants and trees.
This can even be seen in places like the Peninsula of Florida.
In most locations, there is virtually nothing in the way of humus. Bare sand can be seen on the ground in undisturbed locations of the upland biomes.

Exceptions are where some mechanism provides an input of nutrients, such as volcanic activity, rivers that bring in sediment from distant highlands, etc.

It is thought that dust from the Sahara desert may be an important nutrient source for Eastern parts of South America.

The minerals are washed out of the soil in a predictable sequence based on solubility, with aluminum one of the last to remain.
This is why bauxite is often found in such places.

Nicholas McGinley
Reply to  Dean skallman
June 8, 2021 9:30 am

The proper name for these biomes is selva, not “jungle”, as someone said above.

Introductory course in physical geography cover this subject in detail.

10(t) Introduction to Soils (

June 7, 2021 11:53 am

It doesn’t take 106 authors to know that when you burn down a tropical forest, the forest loses it’s ability to sequester CO2.

Reply to  nicholas tesdorf
June 7, 2021 1:55 pm

Correct, except that the forest doesn’t lose the ability completely. Ash and charcoal are composed all or in part of carbon, and as horrible as clearcut burning seems, it doesn’t eliminate other plant species that grow in the same area. In fact, the deliberate burning takes place just so that crops can be planted in the same area. Some native American, and other palaeolithic groups practiced forest burning for the purpose of clearing undergrowth, and for clearing land for agricultural use, before 1750, and probably for millenia.

Being mildly basic, just a small amount of real ash would eliminate the entire fake problem of ocean fake acidification.

True forest and grass fires often burn so hot that they do, indeed, locally reduce plant growth for a short time. But many species can only propagate after a fire. Nature (or evolution, take your pick) had the balance figured out, long before humans came on the scene.

But the article that W.E. addresses in the subject doesn’t really blame clearcut burning as a means of the loss of ability to store carbon. And if clearcut burning did remove some unit of measure of carbon uptake into the life cycle, then as Willis points out, the remaining majority of plant life has increased in carbon uptake efficiency to more than compensate.

June 7, 2021 12:34 pm

Seems like a long-winded way for “scientists” to deny world-wide “greening.” Do you suppose that NASA will be their next victim to be ousted from the cult?

Joao Martins
Reply to  dk_
June 8, 2021 11:32 am

NASA will “correct” the color spectrum and change the greens into blues…

Last edited 1 year ago by Joao Martins
Clyde Spencer
June 7, 2021 12:39 pm

.. no less than one hundred and six authors.

“Why 100? If I were wrong, one would have been enough. [In response to the book “Hundred Authors Against Einstein”]”

Clyde Spencer
June 7, 2021 1:02 pm

Willis, you said:

… there’s no indication of a long-term reduction in the sequestration rate.

[Spoiler Alert!]
I can provide some input on that. In my next submission I’ll show that the Summer drawdown of CO2 has been remarkably constant for at least the last 30 years, and not much different 60 years ago.

H. D. Hoese
June 7, 2021 1:18 pm

Another equation determining quality is the number of papers cited published from 2000 and earlier divided by the number since minus the number of no choke shotgun graphs. I calculate that Q= 1/49-6 (from Fig. 2) whatever negative number that comes out to be.

June 7, 2021 2:05 pm

If I had to find fault with your analysis *of the paper*, it would be that they are only talking about tropical forests, whereas your analysis is looking at total carbon sinks.

So I suppose that if we take their “analysis” at face value, we should probably be asking what exactly has changed in the other sinks to take up all this excess C02 no longer being absorbed by tropical forests?

Rud Istvan
Reply to  Philip
June 7, 2021 2:34 pm

NASA satellites show a global terrestrial greening of about 20% over the period, especially since all shrubs and trees are C3 so do better with more CO2. So even IF this 106 author paper were true (it isn’t) about tropical forests, it cannot be true generally.

June 7, 2021 2:15 pm

If the Carbon emissions by human activity per year have significantly increased since 1959 (comparing to Fig1) and the multiyear smoothing cycles around 40 to 50% sequestered, then the GTonnes of carbon sequestered per year has significantly increased.
Looking at Fig1 shown above, the average % sequestered has stayed the same or has a slight upward trend.

The climate models probably assume constant Gtonnes absorbed by nature per year but this study highlights the influence of natural greening despite AGW. Large natural variations per year but long term trends are not alarming.

Rud Istvan
Reply to  tygrus
June 7, 2021 2:55 pm

Familiarize yourself with the so called Bern model of sequestration. It is foundational to the IPCC and ‘all’ GCM’s (I haven’t personally checked them all), and says all natural ‘carbon’ sinks eventually saturate. WE’s figure shows observationally that they don’t on the relevant time scales.

Further observation. There is more ocean than land sequestration, simply because oceans are 71% of Earth’s surface. And more of the ocean sequestration is permanent (on million year scales) thanks to calcifying phytoplankton like foraminifera and coccolithophores, while very little of the terrestrial ‘wood’ lasts for more than a very few hundred years (tree lifetimes) since end of the Carboniferous age thanks to the evolution of rotting fungi.
In fact, were it not for plate tectonic subduction andesic (not basalt) volcano recycling of ocean formed calcium carbonates, it is estimated IIRC that all life would cease in about 2.5 million years from plant CO2 starvation.

Nicholas McGinley
Reply to  Rud Istvan
June 8, 2021 9:48 am

A good solid asteroid strike right into a nice thick formation of carbonate rock likely does wonders, too.

Last edited 1 year ago by Nicholas McGinley
June 7, 2021 2:56 pm

Proof that Willis has no clue, RE: Q ≈ 1/N2 (I could have have said he is full of $*** but that is disrespectful)

Last edited 1 year ago by ntesdorf
Reply to  nicholas tesdorf
June 7, 2021 4:08 pm

According to Eschenbach’s formula, if an individual submits a HALF-assed paper (N=0.5) about thunderstorms, then the quality of said paper quadruples.

Reply to  Willis Eschenbach
June 8, 2021 9:15 am

Having written papers with up to 6 authors, it is a fact that after 3or4 the rest are freeloaders. They may have referred patients or the use of their machine, but they are in no way associated with the science.

Izaak Walton
June 7, 2021 2:57 pm

You are comparing apples to oranges. You state for example that “In any case, there’s no indication of a long-term reduction in the sequestration rate. ” which the authors agree with since they state in their abstract that:
the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass10 reinforce our conclusion that the intact tropical forest carbon sink has already peaked”

Secondly you also distort the amount of measurements that the authors did to calculate the amount of carbon sequestered in the forests. For example consider the following:

Height of individuals from ground to the top leaf, hereafter Ht, was measured in 204 plots, using a laser hypsometer (Nikon forestry Pro) from directly below the crown (most plots), a laser or ultrasonic distance device with an electronic tilt sensor, a manual clinometer, or by direct measurement, that is, climbing the tree.”


In all plots, all woody stems with ≥100 mm diameter at 1.3 m from the base of the stem (‘diameter at breast height’, DBH, in mm), or 0.5 m above deformities or buttresses, were measured, mapped and identified using standard forest inventory methods64,65. The height of the point of measurement (POM) was marked on the trees and recorded, so that the same POM is used at the subsequent forest census.”

and they did this for over 200 seperate plots in various forests. And the fact that the plots were scattered across Africa and studied by different researchers accounts for the large number of authors.

Rud Istvan
Reply to  Izaak Walton
June 7, 2021 3:25 pm

Izaak, you obviously have spent the Nature paywall money; I didn’t.
But your detailed methodological study approval reminds me of an old Winston Churchill aphorism, cited somewhere in ebook ‘The Arts of Truth’ and here just paraphrased:
“The extreme length of your analysis defends it well from brief critical rebuttal.”

To be more specific and intentionally more personal, WE showed their baseline analysis cannot apply globally. One of my comments thereto showed that even if the paper were true, is contradicted by net global greening so doesn’t matter. The other showed their future projection method was triply absurd. NOT a good look.

Reply to  Rud Istvan
June 7, 2021 8:01 pm

As in all from the commenter you are responding to, rule 5 applies.

But more FYI, I did download the pdf from Willis link, above, and IMO in the comment you were presented with minor supporting language — cherries, rather than apples and oranges — out of context of the paper and of Willis citation. The authors (I think cited as Hubau, W., Lewis, S.L., Phillips, O.L. et al, Nature 2020) don’t know where the carbon is going, either, but seem to agree that one place it isn’t going is into the stems and trunks of trees.

The Hubau paper is from a year ago, but in the last week, another study, summary just spotted at CO2 Coalition, might present a clue. From the Correa-Diaz et al Forest and Ecology Management, (6 June 2021) study, I’m left with the impression that forest leaf cover and other plants may account for the increased greening and carbon capture, and there may be additional lag between increased capture and tree growth in trunks and stems, which Hubau would have missed.

The Hubau paper perhaps suffers from their own narrow definition of carbon capture, which is more-or-less where I think Willis may be going. I’m looking forward to both Clyde and Willis’ future presentations on this subject


Last edited 1 year ago by dk_
Izaak Walton
Reply to  Rud Istvan
June 7, 2021 8:28 pm

I am not sure what you mean by “baseline analysis”. Is it their claim that
Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature” or something
different? The whole point of the paper was that trends in tropical forests Africa and the Amazon are different, i.e. the “asynchronous” in the paper title. It is not a paper
about global trends in terrestrial carbon sinks.

And again the authors state that:
Given that the overall global terrestrial carbon sink is increasing, a weakening intact tropical forest sink implies that the extra-tropical carbon sink has increased over the past two decades.”

So they are well aware that losses in tropical forests are more than compensated by increases elsewhere. Their modelling also seems reasonable if simplistic. They took their data from between 1983 and 2014 and performed a linear extrapolation out to 2040. They also used three different estimates for future CO2 levels. The level of confidence the authors have in their estimates is probably quite low given that they describe them as “tentative”. And their Fig. 3 shows that they include very large error estimates in their predictions.

This is a solid paper that is based on 30 years of actual measurements of 244 forest plots in Africa and compares them to measurements of 321 Amazon plots. It does not set out to make claims about global carbon sinks despite what Willis appears to think.

Reply to  Izaak Walton
June 7, 2021 9:13 pm

Apologies to all for verboseness, rendered with the intent to provide accurate context.


It is not a paper

about global trends in terrestrial carbon sinks.


It does not set out to make claims about global carbon sinks despite what Willis appears to think.

Hubau [emphasis added]
From Abstract

 Overall, the uptake of carbon into Earth’s intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass10 reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth’s climate.


Globally, the terrestrial carbon sink is increasing. Between 1990 and 2017 the land surface sequestered about 30% of all anthropogenic carbon dioxide emissions. Rising CO2 concentrations are thought to have boosted photosynthesis more than rising air temperatures have enhanced respiration, resulting in an increasing global terrestrial carbon sink.


 Our carbon gain and loss models (Table 2) can be used to make a tentative estimate of the future size of the per unit area intact forest carbon sink (Fig. 3). Extrapolations of the changes in the predictor variables from 1983–2015 forward to 31 December 2039 (Extended Data Fig. 5) show declines in the sink on both continents (Fig. 3). By 2030 the carbon sink in aboveground live biomass in intact African tropical forest is predicted to decline by 14% from the measured 2010–15 mean to 0.57 Mg C ha−1 yr−1 (2σrange, 0.16–0.96; Fig. 3). The Amazon sink continues to rapidly decline, reaching zero in 2035 (2σ range, 2011–2089; Fig. 3). Our estimated sink strength on both continents in the 2020s and 2030s is sensitive to future CO2 emissions pathways (CO2-change)38, resulting temperature increase (MAT, MAT-change) and hydrological changes (MCWD), plus changes in forest dynamics (CRT), but the sink is always lower than levels seen in the 2000s (see Methods and Supplementary Table 5). Therefore, the carbon sink strength of the world’s two most extensive tropical forests have now saturated, albeit asynchronously.

From Conclusion

Given that the overall global terrestrial carbon sink is increasing, a weakening intact tropical forest sink implies that the extra-tropical carbon sink has increased over the past two decades. Independent observations of interhemispheric atmospheric CO2 concentration indicates that carbon uptake into the Northern Hemisphere landmass has increased at a greater rate than the global terrestrial carbon sink since the 1990s, with a further disproportionate increase in the 2000s10. The interhemispheric analysis suggests a weakening of the tropical forest sink by ~0.2 Pg C yr−1 between the 1990s and 2000s10, which is similar to the 0.17 Pg C yr−1 weakening over the same time period that we find. This reinforces our conclusion that the intact tropical forest carbon sink has already saturated.

Concluding sentence, Hubau

At the international level, given that tropical forests are likely to sequester less carbon in the future than Earth System Models predict, an earlier date by which to reach net zero anthropogenic greenhouse gas emissions will be required to meet any given commitment to limit the global heating of Earth.


The level of confidence the authors have in their estimates is probably quite low given that they describe them as “tentative”. And their Fig. 3 shows that they include very large error estimates in their predictions. This is a solid paper that is based on 30 years of actual measurements of 244 forest plots in Africa and compares them to measurements of 321 Amazon plots.

Hubau, Methods

First, each census interval value was interpolated for each 0.1-year period within the census interval. Then, for each 0.1-year period between 1 January 1983 and 31 December 2014, we calculated a weighted mean of all plots monitored at that time, using the square root of plot area as a weighting factor6. Confidence intervals for each 0.1-year period were bootstrapped.

Trends in carbon gains, losses and the net carbon sink over time were assessed using linear mixed effects models (lmer function in R, lme4 package72), providing the linear slopes reported in Fig. 1. These models regress the midpoint of each census interval against the value of the response variable for that census interval. Plot identity was included as a random effect, that is, by assuming that the intercept can vary ran-domly among plots.

Observation: Hubau does not use 31 years of measurements, but applies analysis methods (some which are generally disapproved of strenuously elsewhere by N.S., among others [Monckton, take notice]) to plot trends over gaps in data coverage that are in turn projected into the future. Hubau does intend their interpretation of their models to be taken and considered in a global context for consideration of global political policy.

Willis’ interpretation of Hubau seems most reliable, but I’m just a grumpy curmudgeon.

Last edited 1 year ago by dk_
Mike Dubrasich
Reply to  Izaak Walton
June 7, 2021 9:38 pm

30 years is a blip. 300 plots per continent is next to nothing. Solid is a joke. It’s angels on pinheads.

But anyhow, as I noted above, carbon fixation in forests is transitory. Whatever is fixed burns up (oxidizes) eventually (unless it becomes coal). There is an exception terrestrially: if land with marginal climates warms and/or becomes humid, then trees will grow where they didn’t before (tundra, deserts, etc.). That will increase fixation temporarily (until those forests burn — and they all do).

The oceans are different. Carbon fixed in calcium carbonate exo- and endo- skeletons can be permanently (more or less) deposited in reefs, shoals, and seabeds. The White Cliffs of Dover and other limestone formations are composed of formerly atmospheric CO2.

The oceans are where anthro and non-anthro CO2 goes to be sequestered. If I were a Carbon Cycle modeler (I’m not), I would model the oceans.

Nicholas McGinley
Reply to  Mike Dubrasich
June 8, 2021 9:59 am

Cliffs of Dover are miniscule compared to the really large and deep carbonate formations.
Note that virtually all sedimentary rocks contain at least some carbonates.
There are continent sized accumulations of mineralized CO2 that are in many places a mile deep or more. Some of the layers are almost pure limestone.

Last edited 1 year ago by Willis Eschenbach
Nicholas McGinley
Reply to  Nicholas McGinley
June 8, 2021 10:04 am

Aaw, I hate it when the photos just post as a link.
Anyone know why that happens and how to prevent it?

Anyway, I love that now we can upload pictures from our devices, directly.

There is an unbelievable amount of carbonate containing rock on the Earth these days:

Izaak Walton
Reply to  Willis Eschenbach
June 7, 2021 9:16 pm

You seem to use the “measurements” and “models” inconsistently. You state for example that “Now, it turns out that we can actually measure roughly how much human-generated CO2 is sequestered each year.” When in fact none of that is
actually measured. Most of the terms are modelled or estimated from various data sources about mining, concrete production, land use change etc. And if one wants to get technical CO2 levels aren’t measured but rather what is measured is the change in absorption of a laser beam in a cavity and then that is converted into a concentration using a model. So if you are happy to call all of that a measurement why isn’t what the authors did a measurement of carbon in a forest?

Ultimately close to 100% of measurements today are fundamentally measurements of a voltage drop across a resistor. Every time you see a measurement using an electronic sensor it is actually reading a voltage and then using a series of models to convert that voltage into something useful. You simply cannot escape the use of models. Whether you call it a measurement or a model is up to you.

Finally I never claimed that increasing the number of authors automatically makes a paper stronger. I simply stated that in this case there is a very good reason for the large number of authors — the different authors were responsible for looking after the different forest plots. Given that here they used 244 different plots across Africa this is a strength not a weakness. Had they used 2 plots and so had only 4 authors for example then the paper would have been a lot weaker. The paper announcing the discovery of the Higgs boson had a couple of hundred of authors and it certainly wasn’t the weaker for it.

Loren C. Wilson
June 7, 2021 6:01 pm

Willis: “Now, it turns out that we can actually measure roughly how much human-generated CO2 is sequestered each year. The calculation is not all that complex. We know how many gigatonnes (“GT”, 109 metric tonnes) of carbon are emitted each year from the burning of fossil fuels plus cement manufacture. We know that for every 2.13 GT of carbon emitted, the atmospheric carbon dioxide level increases by one part per million by volume (ppmv). We routinely measure the atmospheric carbon dioxide level at the Mauna Loa Observatory.
So we take a look at how much carbon is emitted in a given year and we calculate how much the CO2 level should have increased. We subtract from that the actual increase in CO2 during that year, and the difference is the amount sequestered in that year by various carbon sinks around the planet.”

This analysis presumes that the natural sources of CO2 did not change during the year, which is a big assumption. We cannot assume that nature produces CO2 at a steady state. The stated uncertainties in the major sources of non-anthropogenic CO2 are as large as what humans produce. we do not have an accurate material balance of CO2 inputs and removals from the atmosphere.

June 7, 2021 6:17 pm

You are using a mass balance that does not include a year-to-year increase in natural emission rates which allows the IPCC to claim about half of anthropogenic emissions accumulate in the atmosphere. The truth is that every molecule that reaches the surface of cold polar waters will be absorbed, and most will be food for phytoplankton. There is no global accumulation in the atmosphere beyond a year. The increase in atmospheric concentration is the result of year-to-year increases in natural emissions. During each year, concentrations do build up as sea-ice effectively closes the sinks. That buildup is completely consumed when the ice melts.


John Hultquist
June 7, 2021 9:06 pm

“We routinely measure the atmospheric carbon dioxide level at the Mauna Loa Observatory.”

 True, but . . .
For monitoring carbon dioxide concentration in the atmosphere, the Total Carbon Column Observing Network (TCCON) was formed in 2004, and by 2015, consisted of 23 monitoring stations worldwide. TCCON is a global network of stations that measure the amounts of CO2, CO, methane, nitrous oxide and other trace gases in the atmosphere.  

Elsewhere, I have read that Mauna Loa and 6 (?) other sites are continually checked against each other. All this is costly and well documented – and I’m not going to search it up again.

Reply to  John Hultquist
June 8, 2021 12:54 am

So there are other measuring sites (aka they have validation) and your point is ???

John Hultquist
Reply to  LdB
June 8, 2021 12:24 pm

 Over the last 10 years I have seen many people object to Mauna Loa as a CO2 observation site. It is actually a good site and there are others. Thus there is cross-checking.
My point was simply to add to the information for those not familiar with the issue of measuring CO2 in the atmosphere.
I made the assumption, perhaps wrongly, that there are people that did not know there are other sites besides Mauna Loa.  

June 8, 2021 1:40 am

Good statement-Sign me up as a co writer -We will outnumber them 😉

June 8, 2021 3:41 am

older trees use less carbon
so remove n plant new ones
listen for the screams

Crispin Pemberton-Pigott
June 8, 2021 6:53 am


I was quite sure you were going to demonstrate the falsity of the claim in the paper by first graphing the % of human emissions absorbed, thus showing it was about constant, followed by the slam-dunk graph showing the tonnage which of course has increased enormously since 1950.

Sure the fraction of CO2 we emit through various activities we emit (grossly underestimated because of the increase in farming) but the total has varied during the time covered by the graph, always upwards.

If the core claim of the modeller-scientists is that the capacity of the forests is falling, they expressed it in absolute terms, not %. So what is important is the two line chart of mass emitted and the mass absorbed.

That chart will show that the core claim is nonsense – the mass absorbed has been rising, and rising exponentially.

That they come to the opposite conclusion doesn’t surprise me at all. In the ocean of human knowledge and skill, they lurk out of sight in the deep trenches, which is an appropriate place for their paper.

(You get a cookie for showing readers how to evade the paywall.)

George Ellis
June 8, 2021 7:12 am

The planet is greening, but sequestering is down. Gotcha. /sarc

Steve Z
June 8, 2021 7:58 am

Excellent article (as usual), Willis!

Figure 1 also shows that the percentage of CO2 sequestered seems to have varied less since about 2005 than in previous years. This may be due to an improved tracking of CO2 emissions in recent years, whereas in earlier years people in third-world countries didn’t bother measuring CO2 emissions, so estimates of their emissions were less accurate, and could result in large variations of the (delta ppm) / (emission rate) ratio.

It’s also interesting that the (time-smoothed) sequestration ratio hasn’t changed much since 2005, while global anthropogenic CO2 emissions have increased significantly (particularly from China). The sequestration ratio calculated in Figure 1 does not distinguish between sequestration by photosynthesis or by absorption into the ocean, but both processes are known to accelerate when CO2 concentrations in the air increase (plant growth rates increase with higher CO2 concentrations, and Henry’s Law would force more CO2 into the ocean at higher CO2 concentrations for a given temperature).

The 106 authors of the original study seemed to concentrate on forests in the Amazon and tropical Africa, but it is possible that increased forest growth in other areas is balancing out any losses in the Amazon basin.

If the sequestration ratio hasn’t varied much while emissions have increased from 2005 to 2020, that means that the total sequestration rate (emissions * ratio) has increased while CO2 concentrations have increased. It would be interesting to plot a graph of sequestration rate (emissions * ratio) as a function of CO2 concentration, to determine whether this is a first-order (linear) relationship, or some other function. This could be used to estimate future CO2 concentrations as a function of predicted emission rates.

Nicholas McGinley
June 8, 2021 8:49 am

This so-called study does not even pass the laugh test.

June 8, 2021 9:36 am

I’m afraid I don’t get this claim that mature rainforest is a carbon sink. Photosynthesis traps carbon dioxide as sugars, starch and eventually cellulose and lignin. Eventually all this is broken down down by bacteria and fungi and the carbon dioxide (and plant nutrients) released again. If this did not happen there would be a continuous build up of organic matter (wood, leaf litter etc.) I am sure the late lamented David Bellamy considered the whole system was in balance and therefore carbon neutral. In the carboniferous organic matter did accumulate but this may have been because it was trapped in anoxic conditions or the bacteria needed to break down wood (lignin) had not evolved. Perhaps someone more knowledgeable than I could sort this out for me.

June 8, 2021 1:21 pm

Latest data point shows biggest monthly drop in over 20 years

June 10, 2021 1:33 pm

Curious indeed that climate scientists seem almost embarrassed by trees and plants and always try to downplay their significance. I read something interesting today that could put the cat among the pidgeons. Rising CO2, we are admonished to believe, traps IR in the lower atmosphere causing warming. However there is a parallel effect of CO2 in enhancing – for obvious reasons of the photosynthesis reaction – plant growth worldwide.

Thus global leaf area has recently increased – not decreased – by an amount in the tens of percent. Specifically because of CO2 enhancement of photosynthesis.

But that’s well known – the interesting thing I learned today is that recent infrared spectroscopy research has found that plants’ leaves are surprisingly good at backscattering and re-emitting incident near infrared light. Indeed – trees and plants look unexpectedly bright in IR camera images (see below).

This points to yet another feedback working against warming by CO2. The increased leaf area caused by CO2 rejects an increasing percentage of ground incident IR back upwards – effectively increasing near IR albedo.

Could this be one of the factors causing CO2 warming to have been less than expected? I always suspected and felt that the great efforts to conceal and down-play global CO2 greening are unhelpful to a full scientific understanding of the total effects of rising CO2.

Last edited 1 year ago by Hatter Eggburn
June 11, 2021 1:01 am

As usual I like your thoughtful and well expressed critique, Willis. I’m a biochemical engineer (at least my diploma says I am). One thing that has served me well in my career is to focus on the variables that significantly impact the system I am trying to understand, and set aside the variables that have a minor impact. That is why, for example, when sizing an evaporative cooling tower for a large plant the variables that I used to correctly purchase, install, and run the cooling system were 1. The total heat the tower needed to dispate, 2. The range of heat dissipation rates the plant could expect over a typical year, 3. The temperature of the incoming cooling fluid (water), 4. The desired temperature of the out flow cooling fluid, 5. The desired efficiencies, and costs to operate various cooling systems having various coolants, etc. The most efficient large scale cooling towers all rely on water as the coolant. As you know water not only has an unusually large heat capacity, but it also can absorb an incredible amount of heat because it can change phase. Water also scrubs gases out of the air! Including CO2.
In your analysis, it is my opinion (not worth much I know, but I’m going to give it anyways) that by far the largest sink (and source) of sequestered CO2 is not forests, but rather the living flora and fauna in the oceans, coupled with all the CO2 scrubbing done by water in the storm layer (second ocean layer). This sink/source of CO2 sequestration so dominates the movement of CO2 into and out of the air it effectively buffers ALL other mass transfers of CO2 planet wide by several orders of magnitude. Am I way off in my thinking?

June 15, 2021 5:02 am

Dear Mr. Eschenbach,
Allow me to tell you that I enjoy your articles hugely, and as an editor of the only skeptical climate web site in Denmark, I have taken the liberty of translating some of your articles (partly or in full) into Danish (an obscure incomprehensible language) for our site, and they have been very well received. The last one I published was your story about the paleo climate model work, which based on 58 variable parameters basically concluded nothing. I loved it.
Best regards,
Soren Hansen

%d bloggers like this:
Verified by MonsterInsights