Is there enough fossil carbon in the atmosphere to create global warming? Lessons from mistakes, misinterpretations, and propaganda

 

The great holobiont called the "biosphere" continuously exchanges carbon with other parts of the Earth system: the hydrosphere and the geosphere. It is a fascinating section of the science of the atmosphere that, just like all other sections, is subjected to misinterpretations, mistakes, and sheer propaganda,   

Earth's climate is one of the most fascinating fields of study nowadays and if you are interest you can learn something new every time you stumble into a new report. Even the so called "debate," biased as it is, may be useful to learn something not just about climate science, but about human psychology as well. Let see an example starting from a comment that recently appeared on twitter,

"Goggle Bob" defines himself as "Engineer that likes technical financial charting (energy, precious metals, commodities, cryptos); as well, a student of the fiat money system." 

First lesson learned: people will think that something they don't understand is "very good science" if it agrees with their personal biases. 

Now, let's go to the paper by Skrable et al that Google Bob cites. It is not an easy paper to digest, but it is an attempt to quantify the fraction of atmospheric CO2 that's the result of the burning of fossil fuels. It is all wrong, as we'll see in a moment, but it is a good occasion to learn something about atmospheric physics and hydrocarbon dating.

It is all about the "Suess Curve;" proposed by Hans Suess in 1967. The curve is about the fraction of the 14C isotope contained in the atmosphere as a function of time. 14C is an unstable isotope, but it is continuously created in the atmosphere by a reaction of carbon nuclei with cosmic rays, and its concentration can be taken as approximately constant, apart from human perturbations. One of these perturbations is the burning of fossil fuels. Since 14C gradually decays with time, those carbon materials which are not continuously exchanged with the atmosphere tend to lose it. So, fossil hydrocarbons contain essentially zero 14C, and burning them is expected to reduce the fraction of 14C. 

Quantifying this amount is not easy, but the final result is that fossil fuels generated about 75% of the extra 145 ppm (from ca. 280 to 425 ppm) of CO2 relative to pre-industrial times. The rest was generated mainly from deforestation and cement production. Another conclusion is that just about 45% of the carbon generated by fossil fuels remains in the atmosphere right now; the rest is stored somewhere in various reservoirs in the ocean and in the biosphere. This is a story I already knew in its main lines, but the discussion about the paper by Skrable et al. led me to go deeper into the matter. 

Second lesson learned: bad science can lead you to learn some good science. 

Now, let's go into the details. At a first read, the paper by Skrable et al. looks legitimate. For someone like me, not an expert in atmospheric radiochemistry, the way the paper is written seems to make sense: there are estimates, equations, and conclusions, all written in the standard jargon of scientific papers. But the  problem, a big one, is their statements that "the quantity of anthropogenic fossil CO2 in the atmosphere in 2018 represents about 23%  of the total amount of anthropogenic fossil-derived CO2 that had been released to the atmosphere since 1750." They also say that ""the atmospheric concentration, <CF(t)>, of anthropogenic fossil derived CO2 in 2018 is 46.84 ppm." And that "the percentage of the total CO2 due to the use of fossil fuels from 1750 to 2018 increased from 0% in 1750 to 12% in 2018, much too low to be the cause of global warming."  (boldface mine)

You only need to know the basic elements of climate science to understand that the final statement is a flag for something badly wrong. Today, we have about 425 ppm of CO2 in the atmosphere, which is about 145 ppm more than the pre-industrial concentration of 280 ppm. Let's assume that the authors are right in their estimate (47 ppm of CO2 resulting from fossil fuels). It means that there are about 100 ppm of extra CO2 in the atmosphere that are NOT the result of fossil fuel burning. And where does this huge amount of carbon come from? 

You would have to think that the total ca. 300 ppm of CO2 emitted by the burning of fossil fuels was almost wholly absorbed by the reservoirs. And not only that: this CO2 must have triggered a huge release of carbon that had been stored in some surface reservoirs for a short time. Otherwise, it would be depleted in 14C and indistinguishable from fossil carbon. Difficult to believe, but even if it were true, the current CO2 excess would still be an indirect result of hydrocarbon burning. No matter how you see it, the statement that "the total CO2 due to the use of fossil fuels ... is much too low to be the cause of global warming." simply makes no sense. It is not a specific isotope of carbon that generates warming; it is the total amount. 

From this, the authors do much worse when they state that "unsupported conclusions of the dominance of the anthropogenic fossil component of CO2 and concerns of its effect on climate change and global warming have severe potential societal implications that press the need for very costly remedial actions that may be misdirected, presently unnecessary, and ineffective in curbing global warming." In Italy we have a way of defining this kind of statements as "peeing outside the pot," and I think you understand what it means. 

Third lesson learned: bad scientific papers can often be identified by their politically-oriented statements.

So, what was actually wrong with Skrab's paper? Examining in detail a scientific paper dense with equations, numbers, and tables is a lot of work (and, in Italian, we have a principle describing how unrewarding it is, but I won't report it here because it uses scatologic terms). In this case, though, there is a crystal clear explanation provided by Andrews and Tans that highlights the trivial mistakes that Skrab et al. made. 

Without going into the details, the main mistake in Skrab's paper was to neglect the effect of nuclear explosions in creating an extra amount 14C, thus giving the impression that the fraction of fossil carbon in the atmosphere is lower than what it actually is. It is more complicated than that, but it is enough to pinpoint the most glaring mistake in the story. 

Fourth lesson learned: a good rebuttal to a bad paper can teach you a lot!

Now, how can it be that a group of scientists with a good reputation in their field choose to deal with a subject they are not familiar with and end up making fools of themselves? It may happen that a scientific revolution comes from newcomers in the field; for instance, when Galileo showed that planets couldn't possibly move because they were pushed by angels, he made a fundamental contribution to a field that wasn't his; theology. But that's rare. Making a fool of oneself is much more common. It could be easily avoided with a minimum of humility: before publishing your paper, why don't you submit it first to the experts in the field? That doesn't mean that the experts are always right, but they can point at the mistakes that you may well make if you are an amateur. Nevertheless, it happens all the time.

Fifth lesson learned: scientists can be blinded by their preconceived ideas just like everyone else. 

To conclude, as you may have imagined, the statement that "the total CO2 due to the use of fossil fuels ... is much too low to be the cause of global warming." is making the rounds on Social Media, being reported by people who made no effort to understand why it was uttered, nor why it is wrong. And so it goes

Sixth (and final) lesson learned: Politics always trumps science in the debate.  

The Reptilian Mirage Suit: Learning the Purpose of Human Ears

Another interactive lecture delivered by Meuianga (honorable) Mera Te Aì 'Enge'ite, chief scientific officer of the Reptilian Starfleet

Welcome, space cadets! It is a pleasure to have you again for a new lesson on exobiology, and specifically about the habits and usages of these fascinating creatures we call "naked apes" or "humans"

-- It is truly a pleasure, Meuianga.
-- Yes, we are learning a lot. It is a pleasure to learn from you. 

Ah, cadets, today we'll see something really interesting. I've beamed for you to our spaceship another of those interesting human specimens. This time, we have a female to examine. As last time, please be gentle with her. She is lightly sedated, but please make sure that you don't scare her, and always remember the basic Starfleet rule that we must respect all lifeforms we encounter. And here she is. 

-- A very interesting specimen, Meuianga.
-- She looks a little dazed. Is she intelligent?

Yes, cadets, she is very intelligent - you see her a little dazed because she is sedated. But she is at a higher level of intelligence compared with the average naked ape. She is one of their technology specialists; some of them are rather clever. This is one. Later on, we'll test her intelligence, to see how she compares with ours. You'll see that she does reasonably well, of course within the limits of her species.

But today I have another element that I wish to examine for your training. As you saw in our previous lessons, we are focusing on some anatomical elements of these creatures' bodies. Their adaptation to their environment is sometimes remarkable. And so, I invite you to examine the fleshy protrusions she has on both sides of her head. Please be gentle with the specimen, but do examine this curious entity, and tell me what's your impression.

 
-- Ah, Meuianga... it is rather weird
-- Yes, you see, Meuianga, it is... how could I say....
-- Meuianga, I am sorry, this may go against the Starfleet rules, but isn't this thing a little disgusting?

Ah, good, good, cadet Epu Te 'Eyingua Ruìze'itan. You understand that we have to take into account that our reaction to some features of the alien species we encounter may be negative. But we have to overcome this emotional reaction. If you have to learn how to deal with these creatures, you will also have to learn that in an ecosystem, everything that exists has a reason to exist. And it is the same for this fleshy protrusion. It is, indeed, a fascinating story -- just like many things are fascinating with these creatures.

-- But Meuianga, it is so strange. It is really part of the creature?
-- Maybe it is a polyp?
-- Or a parasite that has attached itself to the head of this ape?

No, no... cadets. It is a regular feature of the naked apes. All of them have these "ears" they are fleshy protrusions that grow around the auditory channel, but they are bona fide elements of the genetic setup of these creatures. But on one point, cadets, you are right. One of the features of this thing has no adaptive evolutionary value. Can you locate it?

-- Hmm.... Meuianga, maybe the whole structure is purely decorative?
-- Is it a sex signal?
-- Does this creature use these strange entities to signal its willingness to mate?

Oh... I see that you are getting into this matter. Indeed, these creatures have many ways to signal their willingness to mate. And even this fleshy polyp, if you like to call it this way, has a certain value in this sense. But there is a specific feature of the excrescence that has this characteristic. Can you see it?

-- ..... Hmmmm
-- Well.... maybe..
-- Ah... difficult.

I understand you, cadets. It takes a certain practice to understand some features of this species. Not for nothing I have been working on them for several hundred revolutions of their planet around the star. Now, let me show you on screen this picture that our female specimen nicely provided for us

-- Oh... that's interesting, Meuianga.
-- Yes! What is that round thing?
-- Remarkable. A small sphere attached to that protrusion. It is eerily beautiful...

Yes, cadet Ìtxeyeai Te Zuäk Nayitä'ite. You noted its characteristic. The little sphere is called an "earring," and female apes often wear one on the lower protrusion, called the "earlobe." Males also wear earrings, but more rarely.

Now, you should note two things. The first is that the earlobe of this creature is pierced. It has a hole that goes through it. It is not part of their genetic setup. It is made with a drill. I guess it has to be painful, but it seems to be very common with these creatures. But the most important point is to note that the earlobe has no adaptation value whatsoever. It is just there, and I venture to say that it has developed as a support for these decorative signals. By the way, the round thing is called a "pearl." It is a secretion of some bivalve molluscs living on planet Earth.

-- Truly fascinating, Meuianga. So it is a sexual signal?

Yes, cadet Zayo Te Yuutxha Spälsloaynla'ite, one of the many sexual signals that these creatures use. There are many others -- some are rather explicit in indicating a willingness to mate. This one has a moderate strength, but that's the idea, indeed.

-- You know, Meuianga, I feel bad about not having these earlobes.

Ah, cadet, you are funny. But wait for a while. We are moving to something that you'll find interesting. But before getting to that, let me go back to the examination of this protrusion. You noticed that it is quite elaborate in those fleshy circumvolutions inside. Do you think they have a purpose?

-- Another difficult question, Meuianga.
-- They might have a purpose? Or maybe they are another sexual signal?
-- I don't think so. You didn't tell us that they wear decorations also in those circumvolutions, did you?

Exactly, cadet Ngoawa Te Zìuìtkip Lrrher'ite. These circumvolutions do have a specific adaptive value. But in order to understand that, I must ask you another question. If these protrusions have adaptive value, why do we reptilians not have them?

-- Ah... That's truly fascinating.
-- You mean that the naked apes have features we didn't develop?
-- Maybe they are better adapted than us?

Oh, no, cadets. No species is more adapted than another species. These creatures are perfectly adapted to their ecosystem. It is just that they are different creatures. And the point is that they collect sound waves inside a specific organ that's called the cochlea. So, they use their "ears" as a way to amplify sound waves and send them into the cochlea. It is quite sophisticated but not as good as our sound dome; is the ball of fat you have inside your elongated cranium that amplifies sound waves. We are better than them at detecting vibrations, also because we evolved in a denser atmosphere. 

Incidentally, some Earth mammals have the same device. They are marine mammals called Dolphins and Whales in the ape language. Their dome can be quite large. Let me show you one of these creatures. Do you see the dome? It is full of fatty oils. It is a remarkably efficient resonating device Anyway, the point is that we don't need ears, the apes do. But that doesn't tell us why the circumvolutions inside the ears.

-- Meuianga, you know that we are fascinated.
-- But we need your help
-- You know much more than us.

Ah, cadets, you have many things to learn, but you are learning a lot. And for this, I shall demonstrate for you a use of your mirage suit. You have it, it is part of your training materials. You'll use it especially when you'll move to the surface of planet Earth, but today we can have a taste of how it works. Would you please activate it?

-- Yes, Meuianga. We'll try...

-- It looks like it is already set on "naked ape"

-- Yes, there is a button

-- There we go....

So, cadets, don't you look nice in your mirage suit? You really look like naked apes dressed up with our nice Starfleet uniforms. 

-- Well... maybe...
-- Strange...
-- We feel very strange, Meuianga.
-- Not sure we want to look like thise naked apes....

It is all right. The mirage suit can have strange effects; you'll have to learn how to use it well. It is not just a mirage; it changes you. It turns you into the mirage you want to become. But, today, we are examining just a specific feature of the naked ape, a feature that your mirage suit has reproduced. Now you have human ears! Touch them!

-- Ah... remarkable, Meuianga.
-- We have these weird protuberances. But we hear through them.

Yes, you do. Now, a little experiment. You know that you are detecting sound waves by means of a mechanism called the cochlea, which is inside your human head. Now use your hands to cover your inner circumvolutions, but NOT the opening to the cochlea. That shouldn't affect what you hear, don't you think so?

-- Well, Meuianga, that looks logical.
-- But you are teaching something interesting.
-- We are sure of that.

Of course, I want to teach you interesting things. There are so many things to learn for you. And for me, too!!! Now, let's do this experiment, I'll sing for you the Starfleet song, and you'll go covering and uncovering the circumvolutions. Then you'll tell me what you heard. Let me go, you'll follow me with the chorus....

In the vast expanse of cosmic might,
We sail through stars, our reptilian flight.
From far-flung corners to unknown domains,
We are the crew of proud reptilian reigns.

(Chorus)
Starfleet, our ships blaze through the night,
Conquerors of galaxies, a formidable sight.
With scales that shimmer, and eyes that gleam,
We soar as one, fulfilling our dream.

Our empire vast, from world to world we roam,
A legacy built, on territories we've known.
In noble pursuit of knowledge and might,
We traverse the cosmos, guided by light.

(Chorus)
Starfleet, our ships blaze through the night,
Conquerors of galaxies, a formidable sight.
With scales that shimmer, and eyes that gleam,
We soar as one, fulfilling our dream.

So let the cosmos bear witness to our might,
The proud reptilian crew, shining bright.
In the depths of space, our legacy unfurled,
We conquer the galaxies, the masters of the world.

Truly good, cadets. You know, it is strange to hear the Starfleet hymn sung by creatures that look so much like naked apes wearing Starfleet uniforms! Who knows, one day, we might enlist some of them as crews of our ships. But never mind that. That was an experiment. How did it go?

-- Ah... Meuianga, yes... truly strange
-- It was different with and without the covering of the circumvolutions.
-- Yes, indeed. It had more depth when the circumvolutions were not covered.
-- How was that?

Well... cadets, first of all, it is a miracle of the mirage suit that reproduces so well not just the outer shape of the naked apes but the way their sensorial system works. And now you understand the meaning of the circumvolutions. They are a sound-wave interference system that provides information on the direction from where the sound comes from. Not as efficient as our sound domes, but it works nicely for the naked apes.

-- Fascinating, Meuianga, truly fascinating.
-- It was an unbelievable experience.
-- Yes, with the circumvolutions uncovered we heard you as if you were singing from the depth of the galaxy
-- An eerie sound. Beautiful!

Glad that you liked it, cadets. Now you learned something about the naked apes and also how to hone your observational skills on all the details. This is the way to learn; this is the way of the Starfleet officer that you are going to become.

-- Meuianga, thank you so much... but there is one thing. 
-- I feel strange, don't you, fellow cadets?
-- Yes, these mirage suits are truly sophisticated devices.
-- You see, Meuianga, I think we all feel the same.... looking at the human girl, there is this strange sensation....
-- Very, very strange...

Cadets, cadets, control yourselves. The human girl is surely a nice-looking specimen, and I understand that the mirage suit can have some weird effects if worn for some time. You'll have to learn how to use it properly, and maybe one day you'll want to experiment with these strange -- let's say -- "sensations." But it is not for this reason that we beamed up this creature. And I see that she is a little shocked having seen you turning from nice looking reptilians into this ape form. Now, act again on the controls of your suit, and return to your normal shape. Then, we'll beam the girl back. I guess she's learned something, too. And see you next time for another lesson!

(The images of the aliens are made using Dall-E. Thanks to Ilaria for having posed as the human female)

Lectures by Meuianga Mera

Why Naked Apes have Small Mouths. Explained by Meuianga Mera, Chief Scientist of the Reptilian Starfleet

The Red Mouthed Apes: A Lecture by Meuianga Mera, Chief Scientific Officer of the Reptilian Starfleet

The Naked Ape -- A Tale Told in Space

The Reptilian Mirage Suit: Learning the Purpose of Human Ears

The Evolutionary Game: How did Elephants survive the onslaught

Invisible Friends -- a Very Holobiontic Book

 

I am sure it is a very holobiontic book. I can't wait to read it!!

https://pelagicpublishing.com/products/invisible-friends-microbes-jake-robinson

Conserving old growth forests is key to stabilising the Earth’s climate

From the Blog of the Club of Rome




© Greatandaman | Dreamstime
By Ugo Bardi, member of The Club of Rome


02 May 2023 – Do forests create rain? It is a question that has been debated for a long time. We know that trees produce huge amounts of water vapor that is pumped from humidity in the ground and condensed into clouds that generate rain, but the mechanisms that govern condensation and vapor water movements are still not completely clear.

In our new paper, a group of researchers led by Anastassia Makarieva of the Theoretical Physics Division of Petersburg Nuclear Physics Institute (PNPI) and the Institute for Advanced Study of the Technical University of München (TUM) highlight how evapotranspiration – the evaporation of water by trees, modifies water vapor dynamics to generate high moisture content regimes that provide the rain needed by land ecosystems. The research is a significant step forward in understanding the critical need to conserve old-growth forests to stabilise the Earth’s climate and maintain the biodiversity needed for the ecosystem to survive.

The study titled “The role of ecosystem transpiration in creating alternate moisture regimes by influencing atmospheric moisture convergence” shows that two potential moisture regimes exist: one is drier, with additional moisture decreasing atmospheric moisture import, and one is wetter, with additional moisture enhancing atmospheric moisture import. In the drier regime, that may be caused by deforestation, water vapor behaves as a passive tracer following the air flow. In the wetter regime, it modifies atmospheric dynamics and amplifies the atmospheric moisture import, creating rain.

There is still much that we need to understand about these mechanisms, but we are starting to understand how forests and the atmosphere form a system of connected elements that affect each other. One thing is clear: forests are crucial to the stability of the Earth’s climate.

Not only do trees store carbon in a form that does not cause greenhouse warming, but they actively cool the planet, due to how moisture condensation is managed. Forests also control the water cycle on land, pumping water vapor from the oceans inland by a mechanism called the biotic pump. Old growth forests generate giant flows of water known as “flying rivers” that fertilise entire continents. Our study shows that the non-linear precipitation dependence on atmospheric moisture content has wide-ranging implications. Atmospheric water flows do not recognize international borders, meaning deforestation disrupting evapotranspiration in one region could trigger a transition to a drier regime in another.

Our results indicate that the Earth’s natural forests, in both high and low latitudes, are our common legacy of pivotal global importance, as they support the terrestrial water cycle. Their preservation should be a recognised priority for our civilisation to solve the global water crisis. Important on-going work calls for re-appraisal of the forest’s role in the global temperature regime.

The study was performed by an international research team that included scientists from North and South America, and Eastern and Western Europe.

Is Gaia going to die of heat stroke?

 

Figure from the recent paper by Duffy et al. on "Science"

What is the maximum temperature that the Earth's Holobiont (aka "Gaia") can withstand before collapsing? Some data from a recent paper in "Science" indicate that we are not so close to the "Venus scenario" that would sterilize our planet. Nevertheless, the system is under stress

As you see in the figure at the beginning of the post, the optimal average temperature of planet Earth for the standard C3 photosynthesis (that of trees) is around 16 C, not far from the current value of around 18 C. (note that the graph takes into account not just temperature, but CO2 concentrations, supposed to be affecting temperature). Switching to the C4 mechanism (grass and others) moves the maximum to about 28 C;  10 degrees higher than it is now. 

So, we have a comfortable range in terms of plant life, and consider that the "zero" in the curve doesn't mean that all plants die; just that they are less efficient, especially in the hot equatorial zones. Note also how the "respiration" curve keeps growing as a function of temperatures; in the paper, they say that it keeps growing up to 60-70 C. 

Complicated story, but in any case, Gaia is not going to die soon. Note that during the Eocene, some 56 million years ago, the Earth's temperature was indeed some 8-10 degrees higher than it is now, and the planet was covered with lush forests. It is believed that C4 photosynthesis didn't appear on Earth before 35 million years ago. So, even an extra 10 C of warming will not destroy the biosphere: Gaia has a thick skin.

Eventually, the increasing solar irradiation will kill the Great Earth Holobiont but, hopefully, that will take a few hundred million years (at least). About humans, though.... well, it is another story. Do we still have a few decades left? Maybe. 

Is Rewilding a Good Idea? Why We Need to Rethink Our Approach to Ecosystem Regeneration

Rewilding is a popular idea nowadays. Given the poor performance of humans in managing ecosystems, the temptation to leave the wheel to Gaia is strong. But it is also true that in the long history of the Earth, Gaia has not always been firmly in control. Maybe she was drunk, maybe she was stoned, but Earth without humans has been "wild" in the sense that it went through all sorts of oscillations -- sometimes true catastrophes. Just think of the alternance of ice ages/interglacials of the past 2-3 million years. So, what do we mean with "rewilding"? Returning Eurasia to the "Mammoth Steppe" of the ice ages? Or to the lush forests of the Eocene? Or what, exactly? Here, Helga Ingeborg Vierich criticizes the concept of rewilding and proposes better ideas to manage the ecosystem. In general, the correct approach should not be "rewilding" but "regeneration"

By Helga Ingeborg Vierich -- From "The Proud Holobionts" Forum

Is the term we are looking for here really "re-wilding”? I ask this because the term “wild” implies that it is not “tame” - “wild” is usually present as the opposite of “domesticated”.

The term further prevents an understanding of reality. What is that reality? Well, let us start with this: the human species IS part of the ecosystem of this planet.

Homo sapiens and earlier ancestral forms have been keystone species for at least a million years. For 99.99% of our evolutionary history, we humans were keystone ecological engineers. Like beavers and otters and wolves and whales and elephants, we were increasing and stabilizing the diversity of life in every ecosystem we inhabited.

This positive effect on ecosystems was not, however, due to anything genetic or innate in human behaviour, it was due to learned and shared patterns: in other words, it was “cultural”.

Starting in a few places on the planet, a cultural change to more ecologically destructive economies changed all that. At first it only effected a tiny proportion of humanity and of the ecology of the planet, but then it grew and coalesced into larger and larger cultures containing higher and higher proportions of the human beings, and more and more surface areas around the globe.

Today we call it our “civilization” as if it was a positive and progressive change in our relationship with the planet and each other.

It has been nothing of the kind. Each state level society with civil - urban - population concentrations, has been requiring far too much deforestation and other resource extraction. The reality is that there is nothing positive about the progressive destruction of ecosystems in support of greater and greater urbanization and an extremely expensive (though tiny) “upper” class of humans.

This has not just disrupted the positive trophic flows that characterized the human past, after the “industrial revolution” began, it has reversed them. Now, the global industrial economy is the main driver of species extinction, environmental pollution with toxins and plastics, and climate change.

Just look at this chart below...

So our job now is NOT to “leave nature alone” but to relearn our species' responsibility within the planetary ecosystem, and RENEW that positive effect on diversity and stability.

Humans will not be able to do this if they continue to be guided by corporate and political elites whose main goal is to enrich themselves and stay “in power” over inegalitarian cultures competing for control of the planet’s diminishing resources of minerals, fossil carbon, water, and “arable soil”. I am very afraid that what this means is incomprehensible to most people in this present industrial and financially-driven culture.

1: Stop industrial agriculture. The planet cannot afford it. 

2, Restore predators and critical keystone species to every available habitat, and stop killing them for “fun” or “profit”. Beavers, wolves, lions, bison, bears, caribou, otters, and all the other component species of a diverse and healthy ecosystem will restore positive trophic flows. That includes diversity of plants, and is vital: 

3. Stop the destruction of forested ecosystems: the lumber and paper industries must be radically scaled back. Stop this silly substitution of “commercially valuable” tree plantations and restore actual forest ecosystems. Above all, immediately stop the cutting down of existing forest ecosystems. Recycle paper, plastic, all metals, and so on. 

4. All industrial scale “commercial” fishing, as well as “fish farming” must be stopped. 

5. TAX the rich and the corporations - and stop all investment of money (gambling) in any industry.

6. Begin taking the necessary steps to close down the petroleum-powered automobile industry: no more ”new models” every year. Restore and enlarge electrically powered public transit - trains and street cars and buses... encourage bicycles by increasing bike lanes in all towns and cities.

Trophic Rewilding: A Cure for a sick Planet?

 

The Mammoth Steppe was a huge area that extended over most of Northern Eurasia, including part of Alaska. It existed during the last glacial period, 126,000 YBP–11,700 YBP. Then, it was superseded by modern boreal forests during the thaw that led into the Holocene. The question of what factors led to this huge switch in the dominant biome is far from being clear. If "rewilding" some areas of the Earth is a good idea, should we strive for forests or steppes? After all, they are both "natural" environments?   

You may have already seen this paper just appeared on "Nature" with the title: "Trophic rewilding can expand natural climate solutions." The study is led by Oswald Schmitz of Yale University and is an assessment of the role of natural trophic chains on climate and of the perspectives of using "rewilding" as an important method for the mitigation of global warming. It has been described as a "landmark paper," and in several respects, it is. It is part of a general movement in favor of rewilding, and there is even a "Global Rewilding Alliance." 

The concept makes plenty of sense. It provides an alternative to the multiple bizarre ideas that have been proposed as "solutions" for the climate change problem, including cutting down the Boreal  Forests to increase Earth's albedo. On the other hand, it is still a subject in its infancy. One problem is that the authors do not mention that there is not just carbon sequestration at play in the climate game. They miss the effects of forests on the hydrological cycle (the kind of effects studied by Gorshkov, Makarieva, and others). But I think that it could be possible to merge these concepts together. In both cases, the idea is to restore the ecosystem to its maximum metabolic rate, balancing the disturbing effect of human activities. 

A deeper problem lies in understanding why exactly trophic chains have the effects claimed in the paper. The paper reports several estimates of the amount of carbon stored by various biomes, noting how it increases when a more diverse ecosystem is restored. To give an idea of the approach of the paper, the authors write that: 

The dividend of creating dynamic landscapes and seascapes is illustrated by the 1.2 million Serengeti wildebeest still found in Africa. This population annually migrates throughout the 25,000 km2 savannah– woodland landscape tracking lush vegetation created by seasonally and spatially varying rainfall. During the migration, wildebeest consume large amounts of grassland carbon and return it as dung that is incorporated by insects into soil storage. In the early twentieth century this dynamic was halted when the wildebeest population plummeted to 300,000 animals, decimated by rinderpest disease transmitted from domestic cattle. Consequently, there were too few animals to fully graze the landscape. The increased standing grass fuelled more frequent and intense wildfires that released carbon stored in the biomass across 80% of the landscape, which rendered the Serengeti a net source of atmospheric CO2 (ref. 47). Similar alterations of fire regimes followed the near-prehistoric extinctions of other large herbivores, the legacies of which persist today. Fire is an essential natural process in most of these systems, but the loss of natural grazing increases their frequency and intensity. Restoring the wildebeest population through disease management led to less frequent and intense wildfires, and gradually restored the Serengeti back to being a carbon sink. The Serengeti now stores up to 4.4 MtCO 2 more than when the wildebeest population was at its lowest. 

Which is truly fascinating. But why exactly should more diverse ecosystems store more carbon? One could say that if there were no wildebeest, then the forest would cover the Serengeti Park, and wouldn't a forest store more carbon than a savanna? Not necessarily. Large herbivores can sequester a lot of carbon in the soil, and it seems that the deep, fertile soil that Europeans found in the central area of North America was the result of the work of the huge herds of large ungulates living there. So, in terms of carbon storage, is a forest better than a savanna, or is it the reverse? 

Probably there is no clear-cut answer, and maybe there will never be one. Biomes are always dynamic; they change all the time. Although, in general, the ecosystem strives for stability, it may not be able to reach it except as an average -- it is sensible to even minor triggers such as the Milankovich oscillations that triggered the cycles of ice ages of the past two million years or so. But the Milankovich effects are just that: triggers. For the huge Earth ecosystem to move from a cold to a warm status, and the reverse, it takes enormous forces at play. In any case, the trophic chain remains the crucial factor in the ecosystem, the backbone of holobionts in their extended definition.

h/t John Day and Михаил Войтехов