How to Freeze a Holobiont: The Great Proterozoic Catastrophe

 

Image created by Dall-E

One of the great features of climate science is that you always learn new things. It is the story of how our planet evolved, changed, and arrived where we are, silly naked apes as we are. One of the most fascinating moments of this long history is the "Snowball Earth" period. Some 700 million years ago, in the Sturtian period, at the end of the Proterozoic Eon, the whole planet got frozen, covered by an ice sheet. Yes, Earth was all white, ice-covered, and nicely frozen. The great holobiont that some call "Gaia" nearly died. It may have survived, barely, because some small areas, maybe volcanic hot springs, remained ice-free.

Why this event? An ongoing research effort is aimed at unraveling the story. The latest results show that the great freezing was preceded by the "Franklin Large Igneous Province" (Franklin LIP). It was another spectacular event but for the opposite reasons. It involved a gigantic volcanic eruption that spread molten lava over a huge region that went from the regions now called Alaska and Greenland. It lasted about one million years. Earth's history is never boring!

Now, some recent data show that the Franklin LIP took place immediately before the great Snowball Glaciation. And the proposal is that the LIP caused the snowball. 

Great, but one moment. There have been several Large Igneous Provinces, LIPs, in the later history of Earth. In most cases, the result was warming, not cooling. The "great dying" of the end of the Permian, about 250 million years ago (at the "Permian-Triassic" boundary) was caused by a giant LIP in the region called Siberia today. The demise of the dinosaurs (apart from birds) was caused by another huge LIP taking place in the Deccan region in what is now India (an asteroid may have helped, but the LIP was probably the main cause). Smaller LIPs also caused havoc in the ecosystem. 

The basic idea is that these huge eruptions inject large amounts of CO2 into the atmosphere, generating a rapid and catastrophic warming that, in turn, causes a dieoff in the ecosystem. So, what did the Franklin LIP have that is different from the more recent LIPs? Is this a new demonstration that climate science is all wrong, actually a hoax created by the appliance industry to force us to cook on induction stoves?

Well, no. If you know the basic mechanisms that control CO2 concentrations and consequently Earth's temperature, the story makes plenty of sense. The Franklin LIP was not different (not so much, at least) from the later LIPs. But the world in which these eruptions took place was completely different. 

Let's start from the beginning: How do LIPs emit CO2? It is because the volcanic lava contains carbonates, compounds that can decompose, producing CO2 and oxides. As for all chemical reactions, the equilibrium between CO2 release and uptake depends on temperature. At the high temperatures of molten lava, carbonates tend to decompose, but, when the lava cools down, the reverse reaction occurs. Now, CO2 reacts with silicates to form carbonates. If the mass of lava is truly huge, as it was in the Franklin LIP, then it is no surprise that the CO2 drawdown is massive. If the temperature is hot enough, but not too hot, the drawdown is also rapid, at least on the geological time scale. Starved of CO2, the atmosphere doesn't act any longer as a blanket to keep the Earth warm. Bang! It is snowball Earth. 

Now, there comes the fundamental point: at the time of the Franklin LIP, the interplay between CO2 release and uptake took place in a relatively simple world: There was no life on land; it only appeared a couple of hundred million years later. So, since the LIP took place mainly on land, it didn't interact with the land biosphere. Then, fast forward 400 million years in the future, and you are now seeing the huge, gigantic, enormous, appalling lava landscape that we call the Siberian LIP. Same thing as before, but with a profound difference. By then, life had spread on land and had plenty of time to create huge reservoirs of carbon that resulted from the decomposition of living matter. This carbon we call "coal." In addition, there were also reservoirs of kerogen (solid hydrocarbons dispersed in the soil) and those hydrocarbons that the naked apes living today on Earth call "fossil fuels." 

Imagine the lava spewing out from the Siberian LIP going through this mass of fossil carbon, and you see that there was a factor that didn't exist with the Franklin LIP: coal was burned by the hot lava and turned into CO2. The same thing happened some 190 million years later with the Deccan LIP. Huge amounts of carbon were turned into CO2 and the resulting warming wrecked the whole ecosystem. Bang! Another mass extinction (the poor dinosaurs were boiled alive). That was the rule with all the Phanerozoic LIPs; their correlation with mass extinctions is reasonably well established, although the details can be complicated. You can find more information in this paper by Ernst and Youbi.

And there we stand: the story of life on Earth is an incredible adventure that sees the geosphere, the atmosphere, and the biosphere interacting with each other, usually resulting in a certain degree of stability but sometimes leading to great upheavals. It is what's happening now, with a large tribe of naked monkeys having taken control of the biosphere and playing the role of a Large Igneous Province by burning the huge reserves of fossil hydrocarbons built over the Phanerozoic Eon. For sure, this new "artificial LIP" will not lead to cooling but to warming. A huge and rapid warming. Gaia will probably survive it, but the monkeys... well, it all to be seen

A simple discussion of the recent results on the Franklin LIP  can be found on Anton Petrov's blog.

How Gaia survived Snowball Earth is described in this post by Ugo Bardi https://theproudholobionts.blogspot.com/2022/12/how-gaia-saved-earth-from-cold-death.html

The paper on the Franklin LIP by Dufour et al. that stimulated this post can be found at https://www.sciencedirect.com/science/article/pii/S0012821X23002728

The link to the paper by Ernst and Youbi on mass extinctions is: https://www.sciencedirect.com/science/article/pii/S0031018217302857

If you cannot access these papers, ask me for a copy

Tickling Gaia's Feet. How to Deforest Oneself to Death

Image from Dezgo.com

A few years ago, I published the article reproduced below on my blog "Cassandra's Legacy" I think it is worth republishing it because the debate on global warming has entered a frenzied phase. On one side, the rapid rise of temperatures is evident, and it is worrying people a lot. On the other side, it has caused many people to take refuge in the usual cherry-picking. Hannibal's elephants crossing the Alps is a typical argument that revolves around the idea that "Climate has Always been Changing." 

But it is true that the climate has always been changing. A little, at least. The question is why. In this post, I advance the hypothesis that human actions were an important contribution to the creation of the "Roman Warm Period" (RWP) by deforesting the land, while after the collapse, the forests returned, creating the LALIA (Late Antiquity Little Ice Age). Small variations, but enough to affect humans a lot. These data may be seen as a confirmation of the importance of forests in affecting the atmosphere's temperature as an effect of the operation of the "biotic pump." Tickling Gaia's feet may be very dangerous if She decides to stomp you out. 

Sunday, February 14, 2016

The collapse of the Western Roman Empire: was it caused by climate change?

Image from the recent paper by Buentgen et al., published in "Nature Geoscience" on February 8, 2016. The red curves are temperature changes reconstructed from tree rings in the Russian Altai (upper curve) and the European Alps (lower curve). Note the remarkable dip in temperatures that took place starting with the 6th century AD. But, by then, the Western Roman Empire was past and gone. Its collapse was NOT caused by climate change. 

The relationship between climate and civilization collapse is a much-debated subject. From the recent collapse of the Syrian state to the much older one of the Bronze Age civilization, climate changes have been seen as the culprit of various disasters befalling human societies. However, an alternative view of societal collapse sees it as the natural ("systemic") result of the declining returns that a society obtains from the resources it exploits. It is the concept termed "diminishing returns of complexity" by Joseph A. Tainter.

On this point, there may well exist several causes for societal collapse. Either climate change or resource depletion may sufficiently weaken the control structures of any civilization to cause it to fold over and disappear. In the case of the Western Roman Empire, however, the data published by Buentgen et al. completely vindicate Tainter's interpretation of the collapse of the Roman Empire: it was a systemic collapse, and it was NOT caused by climate change. 

From the data, we can see that there was a cooling episode that probably affected the whole of Eurasia, starting at the beginning of the 6th century AD.  This period is called LALIA (Late Antiquity Little Ice Age), and it seems to have been stronger than the better-known LIA (Little Ice Age) that took place during the 18th and 19th centuries. The LALIA was caused, at least in part, by a series of volcanic eruptions that injected large amounts of particulate in the atmosphere; cooling it by reflecting sunlight. Overall, temperatures went down by a couple of degrees in comparison to the time that we call the "Roman Warm Period."

A brutal cooling, yes, and it surely had effects on human life, as discussed at length in the paper by Buentgen et al. But it had nothing to do with the fall of the Western Roman Empire, whose decline had started at least two centuries before. The Empire started its final disintegration phase at the beginning of the 5th century when it ceased to be able to garrison the fortifications at the borders. Then, Rome was sacked for one first time in 410 AD; and finally destroyed by the Vandals in 455 AD. That was the true end of the Western Empire, even though, for some decades, there were still individuals who claimed the title of Emperors. But all that took place in a period of relatively stable climate, at least from what we can say about the available data. So, the collapse was systemic, related to factors other than climate and, in my opinion, mainly related to the collapse of the Roman financial system; in turn caused by mineral depletion.

But could it be that, after all, there is a correlation between the Roman collapse and climate change? Just it would be the reverse of what it had been sometimes proposed: could the Roman collapse have caused the LALIA cooling (or, at least, contributed to it)? The idea is not farfetched: the population collapse that took place with the fall of the Empire could have led to a considerable level of reforestation of Western Europe, and that would have absorbed CO2 from the atmosphere. That would have been an added factor to volcanic cooling. It is an idea already expressed some time ago by William Ruddiman. It seems to be out of fashion nowadays, but I think that it should be explored more.

In the end, this story can teach us a lot: first of all, how fragile climate is. In the interpretation by Buentgen et al., just three volcanic eruptions - relatively large ones, but not truly gigantic - were sufficient to cause a two-degree cooling extending all over Eurasia. Think of what could be the effect if something similar were to happen in our times! Then, it shows also how the situation, today, has completely changed. Temperatures have taken a completely different trend with the start of large-scale emissions of greenhouse gases in the atmosphere. Incidentally, these data also confirm the "Hockey Stick" data by Michael Mann and others. Global warming is real, the earth's climate is fragile, and we are in big trouble.

Additional note: The data published in "Nature" generated a truly awful article in the "Daily Express" titled "Mini-ice age 1,500 years ago contributed to fall of Roman Empire". There, they put together an incredible mix of unrelated things, showing, for instance, gladiator games that had ceased to exist at least one century before the LALIA. Then, they say that the 6th-century cooling "contributed to the collapse of the Eastern Roman Empire." Which is an interesting extrapolation since the Eastern Empire didn't collapse until about a thousand years after the LALIA!!  At least, they should go back to junior high school, but, on the other hand, think of how they report about climate change: what would you expect from them when they discuss the Roman Empire?

(h/t Graham Readfearn)

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.

How Forests Create Rain: a New Study Demonstrates the Effects of Evapotranspiration

Image created by Dall-E

The idea that forests create rain has been known by peasants for hundreds, perhaps thousands, of years. The first scientific studies go back to Alexander von Humboldt (1769–1859), but the subject remains controversial. Nevertheless, we are starting to understand the deep and complex interactions between the atmosphere and the biosphere. They form a true "holobiont," a system of connected elements that affect each other in non-linear ways. A recent paper published by a research group led by Anastassia Makarieva shows how evapotranspiration, the evaporation of water by trees, modifies the water vapor dynamics and may generate high moisture content regimes that provide the rain needed by the land ecosystem. There is still much that we need to understand about these mechanisms, but one point is clear: forests are a crucial element of the stability of Earth's climate, and they must be preserved as much as possible (U.B.)

This is the press release about the new study. You can find the complete text here.

Forest transpiration and the terrestrial water cycle: A non-trivial relationship

Link

As water scarcity globally grows, and deforestation threatens the remaining natural forests, understanding how vegetation impacts the water cycle becomes increasingly important.  In their new paper, “The role of ecosystem transpiration in creating alternate moisture regimes by influencing atmospheric moisture convergence” published in Global Change Biology, an international and interdisciplinary team led by TUM demonstrated the existence of two potential moisture regimes – one drier, with additional moisture decreasing atmospheric moisture import, and one wetter, with additional moisture enhancing atmospheric moisture import. In the drier regime, water vapor behaves as a passive tracer following the air flow. In the wetter regime, it modifies atmospheric dynamics.

The team based their analysis on the previously established non-linear dependence of precipitation on atmospheric moisture content – increasing absolute humidity leads to a negligible precipitation increment if the atmosphere is dry, but to a large increment when the atmosphere is sufficiently wet. Combining this dependence with a full consideration of the water budget, the researchers showed that an increase in precipitation in humid conditions facilitated by increased evapotranspiration, should lead to enhanced moisture import. They illustrated these patterns with the data from the Amazon basin and the Loess Plateau in China.

Dr. Anja Rammig (TUM School of Life Sciences and study author) considers these results as having profound implications for the ongoing studies of the resilience of the Amazon forest in the face of the danger of deforestation and climate change. Dr. Scott Saleska (University of Arizona, study author) believes that the new results are in agreement with the profound role of leaf phenology in the Amazon forest for water cycle regulation. By forcing a decline in forest evapotranspiration, deforestation can dehumidify the atmosphere and thus drive the forest into the drier regime where transpiration of the re-growing vegetation would further aggravate aridity by decreasing moisture import. Getting out of this landscape trap could be impossible. Dr. Ruben Molina (University of Antioquia, Colombia, study author) hopes that the study findings will raise the awareness of the importance of tropical forest conservation.

Dr. Andrei Nefiodov (Petersburg Nuclear Physics Institute, Russia) participating in the study says that the new results corroborate the concept of the biotic pump of atmospheric moisture that emphasizes the dominant role of natural forests in transporting moisture inland. Dr. Antonio Nobre (INPE, Brazil, study author) compares this biotic moisture pumping to a beating heart, and highlights the good news: even in arid lands, by restoring the vegetation one should be able to enhance the atmospheric moisture convergence and streamflow. To achieve that, the ecological restoration strategy should be carefully designed to guide the ecosystem transition from the dry to wet regimes.

“I suspect that natural vegetation will be best for maintaining a moist and productive environment as these systems kept the world green and productive long before people got involved” – emphasizes Dr. Douglas Sheil (Wageningen University, author), collaborating on the research. “We do need to take into account the holobiontic relationships among all ecosystem elements that allow for an efficient regulation of the water cycle,” adds another author Dr. Ugo Bardi (Club of Rome, University of Florence).

Anastassia Makarieva (Institute for Advanced Study, TUM, lead author) emphasizes the need for a broad international cooperation in the studies of the ecology of the water cycle: “We have shown that the non-linear precipitation dependence on atmospheric moisture content, first noted by our co-author Dr. Mara Baudena (CNR-ISAC, Italy) and her colleagues, has widely ranging implications. The atmospheric water flows do not recognize international borders, thus deforestation disrupting evapotranspiration in one region could trigger a transition to the drier regime in another. Our results indicate that natural forests of the Earth, in both high and low latitudes, are our common legacy of pivotal global importance as they support the terrestrial water cycle. Their preservation should become a widely recognized priority for our civilization to solve the global water crisis.”

The Role of the Forest Holobiont in Earth's Climate: More Important than it was Believed so far

Above, the talk by Anastassia Makarieva at the International Conference on Basic Science for Sustainability in Belgrade, on Sep 22, 2022

It is about an innovative and important interpretation of the current climate situation. Anastassia is proposing that the warming of the atmosphere may be caused not just by the accumulated CO2, but by a radiative forcing of the same order of magnitude generated by deforestation. Earth's forests are giant holobionts coupled and embedded in the even larger holobiont that's the whole ecosystem. It is not surprising that they strongly affect climate, and not just by the conventional factors, albedo and carbon sequestration. There is much more than that, as you can learn by watching the clip, above.  

I don't have to tell you the consequences of this concept. If it turns out to be true (and I think it might well be), it means that we have done a lot of wrong things in trying to mitigate global warming, for instance proposing "biofuels" obtained from wood. But there is much more: it is a complete revolution in the way we see Earth's climate system. Forests not only cool the atmosphere, but also stabilize the climate. This means not only that we need more forests, but that some ideas such as carbon sequestration and geoengineering could do a lot of damage if not coupled with reforestation.

On the other hand, Anastassia's ideas could also be misunderstood as meaning that Climate Science, as it has been proposed so far, is all wrong. And that's sure to happen if her ideas come into the hands of politically minded people who would use that to propose that there is no such thing as global warming, climate emergency, etcetera.  But if we believe in Science (true science, not TV science) we must not be afraid of the truth.

Onward, fellow holobionts!

Forests: Holobionts that Dominate the Land's Ecosystem

 

The beech ("Fagus") forest of Abbadia San Salvatore, in Tuscany, Italy. A living holobiont in all its splendor. (photo by the author).

Not many people, today, have a chance to see a fully grown, mature forest. Of course, trees are common even in cities, and there are many places where trees grow together in sufficient numbers that they can be termed "woods." But mature forests have become rare in our urbanized environment. 

One such mature forest survives on the slopes of the Amiata mountain (Monte Amiata), an ancient volcano located about at the center of Tuscany, Italy. Not really a "pristine" forest, but managed by humans with a sufficiently light hand so that it can grow according to its tendency of forming a "monodominant" forest. It is composed nearly completely of a single species of trees: the Fagus sylvatica the European beech. In the photo, below, you can see the east side of the Amiata mountain seen from the valley. 

Our remote ancestors were, most likely, savanna creatures: they weren't used to forests. We may only imagine the awe they felt when they migrated north, from their original African home, to walk in the great forests of Eurasia, by then emerging out of the last ice age. It is a sensation that we can still feel, today. Not many of us are acquainted with the subtleties of a forest ecosystem, but we can recognize that we are looking at something gigantic: an enormous creature that dominates the land. 

A forest is much more than just trees -- it is the true embodiment of the concept of "holobiont." (at least in the version called "extended holobiont" by Castell et al.).  It is an assembly of different creatures that live in symbiosis with each other. The beauty of the concept is that the creatures that form a holobiont are not altruistic. Individual trees don't care about the forest -- they probably don't even know that such a thing as a "forest" exists. They all act for their own survival. But the result is the optimal functioning of the whole system: a forest is a holobiont is a forest.

It has been only in recent times that we have been able to understand part of the intricate network of relations that create the forest holobiont. You may have heard of the "mycorrhiza," the association between tree roots and fungi -- a concept known since the 19th century. It is a typical symbiotic relationship: the plant provides food (carbohydrates) to the fungus, while the fungus provides minerals for the plant. The intricate network of tree roots and fungi has been termed the "Wood Wide Web" since it connects all trees together, exchanging sugars, nitrogen, minerals, and -- probably -- information. 

But trees also get together above ground to support each other. A monodominant forest, such as the beeches of Monte Amiata forms a relatively uniform canopy that provides several advantages. It shades the ground, maintaining it humid, and avoiding the growth of competing species. The trees also shield each other from the gusts of wind that may topple an isolated plant. 

The canopy is the interface between the ground and the atmosphere. Trees evaporate enormous amounts of water in a process called "evapotranspiration." Trees do not do that to favor other trees -- it is their way to exploit the sun's heat to pull water and nutrients all the way from the roots to the leaves of the crown. Evaporated water is a byproduct of the process and, yet, it is fundamental for the survival of the forest. 

It is a complex story that sees water being transferred from the ground to the atmosphere, where it may condense around the particles of volatile organic compounds (VOCs), also emitted by the trees. The result is the formation of low-height clouds that further shield the ground from solar heat and that will eventually give back the water in the form of rain. 

But it is not just a vertical movement: the condensation of water droplets above the canopy of a forest creates a depression that generates wind. This wind may transport inland humid masses of atmosphere from the oceans, where the water had evaporated. It is the mechanism of the "biotic pump" that guarantees abundant rain whenever forests exist. Cut the forest, and you lose the rain. It is not enough to plant trees to have the rain back. You have to wait for the forest to mature and form a full canopy to trigger the biotic pump. 

So, we have all the reasons to be awed at the sight of a fully grown forest. And we have all the reasons to keep it the way it is. The whole planetary ecosystem depends on healthy forests, and we have only recently learned how important forests are. Yet, we keep cutting and burning them. Is it too late to remedy the damage done? Maybe not, but we'll have to see. 

To learn more

Holobionts: https://theproudholobionts.blogspot.com/2022/08/holobionts-new-paradigm-to-understand.html

About the biotic pump: https://www.bioticregulation.ru/pump/pump.php

About the role of forests on climate: https://www.nature.com/articles/s41467-021-24551-5, see also https://theproudholobionts.blogspot.com/2022/08/forests-do-they-cool-earth-or-do-they.html

For a more detailed discussion of forests as holobionts: https://theproudholobionts.blogspot.com/2022/02/the-greatest-holobiont-on-earth-old.html

Below: one of the beeches of the Monte Amiata, shown with Ugo Bardi's wife Grazia, and his Grand-Daughter, Aurora

Oceans and Climate: we need more whales!

Judith Curry provides the link to a 10-year-old paper, still interesting for us

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2009GL041961

The idea is of activating the ocean metabolism by artificially upwelling nutrients from the deeper layers to the surface, which can be metabolized by photosynthetic organisms. It is similar to that of fertilizing the ocean by dumping iron oxide in the water.

The interesting thing is how sensitive is the Earth holobiont to this kind of manipulation. According to the article, artificial upwelling would "be able to sequester atmospheric CO2 at a rate of about 0.9 PgC/yr," which is about a tenth of the current carbon emissions. In itself, it would not change the trend, but it is still a lot, and if it were continued for decades it would make a difference considering the unavoidable decline of fossil fuel production generated by depletion.

But, of course, things like pipes and flap valves could hardly be deployed in the necessary amounts, considering that humans see it as much more important to use their remaining resources to make war on each other. Yet, it is impressive to think that what the pipes are supposed to do used to be done by whales before they were exterminated (https://www.pnas.org/doi/10.1073/pnas.1502549112). So, humans have already modified the Oceans' system in the opposite direction. 

Likely, more whales would cool the planet. And they would produce themselves if just left in peace, no need for huge pipes and pumps!

Feathered Dinosaurs -- The Many Faces of Gaia

 

A feathered T-Rex? Why not? (Image from Safari Ltd.)

A recent paper by Olsen et al. appeared on "Science Advances". It discussed the fauna and the climate of the Earth of Late Triassic, just before and during one more of the great mass extinctions of its long history.

The authors claim that "The Late Triassic and earliest Jurassic are characterized as one of the very few times in Earth history in which there is no evidence of polar glacial ice sheets," which I am not so sure about. Anyway, this Late Triassic Iceless age is interesting for us because it is where we may end as the result of the current burst of fossil carbon combustion, deforestation, and marine desertification. It is another example of ice-free earth, probably similar to the Eocene epoch, some 30-50 million years ago.

It seems that the Late Triassic was not so hot, despite the high CO2 concentrations (maybe 1000-6000 ppm). In the high latitude regions, the temperature was cold enough that ice would form in winter, likely not perennial. Dinosaurs lived in the Northern and Southern areas of the Pangea, and they already had "filamentous integumentary cover" -- beautiful term! -- that is protofeathers, clearly used for thermal insulation. In the equatorial regions, instead, the heat made life easier for cold-blooded animals, the pseudosuchia -- which indicates crocodile-like creatures. Apparently, it was too hot for dinosaurs there.

Does this have some relevance to the current climate? Everything is correlated, although it must be said that the conditions of the earth some 200 million years ago were quite different. The fact that there was ice at the poles, despite a very high CO2 concentration, is no proof that CO2 is not the greenhouse gas we know it is. Among many other things, the solar insulation at that time probably around 2% lower than it is today.

Today, if we were to go back to those CO2 concentrations, crocodiles may still have a good time, but they will probably invade a much larger share of latitude. On this point, this is a paleontological study, so they don't mention modeling the climate of those times. They tend to attribute the low temperature to volcanic ashes. They seem to say that the mass extinction was caused by cooling, unlike the later K-Pg event. That despite the fact that the CO2 concentration was so high. Their main conclusion is that dinosaurs were adapted to cold temperatures, and they were mostly feathered. Which means that the creatures seen in "Jurassic Park" are all wrong!

They also report this interesting graph with the CO2 concentrations over 300 million years. It is stuffed with acronyms, apparently well known by paleontologists, but not so much by us, mortals. Anyway, "EPE" stands for "End Permian Extinction" (the huge one)   "ETE" stands for "End Triassic Extinction" (less well-known, but it was not a joke). "T-OAE" stands for "Torcian Oceanic Anoxic Event" (quite an event, it must have been). The "K-Pg-E" is an acronym of acronyms, but you know what it stands for: it is the end of the dinosaur age -- the big asteroid falling on Earth (maybe) or/and the Deccan giant igneous province (more likely). Finally, the PETM is the "Paleocene-Eocene Thermal Maximum", quite a maximum in temperatures, but it didn't do as much damage as one would have expected. 

Anastassia Makarieva Speaks About the role of Forests in Protecting Earth's Climate

 

Anastassia Makarieva in a recent talk recommendsed the preservation of the natural forest holobiont:

International climate discourse mentions forests in two contexts: as carbon deposits and as renewable sources of materials and energy.

If implemented in global policies, this narrow view on forests can, contrary to expectations, worsen climate destabilization. Two crucial aspects are undervalued and understudied.

The first is the major role of forests as regulators of the various aspects of the water cycle, including cloud cover (a major source of climate uncertainties) and ocean-to-land and transcontinental transport of atmospheric moisture.

The second is the difference in the environmental functions of primary forests, largely unperturbed by anthropogenic activities, versus exploited tree stands. While the former have evolved to maximize environmental homeostasis, the latter were selected to maximize economic productivity. The two cannot be maximized simultaneously.

Successful strategies of climate change mitigation should prioritize preservation of still extant self-sustainable natural forests for humanity to continue benefiting from their climate stabilization potential.