How did nature cool the planet?
How did nature manage to take all of the incoming heat energy from solar radiation that constantly enters the atmosphere, and stabilise the climate by sending the same amount of energy back into space?
How did nature craft this planet from a set of hot dead rocky land masses and oceans full of complex life, as it was 420 million years ago, to a planet with rich deep soils, with green plant growth covering all the ice free land, and with that green growth driving the evolution of abundant and increasingly sophisticated animal life in complex self-sustaining ecosystems?
What was the process that nature used to bring down concentrations of carbon dioxide in the atmosphere all the way from about 8,000 parts per million to as low as 100ppm? And where did all that carbon go?
We are all now painfully familiar with how humans have come to put this whole system in jeopardy. We know that the abundance of life and the richness of ecosystems on this planet are now under great pressure, and these systems are being depleted at rates that threaten catastrophic collapse. We know that it is the burning of fossil fuels that is driving the planetary scale destruction. We know that we have a heating planet and an industrial system that has now overwhelmed the climate balance that nature managed to sustain for hundreds of millions of years.
We want to solve climate change. We want to avoid tipping the climate further into chaos. We want to have enough food and water to ensure social stability and avoid chaos. We also want the global industrial system that supports human civilisation to continue to operate without interruption.
We humans are a clever lot, but despite everything we have learned, the climate debate we have been having for the last 60 years has been fairly dumb.
Some of us have become misled by the presumption that the needs of the industrial system and those of the planet are necessarily at odds, and that one must be sacrificed for the sake of the other. Those misled by that presumption take up ideological positions for or against the industrial system, and divert discussions into political areas such as how best to distribute the costs of reduced burning of fossil fuels, or even more ignorantly, into whether or not we need serious global action in the first place. Such debate is not really constructive, and serves to divert our attention from what is needed in the real world.
Even when ideology, politics, and economics are put aside, the debate is still dominated by a narrow focus that simply presumes our power to act on climate change is mostly based on what we can do about carbon dioxide concentrations. This singular focus has been far too simplistic, because water is a much more powerful driver of global heat exchanges than carbon dioxide. The singular focus is also largely ignorant to the power nature has to draw carbon down from the atmosphere, and to reduce atmospheric concentrations far more easily and safely than anything that humans have dreamt of to date.
Learning from Nature
Humans have only one realistic option to significantly influence the climate system at the global scale, and at the rate of change required to minimise the risk of tipping the system further into chaos. We must understand nature’s powerful processes that drive global cooling and carbon draw down, and then leverage that knowledge with action that both reduces the way we interfere with nature’s processes and helps to repair the damage we have already done.
Nature has all the answers we need, and there are people and organisations around the planet that have already put the lessons from nature into practice, and found that working together with natural processes is very profitable., far more profitable than ignorantly working against them. We don’t need to completely repair all the damage we have done to our natural systems; we only need to boost nature’s cooling and carbon drawdown system by a small percentage in order for it to regain the power to stabilise the system.
In this article we will explore how nature created a stable climate in the first place, what we have done to disrupt nature’s balance, and what we need to do to restore that balance, even as we continue to burn fossil fuels. We will be drawing heavily on the work of soil microbiologist and hydrologist Professor Walter Jehne, who has worked with the CSIRO and other scientific institutions on the green revolution, the ongoing search for ever more productive agriculture.
The best solutions for improving agricultural yields also happen to be the best way to solve climate change. They involve understanding the dynamics of the Earth’s soil-water-carbon system, and how it acts as a great sponge, and that this drives nature’s cooling and carbon draw down system at the local level, at the global level, and at all scales in between.
When we understand the dynamics of the soil-water-carbon system, we will be able to see what we are doing to reduce the effectiveness of this cooling and carbon capture process, and we will fully comprehend the real power we have to change the balance in favour of the natural cooling system.
As already mentioned, we are already doing the things we need to, just not yet on a broad enough scale, primarily because of the narrow and ignorant climate debate that has diverted our attention. It is time to zoom out, inform ourselves, and put the lessons about nature’s solution into practice on an effective scale.
Heat, water and climate change
Climate is all about water
95% of the heat dynamics of the planet Earth are driven by hydrological processes, but hydrology has largely been ignored in the climate debate for 60 years. The water cycle that drives climate was left out of early analysis. Possible explanations for this accident of history include: the narrow context was set in President Carter’s original invitation for academia to determine just what we could do about climate change; the presumption that water played such a dominant role in the climate system that we couldn’t hope to control it, or significantly influence the processes; and the fact that the water system is very complex, with water volumes being variable in time and space, locations and seasons, and so water was simply too difficult to model mathematically.
The focus on carbon dioxide is too narrow
Only 4% of the heat dynamics of this planet are driven by carbon dioxide. Climate change is certainly caused by the accumulation of greenhouse gases as a direct result of burning fossil fuels; this is certainly beyond question. But water has about 20 times more influence over global heat dynamics than carbon dioxide, and we humans actually have significant power to influence the planet’s hydrology.
We simply must step outside the thinking that carbon dioxide must be the main focus when it comes to climate action. We do not even have viable industrial scale technologies that can do anything about carbon dioxide concentrations, but we have had the power to change the Earth’s water processes for thousands of years. We just haven’t learned to use that power responsibly, at least at the mainstream collective level.
With a broader perspective, we will discover that we simply need to give nature a bit of a helping hand in order to restore the balance in carbon and energy cycles, which are overwhelmingly driven by water.
Regenerating Earth’s soil carbon sponge will enable global cooling
Carbon is sequestered in healthy soils, and in the biological systems they support. This is how nature took control and regulated climate. We will explore how this constitutes an enormous soil-carbon sponge shortly. This carbon-sponge effect of healthy soils is very good news for us humans, because the quality and volume of healthy soil is something that we humans can control.
We can regenerate the carbon sponge on any scale we choose. If humanity as a collective becomes wise enough to adopt sustainable agricultural practices, we can regenerate the very mechanism of global cooling and carbon draw down at the global scale. We can regenerate the carbon sponge on a national or regional scale, cooling regions and dramatically improving their agricultural yields in the process. We can do this for urban areas, just one town or city at a time. We can do this down to the level of individual farms, even if rural communities are not united around the idea of regenerative agriculture. Taking advantage of this control of the soil-carbon sponge is our agency, our power to significantly repair the natural system.
As we support and nurture the very processes that deliver our food and water, and thereby our social stability, as well as the other ecosystems that work together to form the biosphere, repairing our soil volumes will help the hydrological processes to safely and naturally cool regions and the planet.
The carbon cycle currently has an annual deficit
We have known the trajectory of carbon dioxide concentrations in the atmosphere since the work of Charles Keeling in the 1950s. This version of his chart shows the steady rise of the trend in concentrations over a 50 year period, along with the annual cycle in the levels measured at Mauna Loa.
Keeling discovered that there was a seasonal variation in carbon dioxide concentrations, with a large amount of carbon being emitted throughout the northern winter, and a large amount of carbon being drawn down out of the atmosphere throughout the summer and spring. The reason that concentrations are increasing fairly consistently year after year is that there is more carbon being emitted than being drawn down, and the measured deficit is about 10 billion tonnes per year.
Climate change is retained energy
The incoming solar energy to the Earth averages out across the planet’s surface area to 342 W/m2 . For a stable climate this incoming energy must be balanced by the same amount of energy going out into space as heat, but currently there is only 339 W/m2 of outgoing energy. So, there is approximately 3 W/m2 of energy retained by the Earth.
Effective action on climate change requires that the net energy being retained within the planet’s systems is reduced by this 3 W/m2. This sets the goal that boosting nature’s cooling and carbon draw down system must achieve. Once we have identified the main processes of the soil carbon sponge, we can look at the numbers and compare the potential to boost those processes by even a small percentage and easily reach this goal.
Simply note for now that this is less than 1% of incoming solar radiation. Also, this 3 Watts will only correct the future retention of heat, not the legacy excess heat already in the system
Climate extremes are all water related
The droughts and floods that are exacerbated by climate change involve an excess or lack of water. The wildfires that are exacerbated by climate change are the result of a lack of retained water in various ecosystems, like forests and grasslands. The increased storms and hurricanes and the rise of sea levels that come with climate change are both about water. The systemic aridification of large regions of continents is driven by a lack of retained water.
All of these climate extremes are driven by hydrological processes, with dangerous positive feedback effects, which means that the worse things get, the faster things will get worse, on an exponential trajectory. These climate extremes are all happening now, well in advance of the 2 degree global temperature rise that has been agreed (politically) to represent the theoretically safe level.
Dangerous climate extremes are already our new reality
Incoming solar radiation heats the atmosphere at the equator, creating Hadley Cells, which draw moisture upward into the atmosphere from the tropics and deliver hot dry air falling in the temperate zones. These cells are part of the natural process that has been self-regulating the climate for hundreds of millions of years, but now with the excess of energy being retained in the Earth system, these cells have expanded both northward and southward by some 300km.
This hot air being forced further from the equator also pushes back the reach of the polar vortices, cool cells of moist air which usually deliver reliable winter rains to the temperate zones, but are now delivering their rains 300km closer to the poles than they used to, resulting in increasing aridification on a global scale.
For example, a large region of South Western Australia has experienced a now permanent 20% decrease in rainfall and a 30 to 40% decrease in stream-flow soil-recharge. Similar outcomes are playing out across California and the south west of the United States, in the Middle East, and across southern Europe from Spain right across to Syria. We know that in Syria this has led to social crisis and collapse, with farms being abandoned after 10,000 years of productive agriculture, and with soils and hydrology systems having collapsed.
So now we have a good sense of the big picture. We now live in a world of intensifying dangerous climate extremes. The question is what can we do about it?
We must dramatically increase the draw down of carbon
The Paris Agreement in 2015 saw nations commit to the goal of zero net carbon emissions, sometime this century and the sooner the better. This requires that biological processes and natural carbon sinks which draw down greenhouse gases are dramatically expanded in scale. We must of course do as much as we can to reduce emissions, but the numbers simply demand that we focus on the draw down side of the equation.
Across the planet 120 billion tonnes of carbon is drawn down per year by green plants and put back into the biosystem. 130 billion tonnes of carbon is currently emitted per year. So we have a 10 billion tonne per year carbon deficit.
The residual biosystems we have now – the land surface vegetation – is perhaps half what it was 8,000 years ago, as we have degraded forests and grasslands, and have created 5 billion hectares of man-made desert and wasteland. The question for us now is can we increase the draw down of carbon by regenerating that biosystem?
We must regenerate the Earth’s soil-carbon sponge
It is important to point out that while we need to draw down an additional 10 billion tonnes of carbon per year just to balance emissions, we will need to draw down something like 20 billion tonnes per year to get concentrations to fall at a significant enough rate.
None of this extra draw down of carbon is possible if these biosystems do not have water, and that water can only come from the soils. The good news is that we can do this. We can draw down an additional 20 billion tonnes per year by land regeneration. We can extend the area, the productivity, but particularly the longevity of green growth. The more green growth, the more water is retained by ecosystems, and the more carbon is incorporated into living systems, allowing nature to balance the carbon and energy cycles and stabilise the climate.
Oceans will release more greenhouse gases
There is an equilibrium reached between the concentrations of carbon dioxide in the atmosphere and those in the oceans. There is about 30,000 billion tonnes of carbon in the oceans, and this is just the CO2 dissolved in the water, it does not include all the limestone and carbonates. This excess of dissolved carbon is also why oceans are becoming acidic.
As we draw down more carbon from the air, there will be a rebalance, with the oceans releasing thousands of tonnes of carbon back into the air, because it is a buffered equilibrium system. This point is just a cautionary note that only really comes into play when we need to scrutinize the numbers in detail.
Nature’s cooling system
Nature created a balanced system
Natural processes held climate, energy, and greenhouse gases in a stable equilibrium for hundreds of millions of years. The system managed to ensure that the 342 W/m2 energy coming in from solar radiation was exactly matched by 342 W/m2 dissipated out into space.
Human activity has now disturbed the system on such a scale that it is not only dangerously out of balance, but becoming ever more so each year.
We need to rebalance the system
We need to return the system to that balance, by ending the retention of excessive heat in the system. This means that the natural processes operating on the global scale need to be freed from excessive depletion by human activity, in order to regain their power to balance the climate.
But we need to go further than that, if we are going to deal with the legacy of retained heat already trapped within the system, which is why we need to actively help to repair the natural processes. Fortunately, this active repair is not really a challenge at all, once we reach the required broader perspective, and the regeneration of those processes and systems comes with enormous gains rather than costs.
To understand the global process, it will be instructive to follow the evolution of the climate balancing system, and see how climate stability was the result of new emergent processes of living systems in interaction with nonliving natural resources.
Life on land changed the planet
Around 420 million years ago, there was only dead land and a baking planet. The oceans were teeming with complex life, but the land masses of Earth were nothing but rock. The complex life in the ocean depended on nutrients leached from the rocky land, and this dependence on land based processes was the limiting factor on ocean life after the Cambrian Explosion. At that time the carbon dioxide concentrations in the atmosphere were about 7,000 to 8,000ppm.
Nature’s cooling system gradually emerged as life reached onto land. As this cooling system evolved and expanded, great volumes of carbon were drawn down from the atmosphere and captured into ecosystems on land, which became so teeming with life that the draw down of greenhouse gases had reduced atmospheric carbon dioxide concentrations to around 100ppm.
That period of such an enormous draw down of carbon into forests and soils was the source of our fossil fuels, and of course the rapid burning through those fossil fuel resources is the reason we are once again heading for dying land and a baking planet.
Learning about the process of the evolution of nature’s cooling and carbon capture system is not only critical to repairing the Earth’s cooling system as far as necessary, but is also fascinating to see how all of the pieces come together.
New forms of life began to dissolve rock
First, fungi and lichens reached onto land and used enzymes to dissolve rocks into nutrients. This gave them a competitive advantage over ocean dwelling organisms in the race to exploit the nutrients contained within the rocks. Fungi are biochemical beings with a lot in common with us humans. Like us, they cannot fix their own energy, or synthesise their own sugars; only plants and algae can do that, along with some bacteria.
So fungi and algae got together symbiotically to form lichen. Lichens are found all over the planet today, and they dissolve rocks, buildings, concrete, wood, even cars. As they came onto the land and began to biodegrade rock, they created gaps in the rock structures and left organic detritus, particularly the cast off cell walls of the fungal-algal lichen cells in those gaps.
The organic detritus in between the rock particles can hold water, and this is profoundly important. Mineral deposits combined with organic matter can hold even more water.
Where did fungi come from?
This question might seem like a rather trivial tangent, but it is likely that the better we understand fungi, the better we will understand soil and the soil-water-carbon system, which offers us the solution to climate change.
About 3.8 billion years ago, long before life came onto land, lipids self-organised in the primordial soup into micelle structures within an oil membrane. Lipids are fat molecules with one end that is attracted to water, and the other end is repelled by water. Under the right conditions, these properties create micelles, which are self-assembling molecular structures that are generally spherical in shape, and have a semi-permeable outer membrane which encloses a drop of oil but excludes water.
These micelles selectively absorb some chemical nutrients from the surrounding primordial soup outside the micelle, while excluding other chemicals, changing the relative concentrations between the inner and outer environment. For example, if there were 10ppm of phosphorus in the environment, there might be 100ppm inside the lipid structure. ‘Toxic’ elements like cadmium could be excluded, so that if the environment contained 200ppm, there might be only 2ppm cadmium inside the micelle. This process of concentration of nutrients and exclusion of toxins led to the creation of the first living cells.
Fungi are essentially just a linear tubular extension of this process. When they developed a symbiotic relationship with algae and gained the ability to reach onto land, they flourished. We will see shortly how by colonizing the rocks and breaking them up, fungi were able to create the soil matrix structure that can hold water. and how fungi have a critical ongoing role in life on land and nature’s cooling and carbon capture system.
Plant and animal life boomed
This process of storing water and releasing nutrients from rock allowed plant life to evolve very rapidly, in a sequence that went from lichens, to mosses, to ferns, to cycads, to gymnosperms, to angiosperms, and – about 50 million years ago – grasses.
Parallel with that plant evolution we had the herbivores, the insects, and everything that was feeding on those biosystems. Very rapidly that period of pedogenesis, of soil formation, because soil is simply a mixture of mineral particles and organic detritus, enabled life to spread right across the 13 billion hectares of ice free land on this planet. Within 100 million years we had a planet which was in the carboniferous-Permian period, with very lush forests, and deep organic soils, both teeming with life.
Rock was transformed into rich soil
Before soil, the rock was composed of tightly packed nutrients, like phosphorus, calcium, zinc, and magnesium, along with other mineral particles. When water meets rock it just runs off, with no effect, except for physical erosion which happens at a glacial pace over geological time periods. So before soil these nutrients were almost completely locked up and not able to support life. But when life began dissolving rock, the interaction between water, inorganic materials, and biological organisms was dramatically transformed.
The lichens grew on the rocks and solubilised them. This eating away at the rock creates gaps in the structure of the surface ground material. The gaps are occupied by the organic detritus left behind when lichens move on. Professor Jehne suggests we picture the organic detritus as “carbon bed springs” connecting the other rock particles, but also preventing them from clumping back together and once again becoming impervious to water filtration.
On the left we see a representation of rock, as tightly packed particles, with no gaps to allow water to infiltrate. On the right we see soil, with the larger particles having had their surfaces dissolved by the lichens, which are represented as growing on the rock as the little eyebrow shape over the phosphorus deposit. The soil on the right now has a network of voids between the rock particles, which are held together by the ‘bed springs’ composed of organic matter.
Rock has a bulk density of 2.6 to 3.5 g/cc (grams per cubic centimetre). Healthy soil has a density of about 1.2 g/cc. Straight away you can see that healthy soil is made up by 66% of voids of nothing but air. Nature has simply taken sunlight, carbon dioxide, and water, and created carbon chains and added them to the matrix, creating soil.
Rich soils exponentially increase the capture of water and carbon
What is powerful about healthy soil, and it really is the central element of the whole sponge discussion, is that now we have 66% of the volume of the matrix which is available for infiltrating and retaining water. That retained water is what can sustain plant growth. Because of these voids, and the increased surface area exposed by them, this healthy soil can vastly increase the availability of nutrients. Now we have the phosphorus, the calcium, and the zinc all exposed for microbial activity.
So the bio-productivity of that soil increases exponentially, simply by creating those voids. The rootability of these soils vastly increases, that is the roots can grow, and penetrate and proliferate. Instead of 6 inches, they can grow down to 6 feet, or 20 feet, so the volume of soil resource that is now available for plant growth, and the drawdown of carbon that we mentioned earlier, is exponentially increased.
Soil formation is the engine of nature’s cooling and carbon capture system
So the whole bio-productivity of these healthy soils, the resilience of those soils, the capacity to infiltrate, to buffer, to extend life vastly increases. This process is what nature did to create the biosystem, to create the hydrology, and in very simple terms, that is all we have to do.
The process is taking sunlight, carbon dioxide and water to produce plants, using photosynthesis to create sugars, and fungi and microorganisms that convert those sugars into stable soil carbon, which is just the carbon based organic detritus or ‘bed springs’. This process is how the Earth ran 95% of its heat dynamics and its natural hydrological cooling.
So, if we have to draw down 20 billion tonnes of carbon, if we have to rebuild this soil-carbon sponge, we simply need to copy nature, and speed up the soil formation process.
Agriculture can work with or against nature
Most of Nature’s richness lives below the ground
About 30% of the biomass of plants lives above the ground. About 30% lives in the roots below the ground. For some ecosystems this is increased to about 80%, such as prairie grasslands where the root to stalk ratio is 5 to 1. In addition to the biomass in the roots, there is also 30 to 40% of the nutrients that are actually exudated out from the roots, as sugars and amino acids and various substances, and these are critical for feeding the microbial ecology.
This supports a vast population of the fungi, the bacteria, the protozoa, the nematodes, the actinomycetes, the collembola, the earthworms, that whole life in the soil.
There is ten times the weight of organisms living down under the ground than there is of animals or humans grazing above the soil. And all of those organisms are driving the solubilising of nutrients from surfaces, the fixation of nutrients, the access, uptake and cycling of nutrients, constantly just driving the energetics and nutrient availability and productivity of those systems.
There is 25,000km of fungal hyphae (long, branching filament structures) per cubic metre of healthy soils. This is twice the diameter of the Earth, and this fungal hyphae is growing in every cubic metre of healthy soil systems. So there is massive activity and diversity in the life of our soils. The soil is a living organism, a living microbiome, and really it is managing and enhancing that microbiome that is critically important.
Nature converts carbon into rich living systems
All of the organisms thriving in the soil – the fungi, the bacteria, the protozoa, the nematodes, the actinomycetes, the collembola, the earthworms, that whole life in the soil – these are all carbon based organisms.
Every cell, every protein, all the building blocks of life, are built on chains of carbon atoms. So all of that biomass living and thriving underground is made of carbon. Some fascinating detail of the chemical composition of life can be found here: What is the elemental composition of a cell?
As should be patently clear by now, richer soil systems means more captured carbon, and richer and more diverse natural systems of plants and animal life. Richer soil systems also mean greater agricultural yield, as we will explore next.
Two options for plant carbon: Capture or Burn
Agriculture tends to focus on maximising yield, the weight of produce created per unit of land, which is understandable. But what really matters is what happens to the carbon that has been captured by photosynthesis in the growth of plants.
There are only two things that can happen to that carbon in plants, and only two things that have happened to that carbon over the last 420 millions years.
Burn – That plant carbon can burn, in other words oxidise, and be turned back into carbon dioxide and released into the atmosphere. There are many current agricultural practices that simply burn plant carbon. If soil systems become dangerously depleted as a result, everything on and in the land will burn in one way or another, and soil will collapse back to lifeless rock.
Capture – Alternatively the carbon in plants can be captured and stored as stable soil carbon, which is what nature does. Stable soil carbon consists of the carbon chain structures or organic detritus of once living cell tissues, the bed springs that hold the soil matrix together.
Obviously again, the more life that is in the soil, the faster that organic detritus accumulates, and the more carbon is captured into the soil-water-carbon system.
We have the power to choose the amount of carbon we burn versus the amount of carbon we capture and fix in the soil. We can decide how we use land and what agricultural practices we use, and it is these decisions that give us the power to copy nature and regenerate the soil-carbon sponge.
Nature’s tendency is to capture carbon into rich living systems
As the glaciers retreated after the last ice age some 9,000 years ago, what was left behind was rock, gravel, clay, and swamps, so a rich mineral environment, but one without life.
Since then the process of soil formation, water retention, and the creation of bed springs – or soil carbon structures – has created some of the world’s most productive soils, with 10 metres of beautiful prairie soils, with carbon content as high as 8%, able to retain rain, and with that rain able to extend the longevity of green growth, and maintain massive populations of herbivores, creating resilient and productive biosystems.
In a relatively short time, nature converted vast areas of the wasteland exposed by glacial retreat into rich living grassland systems. Nature’s capacity to grow healthy soils and fix carbon is prodigious.
Agriculture tends to burn carbon back into the atmosphere
Burning carbon is a profoundly destructive misuse of our natural resources. To the extent that we capture carbon in soil, we get living land and a cooling climate. To the extent that we burn carbon back into the atmosphere, we get dying land and a baking planet.
As we have seen, the capacity for natural systems to grow healthy soils and fix carbon is prodigious. But when we humans start to convert natural systems into agricultural systems, and focus on just trying to maximise agricultural yield, while forgetting about – or not caring about – preserving and building soil system capital, we subject the land to relentless destructive processes. A few of the ways we get things wrong:
Clear – We used to have 8 billion hectares of primary forest on this planet, we have cleared 6.3 billion hectares, while in some areas forests have regenerated, but overall we are down to only 3.5 billion hectares of forest.
Burn – We burn 350 million hectares of forest every year. That is 10% of our residual forests. In addition, every year we burn some 2 billion hectares of grassland, crop stubbles, and rangelands.
Cultivate – When we cultivate the land, we expose the life within it to ultraviolet radiation, which kills the microorganisms, and of course that oxidises carbon.
Over-fertilise – We add fertiliser, and for every gram of nitrate for example we add to the soil, as in a compost process, 30 grams of carbon is oxidised back into the atmosphere. That is just the biological composting reactions.
Irrigate – By irrigating land we are restricting the fungal growth, and preventing various organisms from growing, and so restricting the bio-productivity of soils, while consuming water which could otherwise be retained by far more productive systems.
Fallow – Leaving fields bare is obviously just starvation of the living soil system. If the fungi haven’t got exudates (nutrients released by plant roots into soil) they can’t grow, and everything just slows down and dies, or sits in a resting state until plants come back again.
Biocides – Adding biocides (any chemical that destroys life by poisoning, especially a pesticide, herbicide, or fungicide) is just killing all of the soil life outright.
All of these processes are oxidizing carbon back into atmospheric carbon dioxide, and devolving soil back to compacted ground, less able to retain water and having lower productivity.
‘More-on’ agriculture is very destructive
Professor Jehne rather cheekily refers to these destructive processes as “more-on” agriculture, due to the overuse of chemicals like fertilizers and pesticides. These chemicals and techniques degrade the soil system to such an extent that farmers keep adding more and more of these destructive chemicals and techniques in vain attempts to sustain agricultural yield.
The tragedy is that we have invested 40% of our agricultural spending on inputs that are actually driving this depletion of the soil system and its capacity to hold water and deliver agricultural yield, while at the same time not only reducing the soil-carbon sponge’s capacity to draw down more carbon, but actually burning the carbon it helped to capture and sequester in the past.
Of course burning fossil fuels is now responsible for a lot of the carbon dioxide in the atmosphere, but for thousands of years we have been oxidizing carbon from the landscape. Clearly, given what we already know about the soil-water-carbon system, these agricultural practices that oxidise plant carbon are either ignorantly or deliberately moronic.
For any industrial mainstream farmers or agronomists reading here, Jehne’s tongue in cheek disparagement is designed to provoke you into expanding your perspective, rather than to offend you and make you look like the villain.
To the extent that you take on the message and change your practices you will become part of the solution, and to the extent that you don’t you will remain an ongoing part of the problem. If you don’t accept the veracity of the message, you can always raise objections via comments.
Agriculture that works with nature is far more productive
Intelligent agriculture burns less carbon and captures more carbon into rich living soils
Regenerative agriculture captures plant carbon into soil. The first and most important step in regenerative agriculture is obviously to stop doing the things just listed that are destructive to the soil-water-carbon system.
Just as importantly, regenerative agriculture involves a change of focus, away from the simplistic focus on yield, and towards a more enlightened and holistic approach that accounts for the soil system as a whole.
Regenerative agriculture is all about bio-digestion, that is having ideal conditions for bacteria to convert the carbon that is contained in plant matter into biological fertiliser that enriches the soil system.
Bio-digestion is critical to soil-carbon regeneration
Bio-digestion is cycling nutrients through a complex network of organisms, in the process of creating stable-soil-carbon.
Bio-digestion involves a complex zoo of microbes in the soil, and also involves a variety of animal life in different natural ecological systems. Central to the process are the fungal networks that distribute the nutrients throughout the system of plants, animals and soil life.
In natural grassland systems it is the herds of ruminants that serve as mobile bio-digesters. Their guts contain the bacteria that break down the prairie grasses and turn them into biological fertiliser which returns the nutrients to the soil. The more nutrients in the soil, the more carbon is captured into the bodies of living organisms and the detritus they leave in their wake.
In grassland crop systems, the stubble plant matter left behind after grains are harvested can be consumed by herbivores and turned into bio-fertiliser. Grasslands evolved symbiotically with herbivores, and without these mobile bio-digesters to turn plant litter into bio-fertiliser, the plant litter inevitably burns (either literally or through oxidization by any of the other destructive agricultural processes), and returns the plant carbon back into the atmosphere as carbon dioxide.
It is not only herbivores that contribute to bio-digestion in natural systems. For example, in some forest systems it is actually bears that play a significant role in bio-digestion, consuming the salmon that return from the ocean to spawn, and converting their carbon into biological fertiliser and enriching the soil. The trees in these vast forests are actually made of protein from fish that spend nearly all their lives in oceans thousands of kilometres away. It may be an ecological insight of sorts to realise that if there were no salmon bringing nutrients into these systems, there would be no bears, and if there were no bears, there would be no forest.
Regenerative agriculture has already learned to copy from nature
Bio-digestion does not necessarily depend on bacteria in the guts of large animals being a part of each ecosystem. There are very successful methods of agro-ecology that use pruning in specific ways to maximise the bacterial conditions for bio-digestion in ground litter, and this process does not require any external inputs at all. These techniques are being used to build very productive soil systems, and to restore very degraded land back to rich forest with plenty of agricultural surplus.
Natural systems thrive because of the process of bio-digestion and the continuous cycling of all the nutrients in the system. To the extent that agricultural processes achieve this recycling of nutrients they are regenerative, and to the extent that nutrients are lost or destroyed the agricultural processes are destructive, and they drive whole biosystems towards crashing back into desert and rock.
We can control how much plant carbon we burn and how much we capture into soil
The big picture perspective on agriculture is the question of whether we have systems that bio-digest plant carbon and capture it into rich healthy soil, or do we have systems that burn plant carbon, and send our soil systems back to hard rock and desert.
With smart, regenerative agricultural practices, we can limit the amount of destruction to the soil systems, and increase the volume of green growth, according to whatever ratio between carbon burning and carbon capture we would like to achieve.
What is important is how much of the roots and root exudates we turn into humates, and mycorrhizal fungi, which are made out of chitin. When the cell walls of these fungi are cast off they leave behind glomalin. Together humates and glomalin form the glue that aggregates soil, and they constitute stable soil carbon.
Intelligent changes to land use and agriculture can deliver stable climate
Profound benefits of capturing carbon
For every gram of carbon that we add into this stable soil carbon, the carbon sponge holds an extra 8 grams of water. This extra water retained in the soil-water-carbon system serves to increase the longevity of green growth. For example, if instead of 10 days of growth after a rain, we get 100 days of growth because of the richer and healthier soil system and its increased capacity to retain water, we have increased the longevity of green growth by 1000% just through building the sponge.
There is a multiplier effect, that extends the longevity of growth, extending the draw down of carbon, and extending the resilience of the system.
Every extra gram of carbon captured into soil massively increases the bio-fertility of the system. 80% of the fertility of soils isn’t about how many nutrients are contained in that soil in total, it is about the availability of those nutrients, the microbial access, cycling, uptake, and solubilising of those nutrients.
Every gram of carbon we put into the soils massively increases the rootability and the volume of soil we have access to. These are powerful, exponential gains, that intensify the microbial activity, build disease resistance, and overall productivity.
Increasing soil-carbon delivers large agricultural dividends
The great dividend of capturing carbon into healthy soil systems is the power to massively increase agricultural yield and productivity, just as nature did with natural systems. Nature doesn’t add truckloads of fertiliser to the soil , or cultivate it, or apply biocides in order to drive bio-productivity. Nature achieves its bounty simply by increasing soil carbon, and we would do very well by imitating nature.
The process does not depend on having nutrient rich soil to begin with. For example, Australia’s CSIRO developed rainforests on sand dunes in Queensland that are the world’s most bio-productive ecosystems, effectively running on crushed glass with next to no nutrients in it. But every molecule is moving a thousand times faster, and therefore giving that productivity, because of the microbial activity. It is not a question of how many nutrients are available, but how well a system circulates them.
More powerfully, because of all the dividends from increased soil carbon, we negate the need for all of the “more-on” stuff, the clearing of forests, the burning of stubble, the tilling of the land surface, the added fertilizers, the irrigation, the starvation of the soil system by leaving fields fallow, and the use of biocides that simply kill everything in the soil.
The innovative farmers in the Healthy Soils Australia initiative are getting 100% of the yield of the mainstream practices, but are getting 300% of the quality and nutritional integrity in their food grains, they are doing it with less than 20% of the inputs, less than 10% of the risk, 300% the reliability, and 500% growth of the natural capital asset, the land’s soil regeneration value.
These are the dividends of regenerative farming, of taking agriculture from the 19th century into the 21st century, which is all about rebuilding healthy soils and the soil-water-carbon sponge. To put it bluntly, without that sponge we have got cactus – nothing, dead, desert.
Transpiration cools the air and the soil
When we have a soil-carbon sponge, we have green growth which drives transpiration, which is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere.
For every gram of water that transpires, that goes from a liquid in plants to a gas in the atmosphere, 590 calories of energy must be absorbed in order to overcome the latent heat of vaporization. This energy must be taken from the soil surface and from the vegetation, and so it can’t avoid but to cool the system at the level near the surface.
The heat of course rises up, and when this water condenses in the upper atmosphere, the heat is released, with most of it being emitted out into space. Nature has driven this hydrological cooling of the planet by these latent heat fluxes for hundreds of millions of years. Even now, with only half of the green vegetation left on this planet, 24% of the incident solar radiation – of that 342 Watts per square metre coming in – some 84 W/m2 is constantly taken back up through these latent heat fluxes.
Green growth can deliver global cooling
Green vegetation is constantly taking 24% of the incoming energy that is striking Earth’s surface and returning it back out to space. If we have a 5% increase in green vegetation and transpiration, we can effectively negate 3 W/m2, which is the very target we determined in the beginning as the excess retained heat in the Earth system, and so the root cause of climate change.
So, we have our answer to the original question of how do we cool the planet by 3 W/m2. Simple, we increase transpiration by 5%.
With only half of the planet’s vegetation that it had 8,000 years ago, there is plenty of scope for a 5% restoration. We are running at 50% green growth, and if we can restore that to around 55%, there will theoretically be as much energy being returned to space as there is coming in from incident solar radiation, and no more retained heat which drives climate change.
We must be careful to acknowledge the uncertainty of the numbers when it comes to overall outcomes. While we can calculate the volumes of heat involved in transpiration with some precision, there are many factors working together in the climate system. which means there are very many feedback interactions, some of which we can not know with any certainty, and likely many other interactions of which we may be currently unaware.
If we do start to boost regenerative agriculture and green growth, then we will have enormous streams of data from which to draw more accurate correlations between increased green growth and global cooling and carbon draw down, and so more reliable projections of the actual volume of transpiration required. If we get the public policy right, there will be many things that are happening at the same time and working together to drive global cooling and carbon draw down, so we have plenty of trump cards in hand.
Green growth is already delivering local cooling
The Australian capital city Canberra was designed originally around an urban forest, which was built up from a ‘clapped out sheep paddock’. The large volume of green growth results in daytime temperatures being 7 oC cooler than the newer urban heat-island concrete suburbs just 2km away. It is all about latent heat fluxes. We have a group called Cool Canberra, and it is all about urban trees, porous pavements, about the water retaining sponge and the infiltration of water into it, in order to maintain these latent heat fluxes.
This micro-climate cooling can be achieved anywhere with soil and water. We will see in a beautiful little video on agroecology to come that this micro-climate cooling can reach out and improve the bioproductivity of neighbouring properties too, without human intervention. Local cooling by transpiration is something that any farm, any community, or any individual with access to soil and water can achieve.
More green growth means more cloud and more cooling
The latent heat fluxes from green growth drive particles of water vapor upwards, creating massive numbers of cloud micro-droplets. These droplets are far too small to fall as rain, so they form into dense high-albedo clouds, which reflect solar radiation directly back out to space, so that it doesn’t even get to the soil surface, making the land surface significantly cooler. Globally, 50% of the Earth’s surface is covered in dense clouds at any one time – well it certainly used to be but it is getting less. These clouds reflect on average 120 W/m2 back to space, which is roughly a third of the total incident solar radiation. So a 2% increase in cloud will offset the required 3 W/m2.
Cloud can only happen if we get micro-droplets, which can only happen if we have a sponge that is transpiring water up into the air.
The sponge is not only the fundamental driver of the cooling process, it is also what we can influence, it is our point of agency. It is what we can do, with every square metre, every acre, every region, every nation. This constitutes grass-roots empowerment of effective climate action.
More green growth means more bacteria and more rain
We need more than cloud, because we need rain to feed the soil-carbon sponge. It takes about 1 million of the cloud micro-droplets to form a raindrop, because it has to coalesce together to make a raindrop that is big enough and heavy enough to fall out under gravity. There are three things that can lead to the formation of rain drops, and these are called precipitation nuclei.
The first is ice crystals, which are very important at high latitudes where water vapor gets colder and colder and eventually forms ice. The second is salt, which accumulates over the oceans and sucks up water, because it is hydroscopic. Salt is also what we use for artificial cloud seeding, where we use silver iodide to increase rainfall from certain types of cloud by a consistent 20 to 30%.
But by far the most important source of precipitation, particularly in inland, tropical and warmer areas, is bacteria. Bacteria is by orders of magnitude the most effective means of nucleating clouds into raindrops. These bacteria are produced in nature. Forests are not just transpiring water vapor, they are also putting up bacteria.
From radio isotope studies, half the rain in the Amazon is precipitated by the bacteria transpiring upwards every day, and each afternoon it comes back down in a thunderstorm. Everyday you have this hydrological cycle, taking heat from the surface, dissipating it upstairs, and returning rain back to the sponge. Five times more water falls as rain over the Amazon each day than flows out from the Amazon River into the ocean, which demonstrates the sheer volume of the process of cycling water to and from the atmosphere on a daily basis.
Vast areas of forest have been cleared, and we have already mentioned the 8 billion hectares of primary forest that we have reduced by 6.3 billion hectares of clearing, so what have we done with our rain?
By regenerating landscapes, we can actually start restoring these hydrological dynamics, especially the bacteria that rise from forests to seed rain, which is critical to replenishing the soil-carbon sponge. It all comes down to cooling, more cooling, rain, and more cooling. These are powerful, natural, simple, and safe processes to cool regions and the planet.
Bare land generates enormous amounts of heat
We can cool the planet, but it all depends on the sponge. There is a vast difference between land systems with rich green growth and those with a bare land surface.
Land systems with plants and grasses get the benefit of cooling via transpiration, along with the albedo, shading and cover effects of the vegetation, so the soil temperature rarely gets above 20 oC.
Bare surfaces like soil, asphalt, and concrete readily get up to 60 oC. There is the same amount of incident energy coming in and heating these two systems, but what is important is how much energy and heat are taken back up.
The Earth is a black body radiator, like a stove. There is a simple fundamental law of physics, the Stefan-Boltzmann equation on black body radiation, which shows that the re-radiation from a black body is proportional to the fourth power of the temperature in degrees Kelvin. That is re-radiation of heat is proportional to T x T x T x T.
So when we have two different surfaces, one at 20 oC and one at 60 oC, we get a massive increase in the re-radiation of heat, infrared energy. from the bare hot surface. Massively more heat energy is continuously accumulated into the surface and lower atmosphere from bare land.
Climate debate without re-radiation and water is misguided
There are three variables that control the greenhouse effect that is driving climate change, both the natural and the man-made greenhouse effect: the amount of re-radiation of heat energy into the atmosphere; the absorption of that heat energy by water vapour molecules in the atmosphere; and the absorption of that heat energy by carbon dioxide in the atmosphere.
In the climate debate, we have largely ignored the first two variables, with our misguided focus on carbon dioxide. We have completely ignored land management and the massive re-radiation effects in our climate models, despite the fact that this re-radiation represents 90% of the force driving the greenhouse effect.
There is up to 40,000 ppm water vapour in the atmosphere, while there is 406 ppm CO2 in the air. Each water vapor molecule can absorb 8 times more energy than a CO2 molecule, 490 calories per gram of water compared to about 72 calories for CO2. So water has far more potential to deal with the retained heat in the Earth system.
So, we have focused on the least powerful of the factors driving the greenhouse effect, carbon dioxide, and we can’t do anything about that for 1,000 years. Drawing down carbon is important, of course, and regenerating the soil-water-carbon system is the most powerful approach at our disposal, and we can no longer afford to ignore it.
We have control over re-radiation, because we can change our patterns of land usage. We also have control over water, because we can change our agricultural practices to ones that replenish the soil-water-carbon system.
We have the power to steer the climate system. All we need now is enough wisdom to drive it in the right direction.
This summary of the argument presented in this article can be used to ponder the big picture, and to navigate back to particular points to consider the details. It can also be used to copy and paste into online discussions.
How did nature cool the planet? Learning from Nature.
Heat, water and climate change: Climate is all about water. The focus on carbon dioxide is too narrow. Regenerating Earth’s soil carbon sponge will enable global cooling. The carbon cycle currently has an annual deficit. Climate change is retained energy. Climate extremes are all water related. Dangerous climate extremes are already our new reality. We must dramatically increase the draw down of carbon. We must regenerate the Earth’s soil-carbon sponge. Oceans will release more greenhouse gases.
Nature’s cooling system: Nature created a balanced system. We need to rebalance the system. Life on land changed the planet. New forms of life began to dissolve rock. Where did fungi come from? Plant and animal life boomed. Rock was transformed into rich soil. Rich soils exponentially increase the capture of water and carbon. Soil formation is the engine of nature’s cooling and carbon capture system.
Agriculture can work with or against nature: Most of Nature’s richness lives below the ground. Nature converts carbon into rich living systems. Two options for plant carbon: Capture or Burn. Nature’s tendency is to capture carbon into rich living systems. Agriculture tends to burn carbon back into the atmosphere. ‘More-on‘ agriculture is very destructive.
Agriculture that works with nature is far more productive: Intelligent agriculture burns less and captures more carbon into rich living soils. Bio-digestion is critical to soil-carbon regeneration. Regenerative agriculture has already learned to copy from nature. We can control how much plant carbon we burn and how much we capture into soil.
Intelligent changes to land use and agriculture can deliver stable climate: Profound benefits of capturing carbon. Increasing soil-carbon delivers large agricultural dividends. Transpiration cools the air and the soil. Green growth can deliver global cooling. Green growth is already delivering local cooling. More green growth means more cloud and more cooling. More green growth means more bacteria and more rain. Bare land generates enormous amounts of heat. Climate debate without re-radiation and water is misguided.
Turning knowledge and agency into action
We have answers
So, we now have answers to the questions posed at the beginning. We know that nature achieved global cooling and massive draw down of carbon by building the soil-water-carbon process. We know that we have agency because we can control the amount of green growth and the consequent cooling by transpiration, replenishing of the soil carbon sponge by seeding more rain, and increasing cooling as a result of increased cloud cover.
We have goals
We estimate that either a 5% increase in transpiration or a 2% increase in cloud cover is probably enough on its own to eliminate accumulating retained energy in the Earth system. We know that transpiration and cloud cover and seeding will all increase along with expanding green growth, so we will inevitably have some mix of these factors, rather than any one of them having to work on its own, so the percentage change required may be even smaller.
We can act at the collective level, from the top down
Imagine a global agreement along the lines of the Paris Agreement on emissions reductions, with agreed targets of a 5% increase in green growth, a 5% increase in transpiration, and a 2% increase in cloud cover.
The politics of this sort of change may be challenging, but with a broader debate on climate change that includes the massive potential of hydrology and green growth for safe and natural cooling of the planet and its regions, and for massive new draw down of carbon in the atmosphere, such a global agreement should be seen as plausible and an ultimate priority.
As to how these particular goals might be achieved once agreed, the most effective model of public policy would be a self-funding market model, where activities that do harm to system goals pay penalties into a fund, which is then fully distributed as rebates to activities that drive outcomes towards the goals. This makes constructive activities grow at the expense of the destructive ones, at just the right speed to generate the overall desired outcome. Arming such a system with the singular goal of regenerating the soil-water-carbon system, and so creating incentives to build that system and disincentives to damaging it, would be the easiest way forward.
Alternatively, the global goal can be the control of greenhouse gas concentrations along a trajectory that satisfies the requirements of the Paris Agreement. This would automatically generate incentives to preserve and regenerate the soil-water-carbon system, and disincentives to deplete it, along with disincentives for all activities that contribute to climate change. This model is explained in another article here, in a rough draft form for now: Global Carbon Sinking Fund.
We can act at the local level, from the bottom up
Those of us involved in agriculture can change our practices and try to influence others to do the same. Healthy Soils Australia might be a good place to start. Here is their introductory video:
We can all deepen our understanding of regenerative agriculture, and begin to see it as not just a profitable alternative to ‘more-on’ mainstream agriculture, but as the only way to replenish the soil-water-carbon system and to protect the planet from climate change. We should want all farming to become regenerative, and to treat the soil-carbon sponge for the natural wonder that it is, rather than having farms that continue burning all that carbon and all the natural systems with it.
This short video on agro-ecology is a great introduction to regenerative agriculture. Syntropy is the approach that uses pruning rather than land animals to achieve bio-digestion, and it can restore depleted land into rich and productive forest and farm combined.
All of us can share this important knowledge and make an effort to broaden the climate debate in online engagement.
Walter Jehne – New Climate Solutions
Here is the video this article has been drawing on. It is quite long at 2 hours, and is full of questions from the audience that disrupt the flow of Jehne’s explanation. With that note of caution, anyone who has been interested and patient enough to have read through this article should also be patient enough to absorb it.
There are many great demonstrations and sketches that help to build a comprehensive perspective and a persuasive argument for change. There are quite a few important explanations that are not included in this article, such as the role of methane in climate change, and the heat domes that now prevent cool moist air from flowing onto land as much as it used to, and how this causes increasing aridification of inland areas.
Thanks for reading.
16 Replies to “Fixing Climate Change – Boosting Nature’s Cooling System”
Thank you for explaining nature’s cooling system in layperson’s terms.
I wish it were compulsory reading for farmers and policy makers alike. QLD’s deforestation rate is abominable and it doesn’t look like being stopped, let alone reversed into green growth.
I appreciate the summary. It helps to find and re-read bits of a very long essay that haven’t sunk in.
I read the discussion about soil carbon and it seems sound. But when the article turns to “Transpiration Cools the Air and Soil”, I have doubts. For a start, units are mixed (calorie – imperial) vs metric elsewhere. The energy of 590 calories for transpiation is meaningless unless accompanied by the volume of water.
Then in “Green growth can deliver global cooling” you assume a linear relationship “to cool the planet by 3 W/m2 … we increase transpiration by 5%”. Yet the next sentence states we have “half of the planet’s vegetation” remaining. If the relationship was linear, why aren’t we cooked already.
Do your claims about restoring green growth stack up?
Hi Gary. Thanks for the comment. You can see the supporting figures in Appendix 1 here. Cheers.
There are details of the Healthy Soils Australia initiative here.
does the greenhouse effect have an impact on weather conditions?
I would love to have a reference for this statement please:
“The residual biosystems we have now – the land surface vegetation – is perhaps half what it was 8,000 years ago, as we have degraded forests and grasslands, and have created 5 billion hectares of man-made desert and wasteland. “
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For years, I have been somewhat sarcastically pointing out that trees/plants are functioning carbon-capture devices whenever people get on their high horse about “carbon capture” tech.
But I was fundamentally right! And while “plant trees” is a flippant answer to “what can we do about climate change”, it has an element of truth in there. We will fail at saving ourselves if we look merely at emissions; we _need to scrub carbon out of the atmosphere_ even *more* than we need to reduce emissions. And the only viable method is via plants doing the scrubbing and then returning to captured carbon to long term storage!
Grow things. Restore the forests and grasslands and all the rest. Return the atmospheric (and oceanic) carbon to biomass and long term storage. I am not expert enough to contribute to methods but I swear I will campaign on this for the rest of my life.
What needs to be prepared to welcome climate change?
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