Listen now | Microbiologist and regenerative agriculture expert, Walter Jehne, on how soil can capture carbon, promote global cooling, and feed billions on very little space. He explains how politics got in the way of progress in the 70s, and why government defence departments are scrambling to speak to him and his team.
Thanks to Rachel and the presenter for the interview and discussions.
The proposal for cooling through boosting transpiration is qualitatively flawed. This cooling mechanism requires significantly increase heating power at the surface to effectively drive it; amplifying the hydrological cycle is a negative feedback mechanism in the event of already severe surface warming. Increasing cloud cover is a second-order negative feedback mechanism on the efficiency of cooling by transpiration.
The discussions lack quantitative rigor. The presenter has not performed an energy and resource requirement calculation to support the engineering feasibility of artificially amplifying the transpiration/precipitation cycle. Energy consumption to source the required freshwater in desiccating regions is beyond what is at our disposal. To increase transpiration by 2 mm/day over 3% of the Earth's surface requires the total power consumption by humanity of 2.7 TW. The cooling from this process is also not enough to fix the total, globally averaged energy imbalance of >3 W/m2 (with respect to preindustrial period).
The rate of carbon fixation through photosynthesis is too slow for climate relevance. Net primary production on land is limited to 40 GtonC per year. It is thus impossible to recapture the ~1000 GtonC already emitted by humans within a decade, even if quadrupling net primary production and converting all of the product to biochar.
Hi Brett, the presenter proposes to increase latent heat (evaporation) transport upwards, away from land. This would require increasing irrigation, which requires freshwater, a limited resource. To have a measurable impact, locally, the increase need to be on the same order of magnitude as what already happens as a result of natural processes. 2mm/day is a modest, measurable increase over background. To have a planetary impact, a big enough surface area on Earth needs to be irrigated, say 3%. These two numbers enables calculating the volume of freshwater needed per day. This flux of freshwater, massive, can only be obtained through desalination technologies (assuming we are not relying on ocean warming;). To do anything in this universe requires energy. Producing freshwater on a massive scale is no exception. One can use the energy consumption in the state of the art desalination process, coupled with the embodied energy of water derived from seawater, to estimate the total energy requirement. I leave it to you as an exercise to run through the research and calculation steps:)
I don't recall hearing him mention the proposition to increase evaporation. He does talk about increasing transpiration. I will re-listen again at some point
We have less than 9 years to convert agriculture to store carbon to retain water but we can't even start in any meaningful way until WWIII is over. There are so many elephants stuffed in the room that it is a wonder that anyone can draw a breath to talk about this stuff.
There is no humanly possible solution to the human caused problems. The earth does not need us to save it. It will fix things itself. It has gone through many changes over the last 3.5 billion years and will go successfully through many more in the next 3.5 billion years.
It looks like hyper-intelligence is going to be a massively unsuccessful evolutionary adaptation.
I must admit I struggled a bit with this, and was left with more questions than answers. My understanding about water vapour as a greenhouse gas is that it's powerful but short-lived, and that it is a positive feedback loop to the main (human) cause of global heating, CO2. As the atmosphere warms, it can hold more water vapour, therefore more heating etc.. Also I'm not sure about the idea that if you reduce emissions, the oceans will just give up some of their CO2 to replace them. Even if that was the case, the massive amounts that are being absorbed by the oceans are also causing acidification, making it problematic for creatures that make shells, disrupting the food chain.
I've never heard that you can feed yourself with just 4sq metres of soil, did I mishear that? It sounds very optimistic. A while back you interviewed Andres Jara, who also talked about no-till farming. In the U.K. it's more commonly known as 'no-dig' and it's becoming very popular with vegetable growers. See Charles Dowding, who has some great videos on the technique, and how to build soil with composting.
It is short lived, however,… given that so much of the planets surface has been degraded and desertified, then there’s a never ending ammount of excess water *not* being retained where soils *should* be, thus…the water continues to cycle in the atmosphere and amplifiers the heat dynamics.
He meant ‘no till’, as in..no ploughing, at agricultural scale, this is done by means of direct seed drilling into existing pastures and grasslands that are not tilled/ploughed, no dig, is the same but at the smaller horticultural scale.
He did say that the 4sqm was collectively intergrated with you and your neighbours chickens, and he was being super optimal on what *could* be done at the optimal prime.
It’s absolutely critical that we all understand the point that Walter is making regarding the heat dynamics of water.
Science fully accepts that water/vapour is a potent GHG, however, a fully holistic appreciation on the impacts of land degradation - global hydrological [dis]function, has long been ignored.
Water, is, on the one hand, the benign elixir of planetary life, yet on the other, is the most brutal conduit of devastation once disrupted and displaced. Ultimately, it will express itself in either form, humanity can either influence for the latter, or the former.
I think that that your discussions with Walter and Anastassia have really pointed to where our focus needs to fall.
Why re-invent the wheel. Natures systems have been doing a fabulous job of regulating the planet's climate for millennia.
Instead of taking the arrogant 'humans know best, industry and technology will solve our woes' approach, I think it's long overdue for humans to transition to supporting nature's systems to bring us back to a habitable equilibrium.
Thanks to Rachel and the presenter for the interview and discussions.
The proposal for cooling through boosting transpiration is qualitatively flawed. This cooling mechanism requires significantly increase heating power at the surface to effectively drive it; amplifying the hydrological cycle is a negative feedback mechanism in the event of already severe surface warming. Increasing cloud cover is a second-order negative feedback mechanism on the efficiency of cooling by transpiration.
The discussions lack quantitative rigor. The presenter has not performed an energy and resource requirement calculation to support the engineering feasibility of artificially amplifying the transpiration/precipitation cycle. Energy consumption to source the required freshwater in desiccating regions is beyond what is at our disposal. To increase transpiration by 2 mm/day over 3% of the Earth's surface requires the total power consumption by humanity of 2.7 TW. The cooling from this process is also not enough to fix the total, globally averaged energy imbalance of >3 W/m2 (with respect to preindustrial period).
The rate of carbon fixation through photosynthesis is too slow for climate relevance. Net primary production on land is limited to 40 GtonC per year. It is thus impossible to recapture the ~1000 GtonC already emitted by humans within a decade, even if quadrupling net primary production and converting all of the product to biochar.
You say "to incease transpiration by 2mm/day over 3% of the earths surface requires power consumtion by humanity of 2.7tw" what do you mean by that?
Hi Brett, the presenter proposes to increase latent heat (evaporation) transport upwards, away from land. This would require increasing irrigation, which requires freshwater, a limited resource. To have a measurable impact, locally, the increase need to be on the same order of magnitude as what already happens as a result of natural processes. 2mm/day is a modest, measurable increase over background. To have a planetary impact, a big enough surface area on Earth needs to be irrigated, say 3%. These two numbers enables calculating the volume of freshwater needed per day. This flux of freshwater, massive, can only be obtained through desalination technologies (assuming we are not relying on ocean warming;). To do anything in this universe requires energy. Producing freshwater on a massive scale is no exception. One can use the energy consumption in the state of the art desalination process, coupled with the embodied energy of water derived from seawater, to estimate the total energy requirement. I leave it to you as an exercise to run through the research and calculation steps:)
Hi Ya Tao
I don't recall hearing him mention the proposition to increase evaporation. He does talk about increasing transpiration. I will re-listen again at some point
We have less than 9 years to convert agriculture to store carbon to retain water but we can't even start in any meaningful way until WWIII is over. There are so many elephants stuffed in the room that it is a wonder that anyone can draw a breath to talk about this stuff.
There is no humanly possible solution to the human caused problems. The earth does not need us to save it. It will fix things itself. It has gone through many changes over the last 3.5 billion years and will go successfully through many more in the next 3.5 billion years.
It looks like hyper-intelligence is going to be a massively unsuccessful evolutionary adaptation.
I must admit I struggled a bit with this, and was left with more questions than answers. My understanding about water vapour as a greenhouse gas is that it's powerful but short-lived, and that it is a positive feedback loop to the main (human) cause of global heating, CO2. As the atmosphere warms, it can hold more water vapour, therefore more heating etc.. Also I'm not sure about the idea that if you reduce emissions, the oceans will just give up some of their CO2 to replace them. Even if that was the case, the massive amounts that are being absorbed by the oceans are also causing acidification, making it problematic for creatures that make shells, disrupting the food chain.
I've never heard that you can feed yourself with just 4sq metres of soil, did I mishear that? It sounds very optimistic. A while back you interviewed Andres Jara, who also talked about no-till farming. In the U.K. it's more commonly known as 'no-dig' and it's becoming very popular with vegetable growers. See Charles Dowding, who has some great videos on the technique, and how to build soil with composting.
It is short lived, however,… given that so much of the planets surface has been degraded and desertified, then there’s a never ending ammount of excess water *not* being retained where soils *should* be, thus…the water continues to cycle in the atmosphere and amplifiers the heat dynamics.
He meant ‘no till’, as in..no ploughing, at agricultural scale, this is done by means of direct seed drilling into existing pastures and grasslands that are not tilled/ploughed, no dig, is the same but at the smaller horticultural scale.
He did say that the 4sqm was collectively intergrated with you and your neighbours chickens, and he was being super optimal on what *could* be done at the optimal prime.
Thanks for the clarification Jay, that makes sense.
You’re very welcome, Tim.
It’s absolutely critical that we all understand the point that Walter is making regarding the heat dynamics of water.
Science fully accepts that water/vapour is a potent GHG, however, a fully holistic appreciation on the impacts of land degradation - global hydrological [dis]function, has long been ignored.
Water, is, on the one hand, the benign elixir of planetary life, yet on the other, is the most brutal conduit of devastation once disrupted and displaced. Ultimately, it will express itself in either form, humanity can either influence for the latter, or the former.
Regards.
I think that that your discussions with Walter and Anastassia have really pointed to where our focus needs to fall.
Why re-invent the wheel. Natures systems have been doing a fabulous job of regulating the planet's climate for millennia.
Instead of taking the arrogant 'humans know best, industry and technology will solve our woes' approach, I think it's long overdue for humans to transition to supporting nature's systems to bring us back to a habitable equilibrium.