I thought a lowering of the recycle rate of water vapor into rain, what type of clouds form over areas of differing aridity and where the rain now actually falls would be more important warming factors As I commented in the previous paper about the biotic pump
Firstly in relation to the biotic pump the principle behind the mechanistic view and why it was discredited by some scientists is that it does not seem to take into account the fact that many plants work on stored energy and the lower light conditions due to clouds favor their growth and hence humidity will still increase over a forest compared to over the ocean as the clouds increase and this coupled with condensation nuclei should create an earlier tipping point into rain.
Secondly due to the fact the world cools from east to west as we rotate and we reduce transpiration over land due to land clearing, how would this play into the biotic pump in a warmer world. My view is that it may strengthen the pumps reversal in the dry cycle and rain more over the ocean and draw moisture away from the land adding to the el nino, la Nina cycle and hence the level of drought conditions we are seeing now in places like the Amazon. We do not see a net decrease in cloud in the near costal regions of the ocean where we see drought and add to this the fact that plants under heat stress start to shut down as this study and many others are pointing out https://theconversation.com/study-shows-hot-leaves-cant-catch-carbon-from-the-air-its-bad-news-for-rainforests-and-earth-246975 If the biotic pump then draws moisture away from the land or the land no longer reaches a critical tipping point then heat domes will form and we see lands quickly dry as we are witnessing. What they now term whiplash. How to work the daily temperature differentials over land vs the sea for our advantage in relation to rehydration and rain creation could be an interesting area of research. Many thanks
Theodore, you mention El Nina and La Nina. There is no correlation between this data and the flow of the Zambezi, see First 6month Report on the Campaign, on the Bring back the Rains page of the www.radio4pasa.com website
I read that cyclical change of el nino/ la nina they relate only a 15% reduction in precipitation but this may change with rehydration efforts, but two other things stand out , firstly the notion that trees need to be widely dispersed for individual water uptake, this might not be the best solution for two reasons firstly shelter belts allow less evapotranspiration in relation to wind and shading created from N-S belts allow dew to be deposited earlier in the afternoon and stay on the ground longer in the morning. When much of the cropland relies on irrigation it would then seem necessary to plan accordingly as in Australia the trees take best where water can settle and soak in in areas of limited rain. Trees are water hogs and will search out water 10-20m from their trunk so it is essential that you chose the right type with deep penetrating tap roots and space them appropriately in areas of irrigated cropping
In relation to ground water I notice a large percentage of the inland perennial water bodies drain into each other then into the river system, have you trialed a system of containment to retain the water at a higher level across the outflow drainage channels (could be as simple as sandbagging) With minimal work this would raise the water level of each so why lose all this water in the wet when it can be used to recharge the ground water and in the deeper lakes be used for aquaculture, atmospheric rehydration and irrigation.
Further to this Australia are trialing two other procedures to tackle erosion and desertification, they are trialing in flow retardation structures and levees across large sections of flat land to hold back and soak wet season rainfall , these can be incorporated in raised road building. The stability of the inflow structures is the key as the down slope erosion is the problem, I have seen 90% shade cloth used quite successfully which is then planted out with swamp sedge etc. Hope this helps
Thank you for your comments, clouds are of course very important. But in this post we are discussing a distinct effect, of the water cycle intensity, on the global temperature.
Yes the biotic pump reversal is a very dangerous thing. The forests must always be winning the "tug-of-war" with the ocean for moisture.
I am unsure I follow this as the second study is not even a real world scenario, I understand the notion that the northern hemisphere land mass on our planet is the largest and therefore the study into high latitude land clearing but to study a globe without the topographic and land distribution this planet has and to say it is relevant makes no sense. the two ways to store energy are in biomass ie chemical accumulation and in thermal mass, chemical accumulation is one pathway for thermal regulation between different states, so to is forced movement through wind and ocean currents over different altitudes and ocean depths primarily through heat regulation, Water cycle intensity one could say is on par with thermal biomass regulation and the ability for high latitude landscapes to store energy and regulate this for prolonged water cycle movement for greater temperature control is essential. As we know It becomes hotter and colder as we dry out landscapes but the average temperature does not change much and such temperature extremes are not conducive to life.
I could not agree more about the World’s focus on the single issue of CO2 – while ignoring the destruction of our soil, our forests and the depletion of our under-ground water. A shortage of water will be our undoing long before Climate Change REALLY kicks in.
In that graph showing the decline in Primary Vegetation, would you be able to give some examples of Primary vegetation < 2kg C/m2? I assume greater than 2 would be the rain forests of Amazon, Congo and the Far East? Would the sub-tropical woodland savannas of Africa fall into the >2 or <2 category? Your boreal forests of the far north? In that graph, what is the difference between the dark maroon and pink classes of disturbed vegetation?
Solar energy falling on cleared land is “unclaimed by Life” is an absolutely brilliant phrase.
“Precipitation and total evaporation (which includes transpiration) are closely matched on the timescale of a few days”. I had assumed that, in southern Africa, the timescale, particularly at the start of our rainy season, would be over a longer time scale of at least several weeks. Some of our “wise” indigenous trees come out into fresh, transpiring leaf in mid-August even though our rains cannot really be expected until late October/early November
“We could perturb this flux by about 3%, or by 2.4W/m2” sounds almost insignificant, but what one has to remember is that energy flux is cumulative. The best illustration of this is that the sun produces heat at the same rate PER UNIT OF VOLUME as the average human digestive system! This small increment of heat from every liter of volume in the sun adds and adds until the total produces the radiation that powers our solar system.
“has a much lower transpiration efficiency corresponding to a grassland”. Is this much lower efficiency of grassland a feature of the seasonality or is it that, even in the middle of a summer growing season, a grassland cannot transpire as much moisture as even a <2kg C/m2 woodland? This is an important point for me to understand – and then to disseminate throughout my community.
I will have to revisit the EVA-FOREST and RGH-FOREST maps as I don’t really understand the point you are trying to make here. What does RGH stand for?
At least those maps can show me where the latitude bands extend to in the next graph. If I read it correctly, deforestation from 50-70N would cause a combined impact of cooling by about 0.4 deg C, while deforestation around the equator including as far South as where I live (15S) would produce an impact of +0.2to+0.4deg C. Why the difference? How important is it to bear in mind that the 10N-10S latitude covers far more of the earth than 50N-70N? I don’t have time to check how much actual land there is in these latitudes, which is obviously an important consideration. I would hate to see any policy (formed on the basis of this graph) that advocated the deforestation of your boreal forests!
“Warming over land is compensated by cooling over the ocean” as a result of suppressing evaporation over a landmass equivalent to ¼ of the earth’s surface. What mechanism explains this, and why does the temperature response change dramatically with the ½ northland, while the Latent Heat flux doesn’t change that significantly through the five different scenarios? This diagram raises (in my mind) more questions than answers!
“I am positive. . . . . . and will again champion thinking”. I love that. Following a terrible drought last (2023/24) rainy season in southern Africa, we are all (naturally) somewhat concerned that we might get a repeat this (2024/25) season which is currently still well below average in terms of rainfall, although we haven’t had the scorching dry weather of last year (yet!) (I recommend interested readers visit the Zambezi River Authority website that shows levels of the Zambezi and Lake Kariba a major source of hydro-electric power for both Zambia and Zimbabwe.) As a result many of us are following various weather forecasting websites and we are mostly very frustrated as they are all, without exception, proving to be hopelessly optimistic, predicting much more rain than actually falls. There was some hope that since Google had made their AI available to the weather forecasters, that the forecasts would become significantly more accurate. I countered that, because their forecasting was based on historic data, it would not compensate for the deforestation, soil degradation and water-table depletion that has taken place in the last few decades. Garbage In still produces Garbage Out, even when supervised by an AI, so, until we run models that include these parameters we can continue to expect poor weather forecasts, and inaccurate Climate Models.
Thank you for your comments. "We could perturb this flux by about 3%, or by 2.4W/m2” sounds almost insignificant" -- current global warming is officially driven by CO2 forcing of (currently) about 2+ W/m2. So it is a lot!
I do not discussed "RGH-FOREST" panel in the post, but it refers to comparison of a forested Earth with the Earth that has albedo and transpiration as a forest, but reduced roughness as a grassland. RGH stands for roughness. So reduced roughness also leads to warming in their study.
Why reduced transpiration warms the Earth was discussed in the first post on this blog.
If you want to call those models 'state of the art', fine. It's just unfortunate that the art quality is that of an average 6 year old not that of Van Gogh or Leonardo da Vinci.
Thank you for this. I appreciate your courage in pointing these things out. I think it's really important that science be open to scrutiny, and that it be rendered in terms understandable to the average citizen. Otherwise we have elite institutions running both the science and the narrative, which is never good.
A couple questions:
1. I also found "internal redistribution of energy in the climate system" a rather vacuous statement by which to explain such a dramatic result. What do you think they mean by it.
2. You mentioned in a reply that land and ocean are in a "tug of war" over water. It would seem that moisture over oceans would naturally travel to the dryer land osmotically at the very least, but you suggest the ocean also "tugs" the water back. Can you elaborate on this tug of war?
dry land actually repels water in many ways least of all gravity that sucks water back into the ocean, Hydrophobic soils and lack of the soil sponge, heat domes reducing cloud formation and lack of vegetation as a medium to draw moisture out of the air into their root systems. In a previous post I mentioned the possibility of the reversal of the biotic pump and possible reasons why the oceans may in the future increase this reversal and draw atmospheric and therefore ground moisture away from the land , All very worrying but yet to be proven.
I thought a lowering of the recycle rate of water vapor into rain, what type of clouds form over areas of differing aridity and where the rain now actually falls would be more important warming factors As I commented in the previous paper about the biotic pump
Firstly in relation to the biotic pump the principle behind the mechanistic view and why it was discredited by some scientists is that it does not seem to take into account the fact that many plants work on stored energy and the lower light conditions due to clouds favor their growth and hence humidity will still increase over a forest compared to over the ocean as the clouds increase and this coupled with condensation nuclei should create an earlier tipping point into rain.
Secondly due to the fact the world cools from east to west as we rotate and we reduce transpiration over land due to land clearing, how would this play into the biotic pump in a warmer world. My view is that it may strengthen the pumps reversal in the dry cycle and rain more over the ocean and draw moisture away from the land adding to the el nino, la Nina cycle and hence the level of drought conditions we are seeing now in places like the Amazon. We do not see a net decrease in cloud in the near costal regions of the ocean where we see drought and add to this the fact that plants under heat stress start to shut down as this study and many others are pointing out https://theconversation.com/study-shows-hot-leaves-cant-catch-carbon-from-the-air-its-bad-news-for-rainforests-and-earth-246975 If the biotic pump then draws moisture away from the land or the land no longer reaches a critical tipping point then heat domes will form and we see lands quickly dry as we are witnessing. What they now term whiplash. How to work the daily temperature differentials over land vs the sea for our advantage in relation to rehydration and rain creation could be an interesting area of research. Many thanks
Theodore, you mention El Nina and La Nina. There is no correlation between this data and the flow of the Zambezi, see First 6month Report on the Campaign, on the Bring back the Rains page of the www.radio4pasa.com website
Bruce Danckwerts, CHOMA, Zambia
I read that cyclical change of el nino/ la nina they relate only a 15% reduction in precipitation but this may change with rehydration efforts, but two other things stand out , firstly the notion that trees need to be widely dispersed for individual water uptake, this might not be the best solution for two reasons firstly shelter belts allow less evapotranspiration in relation to wind and shading created from N-S belts allow dew to be deposited earlier in the afternoon and stay on the ground longer in the morning. When much of the cropland relies on irrigation it would then seem necessary to plan accordingly as in Australia the trees take best where water can settle and soak in in areas of limited rain. Trees are water hogs and will search out water 10-20m from their trunk so it is essential that you chose the right type with deep penetrating tap roots and space them appropriately in areas of irrigated cropping
In relation to ground water I notice a large percentage of the inland perennial water bodies drain into each other then into the river system, have you trialed a system of containment to retain the water at a higher level across the outflow drainage channels (could be as simple as sandbagging) With minimal work this would raise the water level of each so why lose all this water in the wet when it can be used to recharge the ground water and in the deeper lakes be used for aquaculture, atmospheric rehydration and irrigation.
Further to this Australia are trialing two other procedures to tackle erosion and desertification, they are trialing in flow retardation structures and levees across large sections of flat land to hold back and soak wet season rainfall , these can be incorporated in raised road building. The stability of the inflow structures is the key as the down slope erosion is the problem, I have seen 90% shade cloth used quite successfully which is then planted out with swamp sedge etc. Hope this helps
Thank you for your comments, clouds are of course very important. But in this post we are discussing a distinct effect, of the water cycle intensity, on the global temperature.
Yes the biotic pump reversal is a very dangerous thing. The forests must always be winning the "tug-of-war" with the ocean for moisture.
I am unsure I follow this as the second study is not even a real world scenario, I understand the notion that the northern hemisphere land mass on our planet is the largest and therefore the study into high latitude land clearing but to study a globe without the topographic and land distribution this planet has and to say it is relevant makes no sense. the two ways to store energy are in biomass ie chemical accumulation and in thermal mass, chemical accumulation is one pathway for thermal regulation between different states, so to is forced movement through wind and ocean currents over different altitudes and ocean depths primarily through heat regulation, Water cycle intensity one could say is on par with thermal biomass regulation and the ability for high latitude landscapes to store energy and regulate this for prolonged water cycle movement for greater temperature control is essential. As we know It becomes hotter and colder as we dry out landscapes but the average temperature does not change much and such temperature extremes are not conducive to life.
Dear Anastassia,
A LOT to absorb in this substack!
I could not agree more about the World’s focus on the single issue of CO2 – while ignoring the destruction of our soil, our forests and the depletion of our under-ground water. A shortage of water will be our undoing long before Climate Change REALLY kicks in.
In that graph showing the decline in Primary Vegetation, would you be able to give some examples of Primary vegetation < 2kg C/m2? I assume greater than 2 would be the rain forests of Amazon, Congo and the Far East? Would the sub-tropical woodland savannas of Africa fall into the >2 or <2 category? Your boreal forests of the far north? In that graph, what is the difference between the dark maroon and pink classes of disturbed vegetation?
Solar energy falling on cleared land is “unclaimed by Life” is an absolutely brilliant phrase.
“Precipitation and total evaporation (which includes transpiration) are closely matched on the timescale of a few days”. I had assumed that, in southern Africa, the timescale, particularly at the start of our rainy season, would be over a longer time scale of at least several weeks. Some of our “wise” indigenous trees come out into fresh, transpiring leaf in mid-August even though our rains cannot really be expected until late October/early November
“We could perturb this flux by about 3%, or by 2.4W/m2” sounds almost insignificant, but what one has to remember is that energy flux is cumulative. The best illustration of this is that the sun produces heat at the same rate PER UNIT OF VOLUME as the average human digestive system! This small increment of heat from every liter of volume in the sun adds and adds until the total produces the radiation that powers our solar system.
“has a much lower transpiration efficiency corresponding to a grassland”. Is this much lower efficiency of grassland a feature of the seasonality or is it that, even in the middle of a summer growing season, a grassland cannot transpire as much moisture as even a <2kg C/m2 woodland? This is an important point for me to understand – and then to disseminate throughout my community.
I will have to revisit the EVA-FOREST and RGH-FOREST maps as I don’t really understand the point you are trying to make here. What does RGH stand for?
At least those maps can show me where the latitude bands extend to in the next graph. If I read it correctly, deforestation from 50-70N would cause a combined impact of cooling by about 0.4 deg C, while deforestation around the equator including as far South as where I live (15S) would produce an impact of +0.2to+0.4deg C. Why the difference? How important is it to bear in mind that the 10N-10S latitude covers far more of the earth than 50N-70N? I don’t have time to check how much actual land there is in these latitudes, which is obviously an important consideration. I would hate to see any policy (formed on the basis of this graph) that advocated the deforestation of your boreal forests!
“Warming over land is compensated by cooling over the ocean” as a result of suppressing evaporation over a landmass equivalent to ¼ of the earth’s surface. What mechanism explains this, and why does the temperature response change dramatically with the ½ northland, while the Latent Heat flux doesn’t change that significantly through the five different scenarios? This diagram raises (in my mind) more questions than answers!
“I am positive. . . . . . and will again champion thinking”. I love that. Following a terrible drought last (2023/24) rainy season in southern Africa, we are all (naturally) somewhat concerned that we might get a repeat this (2024/25) season which is currently still well below average in terms of rainfall, although we haven’t had the scorching dry weather of last year (yet!) (I recommend interested readers visit the Zambezi River Authority website that shows levels of the Zambezi and Lake Kariba a major source of hydro-electric power for both Zambia and Zimbabwe.) As a result many of us are following various weather forecasting websites and we are mostly very frustrated as they are all, without exception, proving to be hopelessly optimistic, predicting much more rain than actually falls. There was some hope that since Google had made their AI available to the weather forecasters, that the forecasts would become significantly more accurate. I countered that, because their forecasting was based on historic data, it would not compensate for the deforestation, soil degradation and water-table depletion that has taken place in the last few decades. Garbage In still produces Garbage Out, even when supervised by an AI, so, until we run models that include these parameters we can continue to expect poor weather forecasts, and inaccurate Climate Models.
Enough! Bruce Danckwerts, CHOMA, Zambia
Thank you for your comments. "We could perturb this flux by about 3%, or by 2.4W/m2” sounds almost insignificant" -- current global warming is officially driven by CO2 forcing of (currently) about 2+ W/m2. So it is a lot!
I do not discussed "RGH-FOREST" panel in the post, but it refers to comparison of a forested Earth with the Earth that has albedo and transpiration as a forest, but reduced roughness as a grassland. RGH stands for roughness. So reduced roughness also leads to warming in their study.
Why reduced transpiration warms the Earth was discussed in the first post on this blog.
Thank you, Anastassia.
"It's all models, all the way down", as the saying might be restated.
;-(
https://en.wikipedia.org/wiki/Turtles_all_the_way_down
If you want to call those models 'state of the art', fine. It's just unfortunate that the art quality is that of an average 6 year old not that of Van Gogh or Leonardo da Vinci.
Thank you for this. I appreciate your courage in pointing these things out. I think it's really important that science be open to scrutiny, and that it be rendered in terms understandable to the average citizen. Otherwise we have elite institutions running both the science and the narrative, which is never good.
A couple questions:
1. I also found "internal redistribution of energy in the climate system" a rather vacuous statement by which to explain such a dramatic result. What do you think they mean by it.
2. You mentioned in a reply that land and ocean are in a "tug of war" over water. It would seem that moisture over oceans would naturally travel to the dryer land osmotically at the very least, but you suggest the ocean also "tugs" the water back. Can you elaborate on this tug of war?
dry land actually repels water in many ways least of all gravity that sucks water back into the ocean, Hydrophobic soils and lack of the soil sponge, heat domes reducing cloud formation and lack of vegetation as a medium to draw moisture out of the air into their root systems. In a previous post I mentioned the possibility of the reversal of the biotic pump and possible reasons why the oceans may in the future increase this reversal and draw atmospheric and therefore ground moisture away from the land , All very worrying but yet to be proven.