I just submitted my MSc thesis studying crop treatments for drought resilience. Plant breeding for drought tolerance has been hit or miss. Some real success in barley (deeper, stronger root systems), but in general, plants need an irreducibly similar amount of water in their growth phase, and the optimal breeding strategy has been to optimize for yield in well-watered conditions, because this also increases yield under water stress. A lot of things that you think would improve drought tolerance actually decrease yield because they accelerate lifecycle or divert growth at the expense of yield. Transgenic approaches have been a notable failure, even Monsanto Droughtgard for Maize - which appears to only protect against water stress during a very specific part of the Maize lifecycle. Its an extremely complex problem and there doesn't seem to be any popular science content that explains it well - I had to read like 300 papers to get the landscape.
I wonder what new things could be done to boost yields in Africa. With the exception of South Africa and Egypt,
Farm yields for most cereals on the continent are terrible.
Vast majority of African farmers are subistent farmers with low fertilizer use, irrigation systems, or mechanization. We have seen USAID, African VC backed agri firms and government led domestic policies try to improve yields but average yields per hectare is still abysmal. I wonder if it is a soil quality issue..
Do rising CO2 levels increase agricultural output measurably? They certainly do in greenhouse experiments, but can this be a counterweight to production decreases from other climate change effects?
As ever a brilliant analysis. A factor which is also worth consideration when looking forwards is soil degradation from intensive farming. This may reduce the availability or productivity of land. This further increases the need for better varieties with higher yields.
I appreciate your focus on resilience. The vast majority of the focus in climate change discussion is on the increased hazard risk of rising CO2. But historically resilience to weather-related events is what has saved lives.
I believe that as long as we keep innovating new agricultural technologies, the world will be able to keep increasing agricultural production on fewer acres of land regardless of future temperatures.
In particular, we need to innovate new agricultural technologies that work in Sub-Saharan Africa, which got passed up by the first Green Revolution.
Thanks as usual for your insightful analysis. However, I’m struck by your choice of crops to use as examples in the the data on increasing yields of most crops; although giving a nod to the risk of land expansion and deforestation as a potential method for increased supply, the example crops - rice, wheat, and to a somewhat lesser extent corn - are not known to be the most at risk for land use expansion. I’d love to see the same data for crops widely associated with deforestation such as palm oil, cocoa, coffee and soy to see yield improvements of those crops as I am not aware of great improvements for those crops. I suspect the potential for yield improvements as the explanation for increased supply varies between crops and the connection between rising supply and deforestation also varies.
Isn't "modern agriculture" more or less equivalent to "nearly exclusive use of Roundup Ready crops"? Monsanto/ Bayer held the line for awhile by funding scientists but now the bill is coming due via the court system, where alleged cancer may make it harder for this model to continue. Will an alternative to that cropping system be found or society come to accept the increasingly common cancer associated with glyphosate poisoning?
Agriculture is a sector of the economy where Green policies are very destructive. They still have not accepted the technologies of the Green revolution that dramatically increased global food production and virtually eliminated famines. And they are opposed to most new agricultural technologies.
How ironic that Greens oppose the Green revolution!
"We want to produce more food with less land, which means higher yields." --> Not only. This could simply mean less meat. Don't forget that 3/4 of agricultural land is dedicated to the production of animal products, which only represent 18% of the calorie intake around the world. I know that you know that, Hannah, since you produced most of the OWID graphs related to that, I'm just a bit disappointed that you don't raise this key (and extremely straightforward solution) in this article, and that you prefer to insist on science or innovation. Also, you say that "Yields across the world have doubled, tripled, or more over the last 50 years". This is true, but mainly because of chemicals products and mechanization, which are at the centre of land erosion and the pollution of water sources. Overall, my impression is that your conclusion is that more engineering and technology is going to be the key, when in fact we just need more subsidies to encourage more people to manage smaller, less chemically dependent farms, (a lot) less meat, and farms that are oriented towards regenerating the land by planting trees, hedges, and working with nature, not against it via technology...
I would think crop yields are increasing due to economies of scale, polytunnels and to the use petrochemical fertilisers, pesticides and herbicides. I think that the nutritional content and healthy outcomes are probably inversely proportional to the increase in yield.
The graph from one world data excludes pasture for livestock; what would the increase in global increase in agricultural land look like with it? Over half of habitable land is used for agriculture and 77%. of that for animal agriculture. A conversion to plant based eating would free up 2/3rds of the land currently used for agriculture which could be forested. https://georgiedonny.substack.com/p/yet-another-unsuccessful-attempt Yes crop yields for some plants are increasing and others decreasing but the increase in drought, flood and high temperatures doesn't bode well.
I looked up some papers on CEC levels in African soils just for reference. In 5 Nigerian samples, CEC was between 2 and 4. By contrast, Irish (my home) soils - some of which are not so great - are an average of about 18 - and the best soils for arable farming (Rendzinas) are ~42 average.
Thanks for sharing these (conditionally) good news Hannah.
One big cushion we have I think is that most of these calories are lost in heating the bodies of cattle, right? I would like to hope if there's any large scale famine, people would be willing to swap their steaks for pork, chicken, or beans - although, come to think of, not so sure...
It would be really nice to visualise this issue in your bar graph of global food production, where the bars for each year of e.g. corn would stack-up direct human consumption colour-filled, edges and no fill for what goes to make beef, and within the latter the small part of calories from beef that human consume filled in blue.
It would clearly illustrate that risk of famine is more a question of food choices than increased yields.
I just submitted my MSc thesis studying crop treatments for drought resilience. Plant breeding for drought tolerance has been hit or miss. Some real success in barley (deeper, stronger root systems), but in general, plants need an irreducibly similar amount of water in their growth phase, and the optimal breeding strategy has been to optimize for yield in well-watered conditions, because this also increases yield under water stress. A lot of things that you think would improve drought tolerance actually decrease yield because they accelerate lifecycle or divert growth at the expense of yield. Transgenic approaches have been a notable failure, even Monsanto Droughtgard for Maize - which appears to only protect against water stress during a very specific part of the Maize lifecycle. Its an extremely complex problem and there doesn't seem to be any popular science content that explains it well - I had to read like 300 papers to get the landscape.
I wonder what new things could be done to boost yields in Africa. With the exception of South Africa and Egypt,
Farm yields for most cereals on the continent are terrible.
Vast majority of African farmers are subistent farmers with low fertilizer use, irrigation systems, or mechanization. We have seen USAID, African VC backed agri firms and government led domestic policies try to improve yields but average yields per hectare is still abysmal. I wonder if it is a soil quality issue..
https://ourworldindata.org/grapher/cereal-yield
https://open.substack.com/pub/yawboadu/p/east-asia-vs-african-development-05a?r=garki&utm_campaign=post&utm_medium=web
Do rising CO2 levels increase agricultural output measurably? They certainly do in greenhouse experiments, but can this be a counterweight to production decreases from other climate change effects?
As ever a brilliant analysis. A factor which is also worth consideration when looking forwards is soil degradation from intensive farming. This may reduce the availability or productivity of land. This further increases the need for better varieties with higher yields.
I appreciate your focus on resilience. The vast majority of the focus in climate change discussion is on the increased hazard risk of rising CO2. But historically resilience to weather-related events is what has saved lives.
I believe that as long as we keep innovating new agricultural technologies, the world will be able to keep increasing agricultural production on fewer acres of land regardless of future temperatures.
In particular, we need to innovate new agricultural technologies that work in Sub-Saharan Africa, which got passed up by the first Green Revolution.
Thanks as usual for your insightful analysis. However, I’m struck by your choice of crops to use as examples in the the data on increasing yields of most crops; although giving a nod to the risk of land expansion and deforestation as a potential method for increased supply, the example crops - rice, wheat, and to a somewhat lesser extent corn - are not known to be the most at risk for land use expansion. I’d love to see the same data for crops widely associated with deforestation such as palm oil, cocoa, coffee and soy to see yield improvements of those crops as I am not aware of great improvements for those crops. I suspect the potential for yield improvements as the explanation for increased supply varies between crops and the connection between rising supply and deforestation also varies.
Isn't "modern agriculture" more or less equivalent to "nearly exclusive use of Roundup Ready crops"? Monsanto/ Bayer held the line for awhile by funding scientists but now the bill is coming due via the court system, where alleged cancer may make it harder for this model to continue. Will an alternative to that cropping system be found or society come to accept the increasingly common cancer associated with glyphosate poisoning?
Agriculture is a sector of the economy where Green policies are very destructive. They still have not accepted the technologies of the Green revolution that dramatically increased global food production and virtually eliminated famines. And they are opposed to most new agricultural technologies.
How ironic that Greens oppose the Green revolution!
Brilliant, as always, Hannah. I await the Climate Doomers to descend and attack you for defaming their dogma.
BTW, have you seen: https://www.politybooks.com/blog-detail/climate-change-isnt-everything-liberating-climate-politics-from-alarmism
"We want to produce more food with less land, which means higher yields." --> Not only. This could simply mean less meat. Don't forget that 3/4 of agricultural land is dedicated to the production of animal products, which only represent 18% of the calorie intake around the world. I know that you know that, Hannah, since you produced most of the OWID graphs related to that, I'm just a bit disappointed that you don't raise this key (and extremely straightforward solution) in this article, and that you prefer to insist on science or innovation. Also, you say that "Yields across the world have doubled, tripled, or more over the last 50 years". This is true, but mainly because of chemicals products and mechanization, which are at the centre of land erosion and the pollution of water sources. Overall, my impression is that your conclusion is that more engineering and technology is going to be the key, when in fact we just need more subsidies to encourage more people to manage smaller, less chemically dependent farms, (a lot) less meat, and farms that are oriented towards regenerating the land by planting trees, hedges, and working with nature, not against it via technology...
I would think crop yields are increasing due to economies of scale, polytunnels and to the use petrochemical fertilisers, pesticides and herbicides. I think that the nutritional content and healthy outcomes are probably inversely proportional to the increase in yield.
The graph from one world data excludes pasture for livestock; what would the increase in global increase in agricultural land look like with it? Over half of habitable land is used for agriculture and 77%. of that for animal agriculture. A conversion to plant based eating would free up 2/3rds of the land currently used for agriculture which could be forested. https://georgiedonny.substack.com/p/yet-another-unsuccessful-attempt Yes crop yields for some plants are increasing and others decreasing but the increase in drought, flood and high temperatures doesn't bode well.
The answer is not another green revolution which steals tomorrows genetic potential for today https://georgiedonny.substack.com/p/what-were-the-results-of-the-green
We need to eat less meat and dairy
I looked up some papers on CEC levels in African soils just for reference. In 5 Nigerian samples, CEC was between 2 and 4. By contrast, Irish (my home) soils - some of which are not so great - are an average of about 18 - and the best soils for arable farming (Rendzinas) are ~42 average.
Thanks for sharing these (conditionally) good news Hannah.
One big cushion we have I think is that most of these calories are lost in heating the bodies of cattle, right? I would like to hope if there's any large scale famine, people would be willing to swap their steaks for pork, chicken, or beans - although, come to think of, not so sure...
It would be really nice to visualise this issue in your bar graph of global food production, where the bars for each year of e.g. corn would stack-up direct human consumption colour-filled, edges and no fill for what goes to make beef, and within the latter the small part of calories from beef that human consume filled in blue.
It would clearly illustrate that risk of famine is more a question of food choices than increased yields.