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Page 16 https://www.ipcc.ch/report/ar6/syr/ https://www.ipcc.ch/report/ar6/syr/ > Have they modeled all the different plausible crops and agricultural techniq

by mrpopo 4y ago

Page 16 https://www.ipcc.ch/report/ar6/syr/ https://www.ipcc.ch/report/ar6/syr/ > Have they modeled all the different plausible crops and agricultural techniques, which regional environmental conditions they're most suited for, and the transitions between them based on regional climate change effects? Seems so. > It's one thing to model a natural system, but seems quite a bit more complicated to model a system where human technology and decision-making is extremely significant. "Extremely" is a big word. Agricultural yields depend on the weather. A population of 9-10 billion will not be sustained by vertical farms maintained in a synthetic climate.

tablespoon 4y ago
> Page 16 > https://www.ipcc.ch/report/ar6/syr/ https://www.ipcc.ch/report/ar6/syr/ >> Have they modeled all the different plausible crops and agricultural techniques, which regional environmental conditions they're most suited for, and the transitions between them based on regional climate change effects? > Seems so. I'm not seeing it. I'm assuming you mean page 16 of the "Summary for Policymakers," but all that has is a unreadable map of "Maize Yield" projections with the disclaimer: > Projected regional impacts reflect biophysical responses to changing temperature, precipitation, solar radiation, humidity, wind, and CO2 enhancement of growth and water retention in currently cultivated areas. Models assume that irrigated areas are not water-limited. Models do not represent pests, diseases, future agro-technological changes and some extreme climate responses. So it sounds like they are not accounting for things like changes between crops or changing which areas are cultivated, which could be pretty significant. For instance: their tiny map shows the cultivated area in Canada remaining unchanged, but if you're looking at total world agricultural yield of a future warmer planet, it seems like you would have account for more Canadian land becoming arable and agriculture spreading further north. > "Extremely" is a big word. Agricultural yields depend on the weather. A population of 9-10 billion will not be sustained by vertical farms maintained in a synthetic climate. Which is not the way I (or anyone reasonable) would think people would adapt. Instead of the software-engineer techno-fetishist fantasy of "vertical farms", I would think the adaptations would consist of things like: 1. Creating new farms in areas where the climate is currently too cold for productive agriculture, 2. Switching to different crops or different varieties that are hardier against heat and drought or otherwise yield more calories (per whatever limiting factor), 3. Switching to different irrigation techniques that may be more water-efficient, 4. etc.
- hnburnsy 4y ago
  Thank you for raising these points.
- mrpopo 4y ago
  > So it sounds like they are not accounting for things like changes between crops or changing which areas are cultivated, which could be pretty significant. > it seems like you would have account for more Canadian land becoming arable and agriculture spreading further north. It's a map. It's litterally showing the changes by areas. And the map does show areas with increased maize yield, such as Southern Africa, but these don't include Canada or Russia. Potentially the full volume will include other crops yields and more details that you are hoping for. Of course, the world will adapt and change their crops, but it will come at a cost for people who are unable to adapt, such as farmers in underdeveloped countries.
  - tablespoon 4y ago
    > It's a map. One that appears to not answer the question I posed, or answer it in the negative (as in, they're not modeling realistic agricultural adaptations). > It's litterally [sic] showing the changes by areas. Apparently only "in currently cultivated areas." It's hard to get worked up over the predictions of a model that basically assumes everyone continues to do the exact same stuff while everything else changes, even if that would mean individuals fail to meet their short-term goals. It wouldn't have been hard to depict the area under cultivation creeping further north (or the area under cultivation receding in other areas). > Potentially the full volume will include other crops yields and more details that you are hoping for. Those are not the details I'm looking for. It would be closer to what I'm looking for if they took that data, divided the world into plots, then for each scenario picked the highest yielding crop for that plot, to come up with an overall agricultural productivity estimate. I say that's only closer, because it presumably wouldn't reflect other reasonable and straightforward agricultural adaptations.
    - mrpopo 4y ago
      I think you are too much focused on global agricultural productivity, which will not be a life-or-death problem for anyone with access to the global market, such as you. Fear not, global warming will not leave you starving. Global warming and crop yield change will affect, as I said before, farmers in some communities such as central Africa, rural Asia, indigenous populations, who don't import their food from around the world, don't have the means or don't want to do so.

by mrpopo 4y ago

tablespoon 4y ago

> Page 16 > https://www.ipcc.ch/report/ar6/syr/ https://www.ipcc.ch/report/ar6/syr/ >> Have they modeled all the different plausible crops and agricultural techniques, which regional environmental conditions they're most suited for, and the transitions between them based on regional climate change effects? > Seems so. I'm not seeing it. I'm assuming you mean page 16 of the "Summary for Policymakers," but all that has is a unreadable map of "Maize Yield" projections with the disclaimer: > Projected regional impacts reflect biophysical responses to changing temperature, precipitation, solar radiation, humidity, wind, and CO2 enhancement of growth and water retention in currently cultivated areas. Models assume that irrigated areas are not water-limited. Models do not represent pests, diseases, future agro-technological changes and some extreme climate responses. So it sounds like they are not accounting for things like changes between crops or changing which areas are cultivated, which could be pretty significant. For instance: their tiny map shows the cultivated area in Canada remaining unchanged, but if you're looking at total world agricultural yield of a future warmer planet, it seems like you would have account for more Canadian land becoming arable and agriculture spreading further north. > "Extremely" is a big word. Agricultural yields depend on the weather. A population of 9-10 billion will not be sustained by vertical farms maintained in a synthetic climate. Which is not the way I (or anyone reasonable) would think people would adapt. Instead of the software-engineer techno-fetishist fantasy of "vertical farms", I would think the adaptations would consist of things like: 1. Creating new farms in areas where the climate is currently too cold for productive agriculture, 2. Switching to different crops or different varieties that are hardier against heat and drought or otherwise yield more calories (per whatever limiting factor), 3. Switching to different irrigation techniques that may be more water-efficient, 4. etc.

hnburnsy 4y ago
Thank you for raising these points.
mrpopo 4y ago
> So it sounds like they are not accounting for things like changes between crops or changing which areas are cultivated, which could be pretty significant. > it seems like you would have account for more Canadian land becoming arable and agriculture spreading further north. It's a map. It's litterally showing the changes by areas. And the map does show areas with increased maize yield, such as Southern Africa, but these don't include Canada or Russia. Potentially the full volume will include other crops yields and more details that you are hoping for. Of course, the world will adapt and change their crops, but it will come at a cost for people who are unable to adapt, such as farmers in underdeveloped countries.
- tablespoon 4y ago
  > It's a map. One that appears to not answer the question I posed, or answer it in the negative (as in, they're not modeling realistic agricultural adaptations). > It's litterally [sic] showing the changes by areas. Apparently only "in currently cultivated areas." It's hard to get worked up over the predictions of a model that basically assumes everyone continues to do the exact same stuff while everything else changes, even if that would mean individuals fail to meet their short-term goals. It wouldn't have been hard to depict the area under cultivation creeping further north (or the area under cultivation receding in other areas). > Potentially the full volume will include other crops yields and more details that you are hoping for. Those are not the details I'm looking for. It would be closer to what I'm looking for if they took that data, divided the world into plots, then for each scenario picked the highest yielding crop for that plot, to come up with an overall agricultural productivity estimate. I say that's only closer, because it presumably wouldn't reflect other reasonable and straightforward agricultural adaptations.
  - mrpopo 4y ago
    I think you are too much focused on global agricultural productivity, which will not be a life-or-death problem for anyone with access to the global market, such as you. Fear not, global warming will not leave you starving. Global warming and crop yield change will affect, as I said before, farmers in some communities such as central Africa, rural Asia, indigenous populations, who don't import their food from around the world, don't have the means or don't want to do so.