Review of the U.S. Farmers and Ranchers in Action White Paper on Building a Scientific Roadmap to a Carbon-Negative Agricultural System (2024) / Chapter Skim
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Appendix A: Specific, Editorial, and Minor Chapter Comments
Appendix A: Specific, Editorial, and Minor Chapter Comments
Pages 15-42
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From page 15... ...
The discussion included on L72 forward suggests that. Consider revising this part, as GHG emissions from agriculture will most likely be included in the food supply chain systems calculation.
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From page 16... ...
L119–120: "The global boundary for annual GHG emissions was estimated to be 9.8 Gt CO2-eq, a more than 43 Gt CO2-eq reduction from 2015 baseline emissions. Total agricultural emissions are about one-third of the target emissions level." The juxtaposition of "boundary" with "target" is confusing.
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From page 17... ...
doi:10.1017/9781009157926. L137–148: The process categories of "soil carbon sequestration, nitrogen and water use efficiency" do not include agriculture as a provider of energy through biomass, and wind and solar energy, which may hold greater potential for GHG emission reductions than what is listed.
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From page 18... ...
or at least say something about increasing the carbon efficiency of the crop by reducing emissions per unit of product produced. L163: Low carbon or carbon negative or carbon neutral?
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From page 19... ...
McCarl, et al. Greenhouse Gas Mitigation in Agriculture.
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From page 20... ...
CHAPTER 3: SOIL CARBON SEQUESTRATION ON U.S. AGRICULTURAL LANDS Specific Comments on the Text L8: This section is called Soil Carbon Management Research but is more background information than a research discussion.
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From page 21... ...
McCarl, U.A. Schneider, Soil carbon: Policy and Economics.
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From page 22... ...
2019. Managing for soil carbon sequestration: Let's get real istic.
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From page 23... ...
2022. Land use-land cover gradient demonstrates the importance of perennial grasslands with intact soils for building soil carbon in the fertile mollisols of the North Central United States.
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From page 24... ...
2021. Soil carbon sequestration potential and the identification of hotspots in the Eastern Corn Belt of the United States.
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From page 25... ...
GHG emissions? Table 1.
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From page 26... ...
L380: Could comments on N2O emissions control from grasslands, such as changing the forage species or fertilizer, when used, be added? L382: Regarding downstream ecosystems –Are "downstream" systems included in "carbon negative"?
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From page 27... ...
practicing adaptive livestock management." Should climate negative be changed to carbon negative? Also, the next section of the text highlights the important role of forage species in this system, but forage selection is not part of that list.
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From page 28... ...
of gain and hogs, 4 lbs., chickens, 1.5 lbs., and fish 1 lb. One could argue that shifting protein forms can reduce GHG emissions.
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From page 29... ...
L312–318: Shouldn't it be acknowledged in a simple declarative sentence that livestock production will never have net negative GHG emissions, so that puts the burden on row crop agriculture to sequester enough soil C to offset the livestock emissions? Reducing livestock emissions is critically important but acknowledge the limits of going to zero or into the negative.
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From page 30... ...
L85–87: The authors might consider the potential use of green ammonia for on-farm fuel, especially if green ammonia production is decentralized so that it is produced on the farm or in local farmer coop facilities. L87: The sentence "Increasing nitrogen use efficiency will reduce impacts from GHG emissions and nitrogen losses to the environment" might be reworded as this topic is covered elsewhere in this white paper in at least two places.
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From page 31... ...
Another way to frame it, more neutrally, is that food production strongly competes for land resources and releases a number of pollution streams. L26–28: "Food waste and loss are significant contributors to climate change, producing an estimated 10% of global emissions and 18–24% of the food system's GHG emissions…." This statement can't be correct as it is greater that the entire GHG output of agriculture cited in Chapter 1.
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From page 32... ...
greenhouse gas emissions is also likely to be inconsistent with numbers used in other chapters of the white paper. Some estimates for agricultural production are 7% so food waste and loss would be over 50% of all agricultural emissions.
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From page 33... ...
L257–276: This text doesn't make clear how soil health is necessarily linked to reducing post-harvest loss or how adopting regenerative agriculture affects food waste? This is a nicely crafted argument for regenerative agriculture, but it needs to explain further a link to the food waste topic of this chapter.
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From page 34... ...
2005. Greenhouse Gas Mitigation Potential in U.S.
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From page 35... ...
https://www.mckinsey.com/~/media/mckinsey/dotcom/client _service/sustainability/cost%20curve%20pdfs/pathways_lowcarbon_economy_version2.ashx#:~:text =curve%20shows%20the%20range%20of,2030%20time%20horizon. L167: "A key insight from the early research was to distinguish the technical potential for greenhouse gas mitigation -- i.e., the amount that was scientifically and technologically possible -- from the economic potential -- i.e., the amount that farmers would do given their economic circumstances, capabilities, and motivations." In short, farmers need to make money to survive and won't do things that sink farm economics.
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From page 36... ...
2023. Policy challenges to enhance soil carbon sinks: the dirty part of making contributions to the Paris agreement by the United States.
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From page 37... ...
2022. Soil carbon sequestration as a climate strategy: what do farmers think?
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From page 38... ...
L458: Related to the issue of uncertainty and contracting, most agricultural outputs, like soil carbon and yield, have variable effectiveness from year to year. Kim and McCarl argue that longer-term spatially diverse contracts would be better in cap-and-trade systems to manage that variability.
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From page 39... ...
2007. Competitiveness of terrestrial greenhouse gas offsets: Are they a bridge to the future?
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From page 40... ...
L105: It is an overstatement to say "The potential reduction in GHG emissions from these activities was provided" as there were some estimates for some alternatives but not an all-encompassing set of numbers. L113: If reduction in crop emissions is credited to crop production to avoid double counting, is not the estimate that animal agriculture accounts for 39% of total agricultural GHGs double counting?
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From page 41... ...
In addition, depending on the shift, it might lead to reduced acres in production, or to less beef in the diet, meaning fewer direct emissions and fewer feed emissions. L148–177: This risk analysis of GHG emissions reduction potential could be made part of Chapter 3, which presents the potential that medium and high adoption rates of regenerative practices may have in reducing the carbon footprint of agricultural production.
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From page 42... ...
L207–208: Complete agreement on this point! L212: The text says "soil carbon would need to remain sequestered for 100 years to achieve the GWP goals: the well-known problem of permanence" but the rates of accrual would also need to persist across all 100 years, so the question of a saturation point comes into play.
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