Carbon opportunity cost increases carbon footprint advantage of grain-finished beef
Open accessAbstract
Beef production accounts for the largest share of global livestock greenhouse gas emissions and is an important target for climate mitigation efforts. Most life-cycle assessments comparing the carbon footprint of beef production systems have been limited to production emissions. None also consider potential carbon sequestration due to grazing and alternate uses of land used for production. We assess the carbon footprint of 100 beef production systems in 16 countries, including production emissions, soil carbon sequestration from grazing, and carbon opportunity cost—the potential carbon sequestration that could occur on land if it were not used for production. We conduct a pairwise comparison of pasture-finished operations in which cattle almost exclusively consume grasses and forage, and grain-finished operations in which cattle are first grazed and then fed a grain-based diet. We find that pasture-finished operations have 20% higher production emissions and 42% higher carbon footprint than grain-finished systems. We also find that more land-intensive operations generally have higher carbon footprints. Regression analysis indicates that a 10% increase in land-use intensity is associated with a 4.8% increase in production emissions, but a 9.0% increase in carbon footprint, including production emissions, soil carbon sequestration and carbon opportunity cost. The carbon opportunity cost of operations was, on average, 130% larger than production emissions. These results point to the importance of accounting for carbon opportunity cost in assessing the sustainability of beef production systems and developing climate mitigation strategies.
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Written from the paper’s full text.
TL;DR
This study compares carbon footprints of 100 beef production systems in 16 countries, adding soil carbon sequestration and carbon opportunity cost to production emissions. It finds pasture-finished systems have 20% higher production emissions and 42% higher total carbon footprint than grain-finished systems, with carbon opportunity cost averaging 130% larger than production emissions.
Key findings
- In a pairwise comparison of 20 pasture-finished vs. grain-finished systems across 12 countries, pasture-finished systems had 20% higher mean production emissions (p<0.01); including soil carbon sequestration made the difference non-significant, but including carbon opportunity cost gave a 42% higher carbon footprint (p<0.01). Median production emissions and carbon footprints were 15% higher for pasture-finished systems (p<0.01 and p<0.05, respectively).
- Across 100 operations, mean carbon footprint was 177.37 kg CO2e kg⁻¹ retail weight (median 107.14; range −68.3 to 2169.3). Mean production emissions were 52.64, mean soil carbon sequestration was −15.11, and mean carbon opportunity cost was 139.85 kg CO2e kg⁻¹. Carbon opportunity cost was on average 130% larger than production emissions; soil carbon sequestration offset 31.5% of production emissions and 18.9% of production emissions plus carbon opportunity cost.
- Regression analysis found a 10% increase in land-use intensity was associated with a 4.8% increase in production emissions (coefficient 0.48) and a 9.0% increase in carbon footprint including production emissions, soil carbon sequestration, and carbon opportunity cost (coefficient 0.90). Adding soil carbon sequestration reduced the production-emissions coefficient to 0.32.
- Four pasture-finished and one grain-finished operation in Queensland, Australia had negative estimated carbon footprints, partly because dry climates were assigned zero carbon opportunity cost.
Methods
- The authors calculated carbon footprint as production emissions + soil carbon sequestration + carbon opportunity cost for 100 beef operations in 16 countries, drawing on Poore and Nemecek (2018) and Stanley et al. (2018). They conducted a paired t-test on 20 pasture-finished/grain-finished pairs across 12 countries.
- Soil carbon sequestration was estimated as land-use intensity of grazing × a mean improved-grazing sequestration rate of 0.28 Mg C ha⁻¹ yr⁻¹. Carbon opportunity cost used land-use intensity × potential carbon sequestration from LPJmL net primary productivity, with a 2-degree radius, 100-year time horizon, conversion factors of 0.42 for cropland and 0.44 for pasture, and existing carbon stocks of 1100 (cropland) and 3100 (pasture) kg C ha⁻¹; dry climates were assigned zero potential carbon sequestration.
- Regression used log-log multilevel models with country random effects on 72 operations with coordinates (24 studies, 12 countries), with three dependent variables: production emissions; production emissions + soil carbon sequestration; and production emissions + soil carbon sequestration + carbon opportunity cost. Robustness checks varied radius, national/global carbon opportunity cost, a 0.47 Mg C ha⁻¹ yr⁻¹ sequestration rate, and the dry-climate zero-carbon-opportunity-cost assumption.
Limitations
- Stated by the paper: the pairwise comparison has only 20 pairs, so asymptotic normality for the paired t-test may not hold; the underlying life-cycle assessments are not globally representative (one study from Asia, none from Africa); the analysis assumes changes in land-use intensity proportionately change land under production and native ecosystems, which is unlikely due to economic mechanisms; and it is difficult to predict where land-use change occurs.
- Stated simplifying assumptions: global mean estimates are used for soil carbon sequestration and carbon stocks due to lack of spatially explicit global data; the carbon opportunity cost does not account for livestock diet rations, which crops are used for feed, or crop yields, which may underestimate costs if feed crops are grown on high-carbon land.
- Evident from the text: the single mean sequestration rate may overestimate the land-use intensity–carbon footprint relationship if actual rates are higher, but may be conservative if many operations lack improved grazing; the zero-carbon-opportunity-cost assumption for dry climates drives the negative footprints in Australia; and carbon opportunity cost results depend on the chosen radius and local/national/global market-connectedness assumptions.
Model-written summary. Check it against the paper before relying on it.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
5 of 23 cited sources checked · 4 supported · 0 flagged · accuracy not yet measured
- Premisecitation
Reviews and meta-analyses conclude that pasture-finished systems have higher average production emissions than grain-finished systems.
“Reviews and meta-analyses of these studies conclude that pasture-finished systems have higher average production emissions [4, 6, 7].”
Quote in the paperSubstantial claim1 of 3 sources checked- cites [4] M Clark, 2017, Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice, Environ. Res. Lett source
- cites [6] J Poore, 2018, Reducing food’s environmental impacts through producers and consumers, Science source
- cites [7] D Nijdam, 2012, The price of protein: Review of land use and carbon footprints from life cycle assessments of animal food products and their substitutes, Food Policy source
- Premisecitation
Existing global comparisons of pasture-finished and grain-finished systems do not account for both carbon opportunity cost and soil carbon sequestration.
“Existing global comparisons of pasture-finished and grain-finished systems are incomplete as they do not account for both carbon opportunity cost and soil carbon sequestration.”
Quote in the paperSubstantial claim1 of 3 sources checked- cites [6] J Poore, 2018, Reducing food’s environmental impacts through producers and consumers, Science source
- cites [15] A Balmford, 2018, The environmental costs and benefits of high-yield farming, Nat. Sustain source
The Methods (pp. 22–23) describe this paper’s own calculations of carbon opportunity costs and changes in soil organic carbon. The Methods (p. 19) discuss limited beef LCA data, but no passage found in searches for global pasture- versus grain-finished comparisons says those comparisons omit both factors. (LLM, conf=0.73)
Experimental — accuracy not yet measured - cites [16] K Schmidinger, 2012, Including CO2 implications of land occupation in LCAs—method and example for livestock products, Int. J. Life Cycle Assess source
- Premisecitation
Pasture-finished systems have higher land-use intensity on average than grain-finished systems.
“Recent meta-analyses show that pasture-finished systems have higher land-use intensity (measured as area per unit production) on average, since the amount of pasture needed in the finishing stage of pasture-finished cattle is much larger than the amount of cropland needed to provide grain for the finishing stage of grain-finished cattle [4, 6].”
Quote in the paperSubstantial claim1 of 2 sources checked - Findingown data
Across all robustness checks, soil carbon sequestration does not fully offset production emissions.
“Across all robustness checks, carbon opportunity cost is at least 65% larger than production emissions and soil carbon sequestration does not fully offset production emissions (S2 Table in S1 File).”
Quote in the paperSubstantial claim - Findingown data
The relationship between carbon footprint including carbon opportunity cost and land-use intensity has a coefficient of 0.90.
“However, the relationship between carbon footprint, including carbon opportunity cost, and land-use intensity is stronger, with a coefficient of 0.90 (Table 2, Fig 2B).”
Quote in the paperSubstantial claim
- Findingown data
The mean carbon footprint across all studies, including production emissions, sequestration, and carbon opportunity cost, is over three times larger than the mean value for production emissions.
“The mean carbon footprint across all studies, including production emissions, sequestration, and carbon opportunity cost, is over three times larger than the mean value for production emissions (Table 1).”
Quote in the paperSubstantial claim - Findingown data
Pasture-finished systems had 20% higher mean production emissions than grain-finished systems on average (p<0.01).
“The pairwise comparison found that pasture-finished systems had 20% higher mean production emissions than grain-finished systems on average (p<0.01).”
Quote in the paperSubstantial claim - Findingown data
A 10% increase in land-use intensity is associated with a 9.0% increase in carbon footprint, including production emissions, soil carbon sequestration and carbon opportunity cost.
“Regression analysis indicates that a 10% increase in land-use intensity is associated with a 4.8% increase in production emissions, but a 9.0% increase in carbon footprint, including production emissions, soil carbon sequestration and carbon opportunity cost.”
Quote in the paperSubstantial claim - Findingown data
Pasture-finished systems had 15% higher median carbon footprints than grain-finished systems (p<0.05).
“Compared to grain-finished systems, pasture-finished systems also had 15% higher median production emissions (p<0.01) and carbon footprints (p<0.05), indicating that while the magnitude of the difference is sensitive to extreme values, the general finding of higher emissions is robust (S3 Table in S1 File).”
Quote in the paperSubstantial claim - Findingown data
The carbon footprint of pasture-finished systems, including production emissions, soil carbon sequestration and carbon opportunity cost, is higher than that of grain-finished systems (p<0.05) in the majority of robustness tests.
“The carbon footprint of pasture-finished systems, including production emissions, soil carbon sequestration and carbon opportunity cost, is higher than that of the grain-finished systems (p<0.05) in the majority of robustness tests (S4 Table in S1 File).”
Quote in the paperSubstantial claim - Findingown data
The carbon footprint across the 100 beef production operations ranged from -68.3 to 2169.3 kg CO2e kg-1 retail weight, with mean 177.37 and median 107.14.
“The carbon footprint, including production emissions, carbon opportunity cost, and soil carbon sequestration, across the 72 beef production operations with reported latitude and longitude, and the 28 operations without latitude/longitude included in the pasture-finished/grain-finished comparison ranged from -68.3 to 2169.3 kg CO2e kg-1retail weight, with mean 177.37 and median 107.14 (Table 1).”
Quote in the paperNot a substantial claim - Findingown data
More land-intensive operations generally have higher carbon footprints.
“We also find that more land-intensive operations generally have higher carbon footprints.”
Quote in the paperSubstantial claim - Findingown data
Pasture-finished operations have 42% higher carbon footprint than grain-finished systems.
“We find that pasture-finished operations have 20% higher production emissions and 42% higher carbon footprint than grain-finished systems.”
Quote in the paperSubstantial claim - Findingown data
Across all robustness checks, carbon opportunity cost is at least 65% larger than production emissions.
“Across all robustness checks, carbon opportunity cost is at least 65% larger than production emissions and soil carbon sequestration does not fully offset production emissions (S2 Table in S1 File).”
Quote in the paperSubstantial claim - Findingown data
When carbon opportunity cost is also accounted for, the carbon footprint of pasture-finished systems is on average 42% higher than that of grain-finished systems (p<0.01).
“When the carbon opportunity cost is also accounted for, however, the carbon footprint of pasture-finished systems is on average 42% higher than that of grain-finished systems (p<0.01) (Fig 1).”
Quote in the paperSubstantial claim - Findingown data
Differences in carbon footprint between pasture-finished and grain-finished systems are not significant (p≥0.05) in some cases when a smaller radius or higher rate of soil carbon sequestration is used.
“Differences are not significant (p≥0.05) in some cases when a smaller radius or higher rate of soil carbon sequestration is used.”
Quote in the paperNot a substantial claim - Findingown data
The carbon footprint was similar in robustness checks, with the mean value ranging from 141.6 to 210.0 kg CO2e kg-1 retail weight when different radii are used and when zero carbon opportunity cost for arid climates is not assumed.
“The carbon footprint was similar in robustness checks, with the mean value ranging from 141.6 to 210.0 kg CO2e kg-1 retail weight when different radii are used and when we do not assume zero carbon opportunity cost for arid climates (S1 Table in S1 File).”
Quote in the paperNot a substantial claim- The authors state this as an assumption: Life-cycle assessment sites located in climate categorized as dry have zero potential carbon sequestration.
- Findingown data
Negative carbon footprints are estimated for four grass-finished operations and one grain-finished operation in dry eco-climate zones in Australia.
“One exception is that we estimate negative carbon footprints for four grass-finished operations and one grain-finished operation that are in dry eco-climate zones in Australia, for which we assume there is zero carbon opportunity cost.”
Quote in the paperNot a substantial claim- The authors state this as an assumption: There is zero carbon opportunity cost for the four grass-finished operations and one grain-finished operation in dry eco-climate zones in Australia.
- Findingown data
Pasture-finished operations have 20% higher production emissions than grain-finished systems.
“We find that pasture-finished operations have 20% higher production emissions and 42% higher carbon footprint than grain-finished systems.”
Quote in the paperSubstantial claim - Findingown data
Soil carbon sequestration offset 18.9% of the production emissions and carbon opportunity cost, on average.
“Soil carbon sequestration offset 31.5% of production emissions and 18.9% of the production emissions and carbon opportunity cost, on average.”
Quote in the paperSubstantial claim - Findingown data
Pasture-finished systems had 15% higher median production emissions than grain-finished systems (p<0.01).
“Compared to grain-finished systems, pasture-finished systems also had 15% higher median production emissions (p<0.01) and carbon footprints (p<0.05), indicating that while the magnitude of the difference is sensitive to extreme values, the general finding of higher emissions is robust (S3 Table in S1 File).”
Quote in the paperSubstantial claim - Findingown data
A 10% increase in land-use intensity is associated with a 4.8% increase in production emissions.
“Regression analysis indicates that a 10% increase in land-use intensity is associated with a 4.8% increase in production emissions, but a 9.0% increase in carbon footprint, including production emissions, soil carbon sequestration and carbon opportunity cost.”
- Also stated in: § Regression analysis · plain
“This can be interpreted as a 10% increase in land-use intensity being associated with a 4.8% increase in emissions.”
Quote in the paperNot a substantial claim - Also stated in: § Regression analysis · plain
- Findingown data
The carbon opportunity cost of operations was, on average, 130% larger than production emissions.
“The carbon opportunity cost of operations was, on average, 130% larger than production emissions.”
- Also stated in: § Results · plain
“In individual systems, carbon opportunity cost was, on average, 130% larger than production emissions.”
- Also stated in: § Discussion · plain
“The carbon opportunity cost of operations was, on average, 130% larger than production emissions.”
Quote in the paperSubstantial claim - Also stated in: § Results · plain
- Findingown data
When carbon footprints include production emissions, soil carbon sequestration, and carbon opportunity cost, all beef production systems have a higher carbon footprint than when only production emissions are included.
“When we calculate carbon footprints including production emissions, soil carbon sequestration, and carbon opportunity cost, all beef production systems have a higher carbon footprint than when only production emissions are included”
Quote in the paperSubstantial claim - Findingown data
Soil carbon sequestration offset 31.5% of production emissions, on average.
“Soil carbon sequestration offset 31.5% of production emissions and 18.9% of the production emissions and carbon opportunity cost, on average.”
Quote in the paperSubstantial claim - Findingown data
In the regression of production emissions on land-use intensity, the coefficient is 0.48.
“In the regression analysis, when only production emissions are regressed on land-use intensity, the coefficient is 0.48 (Fig 2A, Table 2).”
Quote in the paperNot a substantial claim - Findingown data
When soil carbon sequestration is included, the difference in carbon footprint between pasture-finished and grain-finished systems is not statistically significant at a 95% confidence level (p≥0.05).
“When also including soil carbon sequestration, the difference is not statistically significant at a 95% confidence level (p≥0.05).”
Quote in the paperSubstantial claim - Findingown data
When soil carbon sequestration is added, the regression coefficient of production emissions on land-use intensity is reduced to 0.32.
“When adding in soil carbon sequestration, the coefficient is reduced to 0.32, indicating that soil carbon sequestration offsets a part of the production emissions (Table 2).”
Quote in the paperSubstantial claim - Premisecitation
Most life-cycle assessments comparing the carbon footprint of beef production systems have been limited to production emissions.
“Most life-cycle assessments comparing the carbon footprint of beef production systems have been limited to production emissions.”
- Also stated in: § Introduction · plain
“Most life-cycle assessments of the carbon footprint of grain-finished and pasture-finished systems have been limited to emissions directly attributable to cradle-to-farmgate activities (here referred to as production emissions) [6].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [6] J Poore, 2018, Reducing food’s environmental impacts through producers and consumers, Science source
- Also stated in: § Introduction · plain
- Premisecitation
Grain finishing typically leads to much higher growth rates.
“Grain finishing typically leads to much higher growth rates.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [8] JL Capper, 2013, The role of productivity in improving the environmental sustainability of ruminant production systems, Annu. Rev. Anim. Biosci source
- Interpretationown data
A 10% increase in land-use intensity is associated with a 9.0% increase in the carbon footprint of beef production.
“Hence, a 10% increase in land-use intensity is associated with a 9.0% increase in the carbon footprint of beef production.”
Quote in the paperSubstantial claim - Premisecitation
Pasture and crop management can increase soil carbon sequestration.
“First, pasture and crop management can increase soil carbon sequestration [9, 10].”
Quote in the paperSubstantial claim0 of 2 sources checked - Interpretationown data
The general finding that pasture-finished systems have higher emissions than grain-finished systems is robust to extreme values.
“Compared to grain-finished systems, pasture-finished systems also had 15% higher median production emissions (p<0.01) and carbon footprints (p<0.05), indicating that while the magnitude of the difference is sensitive to extreme values, the general finding of higher emissions is robust (S3 Table in S1 File).”
Quote in the paperSubstantial claim - Interpretationreasoning
The assumptions of asymptotic normality, which are the basis for the paired t-test, may not hold.
“This means that assumptions of asymptotic normality, which are the basis for the paired t-test, may not hold.”
Quote in the paperNot a substantial claim - Interpretationown data
Beef operations with low land-use intensity, including grain-finished operations, have lower carbon footprints than pasture-finished operations and others with high land-use intensity.
“Our conclusion that beef operations with low land-use intensity, including grain-finished operations, have lower carbon footprints than pasture-finished operations and others with high land-use intensity provides important insights for agricultural stakeholders globally such as in Brazil where pasture expansion is a leading driver of forest loss [27].”
Quote in the paperSubstantial claim - Study design and conductreasoning
The true carbon sequestration rates across operations may be lower because not all the life-cycle assessments included are of operations with improved grazing practices.
“However, given that not all the life-cycle assessments included are of operations with improved grazing practices, the true carbon sequestration rates across operations may be lower.”
Quote in the paperSubstantial claim - Interpretationown data
Less land-intensive systems typically have lower production emissions.
“Less land-intensive systems typically have lower production emissions.”
Quote in the paperNot a substantial claim - Study design and conductreasoning
Use of a single mean carbon sequestration rate for diverse locations could lead to overestimating the relationship between land use intensity and carbon footprint if actual sequestration rates on grazed land in the included studies are greater than 0.28 Mg C ha-1 yr-1.
“Our use of a single mean rate for diverse locations could lead to us overestimating the relationship between land use intensity and carbon footprint if actual sequestration rates on grazed land in the studies we include are greater than 0.28 Mg C ha-1 yr-1.”
Quote in the paperNot a substantial claim - Interpretationown data
The differences in carbon footprint between pasture- and grain-finished operations are largely due to differences in carbon opportunity cost.
“The differences in carbon footprint between pasture- and grain-finished operations are largely due to differences in carbon opportunity cost, which account for a large share of the total carbon footprint.”
Quote in the paperSubstantial claim - Interpretationown data
Soil carbon sequestration offsets a part of production emissions.
“When adding in soil carbon sequestration, the coefficient is reduced to 0.32, indicating that soil carbon sequestration offsets a part of the production emissions (Table 2).”
- Also stated in: § Discussion · plain
“In our results, soil carbon sequestration from grazing offsets only a portion of production emissions.”
Quote in the paperSubstantial claim - Also stated in: § Discussion · plain
- Premisecitation
Large soil carbon sequestration rates are only possible under particular agro-ecological conditions and for a limited time period.
“Yet large soil carbon sequestration rates are only possible under particular agro-ecological conditions and for a limited time period [9, 12].”
Quote in the paperSubstantial claim0 of 2 sources checked - Interpretationcitation
If soil carbon sequestration rates are lower in dry climates than other climates, these operations would be more likely to also have positive carbon footprints.
“If soil carbon sequestration rates are lower in dry climates than other climates, as some studies such as Smith et al. (2008) [20] suggest, these operations would be more likely to also have positive carbon footprints.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Smith et al. (2008) [20]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- The authors state this as an assumption: Life-cycle assessment sites located in climate categorized as dry have zero potential carbon sequestration.
- Interpretationcitation
The approach including production emissions, soil carbon sequestration and carbon opportunity cost is more comprehensive for assessing the carbon footprint of land use than conventional land-use change approaches.
“Our finding that land-use intensity and carbon footprint are positively correlated strengthens similar findings from previous studies, none of which included production emissions, soil carbon sequestration and carbon opportunity cost, which is a more comprehensive approach for assessing the carbon footprint of land use than conventional land-use change approaches [14].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [14] TD Searchinger, 2018, Assessing the efficiency of changes in land use for mitigating climate change, Nature source
- Interpretationown data
The near-proportional relationship between land-use intensity and carbon footprint is in part due to the large share of the carbon footprint accounted for by carbon opportunity cost, which is proportional to land area in production.
“This near-proportional relationship is in part due to the large share of the carbon footprint accounted for by carbon opportunity cost, which is proportional to land area in production.”
Quote in the paperSubstantial claim- Rests on an assumption: Carbon opportunity cost is proportional to land area in production.
- Premisecitation
Previous studies on land-use intensity and carbon footprint did not include production emissions, soil carbon sequestration and carbon opportunity cost together.
“Our finding that land-use intensity and carbon footprint are positively correlated strengthens similar findings from previous studies, none of which included production emissions, soil carbon sequestration and carbon opportunity cost, which is a more comprehensive approach for assessing the carbon footprint of land use than conventional land-use change approaches [14].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [14] TD Searchinger, 2018, Assessing the efficiency of changes in land use for mitigating climate change, Nature source
- Study design and conductown data
Robustness checks and nonparametric test of the median reinforce the conclusion that pasture-finished operations have greater production emissions and carbon footprints than grain-finished operations.
“However, our robustness checks (S4 Table in S1 File) and nonparametric test of the median (S3 Table in S1 File), which is robust to small sample sizes, extreme outliers, and heavy-tailed distributions, reinforce the conclusion that pasture-finished operations have greater production emissions and carbon footprints than grain-finished operations.”
Quote in the paperSubstantial claim - Interpretationown data
Beef operations that have been studied in life-cycle assessments are generally not carbon neutral or negative.
“Our analysis also confirms that beef operations that have been studied in life-cycle assessments are generally not carbon neutral or negative.”
Quote in the paperSubstantial claim - Study design and conductown data
The life-cycle assessments that underlie the study were not conducted to be globally representative.
“The life-cycle assessments that underlie our study were not conducted to be globally representative.”
Quote in the paperNot a substantial claim - Interpretationnone given
The analysis is the first global comparison of the carbon footprint of grain-finished and pasture-finished beef production systems that includes production emissions as well as soil carbon sequestration and carbon opportunity cost.
“Our analysis is the first global comparison of the carbon footprint of grain-finished and pasture-finished beef production systems that includes production emissions as well as soil carbon sequestration and carbon opportunity cost.”
Quote in the paperSubstantial claim - Interpretationcitation
Grazing cattle on dry rangeland with little to no carbon opportunity cost could have a small carbon footprint when the grazing also increases soil organic carbon.
“This suggests that grazing cattle on dry rangeland with little to no carbon opportunity cost could have a small carbon footprint when the grazing also increases soil organic carbon, as has been observed in some studies of dry rangeland with finer textured soil [12].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [12] ME McSherry, 2013, Effects of grazing on grassland soil carbon: a global review, Glob. Chang. Biol source
- May combine two claims. 12
- Classified as probably not a substantial claim. 12
May combine two claims.
InterpretationcitationThe finding that production emissions are 20% higher on pasture-finished operations than on grain-finished operations is consistent with Clark and Tilman (2017), which found average emissions were 19% higher though their estimate was not statistically significant.
“Our finding that production emissions are 20% higher on pasture-finished operations than on grain-finished operations is consistent with Clark and Tilman (2017) [4], which found average emissions were 19% higher though their estimate was not statistically significant.”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites Clark and Tilman (2017) [4] source
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationUse of improved grazing practices in some pasture-finished systems has sequestered enough carbon to offset production emissions from finishing.
“Use of improved grazing practices in some pasture-finished systems has sequestered enough carbon to offset production emissions from finishing [11].”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites [11] PL Stanley, 2018, Impacts of soil carbon sequestration on life cycle greenhouse gas emissions in Midwestern USA beef finishing systems, Agric. Syst source
May combine two claims.
Findingown dataThe two operations with the largest carbon footprint values are pasture-finished with degraded or nominal pasture and low or no pasture management, and among the highest land use intensity values.
“The two operations with the largest carbon footprint values are pasture-finished with degraded or nominal pasture and low or no pasture management, and among the highest land use intensity values.”
Quote in the paperNot a substantial claimMay combine two claims.
FindingreasoningFour pasture-finished and one grain-finished production systems in Queensland, Australia are estimated to have negative carbon footprints, in part because the dry climate is assumed to result in zero carbon opportunity cost.
“Four pasture-finished and one grain-finished production systems in Queensland, Australia are estimated to have negative carbon footprints, in part because we assume that the dry climate results in zero carbon opportunity cost.”
Quote in the paperSubstantial claim- The authors state this as an assumption: Life-cycle assessment sites located in climate categorized as dry have zero potential carbon sequestration.
May combine two claims.
PremisecitationBecause grain finishing leads to higher growth rates, proportionally less energy is expended on maintenance rather than growth, so inputs and emissions per unit of beef are lower.
“As a result, proportionally less energy is expended on maintenance rather than growth, such that inputs and emissions per unit of beef is lower [8].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [8] JL Capper, 2013, The role of productivity in improving the environmental sustainability of ruminant production systems, Annu. Rev. Anim. Biosci source
Classified as probably not a substantial claim.
Interpretationnone givenThe study provides a novel assessment of the carbon footprint of beef operations, building upon life-cycle assessments of production emissions to also include carbon sequestration and carbon opportunity cost.
“Overall, this study provides a novel assessment of the carbon footprint of beef operations, building upon life-cycle assessments of production emissions to also include carbon sequestration and carbon opportunity cost.”
Quote in the paperSubstantial claimMay combine two claims.
PremisecitationGreater land use for beef production can displace native ecosystems and reduce land available for restoration.
“Second, greater land use for beef production can displace native ecosystems and reduce land available for restoration.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [13] MN Hayek, 2021, The carbon opportunity cost of animal-sourced food production on land, Nat. Sustain source
Probably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductown dataRegressions with fixed effects produced results very similar to those with random effects.
“Regressions with fixed effects produced results very similar to those with random effects (S5 Table in S1 File).”
Quote in the paperNot a substantial claimMay combine two claims.
Interpretationown dataPasture-finished and other more land-intensive beef production systems have greater production emissions than grain-finished and less land-intensive systems.
“Our results indicate that pasture-finished and other more land-intensive beef production systems have greater production emissions than grain-finished and less land-intensive systems.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
InterpretationcitationThe finding that soil carbon sequestration from grazing offsets only a portion of production emissions is consistent with Garnett et al. (2017), which estimated that soil carbon sequestration from grazing can offset 20-60% of annual emissions from ruminant grazing.
“This finding is consistent with the conclusions of Garnett et al. (2017) [19], which estimated that soil carbon sequestration from grazing can offset 20–60% of annual emissions from ruminant grazing.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Garnett et al. (2017) [19]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Study design and conductnone givenThe analysis examines differences in carbon footprints across operations with different land-use intensity and does not attempt causal inference per se.
“Our analysis examines differences in carbon footprints across operations with different land-use intensity and does not attempt causal inference per se.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductown dataThe pairwise comparison has a relatively small sample of 20 pairs.
“The pairwise comparison of grain-finished and pasture-finished operations has a relatively small sample of 20 pairs.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductown dataThe results cannot be explained by the choice of radius.
“We do this to confirm our results cannot be explained by the choice of radius as NPP values can vary widely over a small area.”
Quote in the paperNot a substantial claimMay combine two claims.
Study design and conductreasoningThe measures of carbon opportunity cost do not account for livestock diet rations, which crops are used for feed, or crop yields.
“They do not account for livestock diet rations, which crops are used for feed, or crop yields for instance.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim. May combine two claims.
Study design and conductnone givenSystems were selected for inclusion if they were in the same subnational region or country, if the study was national in scope, and reported in the same study or within two studies by the same primary author.
“Systems were selected for inclusion if they were in the same subnational region or country, if the study was national in scope, and reported in the same study or within two studies by the same primary author.”
Quote in the paperSubstantial claimMay combine two claims.
InterpretationreasoningGiven the consistent positive relationship between land use intensity and carbon footprint across operations in multiple geographies, a similar relationship would be observed in other regions except in dry eco-climate zones where grazing can have little carbon opportunity cost.
“Nevertheless, given the consistent positive relationship between land use intensity and carbon footprint across operations in multiple geographies, we expect a similar relationship would be observed in other regions except in dry eco-climate zones where grazing can have little carbon opportunity cost.”
Quote in the paperNot a substantial claimMay combine two claims.
Study design and conductreasoningThe results cannot be considered to be globally representative or representative of all operations.
“In addition, our results cannot be considered to be globally representative or representative of all operations.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductown dataResults are robust to other specifications and assumptions checked.
“Results are robust to other specifications and assumptions checked (S6 Table in S1 File).”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Study design and conductown dataThe study includes one study from Asia (Indonesia) and none from Africa.
“For instance, we include one study from Asia (Indonesia) and none from Africa.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
InterpretationreasoningThis may contribute to underestimating potential carbon sequestration and carbon opportunity costs if feed crops such as soy are grown in areas with higher potential carbon sequestration, such as former forest, than other crops.
“This may contribute to us underestimating potential carbon sequestration and carbon opportunity costs if feed crops such as soy are grown in areas with higher potential carbon sequestration, such as former forest, than other crops.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductown dataRegressions with pooled and country fixed-effects specifications generate similar results.
“Regressions with pooled and country fixed-effects specifications generate similar results (S5 Table in S1 File).”
Quote in the paperNot a substantial claim
The authors state this as an assumption.
Reducing land-use intensity results in proportionately less agricultural land area locally.
“This assumes that reducing land-use intensity results in proportionately less agricultural land area locally.”
The authors state this as an assumption.
Life-cycle assessment sites located in climate categorized as dry have zero potential carbon sequestration.
“We assume life-cycle assessment sites located in climate categorized as “dry” in Poore & Nemecek (2018) [6] have zero potential carbon sequestration because they either cannot support substantial additional biomass or are native grasslands or savannas for which restoration does not typically involve reforestation [22].”
The authors state this as an assumption.
The equilibrium carbon stock in native ecosystem is reached after 100 years.
“In effect, this assumes that the equilibrium carbon stock in native ecosystem is reached after 100 years.”
The authors state this as an assumption.
If the amount of land needed to support a given level of food production declines by one unit as a result of lower land-use intensity, then one unit of land will be restored to native vegetation somewhere in the country or world, respectively.
“The national and global carbon opportunity costs assume that if the amount of land needed to support a given level of food production declines by one unit as a result of lower land-use intensity, then one unit of land will be restored to native vegetation somewhere in the country or world, respectively.”
The authors state this as an assumption.
A change in land-use intensity results in a proportionate change in land under production and thus the land area with native ecosystems.
“In our study, we also assume that a change in land-use intensity results in a proportionate change in land under production and thus the land area with native ecosystems.”
The authors state this as an assumption.
There is zero carbon opportunity cost for the four grass-finished operations and one grain-finished operation in dry eco-climate zones in Australia.
“One exception is that we estimate negative carbon footprints for four grass-finished operations and one grain-finished operation that are in dry eco-climate zones in Australia, for which we assume there is zero carbon opportunity cost.”
The authors state this as an assumption.
Global mean estimates of soil carbon sequestration and current carbon stocks in cropland and grazing land vegetation are adequate for the analysis due to lack of spatially-explicit data with global coverage.
“We use global mean estimates of soil carbon sequestration and current carbon stocks in cropland and grazing land vegetation due to lack of spatially-explicit data with global coverage.”
The authors state this as an assumption.
The assumed rate of soil carbon sequestration is drawn from estimates for improved grazing management, so as to lessen the risk of overestimating the carbon footprint of grass-finished systems.
“Our assumed rate is drawn from estimates for improved grazing management, so as to lessen the risk of overestimating the carbon footprint of grass-finished systems.”
The authors state this as an assumption.
Measures of carbon opportunity cost based on mean potential carbon sequestration values in grazing land and cropland, if restored to native vegetation, are adequate.
“Our measures of carbon opportunity cost are also based on mean potential carbon sequestration values in grazing land and cropland, if restored to native vegetation.”
The paper relies on this without support.
Carbon opportunity cost is proportional to land area in production.
“which is proportional to land area in production.”
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Carbon-footprint SD is inconsistent with its coefficient of variation
MinorTable 1 reports a carbon-footprint SD of 26.0 and a mean of 177.37, which give a coefficient of variation of about 0.147, not the reported 1.49.
Reported 1.49 · recomputed 0.146586
“| Carbon footprint | 177.37 | 107.14 | -68.3, 2169.3 | 26.0 | 1.49 | 124.79, 229.96 | kg CO2e kg-1 |”
Claim that every system's full footprint exceeds production emissions has exceptions
MinorThe paper says all systems have a higher footprint after adding sequestration and opportunity cost, but it also reports five systems with negative carbon footprints. Production emissions are reported as positive across the dataset, so those systems cannot have higher full footprints.
“all beef production systems have a higher carbon footprint than when only production emissions are included”
“Four pasture-finished and one grain-finished production systems in Queensland, Australia are estimated to have negative carbon footprints”
Regression sequence described in methods disagrees with Table 2
MinorThe methods say carbon opportunity cost is added in the second regression and soil carbon sequestration in the third. Table 2 instead adds soil carbon sequestration in the second regression and carbon opportunity cost in the third.
“adding carbon opportunity cost in the second regression, and then also including soil carbon sequestration in the third regression”
“| | Dependent variable: PEM | Dependent variable: PEM+SCS | Dependent variable: PEM+SCS+COC |”
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Global food system emissions could preclude achieving the 1.5° and 2°C climate change targets
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Agriculture, Forestry and Other Land Use (AFOLU)
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Should I Use Fixed or Random Effects?
Clark, T. S., & Linzer, D. A. (2014) · Political Science Research and Methods · doi:10.1017/psrm.2014.32 · Cited by 766 · see citing works
Grassland management impacts on soil carbon stocks: a new synthesis
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Assessing the efficiency of changes in land use for mitigating climate change
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Where Tree Planting and Forest Expansion are Bad for Biodiversity and Ecosystem Services
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Trading carbon for food: Global comparison of carbon stocks vs. crop yields on agricultural land
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The environmental costs and benefits of high-yield farming
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The carbon opportunity cost of animal-sourced food production on land
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Flagged first, then by citations
Cited by
Still being checked.
- Authors
- Blaustein-Rejto, D., Soltis, N., & Blomqvist, L.
- Affiliations
- University of California, Santa Barbara (US)
- Venue
- PLOS ONE
- Publisher
- Public Library of Science (PLoS)
- Published
- 2023-12-13
- Volume
- 18
- Issue
- 12
- Pages
- e0295035
- ISSN
- 1932-6203 (ISSN-L)
- PMC
- PMC10718409
- OpenAlex
- W4389669385
- Cited by
- 17
- References
- 24
- Citations by year
- 2026: 3 · 2025: 8 · 2024: 6
- FWCI
- 2.65
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- Locations
- PLoS ONE (publishedVersion, cc-by)
- PubMed (publishedVersion)
- PubMed Central (submittedVersion, cc-by)
- RePEc: Research Papers in Economics (submittedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Topics
- Physical Sciences › Environmental Science › Ecology › Agriculture Sustainability and Environmental Impact
- Physical Sciences › Environmental Science › Environmental Engineering › Environmental Impact and Sustainability
- Physical Sciences › Environmental Science › Environmental Chemistry › Sustainable Agricultural Systems Analysis
- Keywords
- carbon footprint, soil carbon sequestration, land use intensity, climate change mitigation, livestock greenhouse gas emissions
- MeSH terms
- Greenhouse Gases, Animals, Animal Husbandry, Carbon, Cattle, Soil, Carbon Footprint
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-23.
Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-23.
Cited sources are checked by gpt-6-sol.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
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