A decrease in carbon emissions intensity does not mean that total carbon emissions have fallen. Emissions per unit of product may improve while total emissions rise as production expands. The distinction between absolute emissions and intensity in Chapter 5 of Technology and Solutions for Demonstrating Carbon Reduction is a basic standard for interpreting farm performance and corporate targets.
Define the concept and scope of application first
The denominator of an intensity metric depends on how the product is defined. Check whether production-volume and rearing-period data refer to the same boundaries as the emissions data. When the denominator’s definition changes, distinguish actual efficiency changes from changes in calculation. Presenting total emissions alongside intensity makes it possible to examine how expansion in scale affected efficiency gains. Product competitiveness and a company’s absolute reduction target should each be assessed using an appropriate metric. The key is not to apply one improvement rate unchanged to multiple purposes.
GWP is a metric that compares the impact of a greenhouse gas with carbon dioxide over a defined time horizon. GWP100 and GWP20 use 100-year and 20-year time horizons, respectively. The same mass of methane corresponds to different amounts of carbon dioxide equivalent depending on the metric and time horizon used, so report both the original mass and the conversion basis. Do not add together or directly compare figures calculated using different metrics as if they were results under the same conditions.
If feed efficiency improves so that the same amount of production is achieved with fewer inputs, emissions may be reduced. However, outcomes vary with the methane conversion rate, emissions from feed production, and changes in output, so we cannot conclude that total methane emissions and emissions intensity will both fall. Changes in production period, reproduction rate, mortality, and feed formulation should also be evaluated using aligned production outcomes and emissions boundaries.
This approach can link farm productivity goals with emissions-reduction targets. However, additional costs and implementation risks may arise for equipment, feed, and labor, so we should not assume in advance that farmers will be willing to participate or that the incentives they need will be small. Chapter 19 calculates these costs and benefits separately.
Absolute emissions are total emissions over a defined period and within a defined boundary; emissions intensity is emissions per unit of product. Even if improved production efficiency lowers intensity, total emissions may rise if production expands. Report the two metrics separately and align the comparison period and product definition. Total-emissions targets and product-efficiency assessments should be distinguished according to their purpose, while presenting both results together helps show the relationship between changes in scale and efficiency gains.
When explaining farm-level emissions-reduction performance, this book recommends presenting absolute emissions, emissions intensity, and production volume together. This is a practical recommendation for distinguishing changes in total emissions from changes in efficiency, not a universal requirement across all reporting systems. The GHG Protocol Corporate Standard requires reporting of absolute emissions and makes ratio metrics optional. The Scope 3 Standard also recommends that companies using intensity targets report absolute emissions for the corresponding boundary. In actual reporting, first check the mandatory items in the applicable standard, regulation, and contract.
Conditions and limitations of field application
Suppose a farm has reduced emissions per unit of product while also expanding its herd. Improvements in production efficiency and changes in total emissions should be presented as separate outcomes. If an improvement rate is reported without stating which metric was targeted, readers may interpret it as a reduction in total emissions as well. The comparison period and product definition must also be aligned.
A metric’s omission does not by itself justify concluding that the disclosure was selective or in violation of a regulation. The problem arises when omitting material countervailing information distorts readers’ judgment. If total emissions rose but a decrease in intensity is presented as proof that overall emissions fell, or if a decline in total emissions caused by reduced production is described as improved technological efficiency, the evidence and claim do not match. If data are insufficient, specify which metrics could not be obtained and the limits on interpretation.
Policy design considers the goals of reducing total emissions, improving production efficiency, and maintaining food supply together. An intensity metric alone may miss increases in total emissions caused by production expansion, while an absolute-emissions metric alone may not distinguish efficiency gains from reduced production. Managing both metrics is a useful option, but it is not the only possible design. Set primary and supporting metrics to match policy objectives, and separately assess leakage due to shifts in production and distributional effects.
Effects on emissions. Heat stress can change intake and productivity. In that case, the direction of absolute emissions and emissions intensity must be observed separately. A decline in total emissions during a heat wave does not prove a technology’s mitigation effect, and whether production losses qualify for performance payments must be judged under the applicable program and baseline. A simple before-and-after comparison that does not control for season and differences in production leaves these confounding factors unresolved.
Evidence needed for investment review
Purchasing companies and investors should check how product efficiency, farm-level total emissions, and corporate supply-chain targets relate to one another. One metric does not automatically demonstrate that another target has been met. Changes in the production period and the structure of shipments should also be reviewed against the calculation boundary.
The difference in gas concentration inside and outside a barn is affected not only by emissions but also by ventilation and air mixing. Under conditions where air is sufficiently mixed and gas accumulation inside the barn can be ignored, doubling the ventilation rate at the same emissions level reduces the concentration difference by approximately half. To use this relationship in emissions calculations, ventilation rate, background concentration, temperature and pressure, and unit conversions must all be addressed.
Records for feed-additive-based mitigation should connect purchasing and delivery with mixing and actual administration. It should be possible to verify which product was used, for which herd, when, and during any periods when use stopped. Confirmation of actual administration and the evidence supporting the mitigation factor are different types of information and should be managed separately. The fact that records were kept does not by itself establish a quantified reduction for that farm.
Criteria to keep in view when making a decision
Presenting emissions intensity and absolute emissions together makes it possible to read the relationship between productivity improvements and emissions changes more accurately. What is needed is an explanation aligned with the target, not a choice of whichever metric looks more favorable. In before-and-after comparisons, retain the data for both numerator and denominator.
About the author
Bongjun Lee graduated from the Graduate School of Management of Technology (MOT) at Sogang University. He spent seven years at Infitron Co., Ltd. and 20 years at Honeywell, working for a total of 27 years in gas measurement in service engineering, technical sales, and channel management. He is now the founder of AI Safety Korea Co., Ltd., where he is researching livestock methane monitoring and measurement, reporting, and verification (MRV) systems using sensors, AI, and data analytics.