Measurement, not argument.
True Cost Index measures the physical quantities associated with things. It does not convert those quantities into dollars, collapse them into a single score, or use them as a moral ranking.
Definition of true cost
For this site, the true cost of an item is a vector of measured physical quantities. A vector may include greenhouse-gas emissions, water consumption, land occupation, energy use, particulate matter, nitrogen, phosphorus, NOx, SOx, or other physical quantities where the measurement method is established.
The vector is not reduced to one number. The separate quantities remain separate because they measure different things.
Why the site does not use dollars
Many true-cost frameworks convert externalities into money. That can be useful for policy or accounting, but it requires judgment at nearly every step. What is a ton of carbon worth? What is a polluted river worth? What is a health effect worth?
True Cost Index takes a different path. It reports physical quantities in their natural units and leaves interpretation to the reader.
Functional units
Every measurement must identify the functional unit: the precise amount of the item being measured. The functional unit should match the source and data basis wherever possible. Reader-facing units are translations, not replacements for the measurement basis.
| Item | Formal unit used on the item page | Reader-facing translation |
|---|---|---|
| Diesel | 1 U.S. gallon of diesel combusted | Approximately 3.785 liters of diesel burned |
| Natural gas combined-cycle electricity | 1 kWh generated | 0.944 lb CO₂e per kWh; an average U.S. household day is shown separately as 29.6 kWh |
| Chicken | 1 kg edible chicken meat | 2 pounds of edible chicken meat, converted from the kg value |
| Eggs | 1 dozen large eggs, approximately 680 g shelled eggs | One dozen large eggs |
System boundaries
A measurement is complete only when it identifies the item measured, the functional unit, the physical quantities reported, the sources used, and the system boundary necessary to interpret the result.
The boundary is not a footnote. The boundary is part of the claim. Changing the boundary changes what the number means.
Boundary details vary by item. A fuel may distinguish combustion-only emissions from full fuel-cycle emissions. Electricity may distinguish plant generation from delivered household electricity. Food may include feed production, farm operation, processing, packaging, retail, or household use depending on the cited literature.
Units of measurement
True Cost Index uses the units of measurement predominant in the lifecycle assessment literature for the item and category being measured. Greenhouse gases are commonly reported as kg CO₂e. Energy may be reported as MJ, kWh, Btu, or another source-specific unit. Land may be reported as m²-year, hectare-year, or another standard land-occupation unit.
Conversions are allowed only when they are physical and direct. Liters can be converted to gallons. Kilograms can be converted to pounds. Physical quantities are not converted into dollars.
Greenhouse-gas values use GWP100, the 100-year Global Warming Potential basis, unless otherwise stated. GWP20 values, where relevant, should be reported separately rather than mixed into the same table.
Source selection
The preferred sources are peer-reviewed lifecycle assessment studies, government lifecycle inventories, recognized lifecycle databases, and transparent technical reports from credible institutions. Recognized lifecycle databases and models include GREET, ecoinvent, Agri-footprint, and GaBi/Sphera. Advocacy summaries may help identify useful quantities, but they should not carry the method where a primary source is available.
Reconciling disagreement
Lifecycle studies often disagree because of geography, production method, data vintage, system boundary, allocation method, and functional unit. True Cost Index uses a range-plus-working-value approach.
| Element | Meaning |
|---|---|
| Literature range | The credible spread of values found in qualifying sources. |
| Working value | The selected reference value used for the layman summary and main table. |
| Source notes | A short explanation of why that value was selected. |
The working value is not presented as the absolute true value. It is the selected reference value for the stated functional unit under the stated boundary.
When a literature range has not yet been hardened, the item page should say so plainly. A missing range is a source-review status, not a license to imply false precision.
Reader-facing translations
Item pages may translate technical units into familiar quantities: one gallon of diesel, one household day of electricity, two pounds of chicken, or one dozen eggs. These translations are presentation tools. The formal method controls the values.
Headline quantities
Headline values should be properties of the item under the stated boundary. Condition-dependent quantities are noted but not headlined unless a specific condition is selected. Diesel NOx, diesel particulate matter, cooling-system water consumption, and plant-specific emissions controls are examples of quantities that may require a narrower boundary before they can be presented as headline values.
What is excluded
- Dollar-denominated externality calculations
- Single-score rankings
- Health-cost monetization
- Moral ranking
- Claims outside the stated boundary
- Measurements where the measurement itself requires taking an editorial side
Source review policy
Values reflect a stated source review. Updates should be deliberate, not continuous. If a value changes, the source section should make clear what changed and why.
Sources
These are foundational frameworks and recurring source families. Item-specific sources are listed at the bottom of each item page.
- ISO 14040 and ISO 14044 lifecycle assessment standards. Used for: general LCA framing and system-boundary discipline.
- Argonne National Laboratory, GREET model documentation. Used for: fuel-cycle lifecycle modeling concepts.
- ecoinvent, Agri-footprint, and GaBi/Sphera lifecycle databases. Used for: examples of recognized lifecycle datasets that may support future item pages.
- National Energy Technology Laboratory lifecycle assessment publications. Used for: power-generation LCA boundary examples.
- FAO and peer-reviewed food LCA literature. Used for: agricultural supply-chain measurement concepts.