Because EXIOBASE and Earthster utilize different naming taxonomies for environmental exchanges, we employ a specific mapping strategy to bridge the two systems. For the majority of substances, mapping occurs automatically when the chemical identity is identical. This is achieved through string matching supported by synonym reconciliation, such as mapping EXIOBASE’s CO2 to Earthster’s Carbon dioxide or CH4 to Methane. Where automated mapping is not possible, we apply the general assumptions described in the following sections.
Biogenic, land-use, and fossil carbon
By default, all Carbon dioxide, Methane, and Carbon monoxide exchanges in EXIOBASE are assumed to be of fossil origin. The following exceptions were mapped to biogenic or land-use contexts:
Exchanges in EXIOBASE | equivalent in Earthster |
CH4 - agriculture | Methane, land use |
CO2 - agriculture - peat decay | Carbon dioxide, land use |
CO2 - waste - biogenic | Carbon dioxide, biogenic |
CO - non combustion - Chemical wood pulp… | Carbon monoxide, biogenic |
Exchanges specified in units of CO2-equivalents
EXIOBASE reports Perfluorocarbons (PFC) and Hydrofluorocarbons (HFC) directly in CO2-equivalent units rather than mass units. Because GWP characterization factors vary by impact method, there is no single "correct" way to back-calculate the original mass for these generic categories.
To ensure Earthster results follow the EXIOBASE benchmarks as closely as possible, these flows are mapped directly to Carbon dioxide. While not chemically precise, this preserves the intended global warming impact assigned by the EXIOBASE team.
Land occupation
All EXIOBASE land-use flows represent land occupation (measured in area*time). These were mapped to the Land use flowable in Earthster, with the corresponding terrestrial contexts:
EXIOBASE land type | Equivalent Earthster Land use (resource/ground/…) |
Forest area | terrestrial/forest |
Infrastructure land | human-dominated/industrial |
Fodder crops | human-dominated/agricultural/pasture, man made |
Cropland other than fodder crops | human-dominated/agricultural |
Resource use - fossil fuels
EXIOBASE 3.8.2 utilizes a single aggregate flow for fossil extraction: Domestic extraction used - Fossil fuels - total. Because this category aggregates fuels with vastly different energy densities — ranging from Lignite (14 MJ/kg) to Natural Gas (~50 MJ/kg) — we have mapped this generic flow to Coal, anthracite (kg).
Anthracite coal serves as a representative "center of gravity" for global energy extraction. Its energy content of 32 MJ/kg acts as a conservative midpoint, ensuring that the total energy impact is accurately represented without being skewed by high-end or low-end fuel extremes.
Resource use - minerals and metals
EXIOBASE often groups minerals and metals into categories that cover several substances. When a direct match was not possible, we mapped the flow to the representative mineral or metal in the group:
Exiobase mineral/metal | Flowable in earthster (representative of the group) |
Non-Metallic Minerals - Limestone, gypsum, chalk, dolomite | Limestone |
Non-Metallic Minerals - Clays and kaolin | Clay |
Non-Metallic Minerals - Gravel and sand | Sand |
Chemical and fertilizer minerals | Phosphate ore |
Metal Ores - Bauxite and aluminium ores | Bauxite |
Metal Ores - Uranium and thorium ores | Uranium |
Non-Metallic Minerals - Building stones | Aggregate |
For the following cases, we did not map the exchanges to an Earthster alternative as they cover too broad a range of possible minerals:
Metal Ores - Other non-ferrous metal ores
Non-Metallic Minerals - Other minerals
As for ores, we mapped to their "pure" metal equivalents using a conversion factor approach. Mapping to the pure substance and then applying a conversion factor (the concentration of the substance found in the ore) is the preferred solution when the exact concentration of a metal/mineral is known. We applied the average global ore concentration factors from EXIOBASE (available here):
Source mineral/ore | Name in earthster (context: resource/ground) | Conversion factor (kg metal / kg ore) |
Gold ores | Gold | 0.000004 |
Silver ores | Silver | 0.0003 |
PGM ores | Platinum | 0.000001 |
Lead ores | Lead | 0.03716382 |
Copper ores | Copper | 0.0720568269230769 |
Nickel ores | Nickel | 0.025 |
Zinc ores | Zinc | 0.053944196617647 |
Iron ores | Iron | 0.46 |
Resource extraction - fisheries, fodder crops, forestry, primary crops
All resource extraction related to fisheries, fodder crops, forestry, grazing, and primary crops were mapped to Biomass resource/ground.
Water: Consumption vs. Withdrawal
EXIOBASE distinguishes between water Withdrawal (the total volume of water taken from a source) and water Consumption (water not returned to the same source, such as through evaporation or product incorporation). In our implementation, we map EXIOBASE Water Consumption flows to the generic Earthster flowable Water (context: resource/water). This approach aligns with the assumptions of impact methods such as ReCiPe, EF3.1, ImpactWorld+, which prioritize the net balance of water removed from a watershed rather than the gross intake. Consequently, withdrawal-only flows are left unmapped to prevent double-counting and ensure that water scarcity and consumption results are not artificially inflated—a correction that is critical given that treating withdrawals as consumption can inflate results by a factor of over 400%.
Unused domestic extraction
EXIOBASE includes flows for "Unused" extraction (e.g., mining overburden, crop harvest residues). These represent materials that are physically displaced but never enter the technosphere as economic products (e.g., waste soil left at a silver mine).
We leave these unmapped. In a standard LCA, these "waste" extractions do not constitute a depletion of an economic mineral resource.
Economical and energetic statistics
EXIOBASE contains many flows that track the movement of money or the total supply of energy carriers (e.g., "Energy Carrier Supply: Total").
Our Treatment: These are "Accounting Flows" used for economic balancing. Since they do not represent a direct physical emission or a resource being removed from nature, they are not mapped to environmental impacts.
Log of changes
2026-03-13 (release 3.8.2_e002)
Version 3.8.2_e002 corrects many issues. The improvements are as follows:
Mineral Overhaul: We now map minerals to the pure substance instead of generic ores by applying data on average global ore concentrations.
Mass Conversions: We corrected an error where exchanges specified in kilotons (kt) were being converted to kilograms (kg) with the wrong conversion factor.
Unused Extractions: We unmapped "unused" flows (like mining overburden and harvest residues) to prevent them from being counted as useful economic resources.
Fossil Fuels: Impacts for this category now derive from Domestic extraction used - Fossil fuels rather than unused extractions.
Water Accounting: We refined our mapping to focus only on Water Consumption, removing "Withdrawals" to avoid double-counting.
Exact Proxies: We replaced approximate proxies with exact substance mappings for nitrogen oxides (NOx), particulate matter (PM10), and NMVOCs.
Greenhouse Gases: Gases reported in CO2-equivalent units (HFCs and PFCs) are now captured directly as CO2 to preserve their intended climate impact.
Land Use: More resolution for land exchanges: Fodder crops now mapped to human-dominated/agricultural/pasture, man made instead of the more We corrected conversion factors for land-use flows and integrated generic human-dominated/agricultural