Methodology

This page explains how Nios turns an activity into pressures and impacts, which datasets it uses, and where the method has limits. Use it to explain your results to auditors and stakeholders.

How a result is calculated

Nios calculates 17 environmental pressures (metrics) per activity, each separately. See the Metrics reference for the list.

1. Choose the path

For each metric, Nios uses the best data available:

• Tier A impact input: Your direct result becomes the pressure as is.
• Tier B or C impact input: Your factor times the activity's quantity or spend.
• Default: The factor of the activity's sector and country from the factor datasets.

An invalid impact input blocks only its metric, not the whole activity. See Impact inputs.

2. Select the factor

On the default path, Nios derives a metric sector for each metric from the base sector: a GLORIA sector or an EXIOBASE product. GLORIA serves 12 metrics, because it covers more countries. EXIOBASE serves the 5 eutrophication metrics, because GLORIA has no nitrogen and phosphorus data. When the base sector is an EXIOBASE sector, EXIOBASE also serves the other metrics it covers, all but intensive forestry.

The factor's geography follows the activity's country of production, or its country of purchase if you choose so. When a sector has no factor for that country, Nios falls back to a regional, continental, or global factor and shows a warning on the result.

3. Convert the spend

Factors are published per unit of spend in one currency and reference year. Nios first adjusts the activity's spend from its activity year to the factor's reference year with the production country's GDP deflator (IMF World Economic Outlook). It then converts the currency with the annual average exchange rate of the factor's reference year (Eurostat). Quantities convert to the factor's unit.

When a deflator or an exchange rate is missing, Nios doesn't guess. The result is blocked with an issue that names the missing data. See Issues.

4. Calculate the pressure

The converted amount times the factor gives the pressure, the midpoint result in the metric's unit, such as kg CO₂e or m² of land. The Climate lens reports GHG emissions in t CO₂e from this step.

5. Characterize the impact

LC-Impact characterization factors convert each pressure into biodiversity impact in PDF·yr, per ecosystem: terrestrial, freshwater, and marine. By default, Nios uses global characterization factors.

6. Trace origins (optional)

With traced origins on, Nios splits a result's upstream pressure by origin country and characterizes each part with that country's LC-Impact factor, falling back to the continent and then the global factor. This applies only where the factor data has origin detail, and not to climate change, which LC-Impact characterizes globally.

7. Combine the ecosystems

Nios adds the terrestrial, freshwater, and marine impacts into one Nature result. With ecosystem weighting on, it multiplies each by its weight first. Weighting applies when you view results, without recalculating.

Outlier treatment

A few factors in input-output tables are extreme because the source data behind them is small or noisy. With outlier treatment on, Nios caps default factor values at the 1st and 99th percentile per metric.

The cutoffs are computed both within each sector and across all sectors. A value is capped only when it breaks both cutoffs, so a value that is high only compared with other sectors isn't capped for that reason alone. Your impact inputs are never capped.

Scope

• System boundary: Cradle to gate. Results cover each purchase from raw material extraction to the supplier's gate.
• Scope: Purchased goods and services, GHG Protocol Scope 3.1.
• Not included: Use and end of life of the purchased goods, and other Scope 3 categories.
• Environmental pressures: Land use, climate change, water consumption, terrestrial acidification, photochemical ozone formation, and freshwater and marine eutrophication, as 17 metrics. LCA standards call these impact categories. See the Metrics reference.

Scientific frameworks and data

Each project pins one version of each dataset, so the same Collect data gives the same results later. Your Collect data, including base sectors, keeps its history in version history. The Method tab shows the versions a project uses.

Alignment with global standards

In nature footprinting and broader supply chain impact assessment, global standards are still evolving. At this stage, Nios is not formally certified under any single standard.

The methodology follows principles that leading frameworks share:

• Mimics core principles of life cycle assessment (LCA) to ensure scientific grounding and transparency.
• Prioritizes pragmatism by providing actionable insights for decision-makers today rather than waiting for perfect standardization.
• Covers environmental impacts holistically (not only GHGs), in line with the broader framing of the Planetary Boundaries Framework and IPBES drivers of nature loss.

We monitor the development of key frameworks such as CSRD ESRS, TNFD, SBTN, EU PEF, ISO, and the GHG Protocol. We aim for conceptual consistency with these standards where possible and may revisit our stance as alignment between standards matures.

Our methodological choices already overlap with the recommendations of these frameworks:

• Environmentally-extended input-output tables (EEMRIOs) are repeatedly referenced in the TNFD LEAP methodology (e.g., pages 44, 84, 89, 236, 237) as a way to model value chain impacts when company-specific data is unavailable.
• The TNFD biodiversity footprinting discussion paper explicitly refers to LC-Impact (pages 25, 42, 48).

Limitations

• Sector averages: Input-output factors assume one average technology per sector and country. Results are directional estimates, not product footprints. Where you have supplier or product data, add it as impact inputs.
• Spend-based uncertainty: Prices differ between suppliers, so spend is an imperfect proxy for physical flows. Purchaser prices include taxes and margins and can overstate results, so use basic prices, without them, where you can.
• Sector matching: Match is AI-assisted and can pick a different sector when it runs again. Review the matches before you report, see Sector matching.
• Geography: Where a sector has no factor for a country, Nios uses a regional, continental, or global factor.
• Climate characterization: LC-Impact characterizes climate change globally, so traced origins doesn't change it.
• Downstream stages: Use and end of life of purchased goods aren't covered.
• Exclusions: Other impact categories, such as ecotoxicity, invasive species, and ocean acidification, aren't covered yet.
• Ecosystem weighting: How to weight terrestrial, freshwater, and marine ecosystems is a value choice that science hasn't settled. By default, Nios adds them with equal weight, following the Kulionis et al. (2024) translation scheme.