Carbon Audit 2024

The Takeaway

Carbon accounting is only useful when the assumptions behind the final number are visible.

That is why the GEME Carbon Audit 2024 does not begin with a simplified headline about how much carbon one product, one household, or one behavior will always save.

Instead, we publish the framework behind the assessment: what is included, where the system boundary begins and ends, which assumptions are used, and which impacts are not counted.

Why We Conducted a Carbon Audit

Food waste has environmental consequences long after it leaves the kitchen. Collection, transportation, treatment, landfill conditions, energy use, and material recovery can all affect the final outcome.

Household composting changes part of that pathway. However, the scale and direction of the change depend on the local conditions in which the system operates.

A household using renewable electricity in a region with long waste-collection routes may have a different accounting result from a household using a carbon-intensive electricity grid in a city with advanced municipal organic-waste treatment.

For this reason, the purpose of the Carbon Audit 2024 is not to create one universal marketing number. Its purpose is to establish a transparent accounting structure that can be reviewed, challenged, and improved.

What We Tested

The audit reviewed the accounting method and the assumptions used to describe potential environmental impacts within a defined system boundary.

1. System Boundary

We examined where the assessment starts and where it ends. Depending on the scenario, the accounting framework may consider:

• Food scraps entering the household composting process
• Electricity used during appliance operation
• The biological transformation of organic material
• Handling and use of the resulting compost material
• Relevant avoided or displaced waste-management activities

Defining these boundaries is essential. A result can change significantly when production, transportation, household operation, end use, or municipal treatment is added to or removed from the assessment.

2. Input Assumptions

The framework considers assumptions that may influence the calculation, including:

• The quantity and composition of food waste
• The frequency and duration of appliance operation
• Electricity consumption
• The emissions intensity of the electricity supply
• The assumed alternative waste-treatment pathway
• The way the resulting organic material is used

These are model inputs, not universal facts. Where a value depends on location, behavior, or infrastructure, the assumption must be identified rather than hidden inside the final result.

3. Accounting Method

The accounting process follows a straightforward structure:

1. Define the scenario being assessed
2. Set the system boundaries
3. Identify measurable inputs
4. Select and document relevant emission factors
5. Calculate the result within the stated boundaries
6. Record exclusions, limitations, and uncertainties

This approach is intended to make the result traceable. A reader should be able to understand which assumptions produced the number and how changing those assumptions might change the outcome.

What We Did Not Test

The Carbon Audit 2024 is not a universal claim for all households, cities, countries, electricity grids, or waste systems.

It does not establish that every user will achieve the same carbon outcome. It also does not assume that household composting replaces the same waste-treatment pathway in every region.

The audit does not claim that:

• All food waste would otherwise be sent to landfill
• All landfills have the same methane-management performance
• All municipal composting systems have the same emissions profile
• All electricity grids have the same carbon intensity
• All households operate the appliance in the same way
• All resulting compost material is used under identical conditions

Differences in local infrastructure, electricity generation, collection distances, climate, household habits, and end-use practices can materially change the result.

What We Do Not Count

A transparent assessment must identify not only what it includes, but also what it excludes.

We do not count environmental benefits simply because they are possible. A potential benefit is only included when the relevant scenario, boundary, and supporting assumption are defined.

We avoid calculations that:

• Assume universal landfill avoidance without local evidence
• Treat the most optimistic scenario as the normal result
• Apply one regional emission factor to every market
• Count the same environmental benefit more than once
• Present uncertain estimates as guaranteed outcomes
• Hide operational energy use from the assessment

Excluding unsupported benefits may produce a less dramatic headline, but it produces a more credible assessment.

Methods and Boundaries

The detailed methodology should be read together with any carbon figure or environmental comparison derived from the audit.

The methods and boundaries documentation explains:

• The accounting objective
• The selected functional unit
• The system boundary
• The baseline or comparison scenario
• The data sources and emission factors
• The assumptions used in the calculation
• The exclusions and known limitations
• The conditions under which the result should not be generalized

Why Regional Context Matters

Carbon accounting for food waste is highly sensitive to the alternative pathway used as the comparison.

In one location, food scraps may be transported to landfill. In another, they may be collected separately for industrial composting or anaerobic digestion. Some landfills capture methane efficiently, while others do not. Electricity generation can also range from low-carbon renewable sources to fossil-fuel-intensive grids.

These differences mean that a result calculated for one region should not automatically be applied to another.

Where regional data is unavailable, the responsible approach is to disclose the proxy used and explain the resulting uncertainty.

Measurement Before Marketing

GEME develops household systems for real microbial composting. That process can help households manage food scraps closer to where they are generated and return organic material to soil-related use.

But a product category, technology, or biological process should not be described as automatically carbon-negative, zero-emission, or universally superior without a clearly defined comparison.

Our responsibility is to measure carefully, document the method, distinguish evidence from assumptions, and revise the model when better data becomes available.

That is the standard behind Carbon Audit 2024: not a perfect number, but a transparent one.

Frequently Asked Questions

Related Reading

• Explore the GEME Journal
• Explore GK

Real Composting, Clearly Explained

GEME Terra 2 uses real microbial composting to continuously transform household food scraps into concentrated organic compost material, without relying on disposable activated-carbon filter replacements.