How are CO2 emissions from waste calculated?
General: The calculation of CO2 values is a complex process based on sound scientific methods and data. The values presented serve as a guide and can help to make more sustainable decisions and minimise environmental impact. For the calculation, we worked with the external expert team BetterEarth to inform and validate estimates of emission factors using the French government's ADEME database, the German government's Genesis database, the UK government's Genesis database, the commercial Ecoinvent database, official statistics, expert opinion, case studies and secondary research.
Methodology:
Determination of the amount of waste:
- The mass of waste is measured in tonnes
Determination of the composition of the waste:
(The results are limited to the most common waste materials from our customers)
- Construction waste
- Wood waste
- Residual waste
- Paper waste
- Organic waste
- Metal waste
- Plastic waste
- Medical waste
- Electronic waste
- Chemical waste (only incineration as a possible option, therefore no positive balance)
- Building rubble
- Soil and stones / excavated earth
- Mixed construction waste
- Mixed wood A1 - A3
- Waste wood A4, hazardous wood
- Mixed municipal waste
- Mixed packaging
- Glass packaging
- Paper, cardboard, carton
- old files
Different waste components (organic waste, paper, plastic, metal, glass, etc.) have different emission factors, which were determined individually.
What factors influence CO2 emissions from waste?
Factors that influence CO2 emissions are:
- Waste composition
- Landfill degassing
- Transport
- Treatment methods (1) landfilling, 2) incineration and 3) recycling)
Explanation of the factors Treatment methods:
- Landfilling: Emissions from methane (CH4) and CO2.
- Incineration: CO2 emissions from the combustion of organic material and fossil fuels.
- Recycling: Reduction of emissions by avoiding the production of new products.
- Composting: Emissions mainly from the decomposition of organic materials into CO2 and methane.
How are emissions calculated?
The calculation is made by multiplying the amount of waste by the corresponding emission factor:
CO2 emissions= ∑ (quantity of waste component × emission factor of disposal method)
Data collection
The data comes from various reliable sources, including scientific studies, reports from environmental organisations and government databases. Our calculations are based on average values in order to provide as realistic an estimate of CO2 emissions as possible.
What should I bear in mind about the data shown?
The emission factors used are approximate values and should therefore be treated with caution. We are currently working on the certification of the methodology used.
Incomplete process data and therefore not a complete picture: Figures for landfilling, incineration (without energy recovery) and recycling (without avoided emissions) can be used (see more on the last point in the sub-chapter ‘Offsetting avoided emissions’). According to GHGP Scope 3 Category 5 ‘Waste Generated in Operations’, waste-producing companies must include the waste treatment process in their carbon footprint. However, incineration with energy recovery and recycling with avoided emissions cannot be included and declared separately due to double accounting reasons. However, transport can be integrated into the balance for these. These figures are not part of the project.
Impact on the climate:
The figures shown only have an impact on the climate and not on other environmental aspects (such as the circular economy, biodiversity, water and land use).