EN2.3
Composting
Environment
- Waste Management
Composting
Composting is the natural process of recycling organic waste—like food scraps, garden clippings, and paper—into a nutrient-rich material called compost, which can be used to enrich soil.
If users want to assess the emissions impact of their waste management practices, they can consult WRAP’s Carbon Waste and Resources Metric. However, it’s important to note that this metric is not designed for reporting Scope 3 emissions. For more information about principles for GHG accounting and reporting and three “scopes” of emissions, please visit EN1 Measuring Greenhouse Gas (GHG) Emissions.
Key Value
£12
The monetised environmental value of carbon savings per tonne of waste diverted by composting (horticultural use).
PLEASE NOTE: This value is not a “footprint” (i.e. carbon emissions) but a relative measure that can be used to quantify the carbon saving relative to any given treatment option for a given material / treatment combination.
The values are based on CarbonWARM2 which is the latest version of the Carbon Waste and Resources Metric developed by WRAP on behalf of Defra. This updated version provides conversion factors that enable organisations to assess the greenhouse gas (GHG) emissions associated with waste management practices, expressed in carbon dioxide equivalent (CO2e). It serves as an essential tool for evaluating and improving waste management strategies.
The metric values are shown below. The value represents a carbon emission, while negative values represent a carbon saving.
Table 1 Carbon WARM, unnormalised values (tonnes.CO2e/tonne)
| Material | Compost (horticultural use) | Compost (agricultural use) |
| Kitchen waste | -0.055 | 0.006 |
| Garden waste | -0.045 | 0.056 |
| Mixed organics | -0.048 | 0.044 |
|
Average |
-0.049 | 0.035 |
These numbers represent the amount of carbon dioxide equivalent (CO2e) emissions or savings relative to landfill associated with each material. The higher the value, the greater the environmental impact. Theaverage Carbon saving for composting (horticultural use) is 49 kg.CO2e per tonne.
According to the 2021 carbon values from DESNZ/BEIS, Carbon values in 2020 prices per tonne of CO2: central series for 2023 is £252 or 25.2p per kgCO2e. For more information, please visit MeasureUp EN1 Measuring Greenhouse Gas (GHG) Emissions.
Average carbon savings per tonne of waste for composting (horticultural use) is 49 kg.CO2e and Carbon values in 2023 prices per kg of CO2 is £0.252. Thus, the headline value is 49kg.CO2e*£0.252= £12per tonne of waste for composting relative to landfill.
This value represents carbon savings for composting (horticultural use).
Local Needs Analysis Data Source
Before using this MeasureUp value, we encourage you to assess the local need in relation to the activity or outcome.
Here is the most useful initial data source for assessing local need in relation to this value.
To assess local needs related to the value EN2.3 ‘Composting’, use the Household Recycling Rate from the Department for Environment, Food & Rural Affairs (DEFRA).
This indicator reflects the percentage of household waste that is recycled instead of sent to landfill. It is updated annually and available at local authority and regional levels, helping to evaluate the effectiveness of local waste management and sustainability efforts.
Bronze
Effort
Accuracy
Monetised value:
The monetised environmental value of carbon savings per tonne of waste diverted by composting (horticultural use) is £12.
At the Bronze level, you should measure the amount of waste you have diverted by composting (horticultural use), and use this to calculate the approximate carbon footprint of your diverted waste.
Here is an example
Assume as an organization you diverted 100 tonne of waste by composting (horticultural use). If you don’t know material of the waste, you can approximately calculate monetised value of composting relative to landfill as (100tonne* 49 kg.CO2e) *£0.252= £1,200
This value represents carbon savings for composting (horticultural use).
Silver
Effort
Accuracy
At the Silver level, you should measure the amount of waste you have diverted by composting (horticultural use) each type of material and use this to calculate the approximate carbon footprint of your diverted waste.
Table 1 Carbon WARM, unnormalised values (tonnes.CO2e/tonne)
| Material | Compost (horticultural use) | Compost (agricultural use) |
| Kitchen waste | -0.055 | 0.006 |
| Garden waste | -0.045 | 0.056 |
| Mixed organics | -0.048 | 0.044 |
|
Average |
-0.049 | 0.035 |
Here is an example
Assume and as an organization you diverted 100 tonne of kitchen waste and 100 tonne of garden waste. Thus, you can approximately calculate monetised value of the composting (horticultural use) as ((100tonne*55kg.CO2e) +(100tonne* 45kg.CO2e)) *£0.252=£2,520
This value represents carbon savings for composting (horticultural use).
Gold
Effort
Accuracy
At the Gold level, you would be expected to
- Measure more accurately using more specific data for you in-scope activities.
- Track the emissions or savings over time.
This will allow you to show your actual results over time against your estimates as outlined in Bronze and Silver. Think of this as assessing your forecast or budget against your actuals.
Here is an example
A company is assessing the environmental impact of its annual carbon savings from composting (horticultural use) different materials relative to landfill.
| Material | Tonnes2023 | Tonnes2024 | Monetised Value in 2023 | Monetised Value in 2024 |
| Kitchen waste | 50 | 75 | (50 × 55) × £0.252 = £693.00 | (75 × 55) × £0.252 = £1,039.50 |
| Garden waste | 100 | 120 | (100 × 45) × £0.252 = £1,134.00 | (120 × 45) × £0.252 = £1,360.80 |
| Mixed organics | 100 | 80 | (100 × 48) × £0.252 = £1,209.60 | (80 × 48) × £0.252 = £967.68 |
| Total | – | – | £3,036.60 | £3,367.98 |
The monetised benefit increased by £331.38 in 2024 compared to 2023.
This means that more greenhouse gas emissions were avoided due to higher volumes of kitchen and garden waste being composted or processed sustainably in 2024.
This value represents carbon savings for composting (horticultural use).
Support in developing your Gold survey approach is available through the Measure Up partners, so please do reach out to Impact, State of Life or PRD.
| Value Type: | Activity |
What's this?
This is the type of value. Some values are outcomes, which means many different interventions might lead to them, others are specific interventions that have a set value. |
|---|---|---|
| UN SDG Categories: |
|
What's this?
The UN Sustainable Development Goals are global goals adopted in 2015 for all signed up nations to achieve for us to have a sustainable global future by 2030. There are 17 Goals that address the global challenges we face, including those related to poverty, inequality, climate change, environmental degradation, peace and justice. The Goals are all interconnected, and in order to leave no one behind, it is important that we achieve them all by 2030. |
| 2020 Social Value Models: |
|
What's this?
PPN 06/20 Taking account of social value in the award of central government contracts introduced the Central Government Social Value Model in 2020 which all Central Government contracting authorities must use in their in scope procurements. It consists of 5 themes, 8 policy outcomes, and 24 Model Award Criteria which outline key priority areas to achieve more social value. |
| 2025 Social Value Models: |
|
What's this?
|
Evidence
Measure Up focuses on empowering you to numerically measure the impact you’re having. We recommend that numeric reports are backed up with stories and other types of evidence to help illustrate, in human terms, the impact that’s being made on individuals.
We recommend seeking consent from participants in your intervention to collect and tell their story. This should include a little background on the participant, a summing up of life before the intervention, the human impact of the intervention, and the longer term (if known) impact on the person’s life outside of, and after, the intervention.
Providing photographs, audio recordings, video interviews or even artefacts from the intervention (for example, writing, paintings, music from creative interventions) can add more to the story, and convey the emotional impact of interventions more directly.
In some cases it’s appropriate to anonymise or abbreviate the personal information of case study participants. No story should be published or shared without the recorded consent of the individual(s) it concerns. Individuals continue to own the rights to their stories and if they request you stop sharing the story or making it available online you should do so promptly and without need for justification.
Feedback
Measure Up is open, collaborative and transparent. If you have any suggestions or feedback on our pragmatic, recommended approach to measuring and valuing social value, including wellbeing, economic, and fiscal impact, and effects on our environment, please get in touch so we can share and discuss this at our next Advisory Group meeting.
More help
We want to empower anyone to perform and improve their impact measurement – without needing a degree in economics.
If you need any more help, or just someone to do the legwork for you we can help signpost you to software, training and consultancy to help you get to grips with the impact you’re having and value you are creating.
