A new Environment Agency report has reviewed the evidence behind 17 different carbon offsetting approaches which could be used in the UK, including mainly nature based solutions and a smaller number of built environment approaches to help achieve Net Zero carbon emissions.

The Agency found that:

• all the approaches reviewed have strengths and weaknesses in offsetting carbon emissions
• to achieve true net zero, only carbon offsetting projects that remove GHGs can be used
• there are currently only 2 accredited carbon offsetting standards in the UK – the Woodland Carbon Code and the Peatland Code
• some of the approaches remove GHGs from the atmosphere, others reduce the rate of GHG emissions, and some progress from reductions to removals over time
• different offsetting approaches remove GHGs from the atmosphere at different rates and they scored differently across the implementation factors

The report concludes that only carbon offsetting projects that remove GHG emissions will be compatible with true net zero emissions. This is where GHGs emitted into the atmosphere are balanced through equal removals of GHG emissions from the atmosphere.

The Agency has reviewed the evidence behind 17 different carbon offsetting approaches which included mainly nature based solutions and a smaller number of built environment approaches:

1. Woodland creation
2. Upland peat restoration
3. Biochar
4. Hedges and trees outside of woodlands
5. Household insulation
6. Household low carbon heating
7. Soils management: pasture
8. Soils management: arable
9. Enhanced weathering
10. Lowland peat restoration
11. Floodplain restoration
12. Saltmarsh restoration
13. Grassland
14. Seagrass restoration
15. Kelp restoration
16. Constructed wetland
17. Other built environment measures (e.g. renewable electricity consumption, reducing water consumption)

Each of the 17 offsetting approaches were scored using a red, amber and green rating system, enabling them to be ranked from high to low based on how extensively they met each of the following criteria:

• Readiness for implementation
• Speed and scale
• Permanence (impact is not reversed)
• Leakage (reduction in emissions in one area leads to increase in another)
• Additionality (reductions that would not have happened otherwise)
• Co-benefits
• Confidence in the science
• Measuring impact
• Risks and barriers
• Costs

Key findings in the report include issues related to the need to work with other stakeholders and the costs of implementation.

Working with landowners and land managers was found to be vital. Understanding the needs of landowners and other local stakeholders, and designing projects that achieve outcomes for multiple beneficiaries, will help accelerate project implementation.

On costs, the report found that there is currently limited information detailing the costs of implementation. In addition, there are inconsistencies between sources in what is included and excluded from cost assessments.

“More detailed consideration of implementation and operational costs would be required to move forward confidently with implementation for most approaches. These considerations should include the potential to combine multiple funding streams for multiple environmental outcomes.,” the report says.

The Agency will now use the outputs from the report to shape the development of its own carbon offsetting strategy.

The EA’s own Net Zero target, set for 2030, includes reducing emissions by 45%, and addressing remaining emissions using best practice carbon offsetting techniques.

The report is the result of research commissioned and funded by the Joint Flood and Coastal Erosion Risk Management Research and Development Programme from Bristol-based consultancy Eunomia Research & Consulting.

Click here to download the report Achieving Net Zero - A review of the evidence behind potential carbon offsetting approaches in full