To help address the Big Question ‘How do we remove more carbon than we emit by 2050?’, the UK water industry needs a consistent and legitimate method to account and report the greenhouse gas emissions associated with its landholdings and land management activities. This is not currently available and needs to be developed, building on a piece of work started by Yorkshire Water.

Yorkshire Water have developed a land carbon model to calculate carbon stock and flux across its entire land holdings. The model also allows scenarios to be modelled, such as tree planting and peatland restoration, enabling the company to determine additional potential carbon sequestration opportunities across its land holdings to inform its offsetting strategy. 
The model uses land cover and habitat condition from GIS data to determine a baseline. It then calculates sequestration under different scenarios through time. Appendix A provides more information on the model.

There have been two phases of the project so far. Phase 1 was to appraise the potential options, data and methodologies for the model to assess carbon sequestration on Yorkshire Water’s land and how that might fit into the business planning process. 

Phase 2 of the project saw the processing and combination of GIS data, development of a spreadsheet model and production of three key scenarios - a baseline scenario with storage and flux figures, and an output for two main scenarios (planting one million trees and maximising peatland restoration).

Both phases were tailored to Yorkshire Water’s land types. 
Having completed this work, it is apparent that there are several areas where the model and process can be further developed.
1.    The whole industry is committed to reducing emissions (for example, English water companies have a net zero target by 2030 and there are similar ambitions and commitments in other parts of the UK and Ireland). A detailed route map has been developed, which includes offsetting and insetting. Every water company will have a different mix of options, opportunities and challenges, but at present the UK water industry as a whole does not have a clear picture of the potential for offsetting, nor the risks of emissions arising from its land and how this will fit in with the rest of its carbon route map.
2.    In order to meet reduction targets, it is likely that the UK water industry will need to either buy open market offsets or develop offsets using their own available land bank. Many organisations may use tree planting or peatland restoration as methods to offset any remaining emissions once other options have been exhausted. While detailed and specific methodologies are available to calculate carbon offsets from these regimes, methods for other land types and conditions are less clear, so fully accounting for other land types and conditions has not been possible. There may be other opportunities and risks that need to be included in a company's strategy to better inform their offsetting and land strategy. This may also feedback into wider carbon reduction objectives.
3.    The current model uses an inventory-based approach of land cover and habitat condition to assess the overall net sequestration across landholdings. More detailed and wider research is required to focus on the most appropriate parameters and land cover/condition types as well as potential alternative data sources to improve confidence and accuracy of the model. At present there is not a full representation of uncertainty within the model predictions. This leaves the model open to significant external challenge.
4.    The model has only been stress-tested and peer reviewed in a limited way to date.
5.    We need to ensure the model is as user friendly and transparent as possible and applicable to all UK and Ireland water companies (e.g. by ensuring it includes all relevant land cover, management and habitat types).

To avoid inconsistent greenhouse gas emissions reporting we need a common method and accounting system. This is achieved through the carbon accounting workbook (CAW).

The CAW requires annual updating - at the very least to incorporate revised emissions factors issued by BEIS. Previous updates have also included broadening the scope of items that are quantified, and improving functionality.