A recent study by the London Borough of Barnet includes the publication of a Corporate Natural Capital Account (CNCA) that quantifies the value of its parks and open spaces. It shows the benefits from open spaces are around 10 times the cost to maintain them. The report organises data about open spaces into an accounting framework that can be updated each year, linking physical assets to their benefits and economic values. Barnet is the first London Borough to formally create a baseline CNCA for all its open space (there have been partial benefit assessments developed for other Boroughs).
Natural capital refers to natural assets, such as parks and gardens, which provide recreation, health and well-being benefits to people. The Natural Capital Committee has developed a Corporate Natural Capital Account framework to capture the financial value of natural capital assets and to quantify the costs of sustaining these benefits over time.
Barnet’s population is set to increase significantly over the next twenty years, placing increased pressure on the borough’s green infrastructure assets. At the same time, the council is facing significant budgetary pressures. The creation of a Corporate Natural Capital Account for Barnet provides the council with an evidence base to quantify the economic, social and environmental benefits accruing from its green infrastructure assets.
The report suggests that Barnet’s open spaces improve:
- Air quality by absorbing pollutants
- The local climate by cooling during heatwaves
- Resilience to flooding by slowing water flows
- Water quality by filtering water to reduce water treatment costs
- Opportunities for outdoor recreation in more natural environments
- Habitat for a broad range of species
Using available data and valuation evidence, the report estimates the monetary value of some of the largest benefits that natural capital assets within Barnet provide. These include:
- Recreation: Visits made to LB Barnet greenspaces have an estimated value of over £41m per year.
- Physical health benefits: The value (through the avoided health costs of inactivity) of the physical activity supported by Barnet’s greenspaces is over £19m per year.
- Property premiums: Five case study sites are estimated to provide between £70 million – £140 million in residential property premiums for the surrounding area. In addition, the same sites may contribute over £0.2 million in rental premiums each year.
- Climate regulation: Carbon sequestered by LB Barnet’s woodland and grassland is valued at over £70,000 per year
The total value of benefits is estimated at more than £1 billion over the next 25 years. The costs of maintaining these open spaces are estimated at £72 million over the same period – less than a tenth of the benefits they provide.
Data gaps and limitations
The report also acknowledges that there are gaps to consider for research to further develop the natural capital physical flow account:
- For some services provided by natural capital data is not readily available. For example, air pollution mitigation and water flow attenuation (for flood risk management) from different sites in LB Barnet would require modelling that is not in the scope of this project.
- Recreational visitors may represent a significant underestimate as values do not include benefits to tourists and children under the age of 16.
- The impact that open spaces and greenspaces have by enhancing property values is likely to be significant (e.g. in the hundreds of millions), however due to the scope of this project and the complexities in modelling the number of properties within GIS, a full analysis for the Borough was not undertaken. With adequate GIS knowledge and data layers, this analysis could be carried out in future. If this benefit is used in future, overlap with other types of benefits need to be assessed.
Click here to read the full report.