Münster – Climate adaptation in humid forests

Münster is a city in North Rhine-Westphalia, Germany, known for its historic centre and green urban environment. It has a high population density typical of German urban areas. It is part of European NBS network assessing social value of urban nature interventions across 13 countries.

To estimate the social value of nature-based solutions implemented in urban areas through willingness-to-pay assessment, enabling comparison of benefits against implementation and maintenance costs to inform investment decisions.

Challenges addressed 

The main challenge is climate change adaptation, alongside environmental management of the forest ecosystem.

Costs of NbS 

The project adapts 4,000 ha of humid forest in and around Münster to a changing climate. Implementation cost about EUR 4.1 million, and maintenance is estimated at about EUR 0.67 million per year. Over a 40-year lifetime, total costs come to about EUR 19.6 million (2023 prices, 3% discount rate).

The project helps the humid forests cope with a changing climate, safeguarding the nature and recreational value they provide to Münster’s residents, worth about EUR 10.2 million per year (2023 prices).

Benefit–cost ratio 

Over 40 years at a 3% discount rate, the project yields a BCR of 12, a strong return on public investment.

• Application of benefit transfer valuation method based on meta-analysis of 60 primary valuation studies.
• Collection of socio-economic data including GDP per capita and population density. 
• Estimation of implementation costs and annual operational costs by intervention type. 
• Calculation of net present value and benefit-to-cost ratio using 3% discount rate over 40-year lifetime. 
• Sensitivity analysis testing alternative discount rates and cost assumptions.

None available 

Study overview

Münster participated in a European-wide assessment of nature-based solutions (NBS) social value across 85 urban interventions spanning 13 countries. The study evaluated the aggregate social value generated for urban residents through implemented NBS, using benefit transfer methods based on willingness-to-pay meta-analysis.

The research analysed 60 NBS projects where cost data was available, with total implementation costs of US5.39 billion across all projects. The average annual maintenance costs were estimated at US 14.7 million, while median annual maintenance costs were US$ 1 million per project. These costs varied substantially by intervention type, ranging from street tree plantings and green walls to larger infrastructure such as parks, green corridors and sustainable urban drainage systems.

For Münster and comparable German sites, a benefit-to-cost ratio (BCR) analysis was conducted using a 3% discount rate over a 40-year project lifetime. Across all 60 projects assessed, 39 interventions (65%) demonstrated a BCR above 1, indicating positive social returns on investment when valuing benefits to residents. This includes health and wellbeing improvements, quality of life enhancements and other social values captured through citizen preference studies.

The valuation methodology applied a meta-analytic value transfer function accounting for socio-economic factors including GDP per capita and population density. The approach captured direct use values, indirect use values and non-use values of urban nature. Projects classified as 'multiscapes' incorporating multiple nature types showed higher estimated per-hectare values.

Sensitivity analyses confirmed robustness of findings. At a 5% discount rate, the percentage of projects with positive net present value remained stable, while at 1% it increased to 67.3%. Even with a 50% increase in operational costs, 61.67% of interventions retained positive NPV.

The study demonstrates that urban NBS generate measurable social value for residents that can justify public and private investment. For cities like Münster, this evidence supports integrating NBS into urban redevelopment plans, potentially accessing municipal health and wellbeing budgets, real estate development funding or NGO contributions alongside traditional public financing.