Cities and large urban areas are major drivers of global environmental change that has negative impacts on human well-being. Consequently, urban areas are one of the most vulnerable to these impacts since they centre a large share of the population and economy. At the same time, urban areas are an important player in shaping policy towards a more sustainable future and maintenance of nature.
Nature provides various ecosystem services that benefit the well-being of society. The concept of ecosystem services represents a change in thinking about nature as the need for conservation for nature itself, to sustaining nature for the benefits it provides to people. In complex socio-ecological systems such as urban areas, ecosystem services are especially important as they can benefit a lot of people at the same time. Urban areas are commonly characterised by high population density but also densely built infrastructure. Green and blue ecosystem spaces are thus only a fraction of urban areas. This usually means that urban ecosystem services are scarce and benefit a limited number of people.
Ecosystem services are often unequally distributed across urban areas. Moreover, some groups of people need ecosystem benefits in different amounts than others. For example, if we consider social groups of elderly or children, they need a higher provision of cooling since they are more vulnerable to extreme heat. Or different national and ethnic groups need various levels of cultural ecosystem services based on their habits and beliefs. An analysis of the benefits of ecosystem services and societal needs and demands can uncover some distributional injustices in ecosystem service delivery. In most cases, wealthier urban areas have better access to ecosystem services while low-income communities and minorities are usually located in areas with lower environmental quality. This is sometimes caused by the increase of property value with increasing proximity to greenery.
The spatial distribution of ecosystem services and different societal needs are prompting several questions such as: What areas benefit from ecosystem services? Who are the beneficiaries? What areas and what people are disadvantaged due to spatial distribution of ecosystem service benefits? Where should urban planning focus in terms of improving ecosystem service delivery?
Answers to these questions could help decision and policy makers to make better-informed decisions in urban planning and take the first step into discussing a fragment of a very broad concept of ecosystem service justice. To answer the above questions, we selected Prague, Czechia, as a case study location. Currently, we are developing an index, which incorporates supply and demand for ecosystem services while considering various socio-demographic population data.
So far, we are looking into urban cooling supply-demand mismatch and trying to bring socio-demographic data into the analysis. We selected a Wet Bulb Global Temperature (WBGT) as a metric to assess both supply and demand. Here, WBGT represents an experience of temperature and humidity in a given place. Supply is thus assessed as an avoided experience of heat by vegetation cooling. In regulating services, the demand side is often expressed as risk perception. Having WBGT as a metric is allowing to set a limit above which people experience heat stress. Demand is then assessed as an amount of heat that needs to be reduced to a comfortable level. This gives us a pretty good idea about the hot spots of urban cooling provision and areas that are overheating (see preliminary results of mismatch in Figure 1). The map of mismatch demonstrates an unsatisfied demand for urban cooling on an average summer day (>25 °C) in 2018. The unsatisfied demand concentrates mainly in built-up areas with low vegetation, such as city centre, airports, and other built-up areas.
But what role does the population play? Isn’t it enough to know what areas are overheating for planning urban areas? The answer is no, it is not enough. Population and its needs should be the main actor in urban planning. There is no actual demand without a population because people are the ones that are at risk. Meaning that if there is no one living or going through an area that is overheating, there is no risk of heat stress, in theory. On the other hand, the more people live in or use the area, the more people are at risk from heat stress. Moreover, as mentioned above, different population groups have different needs in terms of ecosystem services and those need to be considered in urban planning. Urban cooling ecosystem service is non-rivalry by nature (ecosystem service of cooling provides the same benefits no matter how many people use it), which is creating a challenge for inclusion of population needs into the analysis of priority intervention areas for adaptation.
We are planning to weigh different socio-demographic data into the analysis to create the priority intervention index for urban cooling and further assess other ecosystem services important for urban areas such as recreation, air pollution or flood mitigation. The goal of this research is to help prioritise areas for implementation of adaptation measures where it is needed the most while recognising needs or various social groups.
To this point, urban planning for the implementation of adaptation measures and nature-based solutions has neglected the complexities of the urban socio-ecological system and the different needs of its residents, in most cases. Despite the efforts to make urban areas greener, the efforts may be perceived as a form of injustice for several social groups if urban planning fails to address various societal needs for ecosystem services in decision making. While recognising that the research into priority intervention areas focuses only on a fraction of ecosystem service justice, we believe that it can bring a new perspective to urban planning and trigger a discussion and further research of a complex problem of justice through the lenses of ecosystem services.