The services that society extracts from urban ecosystems are becoming increasingly important with increasing urbanization. A potentially crucial ecosystem service is soil carbon (C) storage, as negative soil C balances have the potential to offset some of the anthropogenic greenhouse gas emissions mitigating climate change. This research studied the soil C storage in the urban greenspaces of 2 districts in a typical Dutch city (The Hague districts’ City Centre and Scheveningen, 21 km2 , 37% greenspace) as a case study. The following research question was addressed: ‘What is the carbon storage potential of urban soils in The Hague?’ Soil samples were collected along a transect going from the suburban seaside towards the city centre of The Hague. The transect crossed a toposequence from sandier dune soils to peaty inland soils. Besides soil C densities, several soil-quality characteristics were measured namely dissolved organic C levels, pH, electrical conductivity, nitrogen, phosphorus, and sulphur levels, calcium carbonate, the water-holding capacity of the soil and the degradability of soil organic C.

Although urban soil can be highly disturbed or altered by anthropogenic activities, the high C densities in The Hague suggested that its potential to store C appeared unaffected. Along the transect, a mean C density of 88 t/ha, of which 82 t/ha was considered organic C, was detected, which was higher than the values currently assigned to urban soils in national C inventories. The urban soil C storage was dependent on the type of vegetation, urbanization extent and land ownership. The hypothesized links between land use and soil type were not apparent in this case study, suggesting that processes driving soil C storage are controlled by different factors.

The total soil C storage of the upper 30 cm of the greenspaces in The Hague was estimated at 18.8 kt of C. The use of high spatial resolution GIS data with a scale of 10 x 10 m enabled the inclusion of small patches in the total soil C storage of The Hague, which proved to be significant as the smaller urban greenspaces, which are typical for dense urban centres, contained similar soil C density as the larger urban greenspaces, such as urban forests.

Soil C storage in urban ecosystems is highly variable. How generalizable these results are across other Dutch cities requires further research. Moreover, to translate current soil C stocks to annual C fluxes further research is required. This study found that urban soil C stocks are underestimated, which potentially also is the case for urban soil sequestration rates that are currently applied in C modelling studies.

This report provides suggestions to improve the sustainability of the waste management of the Hogeschool van Amsterdam (HVA), a higher educational institute located in Amsterdam. The HVA as an institute has an outspoken ambition to improve their waste management with a focus on sustainability. They previously asked several student groups to research specific elements of sustainability within their waste management. This report however, will approach the waste management as a whole and will shed light on what is important to successfully improve their waste management considering all its aspects. The report starts off with a literature review which explains the holistic nature of waste management dilemmas. The literature also shows that the success of sustainable waste management largely depends on the willingness of all involved parties to comply. Therefore, it is important to first create an in-depth understanding of the organizational structure behind the waste management, to ensure all individual management bodies within the organizational structure are on the same page. This is also reflected in the explained mythological approach and the formulation of the research questions. Following the re- search questions, first the organizational structure of the HVAs waste management will be evaluated with a series of interviews and a survey. The interviewees were chosen based on their close involvement with a specific management body within the organizational structure. After the waste management as an organization is established, the waste streams within the HVA are estimated. For a holistic understanding of the waste streams an estimation on the quantity, quality, and composition of all the waste that comes through the HVA is determined. The estimations were made by using data that was made available by the HVAs current waste disposal partner RENEWI, and where later confirmed by verifying them with comparable data sets. Additionally the material based waste streams were evaluated on their environmental impacts, when disposed of on different levels in the waste Hierarchy. With the full understanding of the waste itself and the organization, potential improvement areas are determined. To find fitting solutions the literature on waste managements of higher educational institutes around the world were looked at and experts where approached for in-depth interviews. The results once again emphasized the importance of a holistic approach, pointing out that the success of a sustainable waste management can be significantly harmed by a single unwilling or unknowing actor. It is therefore suggested to involve the students as much as possible, to establish a continuous spread of awareness. Another result is the importance of knowledge on the waste, this can be achieved by better regulating the purchases and drawing information from them. As well as performing waste audits to determine the outflow waste. Putting these two data sets next to each other can uncover preventable problems.