Sustainability assessments can play an important role in decision making. This role starts with selecting appropriate methods for a given situation. We observed that scientists, consultants, and decision-makers often do not systematically perform a problem analyses that guides the choice of the method, partly related to a lack of systematic, though sufficiently versatile approaches to do so. Therefore, we developed and propose a new step towards method selection on the basis of question articulation: the Sustainability Assessment Identification Key. The identification key was designed to lead its user through all important choices needed for comprehensive question articulation. Subsequently, methods that fit the resulting specific questions are suggested by the key. The key consists of five domains, of which three determine method selection and two the design or use of the method. Each domain consists of four or more criteria that need specification. For example in the domain “system boundaries”, amongst others, the spatial and temporal scales are specified. The key was tested (retrospectively) on a set of thirty case studies. Using the key appeared to contribute to improved: (i) transparency in the link between the question and method selection; (ii) consistency between questions asked and answers provided; and (iii) internal consistency in methodological design. There is latitude to develop the current initial key further, not only for selecting methods pertinent to a problem definition, but also as a principle for associated opportunities such as stakeholder identification.

Responses of ecosystems to human-induced stress vary in space and time, because both stressors and ecosystem vulnerabilities vary in space and time. Presently, ecosystem impact assessments mainly take into account variation in stressors, without considering variation in ecosystem vulnerability. We developed a method to address ecosystem vulnerability variation by quantifying ecosystem vulnerability distributions (EVDs) based on monitoring data of local species compositions and environmental conditions. The method incorporates spatial variation of both abiotic and biotic variables to quantify variation in responses among species and ecosystems. We show that EVDs can be derived based on a selection of locations, existing monitoring data and a selected impact boundary, and can be used in stressor identification and ranking for a region. A case study on Ohio’s freshwater ecosystems, with freshwater fish as target species group, showed that physical habitat impairment and nutrient loads ranked highest as current stressors, with species losses higher than 5% for at least 6% of the locations. EVDs complement existing approaches of stressor assessment and management, which typically account only for variability in stressors, by accounting for variation in the vulnerability of the responding ecosystems.

Governments contribute to the transition toward a circular economy (CE) by using criteria in their procurement processes that trigger the supply of circular products and services, namely circular public procurement (CPP). CPP practices are emerging in Europe. However, the effect of CPP is not yet monitored and hence remains unclear. What is the efficacy of CPP in reducing the impacts of goods and services? Analyzing CPP efficacy is an important next step in exploring how to improve its application. This paper presents the results of an effect evaluation of CPP in the Netherlands, using a sample-based mixed-method approach in combination with life cycle assessment for analyzing CPP-induced reduced impacts on global warming and material use. Two thirds of the procurement tenders in which circular procurement criteria were applied in 2017 and 2018 did not result in reduced environmental impacts or reduced material use. One third, however, showed that, as well as how CPP can contribute to the transition toward a CE. The identified remaining challenges are (1) to apply criteria that are ambitious enough to challenge the market and (2) to keep attention on the circularity ambitions up during the implementation phase of the procurement process. Effect indicators are proposed to complement the current monitoring practices of CPP implementation.