This review examines key economic concepts in relation to the price and value of water for the supply and demand of household water. It responds to a series of questions about water and how it is used. These include (1) Why water is (or is not) priced and valued (or not)?; (2) What are the key economic concepts for pricing water?; (3) How is water priced and how are water supply assets valued for full cost recovery?; (4) Who bears the costs and enjoys the benefits of water use?; and (5) When is the price of water expected to change? Examples are provided to demonstrate the universality of the economic concepts while highlighting how their application must be bespoke and account for different socio-economic contexts and bio-physical conditions where water is supplied and demanded.

The idea of green infrastructure (GI) has generated great interest and creativity in addressing a range of challenging and expensive environmental problems, from coastal resilience to control of combined sewer overflows (CSOs). The appeal of GI stems from its cost savings compared to traditional “gray” infrastructure and the multiple benefits it provides, including biodiversity, aesthetics, and carbon sequestration. For example, a “green” approach to controlling CSOs in New York City saved $1.5 billion compared to a “gray” approach. Despite these advantages, GI still does not have detailed design and reliability specifications as compared to engineered gray infrastructure, potentially hindering its adoption. In this paper, we review some of the potential applications of GI in modern environmental science and discuss how reliability and associated (un)certainty in net benefits need to be addressed to realize the potential of this new approach.

Because of their isolation, biotic communities of urban green spaces are expected to be similar to those of oceanic islands. This should be particularly true for insects, which represent an important component of urban faunas. The equilibrium theory of island biogeography (ETIB) allows for the formulation of some hypotheses regarding the influence of the geographical characteristics of green spaces on insect species richness and extinction risk. Based on island biogeography principles, we present eight predictions on how green space characteristics should influence insect species richness and loss. We analysed the current literature in order to determine which predictions were supported and which were not. We found that many studies gave outcomes that support ETIB predictions about the effects of area and isolation of green spaces; we found no strong support for predictions about shape and extent of native habitat in the literature that we reviewed. Most of the available studies dealt with patterns in species richness, whereas insect species loss has been rarely investigated. Future developments in the application of island biogeography principles to urban insect conservation should address temporal trends in species persistence and the analysis of species co-occurrence and nestedness.

This study uses a field experiment involving 251 adult participants to determine which messages related to climate change, extreme weather events, and decaying infrastructure are most effective in encouraging people to pay more for investments that could alleviate future water-quality risks. The experiment also assesses whether people prefer the investments to be directed toward gray or green infrastructure projects. Messages about global warming induced climate change and decaying infrastructure lead to larger contributions than messages about extreme weather events. The results suggest that people are likely to pay more for green infrastructure projects than for gray infrastructure projects.

With increasing urbanization and environmental degradation, urban landscapes are increasingly expected to provide a wide range of ecosystem services typically associated with rural areas, including biodiversity conservation and food production. Because residential landscapes constitute the largest single urban land use, domestic gardens have emerged as a topic of research interest and planning concern. The ecosystem services (or disservices) these landscapes provide, however, have not been rigorously measured, nor have tradeoffs between the services they provide been assessed. In this study, semi-structured interviews were conducted with 59 African American, Chinese-origin or Mexican-origin households with on-lot or vacant lot food gardens in Chicago. Crop plants and cultivated ornamental plants on the lot were inventoried and mapped at the species level. A total of 123 edible plant taxa from 25 families and 288 ornamental plant species from 85 families were identified, for a combined total of 387 species from 90 families. Cumulatively, the gardens of African American households were relatively rich in ornamental plant species and families, while those of Chinese-origin households had a depauperate flora. Crop plant richness was more even across sample types. Shade trees and a developed shrub layer were absent from most gardens, possibly representing a tradeoff in ecosystem services in favor of food production. The richness of the aggregate 2.1 ha of residential property inventoried in this study was comparable with or exceeded that of a 34 ha prairie remnant west of Chicago. However, only 35 (9.6%) of the inventoried species were native to the Chicago area.

The pressures on the use of the seashore are steadily rising, not only in developed countries but worldwide. Anthropogenic activity has long impacted the marine continental shelf down to a depth of approximately –200 m. New activities are now affecting this coastal space such as renewable energies, recreational uses and aquaculture in addition to the traditional ones of navigation or fishing. This evolution raises new sources of conflict amongst users which can require state involvement in order to manage the different stakeholders and pressure groups. However, the coastal space still offers a large potential for development for two reasons. Firstly, the physical three dimensional potential of this space enables the whole water column to be used, principally to increase the fishing productivity as in Japan. Secondly, innovative synergies can be created between socio-technical and ecological uses (a “fourth dimension”) such as the eco-design of wind turbine foundations in order to create fish habitat or sea grass settlement. This new vision in “4D” for the design and the management of coastal infrastructure can potentially reduce the risk of conflict as different uses of the coastal space would not necessarily exclude one another. Indeed, several forms of synergy could be developed such as fisheries with aquaculture or biological sustainability with social acceptability. Until now, limited attempts at such an approach have been done. We suggest this is likely due to the absence of a common eco-engineering vision and the lack of experience amongst biologists and engineers in the co-construction of projects. This eco-engineering, or “green” vision, also takes into account the complexity and resilience of the ecosystem in the long term, if underwater engineered infrastructures are also “eco”-designed to increase ecological gain This new conception, for development within the coastal area, provides for an increased bio-oriented complexity to engineered structure and therefore a better resistance of the ecosystem in the long term to anthropogenic pressures and a reduction in multi-user conflicts.