Nature futures for the urban century : Integrating multiple values into urban management

There is an emerging consensus that the health of the planet depends on the coexistence between rapidly growing cities and the natural world. One strategy for guiding cities towards sustainability is to facilitate a planning process based on positive visions for urban systems among actors and stakeholders. This paper presents the Urban Nature Futures Framework (UNFF), a framework for scenario building for cities that is based on three Nature Futures perspectives: Nature for Nature, Nature for Society, and Nature as Culture. Our framework engages stakeholders with envisioning the three Nature Futures perspectives through four components using participatory methods and quantitative models: identification of the socio-ecological feedbacks in cities, assessment of indirect impacts of cities on biodiversity, development of multi-scale indicators, and development of scenarios. Stakeholders in cities may use this framework to explore different options for integrating nature in its various manifestations within urban areas and to assess how different community preferences result in various cityscapes and distribution of associated benefits from nature among urban dwellers across multiple scales

Current indicators and metrics hinder effective urban climate adaptation

Assessing the effectiveness of climate adaptation action is the focus of intense debate across scientific and policy arenas. Measurement is essential for effective adaptation management and operation, and indicators and metrics (I&M) have a pivotal role. Surprisingly, there are very few systematic efforts to understand the advances in the provisioning of adaptation I&M. Here we analyse 137 publications and 901 I&M sourced in the scientific literature to measure adaptation to climate change, particularly, in urban areas where governments are increasingly placing efforts to prepare populations and infrastructures. A lack of common terminology, standardisation, and reference guidelines has resulted in a field that is complex to track and understand. Furthermore, such complexity has led to diverse, context-specific and sometimes competing approaches to developing I&M. We argue that current I&M proposals are highly technical, not sufficiently grounded on real needs, and have little potential to collectively support effective urban climate change adaptation

Catalyzing action towards the sustainability of deltas

Deltaic systems are among the most dynamic and productive environments on Earth and many have a high population density. Deltas play a central role in food and water security but are increasingly facing hazards such as submergence, riverine and coastal flooding, and coastal erosion. This paper synthesizes efforts of the Belmont Forum Deltas project, an international network of interdisciplinary research collaboration with focal areas in the Mekong, the Ganges Brahmaputra, and the Amazon deltas. The inherent complexity and dearth of knowledge about deltas require disciplinary expertise to advance jointly with interdisciplinary collaboration. An overarching research framework articulates focal research areas and collaborative modules, serving as an umbrella for both crosscutting and specific research questions. These modules have allowed for common definition of goals, responsibilities, and products, but flexible and decentralized disciplinary and interdisciplinary collaborations. Self-organization within and across areas of expertise has proven effective in bringing collaborators to commit to specific efforts. Knowledge co-production workshops focusing on vulnerability and risk have successfully strengthened interactions with regional organizations. As a distributed network, challenges remain in terms of type of and level of interaction and hands-on collaborative work among research partners, including joint fieldwork, but successes far outweigh difficulties. To illustrate these points, we present a review of three research domains built upon different arrangements of disciplinary and interdisciplinary collaborations: advancing biophysical classifications of deltas, understanding deltas as coupled social–ecological systems, and analyzing and informing social and environmental vulnerabilities in delta regions

Denser and greener cities: Green interventions to achieve both urban density and nature

Abstract Green spaces in urban areas—like remnant habitat, parks, constructed wetlands, and street trees—supply multiple benefits. Many studies show green spaces in and near urban areas play important roles harbouring biodiversity and promoting human well‐being. On the other hand, evidence suggests that greater human population density enables compact, low‐carbon cities that spare habitat conversion at the fringes of expanding urban areas, while also allowing more walkable and livable cities. How then can urban areas have abundant green spaces as well as density? In this paper, we review the empirical evidence for the relationships between urban density, nature, and sustainability. We also present a quantitative analysis of data on urban tree canopy cover and open space for United States large urbanized areas, as well as an analysis of non‐US Functional Urban Areas in OECD countries. We found that there is a negative correlation between population density and these green spaces. For Functional Urban Areas in the OECD, a 10% increase in density is associated with a 2.9% decline in tree cover. We argue that there are competing trade‐offs between the benefits of density for sustainability and the benefits of nature for human well‐being. Planners must decide an appropriate density by choosing where to be on this trade‐off curve, taking into account city‐specific urban planning goals and context. However, while the negative correlation between population density and tree cover is modest at the level of US urbanized areas (R2 = 0.22), it is weak at the US Census block level (R2 = 0.05), showing that there are significant brightspots, neighbourhoods that manage to have more tree canopy than would be expected based upon their level of density. We then describe techniques for how urban planners and designers can create more brightspots, identifying a typology of urban forms and listing green interventions appropriate for each form. We also analyse policies that enable these green interventions illustrating them with the case studies of Curitiba and Singapore. We conclude that while there are tensions between density and urban green spaces, an urban world that is both green and dense is possible, if society chooses to take advantage of the available green interventions and create it. Read the free Plain Language Summary for this article on the Journal blog

Multi-molecular markers and metals as tracers of organic matter inputs and contamination status from an Environmental Protection Area in the SW Atlantic (Laranjeiras Bay, Brazil)

The sources and concentrations of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs), faecal and biogenic sterols, and trace metals at 10 sampling sites located in Laranjeiras Bay, a large Environmental Protection Area in the southern Atlantic region of Brazil, were determined to assess the sources of organic matter and the contamination status of estuarine sediments. Organic compounds were determined by GC-FID and GC-MS, and ICP-OES was used to evaluate trace metals. The total AHs concentration ranged from 0.28 to 8.19 mu g g(-1), and n-C-29 and n-C-31 alkanes were predominant, indicating significant inputs from higher terrestrial plants. Unresolved complex mixtures (UCM) were not detected at any site, suggesting that the study area was not significantly contaminated by fossil fuels. The total PAH concentration varied from 3.85 to 89.2 ng g(-1). The ratio between selected PAH isomers showed that combustion of biomass, coal, and petroleum is the rnain source of PAHs in the study area. The concentrations of the faecal sterols coprostanol and epicoprostanol were below the detection limits, suggesting that sewage was not a significant contributor to sedimentary organic matter. The concentrations of the trace metals (As, Cr, Cu, Ni, Pb and Zn) were low, except near sites located at the mouths of rivers that discharge into the study area and near urbanised regions (Paranagua city and the adjoining harbour). In general, the concentrations of PAHs were below the threshold effect concentrations (TEL) levels. Although the As, Cr and Ni concentrations were above the TEL levels, the study area can be considered as preserved from human activities.Brazilian National Council for Scientific and Technological Development (CNPq)CNPq (Brazilian National Council for Scientific and Technological Development) [564316/2008-3

An assessment of urban vulnerability in the Amazon Delta and Estuary: a multi-criterion index of flood exposure, socio-economic conditions and infrastructure

The Amazon Delta and Estuary (ADE) is a region of continental and global ecological importance. Controversy, many of the basic infrastructure and services essential for quality of life and sustainable development of this delta are absent. Using a conceptual model to define socio-economic vulnerability in the urban ADE, a thorough assessment of indicators including sanitation services, housing conditions, household income, population, flood risk and unplanned settlements was conducted in 41 cities at the census sector scale (n = 2938). A multi criterion index was applied to classify urban vulnerability from three dimensions: flood exposure, socio-economic sensitivity and infrastructure. This is the first study to examine urban vulnerability within and between urban areas of the ADE. Results indicated that most of the urban sectors of the ADE are exposed to potential risks due to a combination of flood hazards, poverty and basic structural deficiencies such as insufficient drinking water or inadequate waste water collection, with several sectors being afflicted by similar problems. The assessment of vulnerability indicates that 60-90 % of the urban population live in conditions of moderate to high degree of vulnerability. The ADE cities presented a pattern where vulnerability increases from city center to their newly developed urban areas. Inadequate planning coupled with rapid urbanization has contributed to the development of unplanned settlements in almost half of the urban sectors of the ADE. Combined, these factors contribute to widespread socio-economic vulnerability along the urban spaces of the ADE, increasing exposure to health risks and more frequent seasonal and stochastic events such as storm surges and high flooding levels