A transformative shift in urban ecology toward a more active and relevant future for the field and for cities

This paper builds on the expansion of urban ecology from a biologically based discipline-ecology in the city-to an increasingly interdisciplinary field-ecology of the city-to a transdisciplinary, knowledge to action endeavor-an ecology for and with the city. We build on this "prepositional journey" by proposing a transformative shift in urban ecology, and we present a framework for how the field may continue this shift. We conceptualize that urban ecology is in a state of flux, and that this shift is needed to transform urban ecology into a more engaged and action based field, and one that includes a diversity of actors willing to participate in the future of their cities. In this transformative shift, these actors will engage, collaborate, and participate in a continuous spiral of knowledge → action → knowledge spiral and back to knowledge loop, with the goal of co producing sustainable and resilient solutions to myriad urban challenges. Our framework for this transformative shift includes three pathways: (1) a repeating knowledge → action → knowledge spiral of ideas, information, and solutions produced by a diverse community of agents of urban change working together in an "urban sandbox"; (2) incorporation of a social-ecological-technological systems framework in this spiral and expanding the spiral temporally to include the "deep future," where future scenarios are based on a visioning of seemingly unimaginable or plausible future states of cities that are sustainable and resilient; and (3) the expansion of the spiral in space, to include rural areas and places that are not yet cities. The three interrelated pathways that define the transformative shift demonstrate the power of an urban ecology that has moved beyond urban systems science and into a realm where collaborations among diverse knowledges and voices are working together to understand cities and what is urban while producing sustainable solutions to contemporary challenges and envisioning futures of socially, ecologically, and technologically resilient cities. We present case study examples of each of the three pathways that make up this transformative shift in urban ecology and discuss both limitations and opportunities for future research and action with this transdisciplinary broadening of the field.

The relational shift in urban ecology: From place and structures to multiple modes of coproduction for positive urban futures

This perspective emerged from ongoing dialogue among ecologists initiated by a virtual workshop in 2021. A transdisciplinary group of researchers and practitioners conclude that urban ecology as a science can better contribute to positive futures by focusing on relationships, rather than prioritizing urban structures. Insights from other relational disciplines, such as political ecology, governance, urban design, and conservation also contribute. Relationality is especially powerful given the need to rapidly adapt to the changing social and biophysical drivers of global urban systems. These unprecedented dynamics are better understood through a relational lens than traditional structural questions. We use three kinds of coproduction-of the social-ecological world, of science, and of actionable knowledge-to identify key processes of coproduction within urban places. Connectivity is crucial to relational urban ecology. Eight themes emerge from the joint explorations of the paper and point toward social action for improving life and environment in urban futures.

Cities, planetary boundaries, and degrowth

Cities are the main hubs of human activity and the engines of economic growth. In pursuit of such growth, cities are transgressing their local environmental boundaries. Ongoing urbanisation increasingly contributes to the human pressure on planetary boundaries and negatively affects planetary health. In a telecoupled world, cities externalise impacts by shifting production and many other functions away from their boundaries. At the same time, urban inhabitants and people who follow urban lifestyles but live outside cities are increasingly disconnected from nature. This Viewpoint highlights the role of degrowth in keeping an urban planet within planetary boundaries and suggests areas for further research and policy. Degrowth calls for meaningfully connecting planetary boundaries with cities and ensuring everyone receives a fair share of their ecological capacity. Degrowth calls for lower use of existing resources, highlights political power asymmetries, and moves beyond pricing interventions. Degrowth addresses three key aspects that connect cities and urban lifestyles to planetary boundaries: reducing production and consumption, connecting people and nature, and including nature (to a more substantial extent) in the design of cities and in what is used and consumed in cities. A radical degrowth transformation of cities is necessary to stay within a safe operating space for humanity.

The potential of urban irrigation for counteracting carbon-climate feedback

Global climate changes, especially the rise of global mean temperature due to the increased carbon dioxide (CO2) concentration, can, in turn, result in higher anthropogenic and biogenic greenhouse gas emissions. This potentially leads to a positive loop of climate-carbon feedback in the Earth's climate system, which calls for sustainable environmental strategies that can mitigate both heat and carbon emissions, such as urban greening. In this study, we investigate the impact of urban irrigation over green spaces on ambient temperatures and CO2 exchange across major cities in the contiguous United States. Our modeling results indicate that the carbon release from urban ecosystem respiration is reduced by evaporative cooling in humid climate, but promoted in arid/semi-arid regions due to increased soil moisture. The irrigation-induced environmental co-benefit in heat and carbon mitigation is, in general, positively correlated with urban greening fraction and has the potential to help counteract climate-carbon feedback in the built environment.

Linkages between the concept of nature-based solutions and the notion of landscape

As the effects of Nature-based solutions (NBS) application are usually much broader than only the area under the project implementation, it is necessary to capture the impact on these actions of landscape as well as the influence of landscape type on the NBS effectiveness. The main aim of this study was to detect linkages between the operational of NBS and the landscape dimention, based on a systematic literature review. The results showed the existence of seven linkages: (1, 2) 'input' and 'output' resulting from the consideration of landscape as a scale of NBS implementation; (3, 4) 'stimulator' and 'inspiration' based on the contribution of landscape-based management to the implementation of NBS; (5) 'co-beneficiary' since the implementation of NBS affects aesthetic dimensions of landscape; (6) 'tool' as landscape-based indicators are used to assess the impacts of NBS; and (7) 'foundation' as health-supporting landscapes may be considered as a type of NBS action.

Projected income data under different shared socioeconomic pathways for Washington state

High-resolution income projections under different Shared Socioeconomic Pathways (SSPs) are essential for the climate change research communities to devise climate change adaptation and mitigation strategies. To generate income projections for Washington state, we obtain state-level GDP per capita projections and convert them into projected annual household income. The resulting state-level income projections are subsequently downscaled to the census block-level based on the Longitudinal Origin-Destination Employment Statistics (LODES) dataset. For accuracy assessment, we downscale historical income data from state- level to block- and block group-level and compare the downscaled results against the actual income data from LODES. County-level accuracy assessment is also conducted based on American Community Survey. The results demonstrate a good agreement (Average R2 of 0.67, 0.8, and 0.99 for block-, block group-, and county-level, respectively) between the downscaled income data and the reference data, thereby validating the methodology employed. Our approach is applicable to other states for income projections, which can be utilized by a broader audience, including those involved in demographic analysis, economic research, and urban planning.

Mitigating the effects of climate change in children's outdoor play environments

BACKGROUND

For many children, public playgrounds represent environments that are playful and important in developing good health. Without efforts to facilitate climate change adaptation of outdoor playgrounds there may be a negative impact on children's health and well-being.

AIM

With a special focus on play value, to explore the reasoning and described strategies among professionals responsible for development, planning and solutions concerning outdoor playgrounds in the context of climate change.

MATERIALS AND METHODS

Eight semi-structured interviews were held with purposefully selected interviewees. Analysis was conducted with manifest content analysis.

RESULTS

Four themes with supporting categories; 1: a new design paradigm for outdoor play environments, 2: a need for updated regulation- and security guidelines for outdoor play environments, 3: nature-based play environments are more climate change resilient, and 4: maintenance and construction of nature-based outdoor play environments. The findings showed an overall awareness and a will to use innovative and nature-based strategies and planning to deal with climate change implications for outdoor play environments.

CONCLUSIONS AND SIGNIFICANCE

The findings suggest that the strategies employed lean towards implementation of increased ecosystem services and natural elements. Ensuring strengthened resilience against hazardous climate change effects may positively facilitate diverse play activities with high play value.

Pluvial flood adaptation using nature-based solutions: An integrated biophysical-economic assessment

Globally, flood events are considered the costliest natural hazard. Changes in precipitation patterns and large areas of impervious surfaces in urban environments are increasing the sensitivity of these systems to runoff production. At the same time, projected global sea-level rise may further increase the frequency of compound flooding due to simultaneous storm surge, sea-level rise and pluvial runoff that cause vast socio-economic and ecological impacts to coastal cities. In this context, over the last decade, the role of Nature-Based Solutions (NBS) has been recognised to support climate change adaptation by addressing ideas of multi-functionality, non-linearity and heterogeneity in urban design. Thus, increasing awareness about NBS benefits increases the willingness to accept these solutions. However, empirical evidence of NBS effectiveness at the urban catchment scale is still subject to debate. This study develops a spatial biophysical-economic framework that allows for the integrated assessment of NBS flood risk mitigation impacts, costs and benefits in the face of climate change, combining the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, benefit transfer methods and Geographic Information System (GIS) tools. Specifically, the InVEST Urban Flood Risk Mitigation model was used to assess the biophysical impacts of NBS on urban pluvial flood risk, benefit-transfer methods were used to evaluate the economic implications of such solutions, and GIS was used to integrate and map biophysical impacts and economic implications. For the case of the coastal lagoon city of Aveiro (Portugal), NBS scenarios of green roofs and bioswales under current and future climate conditions were assessed. The main findings of this study show that green roofs scenarios would save 32 % of the flood damages to buildings and infrastructures every year, while bioswales help save only 0.1 %. Moreover, green roofs implementation provides larger benefits in the future climate scenario (representative concentration pathway - RCP - 4.5). The findings confirm the extent to which knowledge on NBS benefits and costs is partial and uncertain, thus requiring constant progress through biophysical-economic assessment to support an evolutive decision making process in climate adaptation planning.

Proposed solutions to anthropogenic climate change: A systematic literature review and a new way forward

Humanity is now facing what may be the biggest challenge to its existence: irreversible climate change brought about by human activity. Our planet is in a state of emergency, and we only have a short window of time (7-8 years) to enact meaningful change. The goal of this systematic literature review is to summarize the peer-reviewed literature on proposed solutions to climate change in the last 20 years (2002-2022), and to propose a framework for a unified approach to solving this climate change crisis. Solutions reviewed include a transition toward use of renewable energy resources, reduced energy consumption, rethinking the global transport sector, and nature-based solutions. This review highlights one of the most important but overlooked pieces in the puzzle of solving the climate change problem - the gradual shift to a plant-based diet and global phaseout of factory (industrialized animal) farming, the most damaging and prolific form of animal agriculture. The gradual global phaseout of industrialized animal farming can be achieved by increasingly replacing animal meat and other animal products with plant-based products, ending government subsidies for animal-based meat, dairy, and eggs, and initiating taxes on such products. Failure to act will ultimately result in a scenario of irreversible climate change with widespread famine and disease, global devastation, climate refugees, and warfare. We therefore suggest an "All Life" approach, invoking the interconnectedness of all life forms on our planet. The logistics for achieving this include a global standardization of Environmental, Social, and Governance (ESG) or similar measures and the introduction of a regulatory body for verification of such measures. These approaches will help deliver environmental and sustainability benefits for our planet far beyond an immediate reduction in global warming.

Analysis of the relationship between supply-demand matching of selected ecosystem services and urban spatial governance: a case study of Suzhou, China

The mismatch between the supply and demand of ecosystem services has become a critical cause of the decline of urban ecological security. Studying the supply-demand matching of ecosystem services and exploring its association with urban spatial governance are imperative for ensuring sustainable urbanization. Taking Suzhou City as a case, the supply and demand values and matching degrees of five selected ecosystem services were assessed. Additionally, we explored the relationship between ecosystem services and urban spatial governance, with a focus on urban functional zoning. The findings indicate that first, the supply value of water production, food production, carbon sequestration, and tourism and leisure fall short of the demand value, while the supply value of air purification exceeds the demand value. The spatial matching of supply and demand shows a typical circular structure, with areas in short supply predominantly located in the downtown area and its vicinity. Second, the degree of coupling coordination between the supply-demand ratio of selected ecosystem services and the intensity of ecological control is low. Urban functional zoning can affect the supply-demand relationship of selected ecosystem services, and intensified development efforts can exacerbate the mismatch between supply and demand. Third, research on the supply-demand matching of selected ecosystem services can facilitate the assessment and regulation of urban functional zoning. Urban spatial governance can be regulated based on land use, industry, and population, with a focus on achieving a better supply-demand matching of ecosystem services. Through the analysis, this paper is aimed to provide reference for mitigating urban environmental problems and formulating sustainable urban development strategies.

Climate change adaption strategies in urban communities: new evidence from Islamabad, Pakistan

Pakistan is urbanizing at the fastest pace in South Asia, and if left unplanned, it will not only reduce adaptive capacity of its residents rather it will be a chaos for its residents. The aim of this study is to answer the question on how urbanites of Pakistan are coping with climate change and which part of the society required support to cope with changing climate? To answer this questions, this study conducted survey through a structured questionnaire, from the urban residents of Islamabad, to explore their coping mechanisms towards climate change. Survey collected information on demographic, social, economic, and physical aspects, using Hackman's Treatment effect model. The sample selection equation is conditional on the adaptations to climate change in the outcome equation. Main independent variables are income, age, education, and occupation. Selection equation is based on perceptions of individuals about climate change which contains dependent variables of changes in temperature of summers and winters, changes in rain fall pattern, fog, hailstorm, and information received from social media and peer groups. With the result of 57.55, the Wald test shows that overall, there exists goodness of fit at the 99 percent confidence level. The value of rho in the Heckman model is 0.40 which implies the Heckman model provides more consistent and more efficient estimates. The results are suggesting that increasing age enhances the likelihood of adaptations as the positive and significant coefficient of age implies that age has probability to adapt to climate change. The positive and significant coefficient of income, education, and occupation implies that urbanites have higher probability to adapt to climate change. Perception is the essential foundation of adaptation, and differences in perception can be transferred to the adapted strategies. Households that experience a greater variation in annual mean temperature are more likely to adopt any adaptation strategy to cope with climate change. Essentially, poverty encompasses the majority of the characteristics that reduce respondents' adaptation capacity and increase their susceptibility to climate change. The major contextual disparities were discovered across union councils in the form of financial, personal, social, physical, and natural capitals of families. Therefore, obligation is on government to offer greater support for individuals who are less affluent in terms of these assets. For this city, officials must offer subsidy schemes to less privileged and marginalized people of urban dwellers to enhance their adaptive capacity.

Indicators for climate change-driven urban health impact assessment

Climate change can cause multiply potential health issues in urban areas, which is the most susceptible environment in terms of the presently increasing climate volatility. Urban greening strategies make an important part of the adaptation strategies which can ameliorate the negative impacts of climate change. It was aimed to study the potential impacts of different kinds of greenings against the adverse effects of climate change, including waterborne, vector-borne diseases, heat-related mortality, and surface ozone concentration in a medium-sized Hungarian city. As greening strategies, large and pocket parks were considered, based on our novel location identifier algorithm for climate risk minimization. A method based on publicly available data sources including satellite pictures, climate scenarios and urban macrostructure has been developed to evaluate the health-related indicator patterns in cities. The modelled future- and current patterns of the indicators have been compared. The results can help the understanding of the possible future state of the studied indicators and the development of adequate greening strategies. Another outcome of the study is that it is not the type of health indicator but its climate sensitivity that determines the extent to which it responds to temperature rises and how effective greening strategies are in addressing the expected problem posed by the factor.

Controlling air pollution by lowering methane emissions, conserving natural resources, and slowing urbanization in a panel of selected Asian economies

The destruction of the earth’s ecosystems is the most pressing issue globally. Carbon emissions account for nearly half of global air pollution. Methane is the primary source of ground-level ozone and a significant source of greenhouse gases (GHGs), with greater warming potential than carbon dioxide emissions. The study examines the impact of the different methane emissions (released by agriculture, energy, and industrial sectors), urbanization, natural resource depletion, and livestock production on carbon emissions in the panel of selected Asian countries for the period of 1971 to 2020. The results show that energy associated methane emissions, livestock production, natural resource depletion, and urbanization are the main detrimental factors of environmental degradation across countries. The causality estimates show the unidirectional relationship running from livestock production and agriculture methane emissions to carbon emissions, from total methane emissions and carbon emissions to urbanization and from urbanization to energy methane emissions and livestock production. The forecasting estimates suggest that total methane emissions, natural resource depletion, and urbanization will likely increase carbon emissions over the next ten years. The study concludes that the energy sector should adopt renewable energy sources in its production process to minimize carbon emissions. Urbanization and excessive resource exploitation must be curtailed to attain carbon neutrality.

Between Participatory Approaches and Politics, Promoting Social Innovation in Smart Cities: Building a Hum–Animal Smart City in Lucca

In recent decades, the interest in social innovation and nature-based solutions has spread in scientific articles, and they are increasingly deployed for cities’ strategic planning. In this scenario, participatory approaches become pivotal to engaging the population and stakeholders in the decision-making process. In this paper, we reflect on the first year’s results and the strengths and weaknesses—of the participatory activities realized in Lucca to co-design and co-deploy a smart city based on human–animal relationships in the framework of the European project Horizon 2020 (IN-HABIT). Human–animal bonds, as nature-based solutions, are scientifically and practically underestimated. Data were collected on the activities organized to implement a public–private–people partnership in co-designing infrastructural solutions (so-called Animal Lines) and soft nature-based solutions to be implemented in the city. Stakeholders actively engaged in mutual discussions with great enthusiasm, and the emergent ideas (the need to improve people’s knowledge of animals and develop a map showing pet-friendly services and places and the need for integration to create innovative pet services) were copious and different while showing many connections among the various points of view. At the same time, a deeper reflection on the relationships among the participatory activities and institutionally integrated arrangements also emerged.

Urban Resource Assessment, Management, and Planning Tools for Land, Ecosystems, Urban Climate, Water, and Materials—A Review

Increasing awareness of global and local climate change and the limited resources of land, surface, water, raw materials, urban green spaces, and biodiversity alter the exigencies of urban development. Already perceivable local climate changes such as heavy rains, droughts, and urban heat islands urge planners to take action. Particularly in densely populated areas, conflicting interests are pre-programmed, and decision making has to include multiple impacts, mutual competition, and interaction with respect to investments into provisioning services. Urban planners and municipal enterprises increasingly work with digital tools for urban planning and management to improve the processes of identifying social or urbanistic problems and redevelopment strategies. For this, they use 2D/3D city models, land survey registers, land use and re-/development plans or other official data. Moreover, they increasingly request data-based planning tools to identify and face said challenges and to assess potential interventions holistically. Thus, this contribution provides a review of 51 current tools. Simple informational tools, such as visualizations or GIS viewers, are widely available. However, databases and tools for explicit and data-based urban resource management are sparse. Only a few focus on integrated assessment, decision, and planning support with respect to impact and cost assessments, real-time dashboards, forecasts, scenario analyses, and comparisons of alternative options.

A transformative mission for prioritising nature in Australian cities

Australia is experiencing mounting pressures related to processes of urbanisation, biodiversity loss and climate change felt at large in cities. At the same time, it is cities that can take the leading role in pioneering approaches and solutions to respond to those coupling emergencies. In this perspective piece we respond to the following question: What are the required transformations for prioritising, valuing, maintaining and embracing nature in cities in Australia? We adopt the mission framework as an organising framework to present proposed pathways to transform Australian cities as nature-positive places of the future. We propose three interconnected pathways as starting actions to steer urban planning, policy and governance in Australian cities: First, cities need to establish evidence-based planning for nature in cities and mainstream new planning tools that safeguard and foreground urban nature. Second, collaborative planning needs to become a standard practice in cities and inclusive governance for nature in cities needs to prioritise Aboriginal knowledge systems and practices as well as look beyond what local governments can do. Third, for progressing to nature-positive cities, it is paramount to empower communities to innovate with nature across Australian cities. Whilst we focus on Australian cities, the lessons and pathways are broadly applicably globally and can inspire science-policy debates for the post COP15 biodiversity and COP26 climate change implementation processes.

Principles for urban nature-based solutions

Nature-based solutions (NBS) were introduced as integrated, multifunctional and multi-beneficial solutions to a wide array of socio-ecological challenges. Although principles for a common understanding and implementation of NBS were already developed on a landscape scale, specific principles are needed with regard to an application in urban areas. Urban areas come with particular challenges including (i) spatial conflicts with urban system nestedness, (ii) specific urban biodiversity, fragmentation and altered environments, (iii) value plurality, multi-actor interdependencies and environmental injustices, (iv) path-dependencies with cultural and planning legacies and (v) a potential misconception of cities as being artificial landscapes disconnected from nature. Given these challenges, in this perspective paper, we build upon and integrate knowledge from the most recent academic work on NBS in urban areas and introduce five distinct, integrated principles for urban NBS design, planning and implementation. Our five principles should help to transcend governance gaps and advance the scientific discourse of urban NBS towards a more effective and sustainable urban development. To contribute to resilient urban futures, the design, planning, policy and governance of NBS should (1) consider the need for a systemic understanding, (2) contribute to benefiting people and biodiversity, (3) contribute to inclusive solutions for the long-term, (4) consider context conditions and (5) foster communication and learning.

Transformative low-carbon urban innovations: Operationalizing transformative capacity for urban planning

Cities can set in motion sustainability transitions through experimentation and innovation. To invest in and mainstream solutions that contribute to urban transformation agendas, urban planners needs to understand which innovations have transformational potential as well as how these innovations can accelerate sustainability transitions. In order to explore this, existing frameworks of transformative capacity provide the guidance, but they are generic, abstract, and challenging to apply for urban planning. As part of our effort to develop a more operational version of the transformative capacity framework by Wolfram (2016), we conducted a systematic scoping review of the academic literature to determine the characteristics of people-based and nature-based low-carbon innovations that constitutes their transformative capacity. After reviewing 65 records, we identified dimensions indicating each of the transformative capacity components through analysis and synthesis. Besides contributing to the science-policy interface through a knowledge synthesis on low-carbon people-based and nature-based innovations, this paper examines bridging frameworks to inform urban planners in developing practical solutions and actionable elements for low-carbon urban futures.

Perception of Ecosystem Services and Adaptation to Climate Change: Mirador Sur Park in Santo Domingo

The rapid urbanization of cities has resulted in the deterioration of urban forests and the loss of important benefits from green infrastructure, such as the removal of Greenhouse Gases (GHG) and carbon sequestration. The Mirador Sur Park is one of the main green spaces in the city of Santo Domingo. The objective of this research was to identify citizen participation in the design and management of urban forests as a strategy for guiding cities towards a more sustainable and resilient model in the face of climate change. In this study, changes in the park’s land use were identified, 136 park users were interviewed to find out their perception of the benefits of forest cover, and the ecosystem services of Mirador Sur Park were quantified using the i-Tree Canopy tool. It was found that the ecosystem services related to the removal of atmospheric pollutants are clearly perceived by the users of the park. However, there are other services that could not be identified if there is no relationship with the users of the park, such as those related to the benefits of human well-being. Citizens’ perception and appropriation are important elements for the co-management of the park, and it would be appropriate for them to become involved in the design and implementation of environmental public policies, as well as nature-based solutions, that contribute to adequate and inclusive urban planning aimed at adapting to climate change.

How do we best synergize climate mitigation actions to co-benefit biodiversity?

A multitude of actions to protect, sustainably manage and restore natural and modified ecosystems can have co-benefits for both climate mitigation and biodiversity conservation. Reducing greenhouse emissions to limit warming to less than 1.5 or 2°C above preindustrial levels, as outlined in the Paris Agreement, can yield strong co-benefits for land, freshwater and marine biodiversity and reduce amplifying climate feedbacks from ecosystem changes. Not all climate mitigation strategies are equally effective at producing biodiversity co-benefits, some in fact are counterproductive. Moreover, social implications are often overlooked within the climate-biodiversity nexus. Protecting biodiverse and carbon-rich natural environments, ecological restoration of potentially biodiverse and carbon-rich habitats, the deliberate creation of novel habitats, taking into consideration a locally adapted and meaningful (i.e. full consequences considered) mix of these measures, can result in the most robust win-win solutions. These can be further enhanced by avoidance of narrow goals, taking long-term views and minimizing further losses of intact ecosystems. In this review paper, we first discuss various climate mitigation actions that evidence demonstrates can negatively impact biodiversity, resulting in unseen and unintended negative consequences. We then examine climate mitigation actions that co-deliver biodiversity and societal benefits. We give examples of these win-win solutions, categorized as 'protect, restore, manage and create', in different regions of the world that could be expanded, upscaled and used for further innovation.

Facing Multiple Environmental Challenges through Maximizing the Co-Benefits of Nature-Based Solutions at a National Scale in Italy

The European Union is significantly investing in the Green Deal that introduces measures to guide Member States to face sustainability and health challenges, especially employing Nature-Based Solutions (NBS) in urban contexts. National governments need to develop appropriate strategies to coordinate local projects, face multiple challenges, and maximize NBS effectiveness. This paper aims to introduce a replicable methodology to integrate NBS into a multi-scale planning process to maximize their cost–benefits. Using Italy as a case study, we mapped three environmental challenges nationwide related to climate change and air pollution, identifying spatial groups of their co-occurrences. These groups serve as functional areas where 24 NBS were ranked for their ecosystem services supply and land cover. The results show eight different spatial groups, with 6% of the national territory showing no challenge, with 42% showing multiple challenges combined simultaneously. Seven NBS were high-performing in all groups: five implementable in permeable land covers (urban forests, infiltration basins, green corridors, large parks, heritage gardens), and two in impervious ones (intensive, semi-intensive green roofs). This work provides a strategic vision at the national scale to quantify and orient budget allocation, while on a municipal scale, the NBS ranking acts as a guideline for specific planning activities based on local issues.

Urban Resilience for Urban Sustainability: Concepts, Dimensions, and Perspectives

Urbanization is a continuous process for a city’s economic development. Though rapid urbanization provides a huge employment opportunity for people, urban threats also increase proportionately due to natural and man-made hazards. Understanding urban resilience and sustainability is an urgent matter to face hazards in the rapidly urbanized world. Therefore, this study aims to clarify the concept and develop key indications of urban resilience and sustainability from the existing literature. A systematic literature review guided by PRISMA has been conducted using literature from 1 January 2001 to 30 November 2021. It argues that sustainability and resilience are interrelated paradigms that emphasize a system’s capacity to move toward desirable development paths. Resilience and sustainability are fundamentally concerned with preserving societal health and well-being within the context of a broader framework of environmental change. There are significant differences in their emphasis and time scales, particularly in the context of urbanization. This study has identified key indicators of urban resilience under three major components like adaptive capacity (education, health, food, and water), absorptive capacity (community support, urban green space, protective infrastructure, access to transport), and transformative capacity (communication technology, collaboration of multi-stakeholders, emergency services of government, community-oriented urban planning). This study also identified several indicators under major dimensions (social, economic, and environmental) of urban sustainability. The findings will be fruitful in understanding the dynamics of urban vulnerability and resilience and its measurement and management strategy from developed indicators.

Nature-Based Solutions Benefit the Economic–Ecological Coordination of Pastoral Areas: An Outstanding Herdsman’s Experience in Xilin Gol, China

Grassland has always had a difficult economic–ecological relationship, as coordination between its ecological conservation and the sustainable development of animal husbandry is required. Nature-based Solutions (NbS), who make full use of the natural ecosystem services, have successfully solved some economic–ecological issues, but still have unclear implementation prospects for grassland management. The Xilin Gol grassland is one of the most typical pastoral areas in China; there is a village chief named Bateer, who has already used NbS for grassland management. To confirm whether the solutions employed by Bateer have been effective for both increasing economic profits and protecting grassland ecosystem, we interviewed him, and many other herdsmen, using questionnaires about their livelihood. Based on these questionnaires, we calculated and compared their income–cost ratios. Meanwhile, we analyzed the NDVI variations inside their rangelands through high-resolution remote sensing images. The results showed that the herdsmen in Bateer’s village had a much higher disposable income and income–cost ratio than others, and their rangelands also had a higher value and a more obvious increasing trend of NDVI. Bateer’s success proves that the NbS can also play a positive role in grassland management, which can provide a valuable guidance for economic–ecological coordination in pastoral areas.

Nature-Based Solutions in Poland against Climate Change

One of the currently promoted methods of counteracting climate change is nature-based climate solutions, which harness the power of nature to reduce greenhouse gas emissions. Sustainable management of ecosystems is a guarantee for sustained human well-being. This underestimated, but extremely efficient and cheap method of integrating nature resources into the urban fabric is an economic “injection” for communal authorities. These “green” benefits should be standard in land-use planning in the era of anthropocentrism. Solutions based on nature were the reason for investigating their perception by Polish municipalities. The survey covered the entire country (all 2477 municipalities) from 20 July to 31 August 2021 through an electronic survey, obtaining 2128 responses (85.9% return rate). In the final result, data were obtained that support the hypotheses posed in the study. The main objective of the research was to check the level of activity of municipalities in Poland in the field of proecological activities using nature-based solutions (NbS). The survey results confirmed little knowledge of nature-based solutions, at the same time giving it an educational dimension. Half of the respondents declared that they learned about NbS only from the survey. Polish decision makers and municipal authorities introduce some solutions based on nature without being aware of their European classification and adequate nomenclature. Environmental awareness in Poland remains largely the domain of urban municipalities, with higher current budget revenues per capita and in the central and western parts of the country. NbS are marginal in rural municipalities, which can be explained by the lack of ecological specialists, less car traffic and more single-family houses and thus modest public areas. The following surveys covering the entire territory of Poland are the first to be carried out on such a large scale.

Integrating ecosystem services into sustainable landscape management: A collaborative approach

The Paiva River is considered one of the least polluted rivers in Europe and its watershed has a high conservation value. However, the Paiva River basin suffers pressures related with recurrent disturbances in land use, such as forest fires, agricultural activities, urbanization and pressures that affect the natural hydromorphological conditions and the continuity of watercourses. Blue and Green Infrastructures (BGINs) emerge to improve biodiversity, sustainability and the supply of ecosystem services while improving socioeconomic aspects. Thus, this article aims to identify priority areas in the basin, for intervention with these infrastructures. For that, a spatial multicriteria decision analysis (MDCA) was carried out according to several data related to the Paiva River Basin. As local politicians and responsible entities for the natural resources management are the main experts on the problems and their possible solutions at the local level, they were involved in this decision-making model. Therefore, these specialized stakeholders did the weighting assignment according to the most or least importance of the same for the work. The map of priority locations to implement BGINs was obtained in the sequel. To the top 5 priority areas, stakeholders attributed the best solutions based on nature. The most recommended BGINs were recovery/maintenance of riparian vegetation and conservation and reforestation of the native forest, both presented in four of the five areas, and introduction of fuel management strips presented in three of the five areas. Thus, we concluded that it is extremely important to include the communities and the competent entities of nature and environment management in scientific projects related to conservation, forming a synergy that makes it possible to combine scientific knowledge with local experience acquired in the field. This project uses a very flexible methodology of local data and can be a great example to be implemented in other hydrographic basins anywhere in the world.

Development and Assessment of a Web-Based National Spatial Data Infrastructure for Nature-Based Solutions and Their Social, Hydrological, Ecological, and Environmental Co-Benefits

Comprehensive datasets for nature-based solutions (NBS), and their diverse relationships have not yet been accumulated into a deployable format. This research describes the development of a novel National Spatial Data Infrastructure (NSDI) system for NBS co-benefits throughout the contiguous United States. Here, we gather and integrate robust geospatial datasets from the social, ecological, environmental, and hydrologic domains using seamless, cloud-based data services to facilitate the trans-disciplinary assessment of NBSs as a function of society and Earth. This research enhances practical decision making and research by assimilating web-based datasets and describing the missing links between national policy and robust adoption of NBSs as a sustainability solution. This NSDI serves to foster participatory planning capabilities and integrate local sustainability goals into decision–support frameworks. Such a platform strengthens the knowledge base necessary for addressing multiple, co-evolving issues of societal relevance, an essential component of fully espousing NBSs within the realm of socio-technological systems and improving policies and implementation regarding sustainable solutions. The efficacy of the proposed platform to serve as a holistic data information system is assessed by exploring important characteristics associated with geospatial NSDI tools, namely, openness, spatial functionality, scalability, and standardization. By placing GIS strengths and weaknesses in the context of transdisciplinary NBSs, we reveal strategic directions toward further co-production of such NSDIs. We conclude with recommendations for facilitating a shared vision of transdisciplinary technologies to strengthen the amalgamation of broad co-benefits and multi-disciplinary influences in sustainability planning.

A new evaluation framework for nature-based solutions (NBS) projects based on the application of performance questions and indicators approach

One of the key features of nature-based solutions (NBSs) is their high effectiveness and economic and resource efficiency in solving problems compared to traditional grey interventions. These aspects, however, have so far attracted little attention in the literature but should be considered, as the evaluation of NBS projects before implementation provides an opportunity to use them as practical tools. This paper aims to present a new evaluation framework of NBS projects (at the stage of solution selection) based on the application of performance questions and the indicators approach. The framework consists of three main stages: (1) the formulation of the project aim(s), including the problem(s) to be solved, the scales of the expected effects and the thresholds to be achieved; (2) the elimination of solutions that do not fit the local conditions and setting requirements; and (3) the examination of the performance questions. To consider the whole spectrum of influencing factors, a systematic review was performed to indicate the main concepts related to the issue of NBS effectiveness, including (1) stakeholders' participation, (2) policy and management capability, (3) economic efficiency, (4) analysis of synergies and trade-offs, (5) adaptation to local conditions, (6) adequate spatial scale and (7) performance in the long term. In the current study around 130 indicators were identified for the evaluation of NBS projects. Regarding the impact on the state of knowledge, the present work contributes to the discussion on the conceptual sphere of NBS and its practical implementation by introducing multi-perspective standards and guidelines for the selection of possible NBS projects, and it deals with the complexity of synergies and the trade-offs between benefits.

A framework for catalysing the rapid scaling of urban biodiversity stewardship programs

Despite growing interest in promoting urban biodiversity conservation, there are few concrete examples of how nature stewardship initiatives can be rapidly scaled, in number and across landscapes. This paper explores the factors that promote or inhibit the proliferation and impact of collaborations between citizens and their local governments that involve residents in municipal biodiversity conservation efforts in their gardens (wildlife gardening). We studied the Gardens for Wildlife Victoria network in Australia, which supports citizen-agency co-development of municipal wildlife gardening programs. In three years the network has expanded from one program to 39 initiatives in various developmental stages in 49% of the local government areas in the state of Victoria. Data are drawn from 21 semi-structured interviews of network participants running or developing programs in 12 municipalities, complemented by a survey of 33 network participants, and participants' evaluation of network workshops. We find that scaling occurs in four different domains of policy, values, locales and participants. Scaling is influenced by six interlinked factors: empowerment of actors; a civil-agency co-design and delivery model; conservation framing; links to and between landscapes and communities; resources - particularly time; and the network's role in promoting innovation and shared learning. Key barriers include short-term, top-down, and monetary agency foci; conservation framed as the principal domain of specialists and professionals; and prioritisation of listed species rather than local species more broadly. We present a framework for considering scaling of biodiversity stewardship and related factors.

Planning nature-based solutions: Principles, steps, and insights

Nature-based solutions (NBS) find increasing attention as actions to address societal challenges through harnessing ecological processes, yet knowledge gaps exist regarding approaches to landscape planning with NBS. This paper aims to provide suggestions of how planning NBS can be conceptualized and applied in practice. We develop a framework for planning NBS by merging insights from literature and a case study in the Lahn river landscape, Germany. Our framework relates to three key criteria that define NBS, and consists of six steps of planning: Co-define setting, Understand challenges, Create visions and scenarios, Assess potential impacts, Develop solution strategies, and Realize and monitor. Its implementation is guided by five principles, namely Place-specificity, Evidence base, Integration, Equity, and Transdisciplinarity. Drawing on the empirical insights from the case study, we suggest suitable methods and a checklist of supportive procedures for applying the framework in practice. Taken together, our framework can facilitate planning NBS and provides further steps towards mainstreaming.

Governance models for nature-based solutions: Seventeen cases from Germany

Nature-based solutions (NBS) for mitigating climate change are gaining popularity. The number of NBS is increasing, but research gaps still exist at the governance level. The objectives of this paper are (i) to give an overview of the implemented NBS for flood risk management and mitigation in Germany, (ii) to identify governance models that are applied, and (iii) to explore the differences between these models. The results of a hierarchical clustering procedure and a qualitative analysis show that while no one-size-fits-all governance model exists, polycentricism is an important commonality between the projects. The study concludes by highlighting the need for further research on traditional governance model reconversion and paradigm changes. We expect the findings to identify what has worked in the past, as well as what is important for the implementation of NBS for flood risk management in future projects.

Reviewing financing barriers and strategies for urban nature-based solutions

Obtaining public and/or private finance for upscaling urban nature-based solutions (NBS) is a key barrier for reaching urban sustainability goals, including climate mitigation and adaptation. We carry out a systematic review of the academic literature to understand the key barriers and corresponding strategies for financing urban NBS. First, we report on specific financing challenges and strategies found for NBS uptake in four urban ecological domains: buildings, facades and roofs; urban green space (parks, trees); allotment gardens (including urban agriculture); and green-blue infrastructure. Across domains, we identify two overarching barriers of NBS finance: (1) coordination between private and public financiers and (2) integration of NBS benefits into valuation and accounting methods. We discuss strategies found in the literature that address these barriers; here, two things stand out. One, there is a large variety of valuation strategies that does not yet allow for an integrated accounting and valuation framework for NBS. Two, strategies aimed at coordinating public/private finance generally look for ways to encourage specific actors (real estate developers, residents) that benefit privately from an NBS to provide co-financing. We visualize our findings into a framework for enabling (public and/or private) finance for upscaling urban NBS.

Nature-Based Urbanization: Scan Opportunities, Determine Directions and Create Inspiring Ecologies

To base urbanization on nature, inspiring ecologies are necessary. The concept of nature-based solutions (NBS) could be helpful in achieving this goal. State of the art urban planning starts from the aim to realize a (part of) a city, not to improve natural quality or increase biodiversity. The aim of this article is to introduce a planning approach that puts the ecological landscape first, before embedding urban development. This ambition is explored using three NBS frameworks as the input for a series of design workshops, which conceived a regional plan for the Western Sydney Parklands in Australia. From these frameworks, elements were derived at three abstraction levels as the input for the design process: envisioning a long-term future (scanning the opportunities), evaluating the benefits and disadvantages, and identifying a common direction for the design (determining directions), and implementing concrete spatial cross-cutting solutions (creating inspiring ecologies), ultimately resulting in a regional landscape-based plan. The findings of this research demonstrate that, at every abstraction, a specific outcome is found: a mapped ecological landscape showing the options for urbanization, formulating a food-forest strategy as the commonly found direction for the design, and a regional plan that builds from the landscape ecologies adding layers of productive ecologies and urban synergies. By using NBS-frameworks, the potentials of putting the ecological landscape first in the planning process is illuminated, and urbanization can become resilient and nature-inclusive. Future research should emphasize the balance that should be established between the NBS-frameworks and the design approach, as an overly technocratic and all-encompassing framework prevents the freedom of thought that is needed to come to fruitful design propositions.

Nature-Based Solutions Tools for Planning Urban Climate Adaptation: State of the Art

Despite the recognized potential of nature-based solutions (NBSs) to support climate adaptation, there are still wide barriers for a wider uptake of such NBS in urban areas. While tailored NBS tools could facilitate and accelerate this process, a comprehensive mapping of their availability and capacity to respond to cities’ challenges is missing. This research aims to provide an overview of tools that intend to facilitate the uptake of NBS for urban climate adaptation supporting cities in overcoming their challenges. To do so, this paper (i) presents the results of interviews and workshops with municipal officers and decision-makers from different European cities that identified the challenges they experience with NBS uptake; (ii) selects and reviews NBS tools and (iii) analyzes them on their capacity to address these implementation challenges. Our research revealed four key challenges that municipal officers experience: resources availability; level of expertise, know-how or competence; the institutional setting, and collaborative governance and planning. The results from the tools’ review show that existing tools can support overcoming a lack of expertise (31), but, to a smaller extent, can also be of use when experiencing the institutional setting (13), availability of resources (11), and collaborative governance and planning (10) as a challenge. This work provides researchers and tool developers with insights into potential market saturation as well as scarcity of certain types of tools that would match cities’ challenges, highlighting needs and opportunities for new tool development.

Diurnal evolution of urban tree temperature at a city scale

Despite the importance of urban trees’ surface temperature in assessing micro-climate interactions between trees and the surrounding environment, their diurnal evolution has been largely understudied at a city-wide scale due to a lack of effective thermal observations. By downscaling ECOSTRESS land surface temperature imaginary over New York City, we provide the first diurnal analysis of city-scale canopy temperature. Research reveals a remarkable spatial variation of the canopy temperature during daytime up to 5.6 K (standard deviation, STD), while the nighttime STD remains low at 1.7 K. Further, our analysis shows that the greenspace coverage and distance to bluespaces play an important role in cooling the local canopy during daytime, explaining 25.0–41.1% of daytime spatial variation of canopy temperatures while surrounding buildings modulate canopy temperature asymmetrically diurnally: reduced daytime warming and reduced nocturnal cooling. Built on space-borne observations and a flexible yet robust statistical method, our research design can be easily transferable to explore urban trees’ response to local climate across cities, highlighting the potentials of advancing the science and technologies for urban forest management.

Monitoring and Evaluating Nature-Based Solutions Implementation in Urban Areas by Means of Earth Observation

Climate change influences the vulnerability of urban populations worldwide. To improve their adaptive capacity, the implementation of nature-based solutions (NBS) in urban areas has been identified as an appropriate action, giving urban planning and development an important role towards climate change adaptation/mitigation and risk management and resilience. However, the importance of extensively applying NBS is still underestimated, especially regarding its potential to induce significantly positive environmental and socioeconomic impacts across cities. Concerning environmental impacts, monitoring and evaluation is an important step of NBS management, where earth observation (EO) can contribute. EO is known for providing valuable disaggregated data to assess the modifications caused by NBS implementation in terms of land cover, whereas the potential of EO to uncover the role of NBS in urban metabolism modifications (e.g., energy, water, and carbon fluxes and balances) still remains underexplored. This study reviews the EO potential in the monitoring and evaluation of NBS implementation in cities, indicating that satellite observations combined with data from complementary sources may provide an evidence-based approach in terms of NBS adaptive management. EO-based tools can be applied to assess NBS’ impacts on urban energy, water, and carbon balances, further improving our understanding of urban systems dynamics and supporting sustainable urbanization.

Mapping the Research Landscape of Nature-Based Solutions in Urbanism

Nature-based solutions (NBS) are an innovative concept that mimics the processes of natural ecosystems, popularized principally in the European Union. With a substantial body of literature amassed since the term’s inception in 2015, there is a need to systematically review existing literature to identify overarching gaps and trends, according to disciplinary focus, geographic scope, and key themes, and direct future research inquiry and policy recommendations. This review consists of bibliometric analysis and thematic analysis for NBS studies in urbanism. NBS studies were found to relate strongly with other concepts of ‘Ecosystem Services’, ‘Green Infrastructure’, ‘Climate Change’, and ‘Risk management and Resilience’, which align with four major thematic goals set by the European Commission. Within NBS scholarship, various sub-themes have emerged, namely, ‘Greening’, ‘Urban Development’, ‘Water’, ‘Wellbeing’, and ‘Governance’. Furthermore, we illustrate that the amount and thematic focus of NBS research have been unevenly distributed worldwide. Analysis of emerging trends shows a recent increase in topics, such as adaptive governance of NBS, and the incorporation of social justice in sustainability transitions. Based on an assessment of extant NBS literature, we offer some recommendations for the future direction of the research fields.

Valuing the Invaluable(?)—A Framework to Facilitate Stakeholder Engagement in the Planning of Nature-Based Solutions

Nature-based solutions (NBS) have emerged as an important concept to build climate resilience in cities whilst providing a wide range of ecological, economic, and social co-benefits. With the ambition of increasing NBS uptake, diverse actors have been developing means to demonstrate and prove these benefits. However, the multifunctionality, the different types of benefits provided, and the context-specificity make it difficult to capture and communicate their overall value. In this paper, a value-based framework is presented that allows for structured navigation through these issues with the goal of identifying key values and engaging beneficiaries from the public, private, and civil society sector in the development of NBS. Applied methods such as focus groups, interviews, and surveys were used to assess different framework components and their interlinkages, as well as to test its applicability in urban planning. Results suggest that more specialized “hard facts” might be needed to actually attract larger investments of specific actors. However, the softer and more holistic approach could inspire and support the forming of alliances amongst a wider range of urban stakeholders and the prioritization of specific benefits for further assessment. Consequently, it is argued that both hard and soft approaches to nature valuation will be necessary to further promote and drive the uptake of NBS in cities.

Stakeholder Participation in the Planning and Design of Nature-Based Solutions. Insights from CLEVER Cities Project in Hamburg

Cities are essential players in responding to the present complex environmental and social challenges, such as climate change. The nature-based solution (NbS) concept is identified in the scientific discourse and further recognized by the European Commission as a part of the solution to address such challenges. Deploying NbS in urban contexts requires the cooperation of different public and private stakeholders to manage those processes. In this paper, the experiences of establishing and managing NbS-related processes following a co-creation approach in the city of Hamburg within the framework of an EU-funded research project (CLEVER Cities) are described and analyzed. The paper identifies and discusses the main emerging factors and challenges from (1) a procedural and methodological perspective and (2) concerning the different roles of the diverse stakeholders involved. This discussion is grounded in the context of existing regulations and novel concepts for citizens’ participation in urban decision-making processes. As research results, the article defines the leading players involved in the process and their roles and interrelationships, along with recommendations for future policy agendas in cities when dealing with NbS planning.

Creating a National Urban Research and Development Platform for Advancing Urban Experimentation

Transformative changes are required for a 21st century sustainable urban development transition involving multiple interconnected domains of energy, water, transport, waste, and housing. This will necessitate a step change in performance goals and tangible solutions. Regenerative urban development has emerged as a major pathway, together with decarbonisation, climate adaptation involving new blue-green infrastructures, and transition to a new green, circular economy. These grand challenges are all unlikely to be realised with current urban planning and governance systems within a time frame that can mitigate environmental, economic, and social disruption. A new national platform for urban innovation has been envisaged and implemented in Australia that is capable of enabling engagement of multiple stakeholders across government, industry, and community as well as real time synchronous collaboration, visioning, research synthesis, experimentation, and decision-making. It targets large strategic metropolitan, mission-scale transition challenges as well as more tactical neighbourhood-scale projects. This paper introduces the iHUB: National Urban Research and Development Platform, its underlying concepts, and multiple layers of technical (IT/AV), software/analytical, data, and engagement, as envisioned and implemented in Australia’s four largest capital cities and five collaborating foundation universities.

Living Labs—A Concept for Co-Designing Nature-Based Solutions

Living Labs are recognized as a progressive form to foster innovation and the strengthening of collaborative planning. The concept has received strong attention by the European Union (EU) research and innovation agendas recently. This contribution investigates how a Living Lab approach could be used for the design and implementation of Nature-Based Solutions (NBS). NBS are gaining acceptance as a more sustainable solution for reducing the exposure to natural hazards and vulnerability to events, such as increased flooding in changing climate. However, a lack of collaborative approaches hinders their broader implementation. A literature review on the theoretical aspects of the Living Labs concept in the context of NBS is conducted, and we compare the theoretical findings with practices that were observed by case studies implementing NBS in a collaborative manner. The Isar-Plan River Restoration in Munich, Germany, and the Mountain Forest Initiative (Bergwaldoffensive). Both of the case studies have already started well before the concept of Living Labs gained wider popularity. Both award-winning cases are recognized good practice for their exemplary in-depth stakeholder involvement. The paper discusses the concepts and approaches of Living Labs and reflects on how it can serve and support in-depth participatory stakeholder involvement.

Stakeholder Mapping to Co-Create Nature-Based Solutions: Who Is on Board?

Nature-based solutions (NBS) are inspired and supported by nature but designed by humans. Historically, governmental stakeholders have aimed to control nature using a top-down approach; more recently, environmental governance has shifted to collaborative planning. Polycentric governance and co-creation procedures, which include a large spectrum of stakeholders, are assumed to be more effective in the management of public goods than traditional approaches. In this context, NBS projects should benefit from strong collaborative governance models, and the European Union is facilitating and encouraging such models. While some theoretical approaches exist, setting-up the NBS co-creation process (namely co-design and co-implementation) currently relies mostly on self-organized stakeholders rather than on strategic decisions. As such, systematic methods to identify relevant stakeholders seem to be crucial to enable higher planning efficiency, reduce bottlenecks and time needed for planning, designing, and implementing NBS. In this context, this contribution is based on the analysis of 16 NBS and 359 stakeholders. Real-life constellations are compared to theoretical typologies, and a systematic stakeholder mapping method to support co-creation is presented. Rather than making one-fit-all statements about the “right” stakeholders, the contribution provides insights for those “in charge” to strategically consider who might be involved at each stage of the NBS project.

Addressing Challenges of Urban Water Management in Chinese Sponge Cities via Nature-Based Solutions

Urban flooding has become a serious issue in most Chinese cities due to rapid urbanization and extreme weather, as evidenced by severe events in Beijing (2012), Ningbo (2013), Guangzhou (2015), Wuhan (2016), Shenzhen (2019), and Chongqing (2020). The Chinese “Sponge City Program” (SCP), initiated in 2013 and adopted by 30 pilot cities, is developing solutions to manage urban flood risk, purify stormwater, and provide water storage opportunities for future usage. Emerging challenges to the continued implementation of Sponge Cities include (1) uncertainty regarding future hydrological conditions related to climate change projections, which complicates urban planning and designing infrastructure that will be fit for purpose over its intended operating life, and (2) the competing priorities of stakeholders and their reluctance to make trade-offs, which obstruct future investment in the SCP. Nature-Based Solutions (NBS) is an umbrella concept that emerged from Europe, which encourages the holistic idea of considering wider options that combine “Blue–Green” practices with traditional engineering to deliver “integrated systems of Blue–Green–Grey infrastructure”. NBS includes interventions making use of natural processes and ecosystem services for functional purposes, and this could help to improve current pilot SCP practices. This manuscript reviews the development of the SCP, focusing on its construction and design aspects, and discusses how approaches using NBS could be included in the SCP to tackle not only urban water challenges but also a wide range of social and environmental challenges, including human health, pollution (via nutrients, metals, sediments, plastics, etc.), flood risk, and biodiversity.

Exploring trade-offs among the multiple benefits of green-blue-grey infrastructure for urban flood mitigation

Climate change is presenting one of the main challenges to our planet. In parallel, all regions of the world are projected to urbanise further. Consequently, sustainable development challenges will be increasingly concentrated in cities. A resulting impact is the increment of expected urban flood risk in many areas around the globe. Adaptation to climate change is an opportunity to improve urban conditions through the implementation of green-blue infrastructures, which provide multiple benefits besides flood mitigation. However, this is not an easy task since urban drainage systems are complex structures. This work focuses on a method to analyse the trade-offs when different benefits are pursued in stormwater infrastructure planning. A hydrodynamic model was coupled with an evolutionary optimisation algorithm to evaluate different green-blue-grey measures combinations. This evaluation includes flood mitigation as well as the enhancement of co-benefits. We confirmed optimisation as a helpful decision-making tool to visualise trade-offs among flood management strategies. Our results show that considering co-benefits enhancement as an objective boosts the selection of green-blue infrastructure. However, flood mitigation effectiveness can be diminished when extra benefits are pursued. Finally, we proved that combining green-blue-grey measures is particularly important in urban spaces when several benefits are considered simultaneously.

The (Re)Insurance Industry’s Roles in the Integration of Nature-based Solutions for Prevention in Disaster Risk Reduction—Insights from a European Survey

Nature-based solutions (NBS) are increasingly being considered as an option to reduce societies’ vulnerability to natural hazards, creating co-benefits while protecting ecosystem services in a context of changing climate patterns with more frequent and extreme weather events. The reinsurance and insurance industries are increasingly cited as sectors that can play a role to help manage risks, by improving disaster risk reduction (DRR) and loss prevention. This paper investigates how the (re)insurance industry could support the transition from a paradigm focused on ex-post responses to ex-ante risk reduction measures including NBS, in line with the Sendai Framework. This paper presents the results of a series of 61 interviews undertaken with the (re)insurance sector and related actors under the EU H2020 Nature Insurance Value Assessment and Demonstration (NAIAD) project. Methods based on a Grounded Theory approach indicate how this sector can play different roles in loss prevention, including ecosystem-based disaster risk reduction (eco-DRR). Results illustrate how the (re)insurance industry, under these roles, is gradually innovating by having a better understanding of hazards and mitigation. The findings of the study contribute to wider discussions such as the possibility of new arrangements like natural insurance schemes and evidence-based assessment of avoided damage costs from green protective measures, in Europe and beyond.

An Observatory Framework for Metropolitan Change: Understanding Urban Social–Ecological–Technical Systems in Texas and Beyond

In Texas and elsewhere, the looming realities of rapid population growth and intensifying effects of climate change mean that the things we rely on to live—water, energy, dependable infrastructure, social cohesion, and an ecosystem to support them—are exposed to unprecedented risk. Limited resources will be in ever greater demand and the environmental stress from prolonged droughts, record-breaking heat waves, and destructive floods will increase. Existing long-term trends and behaviors will not be sustainable. That is our current trajectory, but we can still change course. Significant advances in information communication technologies and big data, combined with new frameworks for thinking about urban places as social–ecological–technical systems, and an increasing movement towards transdisciplinary scholarship and practice sets the foundation and framework for a metropolitan observatory. Yet, more is required than an infrastructure for data. Making cities inclusive, safe, resilient, and sustainable will require that data become actionable knowledge that change policy and practice. Research and development of urban sustainability and resilience knowledge is burgeoning, yet the uptake to policy has been slow. An integrative and holistic approach is necessary to develop effective sustainability science that synthesizes different sources of knowledge, relevant disciplines, multi-sectoral alliances, and connections to policy-makers and the public. To address these challenges and opportunities, we developed a conceptual framework for a “metropolitan observatory” to generate standardized long-term, large-scale datasets about social, ecological, and technical dimensions of metropolitan systems. We apply this conceptual model in Texas, known as the Texas Metro Observatory, to advance strategic research and decision-making at the intersection of urbanization and climate change. The Texas Metro Observatory project is part of Planet Texas 2050, a University of Texas Austin grand challenge initiative.