Integrating solutions to adapt cities for climate change

Shifting forward: Urban ecology in perspective

The world has become urban; cities increasingly shape our worldviews, relation to other species, and the large-scale, long-term decisions we make. Cities are nature, but they need to align better with other ecosystems to avoid accelerating climate change and loss of biodiversity. We need a science to guide urban development across the diverse realities of global cities. This need can be met, in part, by shifts in urban ecology and its linkages to related sciences. This perspective is a "synthesis of syntheses", consolidating ideas from the other articles in the Special Section. It re-examines the role of urban ecology, and explores its integration with other disciplines that study cities. We conclude by summarizing the next steps in the ongoing shift in urban ecology, which is fast becoming an integral part of urban studies.

Associations between violent crime inside and outside, air temperature, urban heat island magnitude and urban green space

There are more incidents of violence in summer and on hot days, a trend likely to be exacerbated by climate change. Urban areas experience additional temperature modulation due to the urban form, however, to date, no studies have considered the effect of the urban heat island (UHI) or green space with respect to the temperature-violence relationship. This study modelled the relationship between the number of daily violent crime incidents that occurred inside or outside between July 2013 and June 2018, and the average surface UHI or percentage greencover (including grasses, shrubs and trees) within each local government area in Greater Sydney, Australia. Panelised negative binomial time series regression models indicated that the violent crime rate was associated with higher surface UHI for crimes committed outside (p = 0.006) but not inside (p = 0.072). Greater percentage of all vegetation was associated with significantly lower rates of violent crime committed outside (p = 0.011) but was not associated with violent crimes committed inside (p = 0.430). More socio-economic disadvantage was associated with higher rates of violent crime committed inside (p = 0.002) but not outside (p = 0.145). Greater temperature was non-linearly associated with higher rates of violent crime committed both inside and outside (p < 0.001). The findings of this study are important because both violence and heat exposure are critical health issues and will be stressed by urbanisation and climate change. The expansion of green space and/or reduction in UHI may mitigate these effects.

Between flood and drought: How cities are facing water surplus and scarcity

Droughts and floods are weather-related hazards affecting cities in all climate zones and causing human deaths and material losses on all inhabited continents. The aim of this article is to review, analyse and discuss in detail the problems faced by urban ecosystems due to water surplus and scarcity, as well as the need of adaptation to climate change taking into account the legislation, current challenges and knowledge gaps. The literature review indicated that urban floods are much more recognised than urban droughts. Amongst floods, flash floods are currently the most challenging, which by their nature are difficult to monitor. Research and adaptation measures related to water-released hazards use cutting-edge technologies for risk assessment, decision support systems, or early warning systems, among others, but in all areas knowledge gaps for urban droughts are evident. Increasing urban retention and introducing Low Impact Development and Nature-based Solutions is a remedy for both droughts and floods in cities. There is the need to integrate flood and drought disaster risk reduction strategies and creating a holistic approach.

The neighborhood built environment and COVID-19 hospitalizations

Research on the associations between the built environment and COVID-19 outcomes has mostly focused on incidence and mortality. Also, few studies on the built environment and COVID-19 have controlled for individual-level characteristics across large samples. In this study, we examine whether neighborhood built environment characteristics are associated with hospitalization in a cohort of 18,042 individuals who tested positive for SARS-CoV-2 between May and December 2020 in the Denver metropolitan area, USA. We use Poisson models with robust standard errors that control for spatial dependence and several individual-level demographic characteristics and comorbidity conditions. In multivariate models, we find that among individuals with SARS-CoV-2 infection, those living in multi-family housing units and/or in places with higher particulate matter (PM2.5) have a higher incident rate ratio (IRR) of hospitalization. We also find that higher walkability, higher bikeability, and lower public transit access are linked to a lower IRR of hospitalization. In multivariate models, we did not find associations between green space measures and the IRR of hospitalization. Results for non-Hispanic white and Latinx individuals highlight substantial differences: higher PM2.5 levels have stronger positive associations with the IRR of hospitalization for Latinx individuals, and density and overcrowding show stronger associations for non-Hispanic white individuals. Our results show that the neighborhood built environment might pose an independent risk for COVID-19 hospitalization. Our results may inform public health and urban planning initiatives to lower the risk of hospitalization linked to COVID-19 and other respiratory pathogens.

Integration of urban science and urban climate adaptation research: opportunities to advance climate action

There is a growing recognition that responding to climate change necessitates urban adaptation. We sketch a transdisciplinary research effort, arguing that actionable research on urban adaptation needs to recognize the nature of cities as social networks embedded in physical space. Given the pace, scale and socioeconomic outcomes of urbanization in the Global South, the specificities and history of its cities must be central to the study of how well-known agglomeration effects can facilitate adaptation. The proposed effort calls for the co-creation of knowledge involving scientists and stakeholders, especially those historically excluded from the design and implementation of urban development policies.

Bonding Performance of Glass Fiber-Reinforced Polymer Bars under the Influence of Deformation Characteristics

Glass fiber-reinforced polymer (GFRP) of high performance, as a relatively ideal partial or complete substitute for steel, could increase the possibility of adapting structures to changes in harsh weather environments. While GFRP is combined with concrete in the form of bars, the mechanical characteristics of GFRP cause the bonding behavior to differ significantly from that of steel-reinforced members. In this paper, a central pull-out test was applied, according to ACI440.3R-04, to analyze the influence of the deformation characteristics of GFRP bars on bonding failure. The bond-slip curves of the GFRP bars with different deformation coefficients exhibited distinct four-stage processes. Increasing the deformation coefficient of the GFRP bars is able to significantly improve the bond strength between the GFRP bars and the concrete. However, while both the deformation coefficient and concrete strength of the GFRP bars were increased, the bond failure mode of the composite member was more likely to be changed from ductile to brittle. The results show members with larger deformation coefficients and moderate concrete grades, which generally have excellent mechanical and engineering properties. By comparing with the existing bond and slip constitutive models, it was found that the proposed curve prediction model was able to well match the engineering performance of GFRP bars with different deformation coefficients. Meanwhile, due to its high practicality, a four-fold model characterizing representative stress for the bond-slip behavior was recommended in order to predict the performance of the GFRP bars.

Health and wellbeing implications of adaptation to flood risk

Adaptation strategies to ameliorate the impacts of climate change are increasing in scale and scope around the world, with interventions becoming a part of daily life for many people. Though the implications of climate impacts for health and wellbeing are well documented, to date, adaptations are largely evaluated by financial cost and their effectiveness in reducing risk. Looking across different forms of adaptation to floods, we use existing literature to develop a typology of key domains of impact arising from interventions that are likely to shape health and wellbeing. We suggest that this typology can be used to assess the health consequences of adaptation interventions more generally and argue that such forms of evaluation will better support the development of sustainable adaptation planning.

Is climate change affecting mental health of urban populations?

PURPOSE OF REVIEW

In this article, we outline an up-to-date overview of the climate change impact on mental health of urban population, conducted by searching the PubMed database for relevant studies published in the past 12-18 months, in English.

RECENT FINDINGS

Climate change is part of a larger systemic ecological problem in which human demands are exceeding the regenerative capacity of the biosphere. We are witnessing a 'climate chaos', a phase of instability and transformation, which is leading humans into a psychological condition of 'systemic insecurity' and a shared feeling of uncertainty. Currently, one of the places where our species is particularly exposed to climate change are cities, due to build-up in urban infrastructure, rapid and chaotic urbanization, high densities and recent rapid growth, social inequality, and 'heat island effect'.The impact of climate change on cities exposes vulnerable groups to the worse mental health consequences. These groups include the homelessness, slum dwellers for whom the 'neighbourhood effects' are being discussed, climate refugees and migrants, young people, and finally those who assist these people.

SUMMARY

In order to realize broader mental health prevention in cities exposed to climate change phenomena, public health approaches are needed. Institutions must avoid reinforcing inequalities among the more vulnerable groups or create new inequalities.

Reinforcing nature-based solutions through tools providing social-ecological-technological integration

While held to be a means for climate change adaptation and mitigation, nature-based solutions (NbS) themselves are vulnerable to climate change. To find ways of compensating for this vulnerability we combine a focused literature review on how information technology has been used to strengthen positive social-ecological-technological feedback, with the development of a prototype decision-support tool. Guided by the literature review, the tool integrates recent advances in using globally available remote sensing data to elicit information on functional diversity and ecosystem service provisioning with information on human service demand and population vulnerability. When combined, these variables can inform climate change adaptation strategies grounded in local social-ecological realities. This type of integrated monitoring and packaging information to be actionable have potential to support NbS management and local knowledge building for context-tailored solutions to societal challenges in urban environments.

Enabling urban systems transformations: co-developing national and local strategies

Transformative urban development is urgent to achieve future sustainable development and wellbeing. Transformation can benefit from shared and cumulative learning on strategies to guide urban development across local to national scales, while also reflecting the complex emergent nature of urban systems, and the need for context-specific and place-based solutions. The article addresses this challenge, drawing on extensive transdisciplinary engagement and National Strategy co-development processes for Australia. This includes generation of two frameworks as boundary objects to assist such transdisciplinary strategy development. An 'enabling urban systems transformation' framework comprises four generic overarching transformation enablers and a set of necessary underpinning urban capacities. This also built cumulatively on other sustainability and urban transformation studies. A complementary 'knowledge for urban systems transformation' framework comprises key knowledge themes that can support an integrated systems approach to mission-focused urban transformations, such as decarbonising cities. The article provides insights on the transdisciplinary processes, urban systems frameworks, and scoping of key strategies that may help those developing transformation strategies from local to national scales. Science highlights • Transdisciplinary national urban strategy development is used to distil generic frameworks and strategy scopes with potential international application. • The frameworks also build on other published framings to support convergent, cumulative and transdisciplinary urban science. • The 'enabling transformations' and 'urban knowledge' frameworks include the perspective of those developing sustainable urban systems strategies. • The enabling framework also informs 'National Urban Policy' and 'Knowledge and Innovation Hub' strategies, and prevailing power imbalances. • The knowledge framework can help frame urban challenges, missions and knowledge programs. Policy and practice recommendations • An urban 'transformation imperative' and 'strategic response' can be co-developed from local to national scales. • Local initiative is crucial to drive urban strategies, but sustained national leadership with coherent policy across sectors and scales is also key. • Diversity in engagement participation and processes generates whole-of-urban-systems and local-to-national perspectives. • Urban solutions are context-specific but generic frameworks can help collaborative issue framing and responses. • Collaborative issue framing informed by generic frameworks can bring broader perspectives to context-specific and contested policy and practice issues.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s42854-023-00049-9.

Establishment and development of ornamental grasses on green roofs and living walls

Ornamental grasses are often used in gardens to improve biodiversity and as additional aesthetical resources. However, their use in green roofs (GR) and living walls (LW) is not so widespread and it has not been studied extensively. The aim of this work is to assess the performance of seven grass species (Imperata cylindrica ‘Red Baron’, Acorus gramineus, Stipa tenuissima ‘Pony Fails’, Carex flagellifera ‘Bronzita’, Carex oshimensis ‘Evergold’, Uncinia rubra ‘Everflame’ and Miscanthus sinensis) for their use in GR and LW. The growth of the plants was evaluated (i.e. biomass production, dimensions), as well as their visual quality and survival. C. flagellifera and C. oshimensis showed coverage levels greater than 75% and good visual quality, while A. gramineus reached 55–60%. I. cylindrica and M. sinensis showed coverages slightly below 50% in the LW, however, both performed well in the GR, though with a lower visual quality. U. rubra did not develop well, reaching the lowest coverage (below 45%) but maintaining a high visual quality. S. tenuissima also attained low coverage in the LW and presented high mortality, especially in the GR. In LW, C. oshimensis stood out in flowering, while S. tenuissima showed the highest flowering rate in GR. The species should be selected considering their characteristics and performance in order to achieve a correct appearance and development. Interspecific interactions are especially important in LW, as species with upward growth should be placed above species with fallen leaves, not below.

Improving urban flood resilience via GDELT GKG analyses in China's Sponge Cities

Urban floods are the most severe disaster in most Chinese cities due to rapid urbanisation and climate challenges. Recently, media data analytics has become prominent in enhancing urban flood resilience. In this study, news media data from the GKG of the GDELT project was innovatively used to examine the pattern of news media responses towards urban flooding in China's Sponge City Programme (SCP) pilot cities. We find that public sentiments toward urban flood events have been more positive in SCP pilot cities from 2015 to 2021. News media responses towards urban floods exhibit strong seasonality, which is significantly connected with rainfall patterns. Most of the media articles were posted during the urban flood event. Finally, we suggest the opportunities and challenges in applying GKG data analytics and new technologies for urban flood resilience. The results can provide beneficial references to urban flood management strategies in China's Sponge Cities for associated policymakers and stakeholders.

Climate Change Impacts on the Road Transport Infrastructure: A Systematic Review on Adaptation Measures

Road transport is one of the main contributors to increasing greenhouse gas (GHG) emissions, consequently aggravating global warming, but it is also one of the sectors that most suffer from climate change, which causes extreme weather events. Thus, strategies, also called adaptation measures, have been discussed to minimize the impacts of climate change on transport systems and their infrastructure; however, a knowledge gap is evident in the literature. Therefore, this article develops a systematic review with a bibliometric approach, still scarce in the literature, in renowned databases, focusing on studies developed on adaptation measures for road infrastructure. The results show that, since the development of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), an increasing amount of studies on the theme have been published in recognized journals such as Science of the Total Environment, Energy and Buildings and Urban Climate, analyzing climate threats such as intense precipitations and high temperatures that have led to biophysical impacts such as flooding and urban heat island. In addition, for each type of adverse weather condition, many impacts on road infrastructure can be listed, as well as ways to detect these impacts, and adaptation measures that can be used to minimize these problems.

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.

An Empirical Study of the Restoration Potential of Urban Deciduous Forest Space to Youth

Urban deciduous forests are an important ecological resource and seasonal landscape in the urban environment. However, in the abundant literature on how urban green space promotes human health and well-being, research on urban seasonal deciduous forests is limited. This study aimed to investigate the physiological and psychological recovery potential provided of urban deciduous forest space for youths and the spatial preferences of youths regarding such spaces. We recruited 120 participants to study the restorative potential of two typical urban deciduous forest landscape spaces (experimental groups) and one urban road environment (control group). The results showed that after 15 min of observation, the blood pressure (especially the diastolic blood pressure (p < 0.01)) and pulse of the deciduous forest trail setting (DFTS) group effectively decreased, and the restorative mood significantly increased. Regarding change in emotional parameters, the DFTS group scored higher on “interest” and significantly higher than the other two groups on positive emotion. The correlation results show that density and level are the key factors affecting spatial preferences regarding complex deciduous forests. An increase in density reduces the mood of re-laxation, and an increase in level decreases fatigue and interest. We suggest (1) constructing foot-paths in urban deciduous forests to reduce their spatial density as to improve the relaxation effect and (2) increasing landscape diversity according to the forest space to facilitate user participation and interest. This study provides a scientific basis for the environmental restoration of deciduous landscapes and for urban forestry management decision-makers based on space type construction.

Addressing Inequalities Toward Inclusive Governance for Achieving One Health: A Rapid Review

Sustainable development goals (SDGs) adopted in 2015 are geared toward sustainable development through various pathways, one being reducing inequality as covered in SDG 10. Inequalities are a threat to health and wellbeing of populations and a planet Earth in which we live. This rapid review aims to identify key issues that are likely to exacerbate inequalities around the six SDGs directly related to One Health, which are SDG 3, 6, 11, 13, 14 and 15, and suggest some actions that may help to address them using inclusive governance taking into account the coronavirus disease of 2019 (COVID-19) pandemic. Informed by the literature on SDGs and using the “inclusive development concept” by Gupta and Vegelin, literature search was done in Google Scholar, PubMed Central, as well as, searching of references in the relevant articles identified using search terms from the six SDGs that are directly related to One Health. In the context of the SDGs, in order to achieve One Health through inclusive governance, and tackle inequalities, the following needs to be considered and addressed: increasing number of armed conflicts; ongoing COVID-19 pandemic; ensuring availability of water and sanitation facilities; improving city and urban areas planning to cope with climate change; improving governance arrangements for addressing climate change factoring gender and human rights; multisectoral planning for conservation of oceans, seas, and marine resources; balancing trade regulation of wildlife trade with conservation efforts; need for a research collaborative involving experts from environmental sciences, wildlife, agriculture and human health to study and develop scientific evidence on contribution of changes in land use practices to occurrence of zoonotic diseases; and need of a legislation for promoting animal welfare to protect public health. Also, inclusion of people with disabilities in the use of digital technologies is critical.

Sustainable and 'smart' restructuring around the making of mega and world-class cities in India: a critical review

COVID-19 has posed newer questions on urban vulnerabilities in India and showcased the importance of acting effectively towards a vision of sustainable urbanization. Several studies during the pandemic explored the need to make cities socially inclusive and ecologically resilient. The Indian Smart Cities Mission is the flagship urban project that envisions economic growth and ensures technology-induced quality of life in tune with global city-making projects like eco-city, world-class city, green city, etc. Here, we critically examine a range of such neoliberal urban projects and explore the extent to which these cities in their 'smart' restructuring embrace a holistic vision of sustainability. We analyse three urban renewal projects: the Lavasa eco-city, the Rajarhat green-city, and the Dholera smart city, arguing why a case-study based approach is significant to study the connection between policy promises and actual socio-environmental realities. Our empirical explorations reveal that processes and practices involved in the making of these projects are 'utopian'; in reality, they tend to uproot the existing urban ecological buffers, critically impacting the quality of urban life across classes. Beyond the capitalist logic of 'accumulation by dispossession', we finally lay out the need to imagine urban commons as scripted with memories, desires, plurality of use, users, and ways of living, and thus to situate the urban planning in practical visions of sustainability and environmental resilience.

New urban models for more sustainable, liveable and healthier cities post covid19; reducing air pollution, noise and heat island effects and increasing green space and physical activity

Cities are centres of innovation and wealth creation, but also hotspots of air pollution and noise, heat island effects and lack of green space, which are all detrimental to human health. They are also hotspots of COVID19. COVID19 has led to a rethink of urban public space. Therefore, is it time to re-think our urban models and reduce the health burden? We provide a narrative meta-review around a number of cutting edge and visionary urban models that that may affect health and that have been reported over the past few years. New urban concepts such as the Superblocks, the low traffic neighbourhood, 15 Minute city, Car free city or a mixture of these that may go some way in reducing the health burden related to current urban and transport practices. They will reduce air pollution and noise, heat island effects and increase green space and physical activity levels. What is still lacking though is a thorough evaluation of the effectiveness and acceptability of the schemes and the impacts on not only health, but also liveability and sustainability, although they are expected to be positive. Finally, the COVID19 pandemic may accelerate these developments and stimulus funding like the EU Next Generation funding should be used to make these changes.

Editorial for Special Issue “Nature-Based Solutions (NBS) in Cities and Their Interactions with Urban Land, Ecosystems, Built Environments and People: Debating Societal Implications”

Today’s cities increasingly serve as the nexus between nature and people in times of strong urban growth and, in some cases, urban decline [...]

COVID-19 pandemic observations as a trigger to reflect on urban forestry in European cities under climate change: Introducing nature-society-based solutions

COVID-19 pandemic observations triggered a reflection by the author on urban forests in European cities under climate change as nature-society-based solutions. This commentary introduces a complementary triad of approaches that are all known but might lead to a novel view of urban nature, including forests, regarding changes in pandemic diseases and/or related to urbanization and climate change: Hybridity, succession, and flexibility: First, allowing for green spaces used by humans and nature but also those that are exclusively for ecosystems to provide space for undisturbed development and thus better control pests and diseases. Second, allow for succession at urban open spaces to let nature experiment on solutions for a drier and hotter climate that urban society can implement in urban forestry. And third, allow planning to set targets in efficiency assessment and monitoring that are matching time periods which natural ecosystems need to adapt to climate change acknowledging nature as a real 'partner' in nature-society-based solutions in one-health cities.