Scale-dependent interactions between tree canopy cover and impervious surfaces reduce daytime urban heat during summer

Protective neighboring effect from ash trees treated with systemic insecticide against emerald ash borer

BACKGROUND

The emerald ash borer (EAB) (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is now the most destructive invasive species in North America. While biocontrol using parasitoids shows promising results in natural forests, strategies are needed to protect high-value trees against invasive EAB populations. Emamectin benzoate is a commonly used systemic insecticide for the protection of valuable trees. Methods that optimize its use allow for reduced quantities of insecticide to be released in the environment and save time and money in efforts to protect ash trees from EAB. We hypothesize that a treated tree can also offer a protective neighboring effect to nearby untreated ash trees, allowing for an optimized spatial planning of insecticide applications.

RESULTS

We sampled 896 untreated ash trees, in the vicinity of treated trees, in Maryland and Washington DC. We recorded signs of EAB infestation (canopy condition, exit holes, wood pecks, epicormic growth, and bark splits). Two subsequent yearly samplings were made of 198 and 216 trees, respectively. We also present a novel proximity index for this particular application. Results show consistent decrease in EAB infestation signs in untreated trees as proximity to treated trees increases.

CONCLUSION

Results support that a neighboring effect occurs. However, proximity to treated trees must be high for a tree to be safely left untreated. This proximity seems rare in forests, but can happen in urban/planted landscapes. Future studies should test and validate these findings, and could lead to a more precise recommended safe index tailored across multiple ash species and geographic regions.

Increasing Green Infrastructure in Cities: Impact on Ambient Temperature, Air Quality and Heat-Related Mortality and Morbidity

Urban vegetation provides undeniable benefits to urban climate, health, thermal comfort and environmental quality of cities and represents one of the most considered urban heat mitigation measures. Despite the plethora of available scientific information, very little is known about the holistic and global impact of a potential increase of urban green infrastructure (GI) on urban climate, environmental quality and health, and their synergies and trade-offs. There is a need to evaluate globally the extent to which additional GI provides benefits and quantify the problems arising from the deployment of additional greenery in cities which are usually overlooked or neglected. The present paper has reviewed and analysed 55 fully evaluated scenarios and case studies investigating the impact of additional GI on urban temperature, air pollution and health for 39 cities. Statistically significant correlations between the percentage increase of the urban GI and the peak daily and night ambient temperatures are obtained. The average maximum peak daily and night-time temperature drop may not exceed 1.8 and 2.3 °C respectively, even for a maximum GI fraction. In parallel, a statistically significant correlation between the peak daily temperature decrease caused by higher GI fractions and heat-related mortality is found. When the peak daily temperature drops by 0.1 °C, then the percentage of heat-related mortality decreases on average by 3.0% The impact of additional urban GI on the concentration of urban pollutants is analysed, and the main parameters contributing to decrease or increase of the pollutants’ concentration are presented.

A Landscape Study of Sediment Formation and Transport in the Urban Environment

Background: Sediment deposition in the urban environment affects aesthetic, economic, and other aspects of city life, and through re-suspension of dust, may pose serious risks to human health. Proper environmental management requires further understanding of natural and anthropogenic factors influencing the sedimentation processes in urbanized catchments. To fill the gaps in the knowledge about the relationship between the urban landscape and sedimentation, field landscape surveys were conducted in the residential areas of the Russian cities of Ekaterinburg, Nizhniy Novgorod, Rostov-on-Don, Tyumen, Chelyabinsk, and Murmansk. Methods: In each city, six elementary urban residential landscapes were chosen in blocks of multi-story apartment buildings typical for Russian cities. The method of landscape survey involved delineating functional segments within the elementary landscapes and describing each segment according to the developed procedure during a field survey. Results: The complexity of sedimentation processes in the urban environment was demonstrated. The following main groups of factors have significant impacts on sediment formation and transport in residential areas in Russian cities: low adaptation of infrastructure to a high density of automobiles, poor municipal services, and bad urban environmental management in the course of construction and earthworks. Conclusion: A high sediment formation potential was found for a considerable portion of residential areas.

Protecting health in dry cities: from evidence to action

Cities in the US and beyond are increasingly claiming heat readiness as the climate crisis escalates, while starting to recognize its disproportionate burden on poorer residents. But are their plans sufficient, and can they implement them fast enough? Mara Kardas-Nelson reports

Healthy built environment: Spatial patterns and relationships of multiple exposures and deprivation in Toronto, Montreal and Vancouver

BACKGROUND

Various aspects of the urban environment and neighbourhood socio-economic status interact with each other to affect health. Few studies to date have quantitatively assessed intersections of multiple urban environmental factors and their distribution across levels of deprivation.

OBJECTIVES

To explore the spatial patterns of urban environmental exposures within three large Canadian cities, assess how exposures are distributed across socio-economic deprivation gradients, and identify clusters of favourable or unfavourable environmental characteristics.

METHODS

We indexed nationally standardized estimates of active living friendliness (i.e. "walkability"), NO₂ air pollution, and greenness to 6-digit postal codes within the cities of Toronto, Montreal and Vancouver. We compared the distribution of within-city exposure tertiles across quintiles of material deprivation. Tertiles of each exposure were then overlaid with each other in order to identify potentially favorable (high walkability, low NO₂, high greenness) and unfavorable (low walkability, high NO₂, and low greenness) environments.

RESULTS

In all three cities, high walkability was more common in least deprived areas and less prevalent in highly deprived areas. We also generally saw a greater prevalence of postal codes with high vegetation indices and low NO₂ in areas with low deprivation, and a lower greenness prevalence and higher NO₂ concentrations in highly deprived areas, suggesting environmental inequity is occurring. Our study showed that relatively few postal codes were simultaneously characterized by desirable or undesirable walkability, NO₂and greenness tertiles.

DISCUSSION

Spatial analyses of multiple standardized urban environmental factors such as the ones presented in this manuscript can help refine municipal investments and policy priorities. This study illustrates a methodology to prioritize areas for interventions that increase active living and exposure to urban vegetation, as well as lower air pollution. Our results also highlight the importance of considering the intersections between the built environment and socio-economic status in city planning and urban public health decision-making.

Land cover affects microclimate and temperature suitability for arbovirus transmission in an urban landscape

The emergence of mosquito-transmitted viruses poses a global threat to human health. Combining mechanistic epidemiological models based on temperature-trait relationships with climatological data is a powerful technique for environmental risk assessment. However, a limitation of this approach is that the local microclimates experienced by mosquitoes can differ substantially from macroclimate measurements, particularly in heterogeneous urban environments. To address this scaling mismatch, we modeled spatial variation in microclimate temperatures and the thermal potential for dengue transmission by Aedes albopictus across an urban-to-rural gradient in Athens-Clarke County GA. Microclimate data were collected across gradients of tree cover and impervious surface cover. We developed statistical models to predict daily minimum and maximum microclimate temperatures using coarse-resolution gridded macroclimate data (4000 m) and high-resolution land cover data (30 m). The resulting high-resolution microclimate maps were integrated with temperature-dependent mosquito abundance and vectorial capacity models to generate monthly predictions for the summer and early fall of 2018. The highest vectorial capacities were predicted for patches of trees in urban areas with high cover of impervious surfaces. Vectorial capacity was most sensitive to tree cover during the summer and became more sensitive to impervious surfaces in the early fall. Predictions from the same models using temperature data from a local meteorological station consistently over-predicted vectorial capacity compared to the microclimate-based estimates. This work demonstrates that it is feasible to model variation in mosquito microenvironments across an urban-to-rural gradient using satellite Earth observations. Epidemiological models applied to the microclimate maps revealed localized patterns of temperature suitability for disease transmission that would not be detectable using macroclimate data. Incorporating microclimate data into disease transmission models has the potential to yield more spatially precise and ecologically interpretable metrics of mosquito-borne disease transmission risk in urban landscapes.

Predicting the effects of temperature on mosquito abundance and arbovirus transmission cycles is essential for mapping hot spots of disease risk and projecting responses to climate change. In urban landscapes, the built environment and natural features create distinctive environments. Buildings and roads generate warmer conditions through the urban heat island effect, while vegetation can have a cooling effect because of shading and evaporative heat loss. We used land cover data to map microclimate temperature in Athens-Clarke County, GA and applied a temperature-dependent vectorial capacity model to predict the effects of microclimate on dengue transmission by Aedes albopictus. The highest vectorial capacity was predicted in patches of trees located in the urbanized portion of the study area. These locations had relatively warm nighttime and cool daytime temperature, which kept temperatures close to the optimum for disease transmission. This work demonstrates the feasibility of predicting variation in mosquito microenvironments in urban landscapes using satellite Earth observations. Incorporating microclimate data into disease transmission models has the potential to yield more spatially precise and ecologically interpretable metrics of mosquito-borne disease transmission risk.

Mapping Human Vulnerability to Extreme Heat: A Critical Assessment of Heat Vulnerability Indices Created Using Principal Components Analysis

BACKGROUND

Extreme heat poses current and future risks to human health. Heat vulnerability indices (HVIs), commonly developed using principal components analysis (PCA), are mapped to identify populations vulnerable to extreme heat. Few studies critically assess implications of analytic choices made when employing this methodology for fine-scale vulnerability mapping.

OBJECTIVE

We investigated sensitivity of HVIs created by applying PCA to input variables and whether training input variables on heat-health data produced HVIs with similar spatial vulnerability patterns for Detroit, Michigan, USA.

METHODS

We acquired 2010 Census tract and block group level data, land cover data, daily ambient apparent temperature, and all-cause mortality during May-September, 2000-2009. We used PCA to construct HVIs using: a) "unsupervised"-PCA applied to variables selected a priori as risk factors for heat-related health outcomes; b) "supervised"-PCA applied only to variables significantly correlated with proportion of all-cause mortality occurring on extreme heat days (i.e., days with 2-d mean apparent temperature above month-specific 95th percentiles).

RESULTS

Unsupervised and supervised HVIs yielded differing spatial vulnerability patterns, depending on selected land cover input variables. Supervised PCA explained 62% of variance in the input variables and was applied on half the variables used in the unsupervised method. Census tract-level supervised HVI values were positively associated with increased proportion of mortality occurring on extreme heat days; supervised PCA could not be applied to block group data. Unsupervised HVI values were not associated with extreme heat mortality for either tracts or block groups.

DISCUSSION

HVIs calculated using PCA are sensitive to input data and scale. Supervised HVIs may provide marginally more specific indicators of heat vulnerability than unsupervised HVIs. PCA-derived HVIs address correlation among vulnerability indicators, although the resulting output requires careful contextual interpretation beyond generating epidemiological research questions. Methods with reliably stable outputs should be leveraged for prioritizing heat interventions. https://doi.org/10.1289/EHP4030.

Tree Transpiration and Urban Temperatures: Current Understanding, Implications, and Future Research Directions

The expansion of an urban tree canopy is a commonly proposed nature-based solution to combat excess urban heat. The influence trees have on urban climates via shading is driven by the morphological characteristics of trees, whereas tree transpiration is predominantly a physiological process dependent on environmental conditions and the built environment. The heterogeneous nature of urban landscapes, unique tree species assemblages, and land management decisions make it difficult to predict the magnitude and direction of cooling by transpiration. In the present article, we synthesize the emerging literature on the mechanistic controls on urban tree transpiration. We present a case study that illustrates the relationship between transpiration (using sap flow data) and urban temperatures. We examine the potential feedbacks among urban canopy, the built environment, and climate with a focus on extreme heat events. Finally, we present modeled data demonstrating the influence of transpiration on temperatures with shifts in canopy extent and irrigation during a heat wave.

Quantifying spatial morphology and connectivity of urban heat islands in a megacity: A radius approach

Urban heat island (UHI) effect is an important ecological consequence of rapid urbanization. Although the spatio-temporal evolution of urban heat islands (UHIs) and their driving forces have been discussed in previous studies, the accurate identification of the spatial morphology and connectivity of UHIs is currently lacking. Taking Beijing City as an example, the radius approach (RA) was applied to identify the thresholds of UHIs, and multiple indexes were calculated to analyze the changing connectivity of UHIs from 2000 to 2015. The results showed that the UHIs in Beijing City formed archipelagos, which composed of single main heat island that occupied >79.85% of the total area, and small heat islands scattered in the centers of surrounding districts. In 15 years, the total area occupied by UHIs increased by 30.04%, indicating that the UHI effect became worse. As for landscape patterns of UHIs, aggregation index (AI) increased by 1.6%, landscape shape index (LSI) decreased by 4.1%, and probability of connectivity (PC) increased by 69.1%, all indicating that the distribution of UHIs became more compact, and the connectivity between islands increased. Different expansion types had different influences on the landscape patterns of UHIs: the edge-expansion reduced the fragmentation of UHIs and increased connectivity between islands, the infilling expansion made the boundaries of UHIs regular, and the leapfrog expansion made the AI slight decrease. Based on the radius approach, identifying the range of multi-center UHIs and their spatial expansion type can provide an effective planning guideline for mitigating the negative UHI effect.

The Trend Inconsistency between Land Surface Temperature and Near Surface Air Temperature in Assessing Urban Heat Island Effects

The credible urban heat island (UHI) trend is crucial for assessing the effects of urbanization on climate. Land surface temperature (LST) and near surface air temperature (SAT) have been extensively used to obtain UHI intensities. However, the consistency of UHI trend between LST and SAT has rarely been discussed. This paper quantified the temporal stability and trend consistency between Moderate Resolution Imaging Spectroradiometer (MODIS) LST and in situ SAT. Linear regressions, temporal trends and coefficients of variations (CV) were analyzed based on the yearly mean, maximum and minimum temperatures. The findings in this study were: (1) Good statistical consistency (R2 = 0.794) and the same trends were found only in mean temperature between LST-UHI and SAT-UHI. There are 54% of cities that showed opposite temporal trends between LST-UHI and SAT-UHI for minimum temperature while the percentage was 38% for maximum temperature. (2) The high discrepancies in temporal trends were observed for all cities, which indicated the inadequacy of LST for obtaining reliable UHI trends especially when using the maximum and minimum temperatures. (3) The larger uncertainties of LST-UHI were probably due to high inter-annual fluctuations of LST. The topography was the predominant factor that affected the UHI variations for both LST and SAT. Therefore, we suggested that SAT should be combined with LST to ensure the dependable temporal series of UHI. This paper provided references for understanding the UHI effects on various surfaces.

Linking green infrastructure to urban heat and human health risk mitigation in Oslo, Norway

The predicted extreme temperatures of global warming are magnified in cities due to the urban heat island effect. Even if the target for average temperature increase in the Paris Climate Agreement is met, temperatures during the hottest month in a northern city like Oslo are predicted to rise by over 5 °C by 2050. We hypothesised that heat-related diagnoses for heat-sensitive citizens (75+) in Oslo are correlated to monthly air temperatures, and that green infrastructure such as tree canopy cover reduces extreme land surface temperatures and thus reduces health risk from heat exposure. Monthly air temperatures were significantly correlated to the number of skin-related diagnoses at the city level, but were unrelated to diagnoses under circulatory, nervous system, or general categories. Satellite-derived spatially-explicit measures revealed that on one of the hottest days during the summer of 2018, landscape units composed of paved, midrise or lowrise buildings gave off the most heat (39 °C), whereas units composed of complete tree canopy cover, or mixed (i.e. tree and grass) vegetation maintained temperatures of between 29 and 32 °C. Land surface temperatures were negatively correlated to tree canopy cover (R² = 0.45) and vegetation greenness (R² = 0.41). In a scenario in which each city tree was replaced by the most common non-tree cover in its neighbourhood, the area of Oslo exceeding a 30 °C health risk threshold during the summer would increase from 23 to 29%. Combining modelling results with population at risk at census tract level, we estimated that each tree in the city currently mitigates additional heat exposure of one heat-sensitive person by one day. Our results indicate that maintaining and restoring tree cover provides an ecosystem service of urban heat reduction. Our findings have particular relevance for health benefit estimation in urban ecosystem accounting and municipal policy decisions regarding ecosystem-based climate adaptation.

Current and future biomass carbon uptake in Boston's urban forest

Ecosystem services provided by urban forests are increasingly included in municipal-level responses to climate change. However, the ecosystem functions that generate these services, such as biomass carbon (C) uptake, can differ substantially from nearby rural forest. In particular, the scaled effect of canopy spatial configuration on tree growth in cities is uncertain, as is the scope for medium-term policy intervention. This study integrates high spatial resolution data on tree canopy and biomass in the city of Boston, Massachusetts, with local measurements of tree growth rates to estimate the magnitude and distribution of annual biomass C uptake. We further project C uptake, biomass, and canopy cover change to 2040 under alternative policy scenarios affecting the planting and preservation of urban trees. Our analysis shows that 85% of tree canopy area was within 10 m of an edge, indicating essentially open growing conditions. Using growth models accounting for canopy edge effects and growth context, Boston's current biomass C uptake may be approximately double (median 10.9 GgC yr^-1, 0.5 MgC ha^-1 yr^-1) the estimates based on rural forest growth, much of it occurring in high-density residential areas. Total annual C uptake to long-term biomass storage was equivalent to <1% of estimated annual fossil CO₂ emissions for the city. In built-up areas, reducing mortality in larger trees resulted in the highest predicted increase in canopy cover (+25%) and biomass C stocks (236 GgC) by 2040, while planting trees in available road margins resulted in the greatest predicted annual C uptake (7.1 GgC yr^-1). This study highlights the importance of accounting for the altered ecosystem structure and function in urban areas in evaluating ecosystem services. Effective municipal climate responses should consider the substantial fraction of total services performed by trees in developed areas, which may produce strong but localized atmospheric C sinks.

Seasonal hysteresis of surface urban heat islands

Temporal dynamics of urban warming have been extensively studied at the diurnal scale, but the impact of background climate on the observed seasonality of surface urban heat islands (SUHIs) remains largely unexplored. On seasonal time scales, the intensity of urban-rural surface temperature differences ([Formula: see text]) exhibits distinctive hysteretic cycles whose shape and looping direction vary across climatic zones. These observations highlight possible delays underlying the dynamics of the coupled urban-biosphere system. However, a general argument explaining the observed hysteretic patterns remains elusive. A coarse-grained model of SUHI coupled with a stochastic soil water balance is developed to demonstrate that the time lags between radiation forcing, air temperature, and rainfall generate a rate-dependent hysteresis, explaining the observed seasonal variations of [Formula: see text] If solar radiation is in phase with water availability, summer conditions cause strong SUHI intensities due to high rural evaporative cooling. Conversely, cities in seasonally dry regions where evapotranspiration is out of phase with radiation show a summertime oasis effect controlled by background climate and vegetation properties. These seasonal patterns of warming and cooling have significant implications for heat mitigation strategies as urban green spaces can reduce [Formula: see text] during summertime, while potentially negative effects of albedo management during winter are mitigated by the seasonality of solar radiation.

Tree Ecosystem Services, for Everyone? A Compositional Analysis Approach to Assess the Distribution of Urban Trees as an Indicator of Environmental Justice

Trees provide a broad amount of ecosystem services in urban areas. Although it is well documented that trees are essential for the well-being and livability of cities, trees are often not evenly distributed. Studies have found that urban residents with a deprived socioeconomic status are associated with a lower coverage and access to urban trees in their communities, yet a fair distribution of trees contributes to the sustainability and resilience of cities. In this context, the environmental justice movement seeks to ensure equal distribution of green infrastructure and its benefits throughout a territory. The objective of this study is threefold: (i) to determine whether urban trees in Guadalajara, Mexico, are distributed equally; (ii) to assess the association between urban trees and socioeconomic status; and (iii) to introduce compositional data analysis to the existing literature. Due to the compositional nature of the data, compositional analysis techniques are applied. We believe this novel approach will help define the proper management of data used in the literature. The outcomes provide insights for urban planners working towards the Sustainable Development Goals to help eradicate the uneven distribution of urban trees in cities.

Understanding the value and limits of nature-based solutions to climate change and other global challenges

There is growing awareness that 'nature-based solutions' (NbS) can help to protect us from climate change impacts while slowing further warming, supporting biodiversity and securing ecosystem services. However, the potential of NbS to provide the intended benefits has not been rigorously assessed. There are concerns over their reliability and cost-effectiveness compared to engineered alternatives, and their resilience to climate change. Trade-offs can arise if climate mitigation policy encourages NbS with low biodiversity value, such as afforestation with non-native monocultures. This can result in maladaptation, especially in a rapidly changing world where biodiversity-based resilience and multi-functional landscapes are key. Here, we highlight the rise of NbS in climate policy-focusing on their potential for climate change adaptation as well as mitigation-and discuss barriers to their evidence-based implementation. We outline the major financial and governance challenges to implementing NbS at scale, highlighting avenues for further research. As climate policy turns increasingly towards greenhouse gas removal approaches such as afforestation, we stress the urgent need for natural and social scientists to engage with policy makers. They must ensure that NbS can achieve their potential to tackle both the climate and biodiversity crisis while also contributing to sustainable development. This will require systemic change in the way we conduct research and run our institutions. This article is part of the theme issue 'Climate change and ecosystems: threats, opportunities and solutions'.

Nature-based approaches to managing climate change impacts in cities

Managing and adapting to climate change in urban areas will become increasingly important as urban populations grow, especially because unique features of cities amplify climate change impacts. High impervious cover exacerbates impacts of climate warming through urban heat island effects and of heavy rainfall by magnifying runoff and flooding. Concentration of human settlements along rivers and coastal zones increases exposure of people and infrastructure to climate change hazards, often disproportionately affecting those who are least prepared. Nature-based strategies (NBS), which use living organisms, soils and sediments, and/or landscape features to reduce climate change hazards, hold promise as being more flexible, multi-functional and adaptable to an uncertain and non-stationary climate future than traditional approaches. Nevertheless, future research should address the effectiveness of NBS for reducing climate change impacts and whether they can be implemented at scales appropriate to climate change hazards and impacts. Further, there is a need for accurate and comprehensive cost-benefit analyses that consider disservices and co-benefits, relative to grey alternatives, and how costs and benefits are distributed across different communities. NBS are most likely to be effective and fair when they match the scale of the challenge, are implemented with input from diverse voices and are appropriate to specific social, cultural, ecological and technological contexts. This article is part of the theme issue 'Climate change and ecosystems: threats, opportunities and solutions'.

The Effects of Historical Housing Policies on Resident Exposure to Intra-Urban Heat: A Study of 108 US Urban Areas

The increasing intensity, duration, and frequency of heat waves due to human-caused climate change puts historically underserved populations in a heightened state of precarity, as studies observe that vulnerable communities—especially those within urban areas in the United States—are disproportionately exposed to extreme heat. Lacking, however, are insights into fundamental questions about the role of historical housing policies in cauterizing current exposure to climate inequities like intra-urban heat. Here, we explore the relationship between “redlining”, or the historical practice of refusing home loans or insurance to whole neighborhoods based on a racially motivated perception of safety for investment, with present-day summertime intra-urban land surface temperature anomalies. Through a spatial analysis of 108 urban areas in the United States, we ask two questions: (1) how do historically redlined neighborhoods relate to current patterns of intra-urban heat? and (2) do these patterns vary by US Census Bureau region? Our results reveal that 94% of studied areas display consistent city-scale patterns of elevated land surface temperatures in formerly redlined areas relative to their non-redlined neighbors by as much as 7 °C. Regionally, Southeast and Western cities display the greatest differences while Midwest cities display the least. Nationally, land surface temperatures in redlined areas are approximately 2.6 °C warmer than in non-redlined areas. While these trends are partly attributable to the relative preponderance of impervious land cover to tree canopy in these areas, which we also examine, other factors may also be driving these differences. This study reveals that historical housing policies may, in fact, be directly responsible for disproportionate exposure to current heat events.

The ‘GartenApp’: Assessing and Communicating the Ecological Potential of Private Gardens

Private gardens make up large parts of urban green space. In contrast to public green spaces, planning and management is usually uncoordinated and independent of municipal planning and management strategies. Therefore, the potential for private gardens to provide ecosystem services and habitat and to function as corridors for wildlife is not fully utilized. In order to improve public knowledge on gardens, as well as provide individual gardeners with information on what they can contribute to enhance ecosystem services provision, we developed a GIS-based web application for the city of Braunschweig (Germany): the ‘GartenApp’ (garden app). Users of the app have to outline their garden on a web map and provide information on biodiversity related features and management practices. Finally, they are asked about observations of well recognizable species in their gardens. As an output, the gardeners are provided with an estimate of the ecosystem services their garden provides, with an evaluation of the biodiversity friendliness, customized advice on improving ecosystem services provision, and results from connectivity models that show gardeners the role of their garden in the green network of the city. In this paper, we describe the app architecture and show the first results from its application. We finish with a discussion on the potential of GIS-based web applications for urban sustainability, planning and conservation.

Greening Blocks: A Conceptual Typology of Practical Design Interventions to Integrate Health and Climate Resilience Co-Benefits

It is increasingly evident that exposure to green landscape elements benefits human health. Urban green space in cities is also recognized as a crucial adaptation response to changes in climate and its subsequent effects. The exploration of conceptual and practical intersections between human health, green spaces, and climate action is needed. Evidence-based guidance is needed for stakeholders, practitioners, designers, and citizens in order to assess and manage urban green spaces that maximize co-benefits for both human health and climate resilience. This paper proposes interventions that provide strategic green space enhancement at the neighborhood and block scale. We propose eight tangible green space interventions and associated metrics to integrate climate resilience and population health co-benefits into urban green space design and planning: View from within, Plant entrances, Bring nature nearby, Retain the mature, Generate diversity, Create refuge, Connect experiences, and Optimize green infrastructure. These interventions represent a hierarchy of functional design concepts that respond to experiential qualities and physical/psychological dimensions of health, and which enhance resilience at a range of social scales from the individual to the neighborhood. The interventions also reveal additional research needs in green space design, particularly in neighborhood-level contexts.