Promoting Health Equity Through Preventing or Mitigating the Effects of Gentrification: A Theoretical and Methodological Guide.

Public health researchers are increasingly questioning the consequences of gentrification for population health and health equity, as witnessed in the rapid increase in public health publications on the health (equity) effects of gentrification. Despite methodological challenges, and mixed results from existing quantitative research, qualitative evidence to date points to the role of gentrification processes in exacerbating health inequities. Here we discuss past methodological and theoretical challenges in integrating the study of gentrification with public health research. We suggest taking an interdisciplinary approach, considering the conceptualization of gentrification in measurement techniques and conceiving this process as a direct exposure or as a part of broader neighborhood changes. Finally, we discuss existingpolicy approaches to mitigating and preventing gentrification and how these could be evaluated for effectiveness and as public health promotion and specifically as interventions to promote health equity.

Restoration in mental health after visiting urban green spaces, who is most affected? Comparison between good/poor mental health in four European cities.

Several mechanisms have been proposed to explain the association between green space and health, and one of these is the restoration theory, based on the idea that it is possible to increase mental health and decrease stress visiting a natural environment. The aims of the present study were to understand what activities are most related to restoration and if these are the same for people with poorer and better mental health. A questionnaire was administered in four European cities and data about restoration outcomes, type of activity carried out in green spaces and mental health were collected and analyzed. A cross sectional design was used and total of 3134 respondents participated to the questionnaire. The restoration experience was measured with the restoration outcome score, and the mental health was evaluated with a subscale related to mental health of the Medical Outcome Short Form. Participants were divided in two groups according to mental health score. A multiple regression analysis was performed to investigate the association between mental health, type of activity and restoration. The cities showed a similar trend in the association between restoration and type of activity performed in green environment. People with poorer mental health seem to be more sensitive to the positive effect of visiting the green environment and restoration was more evident in these people than in those with better mental health. At the same time, the type of activity was less evident in people with better mental health, and they seemed to be less influenced by the visiting of green space. Green prescription is important for the entire population: people with poorer mental health could have important restorative effects and people with better mental health could continue to protect their well-being using green space.

The relationship between residential proximity to outdoor play spaces and children's mental and behavioral health: The importance of neighborhood socio-economic characteristics.

Urban outdoor play spaces are reported to improve children's health. However, there is little empirical evidence on the impact of outdoor play spaces on childhood mental and behavioral health. To fill this gap, we investigated the associations between residential proximity to outdoor play spaces and the prevalence of diagnosed mental and behavioral disorders. We explored whether these associations differ by individual and area-level socio-economic status (SES). This cross-sectional study included 151 110 children who were 0-12 years old in 2014 and were visited in public primary health care centers in Barcelona (Spain). Each child's demographic and mental and behavioral disorders information was extracted for 2005-2014, including diagnoses on disorders of psychological development together with other four types of mental and behavioral disorders. The pediatrician diagnosed mental and behavioral disorders we explored in this study were: mood/affective; neurotic, stress-related and somatoform; psychological development; behavioral and emotional; and overall mental and behavioral disorders. We assessed 300 m network buffer residential proximity to overall outdoor play spaces (i.e., the overall sum of play spaces of any type), outdoor green play spaces, and to a diversity of outdoor play spaces. We used robust Poisson regression models to investigate the association between proximity to outdoor play spaces indicators and each health outcome. We tested interaction terms for indicators of proximity to outdoor play spaces and individual and area SES. For measures with significant interaction terms, we conducted stratified models. We found residential proximity to outdoor play spaces to be protective of disorders of psychological development. Proximity to overall outdoor play spaces, proximity to outdoor green play spaces and proximity to a greater diversity of outdoor play spaces were associated with a 4% (95% CI: 1,7), 4% (95% CI: 1,7) and 5% (95% CI: 2,9) lower prevalence rates of disorders of psychological development respectively. Most of the associations were found to be in the same direction-although more pronounced-in low SES areas, but in the opposite direction for children living in high SES areas. No differences in these associations were found by individual SES. Residential proximity to outdoor play spaces is protective of children's mental and behavioral health living in low SES areas.

Does surrounding greenness moderate the relationship between apparent temperature and physical activity? Findings from the PHENOTYPE project.

BACKGROUND: Physical activity can be affected by both meteorological conditions and surrounding greenness, but few studies have evaluated the effects of these environmental factors on physical activity simultaneously. This multi-city comparative study aimed to assess the synergetic effects of apparent temperature and surrounding greenness on physical activity in four European cities. Specifically, we aimed to identify an interaction between surrounding greenness and apparent temperature in the effects on physical activity. METHODS: Data were collected from 352 adult residents of Barcelona (Spain), Stoke-on-Trent (United Kingdom), Doetinchem (The Netherlands), and Kaunas (Lithuania) as part of the PHENOTYPE study. Participants wore a smartphone for seven consecutive days between May-December 2013 and provided additional sociodemographic survey data. Hourly average physical activity (Metabolic Equivalent of Task (MET)) and surrounding greenness (NDVI) were derived from the Calfit mobile application collecting accelerometer and location data. Hourly apparent temperature was calculated from temperature and relative humidity, which were obtained from local meteorological stations along with other meteorological covariates (rainfall, windspeed, and sky darkness). We assessed the interaction effects of apparent temperature and surrounding greenness on hourly physical activity for each city using linear mixed models, while adjusting for meteorological, demographic, and time-related variables. RESULTS: We found significant interactions between apparent temperature and surrounding greenness on hourly physical activity in three of four cities, aside from the coastal city of Barcelona. Significant quadratic effects of apparent temperature were found in the highest level of surrounding greenness for Stoke-on-Trent and Doetinchem, with 4% decrease in median MET observed for a 10°C departure from optimal temperature (15.2°C and 14.6°C, respectively). Significant linear effects were found for higher levels of surrounding greenness in Kaunas, whereby an increase of 10°C was associated with ∼4% increase in median MET. CONCLUSION: Apparent temperature and surrounding greenness interacted in the effect on hourly physical activity across three of four European cities, with varying effect between cities. While quadratic effects of temperature suggest diminishing levels of physical activity in the highest greenness levels in cities of temperate climates, the variation in surrounding greenness between cities could be further explored, particularly by looking at indoor-outdoor locations. The study findings support the need for evidence-based physical activity promotion and urban design.

Public Transport Strikes and Their Relationships With Air Pollution, Mortality, and Hospital Admissions.

There is limited suggestive evidence of relationships between public transport strikes and either increased air pollution or worse population health. In this study we aimed to assess whether public transport strikes were associated with increases in health events (overall, cardiovascular and respiratory mortality, and cardiovascular and respiratory hospitalizations). We also explored whether air pollution mediated those associations. We used data from the city of Barcelona (Spain) for the period 2005-2016 on strikes, health events, and ambient air pollution (nitrogen dioxide, nitrogen monoxide, particulate matter (PM) with an aerodynamic diameter ≤10 µm, PM with an aerodynamic diameter ≤2.5µm, PM with an aerodynamic diameter ≤1µm, number of particles with a diameter greater than 5 nm per cm3 (particle number concentration), and black carbon). We used linear and quasi-Poisson regression models to explore the associations between air pollution and public transport strikes and between public transport strikes and health outcomes. We also investigated potential causal mediation by air pollution. Overall, this study suggested that public transport strikes are associated with increased overall mortality, respiratory mortality, and respiratory hospitalizations. However, our findings suggest that such increases are not mediated by the increase in air pollution. Our results indicate the need to further investigate these relationships and potential mechanisms.

Physical and mental health effects of repeated short walks in a blue space environment: A randomised crossover study.

INTRODUCTION: Blue spaces may benefit mental health and promote physical activity, although the evidence is still scarce. And benefits on physical health are less consistent. The objective of this randomized crossover study was to assess psychological and cardiovascular responses to blue spaces' exposure. METHODS: A sample of 59 healthy adult office workers was randomly assigned to a different environment (i.e. blue space, urban space, and control site) on 4 days each week, for 3 weeks. For 20 min per day, they either walked along a blue or an urban space or rested at a control site. Before, during and/or after the exposure, we measured self-reported well-being and mood, blood pressure, and heart rate variability parameters. For well-being, we also assessed the duration of these potential effects over time (at least 4 h after exposure). RESULTS: We found significantly improved well-being and mood responses immediately after walking in the blue space compared with walking in the urban space or when resting in the control site. Cardiovascular responses showed increased activity of the sympathetic nervous system, both during and after walking along the blue and urban spaces. However, cardiovascular responses measured after the walks, showed no statistically significant differences between the blue and the urban space environments. CONCLUSIONS: Short walks in blue spaces can benefit both well-being and mood. However, we did not observe a positive effect of blue spaces for any of the cardiovascular outcomes assessed in this study.

Quality of Life Benefits of Urban Rooftop Gardening for People With Intellectual Disabilities or Mental Health Disorders.

BACKGROUND: The number of urban community gardens, including those on rooftops, is increasing. However, few studies have explored the benefits of these gardens for people with intellectual disabilities or mental health disorders. We evaluated the association between urban rooftop gardening and quality of life of individuals with moderate to very marked disability. METHODS: We collected quality of life information with a preliminary version of the INTEGRAL Scale questionnaire from all gardeners (n = 54) and among a comparison group of nongardeners (n = 43). We also conducted semi-structured interviews with participants and technicians, and made field observations. RESULTS: Our results indicated that urban rooftop gardening was associated with better personal development and suggested enhanced physical and emotional well-being, sense of purpose, social inclusion, interpersonal relations (including new perspectives on the urban environment and the changes in social roles), and general quality of life. CONCLUSION: Our study extends the evidence on the potential benefits of urban rooftop gardening in general, and specifically for those with intellectual disabilities and mental health disorders.

Do Physical Activity, Social Cohesion, and Loneliness Mediate the Association Between Time Spent Visiting Green Space and Mental Health?

This cross-sectional study investigated whether physical activity, social cohesion, and loneliness mediate the association between time spent visiting green spaces and perceived mental health and vitality. Questionnaire data were collected from 3,948 residents from 124 neighborhoods across four European cities. Multilevel linear regression analysis revealed positive, but weak, associations between time spent visiting green space and Medical Outcome Study Short Form (SF-36) mental health and vitality score, which suggest small mental health benefits. Single mediation analyses showed that different indicators of physical activity (total, during leisure time, and walking during leisure time), social cohesion, and loneliness were mediators. Multiple mediation analyses showed that physical activity during leisure time and loneliness may explain about 25% of the relationship. The unmediated part of the association suggests that other mediators may explain the association.

Fifty Shades of Green: Pathway to Healthy Urban Living.

Currently half the world population lives in cities, and this proportion is expected to increase rapidly to 70% over the next years. Over the years, we have created large, mostly grey cities with many high-rise buildings and little green space. Disease rates tend to be higher in urban areas than in rural areas. More green space in cities could reduce these rates. Here, we describe the importance of green space for health, and make recommendations for further research. Green space has been associated with many beneficial health effects, including reduced all-cause and cardiovascular mortality and improved mental health, possibly through mediators, such as reduced air pollution, temperature and stress, and increased physical activity, social contacts, and restoration. Additional studies are needed to strengthen the evidence base and provide further guidelines to transport planners, urban planners, and landscape architects. We need more longitudinal studies and intervention studies, further understanding of the contribution of various mechanisms toward health, and more information on susceptible populations and on where, when, how much, and what type of green space is needed. Also needed are standardized methods for green space quality assessments and evaluations of effectiveness of green prescriptions in clinical practice. Many questions are ideally suited for environmental epidemiologists, who should work with other stakeholders to address the right questions and translate knowledge into action. In conclusion, a growing evidence base supports the hypothesis that greener cities are healthier cities.

Exploring pathways linking greenspace to health: Theoretical and methodological guidance.

BACKGROUND: In a rapidly urbanizing world, many people have little contact with natural environments, which may affect health and well-being. Existing reviews generally conclude that residential greenspace is beneficial to health. However, the processes generating these benefits and how they can be best promoted remain unclear. OBJECTIVES: During an Expert Workshop held in September 2016, the evidence linking greenspace and health was reviewed from a transdisciplinary standpoint, with a particular focus on potential underlying biopsychosocial pathways and how these can be explored and organized to support policy-relevant population health research. DISCUSSIONS: Potential pathways linking greenspace to health are here presented in three domains, which emphasize three general functions of greenspace: reducing harm (e.g. reducing exposure to air pollution, noise and heat), restoring capacities (e.g. attention restoration and physiological stress recovery) and building capacities (e.g. encouraging physical activity and facilitating social cohesion). Interrelations between among the three domains are also noted. Among several recommendations, future studies should: use greenspace and behavioural measures that are relevant to hypothesized pathways; include assessment of presence, access and use of greenspace; use longitudinal, interventional and (quasi)experimental study designs to assess causation; and include low and middle income countries given their absence in the existing literature. Cultural, climatic, geographic and other contextual factors also need further consideration. CONCLUSIONS: While the existing evidence affirms beneficial impacts of greenspace on health, much remains to be learned about the specific pathways and functional form of such relationships, and how these may vary by context, population groups and health outcomes. This Report provides guidance for further epidemiological research with the goal of creating new evidence upon which to develop policy recommendations.

Validating novel air pollution sensors to improve exposure estimates for epidemiological analyses and citizen science.

Low cost, personal air pollution sensors may reduce exposure measurement errors in epidemiological investigations and contribute to citizen science initiatives. Here we assess the validity of a low cost personal air pollution sensor. Study participants were drawn from two ongoing epidemiological projects in Barcelona, Spain. Participants repeatedly wore the pollution sensor - which measured carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO2). We also compared personal sensor measurements to those from more expensive instruments. Our personal sensors had moderate to high correlations with government monitors with averaging times of 1-h and 30-min epochs (r ~ 0.38-0.8) for NO and CO, but had low to moderate correlations with NO2 (~0.04-0.67). Correlations between the personal sensors and more expensive research instruments were higher than with the government monitors. The sensors were able to detect high and low air pollution levels in agreement with expectations (e.g., high levels on or near busy roadways and lower levels in background residential areas and parks). Our findings suggest that the low cost, personal sensors have potential to reduce exposure measurement error in epidemiological studies and provide valid data for citizen science studies.

The relationship between natural outdoor environments and cognitive functioning and its mediators.

BACKGROUND: Urban residents may experience cognitive fatigue and little opportunity for mental restoration due to a lack of access to nature. Natural outdoor environments (NOE) are thought to be beneficial for cognitive functioning, but underlying mechanisms are not clear. OBJECTIVES: To investigate the long-term association between NOE and cognitive function, and its potential mediators. METHODS: This cross-sectional study was based on adult participants of the Positive Health Effects of the Natural Outdoor Environment in Typical Populations in Different Regions in Europe (PHENOTYPE) project. Data were collected in Barcelona, Spain; Doetinchem, the Netherlands; and Stoke-on-Trent, United Kingdom. We assessed residential distance to NOE, residential surrounding greenness, perceived amount of neighborhood NOE, and engagement with NOE. Cognitive function was assessed with the Color Trails Test (CTT). Mediation analysis was undertaken following Baron and Kenny. RESULTS: Each 100m increase in residential distance to NOE was associated with a longer CTT completion time of 1.50% (95% CI 0.13, 2.89). No associations were found for other NOE indicators and cognitive function. Neighborhood social cohesion was (marginally) significantly associated with both residential distance to NOE and CTT completion time, but no evidence for mediation was found. Nor were there indications for mediation by physical activity, social interaction with neighbors, loneliness, mental health, air pollution worries, or noise annoyance. CONCLUSIONS: Our findings provide some indication that proximity to nature may benefit cognitive function. We could not establish which mechanisms may explain this relationship.

Natural outdoor environments and mental health: Stress as a possible mechanism.

INTRODUCTION: Better mental health has been associated with exposure to natural outdoor environments (NOE). However, comprehensive studies including several indicators of exposure and outcomes, potential effect modifiers and mediators are scarce. OBJECTIVES: We used novel, objective measures to explore the relationships between exposure to NOE (i.e. residential availability and contact) and different indicators of mental health, and possible modifiers and mediators. METHODS: A nested cross-sectional study was conducted in: Barcelona, Spain; Stoke-on-Trent, United Kingdom; Doetinchem, Netherlands; Kaunas, Lithuania. Participants' exposure to NOE (including both surrounding greenness and green and/or blue spaces) was measured in terms of (a) amount in their residential environment (using Geographical Information Systems) and (b) their contact with NOE (using smartphone data collected over seven days). Self-reported information was collected for mental health (psychological wellbeing, sleep quality, vitality, and somatisation), and potential effect modifiers (gender, age, education level, and city) and mediators (perceived stress and social contacts), with additional objective NOE physical activity (potential mediator) derived from smartphone accelerometers. RESULTS: Analysis of data from 406 participants showed no statistically significant associations linking mental health and residential NOE exposure. However, NOE contact, especially surrounding greenness, was statistically significantly tied to better mental health. There were indications that these relationships were stronger for males, younger people, low-medium educated, and Doetinchem residents. Perceived stress was a mediator of most associations, and physical activity and social contacts were not. CONCLUSIONS: Our findings indicate that contact with NOE benefits mental health. Our results also suggest that having contact with NOE that can facilitate stress reduction could be particularly beneficial.

Exploring ownership of change and health equity implications in neighborhood change processes: A community-led approach to enhancing just climate resilience in Everett, MA.

Traditional planning processes have perpetuated the exclusion of historically marginalized communities, imposing vulnerability to climate (health) crises. We investigate how ownership of change fosters equitable climate resilience and community well-being through participatory action research. Our study highlights the detrimental effects of climate gentrification on community advocacy for climate security and health, negatively impacting well-being. We identify three key processes of ownership of change: ownership of social identity, development and decision-making processes, and knowledge. These approaches emphasize community-led solutions to counter climate health challenges and underscore the interdependence of social and environmental factors in mental health outcomes in climate-stressed communities.

The right to the unhealthy deprived city: An exploration into the impacts of state-led redevelopment projects on the determinants of mental health.

Research shows mental health is impacted by poor-quality physical and social-environmental conditions. Subsequently state-led redevelopment/regeneration schemes focus on improving the physical environment, to provide better social-environmental conditions, addressing spatial and socioeconomic inequities thus improving residents' health. However, recent research suggests that redevelopment/regeneration schemes often trigger gentrification, resulting in new spatial and socioeconomic inequalities that may worsen health outcomes, including mental health, for long-term neighborhood residents. Using the right to the city and situating this within the framework of accumulation by dispossession and capitalist hegemony, this paper explores the potential mechanisms in which poor mental health outcomes may endure in neighborhoods despite the implementation of redevelopment/regeneration projects. To do so, we explored two neighborhoods in the city of Glasgow - North Glasgow and East End - and conducted a strong qualitative study based on 25 in-depth semi-structured interviews with key stakeholders. The results show that postindustrial vacant and derelict land spaces and socioeconomic deprivation in North and East Glasgow are potential mechanisms contributing to the poor mental health of its residents. Where redevelopment/regeneration projects prioritize economic goals, it is often at the expense of social(health) outcomes. Instead, economic investment instigates processes of gentrification, where long-term neighborhood residents are excluded from accessing collective urban life and its (health) benefits. Moreover, these residents are continually excluded from participation in decision-making and are unable to shape the urban environment. In summary, we found a number of potential mechanisms that may contribute to enduring poor mental health outcomes despite the existence of redevelopment/regeneration projects. Projects instead have negative consequences for the determinants of mental health, reinforcing existing inequalities, disempowering original long-term neighborhood residents and only providing the "right" to the unhealthy deprived city. We define this as the impossibility to benefit from material opportunities, public spaces, goods and services and the inability to shape city transformations.

Healthy cities after COVID-19 pandemic: the just ecofeminist healthy cities approach.

The COVID-19 pandemic crisis has compromised the 'healthy cities' vision, as it has unveiled the need to give more prominence to caring tasks while addressing intersectional social inequities and environmental injustices. However, much-needed transdisciplinary approaches to study and address post-COVID-19 healthy cities challenges and agendas have been scarce so far. To address this gap, we propose a 'just ecofeminist healthy cities' research approach, which would be informed by the caring city, environmental justice, just ecofeminist sustainability and the healthy cities paradigms and research fields. Our proposed approach aims to achieve the highest standards of human health possible for the whole population-yet putting the health of socially underprivileged residents in the centre-through preserving and/or improving the existing physical, social and political environment. Importantly, the proposed approach recognises all spheres of daily life (productive, reproductive, personal and political) and their connections with inequities, justice and power dynamics. Last, the just ecofeminist healthy cities approach understands human health as interconnected with the health of non-human animals and the ecosystem. We illustrate the proposed new approach focusing on the implications for women's health and public green spaces research and propose principles and practices for its operationalisation.

Residential Proximity to Urban Play Spaces and Childhood Overweight and Obesity in Barcelona, Spain: A Population-Based Longitudinal Study.

Findings on the relationship between play spaces and childhood overweight and obesity are mixed and scarce. This study aimed to investigate the associations between residential proximity to play spaces and the risk of childhood overweight or obesity and potential effect modifiers. This longitudinal study included children living in the city of Barcelona identified in an electronic primary healthcare record database between 2011 and 2018 (N = 75,608). Overweight and obesity were defined according to the WHO standards and we used 300 m network buffers to assess residential proximity to play spaces. We calculated the risk of developing overweight or obesity using Cox proportional hazard models. A share of 29.4% of the study population developed overweight or obesity, but we did not find consistent associations between play space indicators and overweight or obesity. We did not find any consistent sign of effect modification by sex, and only some indications of the modifying role of area socioeconomic status and level of exposure. Although it is not possible to draw clear conclusions from our study, we call for cities to continue increasing and improving urban play spaces with an equitable, healthy, and child-friendly perspective.

Use of the Natural Outdoor Environment in Different Populations in Europe in Relation to Access: Implications for Policy.

This cross-cultural study explores the relationship of natural outdoor environment (NOE) use with NOE access. Most urban planning recommendations suggest optimal accessibility to be 300 m-500 m straight distance to spaces with vegetation of at least 1 hectare. Exploring this recommendation, we used data (n = 3947) from four European cities collected in the framework of the PHENOTYPE study: Barcelona (Spain), Doetinchem (The Netherlands), Kaunas (Lithuania) and Stoke-on-Trent (United Kingdom) to obtain residential access to NOE (straight or network distances, using 300 m and 150 m buffers, to NOE larger than 1 hectare or 0.5 hectare) and use of NOE (i.e., self-reported time spent in NOE). Poisson regression models were used to examine the associations between residential access and use of NOE. The models with the strongest association with time spent in NOE in the combined sample were for those living within 300 m straight line distance to either 0.5 ha or 1 ha NOE. Noting that the only indicator that was consistent across all individual cities was living with 150 m network buffer of NOE (of at least 1 ha), this warrants further exploration in reducing recommendations of 300 m straight-line distance to 150 m network distance to 1 ha of NOE for a general indicator for cities within Europe.

Sociodemographic determinants of intraurban variations in COVID-19 incidence: the case of Barcelona.

BACKGROUND: Intraurban sociodemographic risk factors for COVID-19 have yet to be fully understood. We investigated the relationship between COVID-19 incidence and sociodemographic factors in Barcelona at a fine-grained geography. METHODS: This cross-sectional ecological study is based on 10 550 confirmed cases of COVID-19 registered during the first wave in the municipality of Barcelona (population 1.64 million). We considered 16 variables on the demographic structure, urban density, household conditions, socioeconomic status, mobility and health characteristics for 76 geographical units of analysis (neighbourhoods), using a lasso analysis to identify the most relevant variables. We then fitted a multivariate Quasi-Poisson model that explained the COVID-19 incidence by neighbourhood in relation to these variables. RESULTS: Neighbourhoods with: (1) greater population density, (2) an aged population structure, (3) a high presence of nursing homes, (4) high proportions of individuals who left their residential area during lockdown and/or (5) working in health-related occupations were more likely to register a higher number of cases of COVID-19. Conversely, COVID-19 incidence was negatively associated with (6) percentage of residents with post-secondary education and (7) population born in countries with a high Human Development Index. CONCLUSION: Like other historical pandemics, the incidence of COVID-19 is associated with neighbourhood sociodemographic factors with a greater burden faced by already deprived areas. Because urban social and health injustices already existed in those geographical units with higher COVID-19 incidence in Barcelona, the current pandemic is likely to reinforce both health and social inequalities, and urban environmental injustice all together.

Green gentrification in European and North American cities.

Although urban greening is universally recognized as an essential part of sustainable and climate-responsive cities, a growing literature on green gentrification argues that new green infrastructure, and greenspace in particular, can contribute to gentrification, thus creating social and racial inequalities in access to the benefits of greenspace and further environmental and climate injustice. In response to limited quantitative evidence documenting the temporal relationship between new greenspaces and gentrification across entire cities, let alone across various international contexts, we employ a spatially weighted Bayesian model to test the green gentrification hypothesis across 28 cities in 9 countries in North America and Europe. Here we show a strong positive and relevant relationship for at least one decade between greening in the 1990s-2000s and gentrification that occurred between 2000-2016 in 17 of the 28 cities. Our results also determine whether greening plays a "lead", "integrated", or "subsidiary" role in explaining gentrification.