Planning for climate justice in American cities

Chingwen Cheng
Arizona State University, USA

In recent years, climate justice has been intensively discussed in a global context (e.g., United Nations Climate Change Conferences) and in terms of the extent to which the least carbon polluting countries (i.e., undeveloped countries and island nations) have suffered most from climate change impacts. To understand climate justice at national and local scale in American cities, this article draws knowledge from well-established environmental justice and hazard research and identifies gaps for local-based climate justice assessment in the United States by utilizing a case study from the Huron River Watershed near Detroit, Michigan.

Social and environmental justice and climate change

Climate change is associated with increased frequency and intensity of extreme weather and aggravated the extent of impacts on the currently hazard-prone areas in cities. As the process of urbanization increases world-wide, more people are likely to be exposed to and suffer from climate change-associated environmental hazards. For example, in a business-as-usual urban growth scenario, by 2030 the Boston metropolitan area is projected to place 13,000 more residents in areas with a high concentration of socially vulnerable groups and a high probability of increased climate change-induced flooding hazards (Figure 1) (Cheng, 2013).

Figure 1
Figure 1: Distribution of projected population growth in 2030 in the Charles River watershed among four growth scenarios highlighted total number of people to be allocated in areas of Climate Change-Induced Flooding Risk Index (RI) Hot Spots (>1.65 Std. Dev.) illustrating Current Trends, the business-as-usual scenario, would expose the most people in areas where have high flooding hazards and high social vulnerability (Cheng, 2013).

Environmental justice research has found strong relationships between poor environmental quality and socioeconomic indicators such as race and the siting of hazardous facilities (Bullard et al., 2008). In addition, hazard studies have identified social vulnerability indicators to natural disasters in American cities. Social vulnerability can be a factor of demographic, social, economic and political status, in addition to urban context (e.g., age, gender, race, income, immigration status, education, occupation, social welfare and medical resources, housing density (Cutter et al., 2003)).

The lack of equity planning in American cities is also reflected in a recent study on hundreds of cities’ sustainability plans that failed to include social justice goals and make equity an accountable outcome compatible with environmental and economic goals of sustainability (Schrock et al., 2015). Several efforts have been made to develop environmental justice indices, notably the recent Environmental Justice Screening and Mapping Tool (EJSCREEN) (USEPA, 2015). Such indices have included measures of potential environmental exposure at the census-tract level using available environmental hazard sources; however, no index to date has taken into account the anticipated impacts of climate change on both local biophysical environments and vulnerable populations.

As vulnerability and adaptive capacity vary from region to region and community to community, climate justice has not been addressed in local planning due to a lack of empirical studies and assessment tools. We applied an environmental justice framework to examine the disparities between climate change-associated hazards and unequal capacity in socially vulnerable groups to mitigate hazards and adapt to climate change.

Figure 2
Figure 2: Huron River watershed study area in Michigan, USA. Image Credit: Author

Case study: The Huron River Watershed

The state of Michigan has a long history in environmental justice, particularly supported by the evidence of hazardous waste facility sites targeting poor and minority neighborhoods since 1970s (Saha & Mohai, 2005). Recent news on the lead-polluted water crisis in a historical motor-manufacturer city, Flint, Michigan, where currently more than 56% of the population are African Americans and more than 40% are under poverty, has once again drawn a national attention on the environmental justice issue.

Table 1To assess regional climate justice issue around Detroit (one of the most polluted cities in Michigan), the Huron River watershed was chosen as a pilot study. The watershed drains more than 2,300 km2 and intersects seven counties in southeast of Michigan, including part of Oakland and Wayne counties that border the core of the metro Detroit area. The watershed contains a population about 500,000 residents across 65 municipalities, including major cities such as Ann Arbor and Ypsilanti along the lower basin of the mainstream (Figure 2).

Table 2A Climate Justice Index (CJI) was developed with equal weights of three indices—the Climate Change-Induced Flooding Hazard Index (CCFHI), Environmental Hazard Index (EHI), and Social Vulnerability Index (SoVI). CCFHI refers to potential increased flooding events, compared to the baseline condition, as a result of changing climate conditions. EHI serves as a proxy for water quality associated with environmental hazard sources (Table 1), assuming that all environmental hazard sites are susceptible to direct and indirect sources for both surface and underground water pollution in each hydrologic sub-basin unit. Table 2 includes a list of 33 indicators applied in building the SoVI. Finally, a Green Infrastructure Index (GII) was employed as a proxy for access to green infrastructure resources.

Figure 3 illustrates the results of the three indices before being synthesized into one single Climate Justice Index (CJI) indicating Wixom is the most sensitive to climate change-induced flooding with high environmental pollution (EHI=5) and high social vulnerability (SoVI=5). Figure 4 illustrates the synthesized CJI, comparing the baseline conditions at zero flooding increase in current climate conditions with lower and higher impact of climate change scenarios. Cities of Wixom, Ann Arbor and Ypsilanti are areas likely to face climate injustice (CJI=3) and Wixom is highly susceptible to climate injustice particularly in the higher climate change impact scenario. To further analyze the spatial distribution of climate justice issues, Figure 5 demonstrates the results of Hot Spot Analysis from ArcGIS and highlighted the cities of Ann Arbor, Ypsilanti and Wixom for climate justice. Unfortunately, those cities are also with high deficiency in green infrastructure resources (GII=5) (Figure 6). Finally, spatial statistics suggest a significant cluster pattern (Moran’s I =0.35) that areas with a high level of climate justice (CJI=5) coincides with high deficiency of green infrastructure (GII=5).

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Policy Impacts

This study highlighted empirical evidence of climate justice concerns around cities of Wixom, Ann Arbor, and Ypsilanti in the Huron River watershed in the state of Michigan. In particular, under the higher climate change impact conditions, climate justice becomes more prominent in the Wixom area.

The Cities of Ann Arbor and Ypsilanti have recently (2012) developed their Climate Action Plans and indicated the development of green infrastructure as one of their “no-regret” strategies. The plans primarily focus on climate change mitigation strategies for greenhouse gas reduction. Equity goal was mentioned in the statement but there was no accountability nor provided with vulnerability assessment. The Huron River Watershed Council (HRWC), a not-for-profit organization, have assisted their watershed communities to develop “community resilient” plans, taking climate-change impacts into consideration, to address water resources management (such as dam operations), water infrastructure, and in-stream flows. Even though the issue of climate justice remains to be addressed in the watershed communities, with additional assistance and resources from the HRWC, communities gained support in building social-political capacity in green infrastructure planning and implementation (Matthews et al., 2015).

Among the hot spots of climate justice communities, Ann Arbor and Ypsilanti have acquired HRWC’s assistance in building resiliency through the understanding of potential climate change impacts on the watershed management systems as well as by outlining strategies to cope with climate change. The Ann Arbor–Ypsilanti area therefore has a greater social-political feasibility to increase its green infrastructure capacity for climate change adaptation and a greater potential to address the issue of climate justice in city’s planning. However, Wixom has not yet made plans for climate change. During the process of this study, the HRWC has reached out Wixom in regards to the climate change adaptation efforts yet no action items have been developed. Consequently, the Wixom area has both low biophysical and social-political feasibility to leverage green infrastructure for climate change adaptation, making Wixom the area with the lease capacity in both biophysical and social-political resilience to climate change and with the highest alert for climate injustice in the Huron River watershed.

Climate Justice in Urban Planning

Amid world leaders’ efforts in reducing carbon emission for climate change mitigation, the impacts of climate change are affecting every community around the world and ongoing conversations on global climate change adaptation strategies (e.g., world refugee for relocating populations on island nations in the face of sea-level rises) are still in the talk. Addressing climate change adaptation and climate justice in local scale is therefore urgent and critically aligns with urban planning practices. While this article presented a climate justice assessment framework in American context, the place-based assessment framework combined with biophysical and social-political feasibility assessment of green infrastructure capacity for climate change adaptation can be applied in any place around the world adjusted with local context on social and environmental vulnerability indicators. The climate justice assessment at a local scale can help to inform decision-making in prioritizing climate change adaptation investment such as applying the “win-win” green infrastructure strategy in areas with the greatest social needs. In turn, green infrastructure can be effectively implemented in every city to optimize ecosystem services benefits while addressing climate justice.


This article is extracted from:

Cheng, C. (2016). Spatial Climate Justice and Green Infrastructure Assessment: A case for the Huron River watershed, Michigan, USA. GI_Forum, 1, pp. 176-190.


Dr. Chingwen Cheng is Assistant Professor at The Herberger Institute for Design and the Arts at Arizona State University.  She is also a Senior Sustainability Scientist at the Julie Ann Wrigley Global Institute of Sustainability.

Header Image: Barge on the Huron River near Detroit, Michigan.  Image Credit: Ivan Cholakov /

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