Juan Declet-Barreto
Senior Social Scientist for Climate Vulnerability

The legend of the mythological Phoenix tells the story of a “female sacred firebird with beautiful gold and red plumage”. It was said that at the end of its centenarian plus life-cycle, the Phoenix ignited herself among a nest of twigs, and, reducing itself to ashes, a new young Phoenix would arise from the smolder.  It’s a fitting metaphor for Phoenix, Arizona, a relatively young city at 150 years, yet located in the Salt River valley, a Sonoran Desert region that has been inhabited and abandoned by people for thousands of years before its current form as a sprawling metropolitan area.

The history of human occupation of the Salt River Valley, is, indeed, a story of birth and rebirth, starting with the Hohokam people, who by the 13th century had engineered an extensive network of irrigation canals for subsistence farming. The Hohokam were remarkably well-adapted to their arid environment. In the absence of sufficient rainfall, they were the only North American culture that used irrigation canals to water their crops. The Hohokam peoples disappeared from the Valley for reasons that are not completely understood, however we know that between AD 1350 to 1450, their population declined drastically, and disappeared from the archaeological record. In the recent past, the Akimel O’odhom (or O’otham) native people have continuously farmed this area for hundreds of years – and live on as a federally-recognized tribe.

Fast-forward to the late 1800s: Phoenix is “reborn” from the ashes of the abandoned Hohokam canals in the Salt River valley, when miners, farmworkers, ranchers, and soldiers rebuilt the irrigation canals to create profitable, export-oriented agriculture. Even at this point in the modern history of the U.S. Southwest, we begin to see the emergence of climate vulnerable communities – an imprint that’s still visible today.

Physiological and structural dimensions of heat vulnerability

But wait – isn’t the late 1800s a little bit too early to talk about frontline and other climate-vulnerable communities? Not according to our new research  that highlights how choices made pre 1900 have reverberated into our current climate crisis.  In our contribution, called “Pathways to Climate Justice in a Desert Metropolis”, we argue that in Phoenix, there are two distinct but intertwined dimensions of heat-related vulnerability: one is physiological; the other structural. Physiological vulnerability to heat is dependent on pre-existing illness, old age, or being exposed to outdoor work, often compromising the human body’s capacity to keep internal temperature near 37.0°C (98.6°F) to avoid death or illness. The public health evidence is clear on this: statistics for Maricopa County in 2016 show that males, people over 50 years of age, people experiencing homelessness, people of color, the poor, the socially-isolated, those without AC at home, or with pre-existing cardiovascular or respiratory disease were significantly overrepresented in heat-related deaths and non-fatal illnesses. The other dimension is structural and can traced back to the late 1800s when the city was founded. Historical racial segregation of people mostly poor and disproportionately of color has resulted in a stratum of the population that is residentially vulnerable to climate change.



Slums along the Salt River irrigation canals where Mexicans and other non-Whites were segregated contrast with elegant housing in uptown in early 20th century Phoenix

 The segregation origins of climate injustices in Phoenix: “Mexican Tenements”

In our research we found, for example, old fire insurance maps that showed that in the early 1900s, Mexicans and other non-Whites were segregated to South Phoenix, the “wrong side of the [railroad] tracks”, where housing was improvised and substandard.  In a time before formal land use regulations, fire insurance maps provide evidence of de facto segregation, as the more unsanitary quarters of the city were designated for Mexicans and other non-Whites to live in. In old photographs from Gov. Barry Goldwater’s collected papers, we found great contrast between slums along the irrigation canals in South Phoenix—where farmhands and their families lived in squalor–, and the elegantly manicured landscapes and houses of the well-heeled in areas north of downtown Phoenix. This is evidence of what geographers focused on social disparities call “uneven economic development”, which refers to inequitable concentrations of wealth in some areas, and squalor and clusters of industrial and other unwanted land uses in others. Environmental contamination from facilities that store or process toxic chemicals, and little shading vegetation were, and continue to be, prominent features of the impoverished areas of South Phoenix, which today are among the hottest and most polluted areas of the Phoenix metro region.

Race-based segregation has existed in Phoenix since the early 1900s

Hang on a second – isn’t Phoenix hot for everybody?

Everyone who lives in Phoenix is affected by the naturally hot desert environment and increases in temperatures from global climate change are uniform throughout the region. But the Phoenix urban core (where many low-income people of color live) warmed faster (6°C/10.8°F) between the 1940s and the present than areas on the urban edge (3°C/5.4°F) in the same period, a gradient of urban-generated heat that is unevenly distributed, and that varies spatially according to topography, land cover, and wind patterns. In addition, not everyone has the same capacity to fend off the worst health effects, nor are people exposed to outdoor heat the same way. Low-income communities have less economic and other resources to help them avoid the worst consequences of extreme heat. For example, the poor have less access to air conditioning (either to have a unit in their home or pay for its use), a key way in which heat deaths are avoided. Similarly, lack of access to preventative health care to deal with pre-existing conditions that can trigger hospital visits during extreme heat episodes (such as cardiovascular disease, obesity, or diabetes), is common among those living in poverty. Further, many low-income workers in Phoenix work outdoors in construction and landscaping, exposing them directly to heat.

The Phoenix urban core warmed much faster than areas on the urban edge due to the Urban Heat Island

Climate adaptation pathways that benefit the poor and vulnerable

Many prescribed adaptations such as electricity for AC, mobility to escape the heat, irrigation for residential shading vegetation, and adequate housing are out of reach for most low-income households, and their neighborhoods also have less trees, parks, and other heat-reducing green spaces.  There are also barriers at larger scales in Arizona– politicians there are mostly opposed to addressing climate change; policies to improve residential indoor cooling like home energy assistance programs reach just 6 percent of eligible persons; substandard housing makes AC-based cooling unaffordable; and grassroots activists are more focused on priorities that affect Latinos such as immigration and the economy than on climate change.

In light of the individual and structural inequities that shape heat vulnerability in Phoenix, what are some ways in which climate adaptation can be realistic for the most vulnerable? We think that an explicitly pro-poor adaptation framework can help identify the physical, financial, human, social, and natural assets of low-income communities that can be harnessed to reduce vulnerability— and this requires purposeful engagement with low-income communities. We concluded our chapter by suggesting pro-poor interventions pathways in metro Phoenix:

  • Reordering of state and local government social priorities – In Phoenix there are large deficiencies in the poor population’s needs for food, shelter, education, health care, and living wage work, which influence climate vulnerability. The public sector has an obligation to help address these.
  • Increasing public subsidies for cooler indoor and outdoor environments – Green spaces, residential weatherization programs, and energy subsidies need to target low-income households, including renters.
  • Support for bottom-up initiatives to community problems – Meaningful engagement with vulnerable communities in decision-making can empower communities to not only focus on immediate issues like jobs or immigration, but also to take on existing and future climate risks.

It wasn’t lost on us that it’s very probable the original Hohokam settlement disappeared because of climate change – but we wonder if the settlers of modern Phoenix considered that. And who can forget that Phoenix has been called “The World’s Least Sustainable City”, while others ask if it’s on the brink of becoming uninhabitable? Adaptation policies must embrace climate justice at the local level while recognizing both the global scale of the climate system and the socio-spatial variability of climate impacts within regions like metro Phoenix. Pro-poor adaptation pathways must do so by calling for a fair distribution of social and climate burdens.

Read the chapter here.