Cross-border Contrast in Roof Albedos: Cd. Juárez, Mexico vs. El Paso, USA
Abstract
The El Paso-Juárez binational metroplex is a continuous urban setting separated by the narrow Rio Grande. The twin border cities lie within the Chihuahuan desert and experience intense summer heat, a significant health hazard for residents, some 1.5 million in Cd. Juárez and 750,000 in El Paso. Further, according to the local National Weather Service, El Paso is warmer today than in the 20th century; continuing increases are expected due to global warming. Initial data gathered from satellite imagery delineates a sharp and obvious contrast in albedo between the contiguous cities. Roof counts verify that Cd. Juárez has a preponderance of white or light-colored roofs on residences, whereas traditional darker-colored roofs predominate in El Paso. The darker roofs in El Paso undoubtedly contribute to residential summer heat load in the city and may contribute to the overall ambient urban heat burden. The low-income of many El Paso residents (annual average $20,050) precludes conventional air-conditioning; only swamp (evaporative) coolers or fans are affordable, resulting in excessive heat exposure. Summer drives by community organizations for fans for vulnerable low-income elderly residents highlight this health issue. Interestingly, roofs on factories and large commercial structures in both cities are white; apparently, style is not a consideration in these settings. Reflective surfaces, such as white roofs, are an emerging geoengineering approach to mitigate the effects of global warming. A switch to white roofs in new construction in El Paso, or even conversion of existing homes, would moderate the summer heat load and perhaps ameliorate the urban heat island effect. An additional benefit of white roofs is a decrease in energy consumption by cooling systems and resultant reduced energy costs. Although some studies caution that light roofs could yield cooler winter temperatures, the summer heat is the primary health concern for this desert region. Residents of Cd. Juárez and El Paso (80% Hispanic, many with cross-border relatives) share common cultural roots yet reasons for roofing differences are not obvious; lower-income in Cd. Juárez may have driven their wiser roof choice. A policy of education, or possibly municipal legislation, regarding roof color could benefit the health and economy of the El Paso community.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGH31B1162A
- Keywords:
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- 0240 Public health;
- GEOHEALTH;
- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 4313 Extreme events;
- NATURAL HAZARDS;
- 4330 Vulnerability;
- NATURAL HAZARDS