Urban Areas describes Southwestern cities—focusing on the large metropolitan areas of Albuquerque, Denver, Las Vegas, Los Angeles, Phoenix, and Salt Lake City—and shows how these regions will contribute to and be affected by climate changes, such as through their “urban metabolisms”—the flows of water, energy, materials, and other resources—and how to minimize the negative effects.
Citation:
Pincetl, S., G. Franco, N. B. Grimm, T. S. Hogue, S. Hughes, E. Pardyjak, A. M. Kinoshita, and P. Jantz. 2013. “Urban Areas.” In Assessment of Climate Change in the Southwest United States: A Report Prepared for the National Climate Assessment, edited by G. Garfin, A. Jardine, R. Merideth, M. Black, and S. LeRoy, 267–296. A report by the Southwest Climate Alliance. Washington, DC: Island Press.
Stephanie Pincetl (Institute of the Environment and Sustainability, University of California, Los Angeles)
Guido Franco (California State Energy Commission)
Nancy B. Grimm (Arizona State University)
Terri S. Hogue (Civil and Environmental Engineering, UCLA)
Sara Hughes (National Center for Atmospheric Research)
Eric Pardyjak (University of Utah, Department of Mechanical Engineering, Environmental Fluid Dynamics Laboratory)
Alicia M. Kinoshita (Civil and Environmental Engineering, UCLA)
Patrick Jantz (Woods Hole Research Center)
Key Findings
The unique characteristics of Southwest cities will shape the ways they will be affected by climate change and the ways they will adapt.
The impacts of climate change on Southwest cities will be largely centered on water scarcity, flooding, wildfires, and extreme temperatures.
Cities are likely to experience more high-temperature days, creating vulnerabilities for persons who lack access to air conditioning.
Many Southwest cities rely on water supplies from large-scale water storage and delivery structures, potentially vulnerable to climate change.
Myriad and overlapping governmental organizations in urban areas (such as for Los Angeles) can create barriers for climate adaptation efforts.
Figure Gallery
Figure 13.1: Population change in Southwest cities, 2000–2010. Source: U.S. Census Bureau, 2010 data (http://2010.census.gov/ 2010census/).
Figure 13.2: Human settlements (impervious surfaces) in the Southwest, 2000 and 2100. The 2100 scenario is compatible with the IPCC A2 high-emissions scenario. Reproduced from the ICLUS web viewer (http://134.67.99.51/ICLUSonline/, accessed on 2/12/2012).
Figure 13.3: FEMA 100-year and 500-year floodplains in California. Adapted from Galloway et al. (2007).
Figure 13.4: Trends in heating and cooling degree days in major urban areas of the Southwest. Trends in heating degree-days (left) and cooling degree-days (right) are based on 65°F (18.3°C) and 75°F (23.9°C) bases, respectively, for the period 1950 to 2009 in seventeen urban areas. Blue circles represent decreasing trends and red increasing trends. The trends are proportional to the diameter of the circles. Filled circles represent statistically significant trends. See glossary for definitions of heating and cooling degree-days. Adapted from Mishra and Lettenmaier (2011) with permission from the American Geophysical Union.
Figure 13.5: Trends in the annual 1-day maximum daily precipitation amounts in major urban areas of the Southwest. Blue circles represent decreasing trends and red increasing trends. The trends are proportional to the diameter of the circles. Filled circles represent statistically significant trends. Adapted from Mishra and Lettenmaier (2011) with permission from the American Geophysical Union.
Figure 13.6: Anthropogenic heat flux estimates for three Southwest cities, shown in watts per square meter. Urban built-up (no vegetation), urban mesic residential (well-watered flood or overhead irrigated), and urban xeric residential (drought-adapted vegetation with drip irrigation) are distinguished by their type of vegetation and irrigation, listed in parentheses. Adapted from Sailor and Lu (2004) and Grossman-Clarke et al. (2005).
Figure 13.7: Embodied CO2 emissions associated with goods and services exported (left) and imported (right), for selected countries. Colors represent trade of finished goods by industry sector. Reproduced from Davis and Caldeira (2010).
Figure 13.8: Average daily net CO2 emissions for different cities around the world during summer months. Adapted from Ramamurthy and Pardyjak (2011).
Figure 13.9: Changes of ozone (O3) concentrations due to the “CO2 dome” effect in Los Angeles. Modeled differences in ozone concentration in parts per billion from two simulations (with and without CO2 emissions in Los Angeles); August-October. Contour lines indicate topography. The darker areas inland, to the south and west of the San Gabriel and Santa Ana Mountains (e.g., at approximately 33.7°N, 117.2°W), show increases in surface ozone, due to increased CO2 aloft. Increased ozone is implicated in air pollution-related deaths. Adapted with permission from the American Chemical Society (Jacobson 2010a, 2501).
Figure 13.10: Per capita water use in Southwest cities (2000–2010). Source: Great Western Institute (2010), Salt Lake City Department of Public Utilities (SLCDPU 2009), Los Angeles Department of Water and Power (LADWP 2011), City of Albuquerque (http://www.cabq.gov/), City and County of Denver (http://www.denvergov.org/), Southern Nevada Water Authority (http://snwa.com/), Salt Lake City Public Utilities (http://www.slcclassic.com/utilities/), City of Phoenix (http://phoenix.gov/), Los Angeles Department of Water and Power (http://www.ladwp.com/).
Figure 13.11: Satellite image of urban Los Angeles (top) and Phoenix (bottom). The two cities are surrounded by undeveloped mountainous areas and public lands. Image by Geology.com using Landsat data from NASA.
Figure 13.12: Total acres burned in wilderness/urban interface zones of six Southwestern cities. Source: U.S. Department of the Interior’s Geospatial Multi-Agency Coordination Group (GeoMAC) Wildland Fire Support (http://www.geomac.gov), State of California Fire and Resource Assessment Program (http://frap.cdf.ca.gov).
Figure 13.13: Public transit use and carbon footprints of Southwest cities. Source: U.S. Census Bureau American Community Survey 2009 (http://www.census.gov/acs/www/data_documentation/ 2009_release/), and Brown, Sarzinski and Southworth (2008).
Figure 13.14: Number of misery and frost days in Phoenix, 1900–2010. Note the increase in misery days, and decrease in frost days during the last 40 years. Source: Ruddell et al. (2012).
Figure 13.15: Average annual minimum temperatures for six Southwestern cities (in oF). Source: Prism Climate Group (2011), Oregon State University, http://prism.oregonstate.edu.
Figure 13.16: Average annual rainfall (in inches) in six Southwestern cities, 1895–2010. Source: Prism Climate Group (2011), Oregon State University, http://prism.oregonstate.edu.