Potential impacts of the continuing urbanization on regional climate: The developing Phoenix-Tucson “Sun Corridor”

The metropolitan region of Phoenix Arizona has, since the 1950‘s, been one of the fastest-growing urban areas in the United States (Chow et al., 2012). It has undergone substantial land use and land cover change (hereafter LULCC) since the Second World War, by shifting economic priorities from a mostly agrarian lifestyle to an urbanized one. As the baby-boom generation reached adulthood in the 1970‘s, an era of very rapid development began, with a large number of job opportunities becoming available in the metropolitan area. By 2010, Phoenix (the largest populated city in Arizona) reached a population of 1.4 million, and had an urban extension of 1,338.26 km2 (US Census, 2010). Meanwhile, Tucson has become the second-largest city, with an area of 588 km2 and a population of about 520,116 (US Census, 2010). With continuing development, both cities are projected to grow towards each other along what has been called the “Arizona Sun Corridor”. By the year 2050, under a high intensity development scenario, the “Sun Corridor” is projected to develop as shown in Figure 1, with urban landscapes replacing agricultural and native semidesert landscapes. Recent research by Georgescu et al. (2012) has suggested that projected urbanization could impact summer-season local to regional temperatures to a level that is as significant as those induced by large scale-climate change.