During the mid-part of the last decade, when the population growth rate was at its highest, the Phoenix area experienced rapid development and urban sprawl. The result has been an intensification of the Urban Heat Island effect. In this edition of Decades, author Sally Wittlinger discusses this uncomfortable consequence of urbanization.

In a desert city such as Phoenix, summertime heat is a way of life, but how much does the built environment contribute to the intensity of the heat on a summer night? In urbanized Phoenix, nights don’t cool down as much as in the surrounding rural areas and on more and more summer nights, the official Phoenix temperature fails to drop below 90 degrees. Climate plays a huge role in the comfort and quality of life of residents, with numerous implications for tourism, energy demand, water use, and the vulnerability of low-income families.

Both the effect of climate change on our future water supply and the size of the population that will need to share in that supply are uncertainties that water planners must consider when making decisions regarding our future. We have options, but we have to be sure that we use water efficiently to meet our urban, agricultural, and environmental needs. This Policy Points offers a clear, succinct overview of the status of Arizona’s water supply and what the current drought really means for water availability.

As Arizona’s population continues to grow, so does the need for electricity. Retail sales of electricity in Arizona have increased along with the population, although sales per person have declined since peaking in 2007, a sign of decreased use and increased efficiency. As we progress in the twenty-first century, action must be taken to increase the sustainability of our energy resources by continuing to conserve and by shifting to the greater use of energy from renewable sources. In addition, we must work to mitigate climate change by reducing greenhouse gas emissions.

Chronicles how the intention to conserve a relic population of Gila topminnow under current resource conditions is generally insufficient. We have let the resource base degrade too far to expect project and site specific responses to stem losses, much less lead to recovery. The Gila topminnow was considered to be among the most common of fishes in the Santa Cruz River system in the early 1940s. Three decades later is was considered endangered; and in another three decades time, its recovery is not foreseeable, given the piecemeal approach to protection efforts.