No abstract

Access to air conditioned space is critical for protecting urban populations from the adverse effects of heat exposure. Yet there remains fairly limited knowledge of the penetration of private (home air conditioning) and distribution of public (cooling centers and commercial space) cooled space across cities. Furthermore, the deployment of government-sponsored cooling centers is likely to be inadequately informed with respect to the location of existing cooling resources (residential air conditioning and air conditioned public space), raising questions of the equitability of access to heat refuges. We explore the distribution of private and public cooling resources and access inequities at the household level in two major US urban areas: Los Angeles County, California and Maricopa County, Arizona (whose county seat is Phoenix). We evaluate the presence of in-home air conditioning and develop a walking-based accessibility measure to air conditioned public space using a combined cumulative opportunities-gravity approach. We find significant variations in the distribution of residential air conditioning across both regions which are largely attributable to building age and inter/intra-regional climate differences. There are also

In the coming decades, ambient temperature increase from climate change threatens to reduce not only the availability of water but also the operational reliability of engineered water systems. Relatively little is known about how temperature stress can increasingly cause hardware components to fail, quality to be affected, and service outages to occur. Changes to the estimated-time-to-failure of major water system hardware and the probability of quality noncompliance were estimated for a modern potable water system that experiences hot summer temperatures, similar to Phoenix, AZ, and Las Vegas, NV. A fault tree model was developed to estimate the probability that consequential service outages in quantity and quality will occur. Component failures are projected to have a percent increase of 10-101% in scenarios where peak summer temperature has increased from 36 to 44 °C, which create the conditions for service outages to have a percent increase of 7-91%. Increased service outages due to multiple pumping unit failures and water quality noncompliances are the most notable concerns for water utilities. The most effective strategies to prevent temperature-related failures should focus on monitoring and correcting chlorine residual and disinfection byproduct concentration, and on cooling pumping unit motors and electronics.

Graduate programs emerging in universities over recent decades support the advanced study of sustainability issues in complex socio-environmental systems. Constructing the problem-scope to address these issues requires graduate students to integrate across disciplines and synthesize the social and natural dimensions of sustainability. Graduate programs that are designed to foster inter-and transdisciplinary research acknowledge the importance of training students to use integrative research approaches. However, this training is not available in all graduate programs that support integrative research, often requiring students to seek external training opportunities. We present perspectives from a group of doctoral students with diverse disciplinary backgrounds conducting integrative research in universities across the United States who participated in a 10-day, National Science Foundation-funded integrative research training workshop to learn and develop socio-environmental research skills. Following the workshop, students conducted a collaborative autoethnographic study to share pre-and postworkshop research experiences and discuss ways to increase integrative research training opportunities. Results reveal that students, regardless of disciplinary background, face common barriers conducting integrative research that include: (1) lack of exposure to epistemological frameworks and team-science skills, (2) challenges to effectively include stakeholder perspectives in his/her research, and (3) variable levels of committee support to conduct integrative research. To overcome the identified barriers and advance integrative research, students recommend how training opportunities can be embedded within existing graduate programs. Students advocate that both internal and external training opportunities are necessary to support the next generation of sustainability scientists.

The capacities of our infrastructure systems to respond to volatile, uncertain, and increasingly complex environments are increasingly recognized as vital for resilience. Pervasive across infrastructure literature and discourse are the concepts of centralized, decentralized, and distributed systems, and there appears to be growing interest in how these configurations support or hinder adaptive and transformative capacities towards resilience. There does not appear to be a concerted effort to align how these concepts are used, and what different configurations mean for infrastructure systems. This is problematic because how infrastructure are structured and governed directly affects their capabilities to respond to increasing complexity. We review framings of centralization, decentralization, and distributed (referred to collectively as de/centralization) across infrastructure sectors, revealing incommensurate usage leading to polysemous framings. De/centralized networks are often characterized by proximity to resources, capacity of distribution, volume of product, and number of connections. De/centralization of governance within infrastructure sectors is characterized by the number of actors who hold decision-making power. Notably, governance structures are often overlooked in infrastructure de/centralization literature. Next, we describe how de/centralization concepts are applied to emerging resilient infrastructure theory, identifying conditions under which they support resilience principles. While centralized systems are dominant in practice and decentralized systems are promoted in resilience literature, all three configurations—centralized, decentralized, and distributed—were found to align with resilience capacities in various contexts of stability and instability. Going forward, we recommend a multi-dimensional framing of de/centralization through a network-governance perspective where capabilities to shift between stability and instability are paramount and information is a critical mediator.