Moderate physical activity, such as walking and biking, positively affects physical and mental health. Outdoor thermal comfort is an important prerequisite for incentivizing an active lifestyle. Thus, extreme heat poses significant challenges for people who are outdoors by choice or necessity. The type and qualities of built infrastructure determine the intensity and duration of individual exposure to heat. As cities globally are shifting priorities towards non-motorized and public transit travel, more residents are expected to experience the city on their feet. Thus, physical conditions as well as psychological perception of the environment that affect thermal comfort will become paramount. Phoenix, Arizona, is used as a case study to examine the effectiveness of current public transit and street infrastructure to reduce heat exposure and affect the thermal comfort of walkers and public transit users.

The City of Phoenix has committed to public transit improvements in the Transportation 2050 plan and has recently adopted a Complete Streets Policy. Proposed changes include mobility improvements and creating a safe and comfortable environment for non-motorized road participants. To understand what kind of improvements would benefit thermal comfort the most, it is necessary to understand heat exposure at finer spatial scales, explore whether current bus shelter designs are adequate in mitigating heat-health effects, and comprehensively assess the impact of design on physical, psychological and behavioral aspects of thermal comfort. A study conducted at bus stops in one Phoenix neighborhood examined grey and green infrastructure types preferred for cooling and found relationships between perception of pleasantness and thermal sensation votes. Walking interviews conducted in another neighborhood event examined the applicability of a framework for walking behavior under the stress of heat, and how differences between the streets affected perceptions of the walkers. The interviews revealed that many of the structural themes from the framework of walking behavior were applicable, however, participants assessed the majority of the elements in their walk from a heat mitigation perspective. Finally, guiding questions for walkability in hot and arid climates were developed based on the literature review and results from the empirical studies. This dissertation contributes to filling the gap between walkability and outdoor thermal comfort, and presents methodology and findings that can be useful to address walkability and outdoor thermal comfort in the world’s hot cities as well as those in temperate climates that may face similar climate challenges in the future as the planet warms.

City governments are increasingly incorporating urban and peri-urban agriculture into their policies and programs, a trend seen as advancing sustainability, development, and food security. Urban governance can provide new opportunities for farmers, but it also creates structures to control their activities, lands, and purposes.

This study focused on Mexico City, which is celebrated for its agricultural traditions and policies. The study examined: 1) the functions of urban and peri-urban agriculture that the Government of Mexico City (GMC) manages and prioritizes; 2) how the GMC’s policies have framed farmers, and how that framing affects farmers’ identity and purpose; and 3) how the inclusion of agrarian activities and lands in the city’s climate-change adaptation plan has created opportunities and obstacles for farmers. Data was collected through participant observation of agricultural and conservation events, informal and semi-structured interviews with government and agrarian actors, and analysis of government documents and budgets.

Analysis of policy documents revealed that the GMC manages agriculture as an instrument for achieving urban objectives largely unrelated to food: to conserve the city’s watershed and provide environmental services. Current policies negatively frame peri-urban agriculture as unproductive and a source of environmental contamination, but associate urban agriculture with positive outcomes for development and sustainability. Peri-urban farmers have resisted this framing, asserting that the GMC inadequately supports farmers’ watershed conservation efforts, and lacks understanding of and concern for farmers’ needs and interests. The city’s climate plan implicitly considers farmers to be private providers of public adaptation benefits, but the plan’s programs do not sufficiently address the socioeconomic changes responsible for agriculture’s decline, and therefore may undermine the government’s climate adaptation objectives.

The findings illuminate the challenges for urban governance of agriculture. Farms do not become instruments for urban sustainability, development, and food security simply because the government creates policies for them. Urban governments will be more likely to achieve their goals for agriculture by being transparent about their objectives, honestly evaluating how well those objectives fit with farmers’ needs and interests, cultivating genuine partnerships with farmers, and appropriately compensating farmers for the public benefits they provide.

Over the past few decades, businesses globally have advanced in incorporating the principles of sustainability as they strive to align economic outcomes with growing and complex social and environmental demands and opportunities. This transition is conditioned by the maturity, scale, and geographical location of a business (among other factors), with particular challenges placed on small enterprises in middle- to low-income communities. Within this context, the overarching research question of this dissertation is why and how business incubation processes may foster sustainable enterprises at the middle and base of the socioeconomic pyramid (MoP/BoP). To explore this question, in this project I used as a case study the experience of a network of social business incubators operated by Tecnologico de Monterrey, a private, non-profit, multi-campus university system in Mexico. Centering on its campus in Guadalajara and in order to understand if and how MoP/BoP businesses address sustainability, I developed a current state assessment of incubator processes, analyzing during two semesters the activities of incubated entrepreneurs and their goals, motivations, and outcomes. The general expectation at the outset of the study was that Tec's social business incubation process, in both its design and implementation, focuses on the economic viability and outcomes of incubated projects and hence does not promote entrepreneur commitment to sustainability goals and practices. The general approach of the research project involved a qualitative, in-depth ethnographic assessment of participants. Data were collected by means of the following research tools: (a) archival and documentary review, (b) participant observation, (c) surveys of participants (entrepreneurs and advisors/mentors), and (d) semi-structured interviews of participants. The overall design of the research was inspired by the transitions management approach and by the intervention research method, while qualitative results were assessed under the grounded theory approach. Results of the research are reported under three general categories: (a) analysis of entrepreneur goals, motivations, and outcomes, (b) identification of social and environmental opportunities, and (c) review of the role of social networks and broader support structures. While results confirmed the general expectation of the study, it was possible to establish (based on the interaction with the entrepreneurs and other actors) that there is both interest and commitment to identify and explore opportunities in social and environmental issues. Thus, the dissertation concludes with a proposal for potential future interventions in this social incubator, exploring a new vision and strategies for a transition to a more sustainability-oriented approach. Finally, key recommendations define the most critical elements of an agenda for transition in the social incubation process at Campus Guadalajara and provide input for other efforts.

Teamwork and project management (TPM) tools are important components of sustainability science curricula designed using problem- and project-base learning (PPBL). Tools are additional materials, beyond lectures, readings, and assignments, that structure and facilitate students' learning; they can enhance student teams' ability to complete projects and achieve learning outcomes and, if instructors can find appropriate existing tools, can reduce time needed for class design and preparation. This research uses a case study approach to evaluate the effectiveness of five TPM tools in two Arizona State University (ASU) sustainability classes: an introductory (100-level) and a capstone (400-level) class. Data was collected from student evaluations and instructor observations in both classes during Spring 2013 and qualitatively analyzed to identify patterns in tool use and effectiveness. Results suggest how instructors might improve tool effectiveness in other sustainability classes. Work plans and meeting agendas were the most effective TPM tools in the 100-level class, while work plans and codes of collaboration were most effective at the 400 level. Common factors in tool effectiveness include active use and integration of tools into class activities. Suggestions for improving tool effectiveness at both levels include introducing tools earlier in the course, incorporating tools into activities, and helping students link a tool's value to sustainability problem-solving competence. Polling students on prior use and incorporating tool use into project assignments may increase 100 level tool effectiveness; and at the 400 level, improvements may be achieved by introducing tools earlier and coaching students to select, find, and develop relevant tools.

With more than 70 percent of the world's population expected to live in cities by 2050, it behooves us to understand urban sustainability and improve the capacity of city planners and policymakers to achieve sustainable goals. Producing and linking knowledge to action is a key tenet of sustainability science. This dissertation examines how knowledge-action systems -- the networks of actors involved in the production, sharing and use of policy-relevant knowledge -- work in order to inform what capacities are necessary to effectively attain sustainable outcomes. Little is known about how knowledge-action systems work in cities and how they should be designed to address their complexity. I examined this question in the context of land use and green area governance in San Juan, Puerto Rico, where political conflict exists over extensive development, particularly over the city's remaining green areas. I developed and applied an interdisciplinary framework -- the Knowledge-Action System Analysis (KASA) Framework --that integrates concepts of social network analysis and knowledge co-production (i.e., epistemic cultures and boundary work). Implementation of the framework involved multiple methods --surveys, interviews, participant observations, and document--to gather and analyze quantitative and qualitative data. Results from the analysis revealed a diverse network of actors contributing different types of knowledge, thus showing a potential in governance for creativity and innovation. These capacities, however, are hindered by various political and cultural factors, such as: 1) breakdown in vertical knowledge flow between state, city, and local actors; 2) four divergent visions of San Juan's future emerging from distinct epistemic cultures; 3) extensive boundary work by multiple actors to separate knowledge and planning activities, and attain legitimacy and credibility in the process; 4) and hierarchies of knowledge where outside expertise (e.g., private planning and architectural firms) is privileged over others, thus reflecting competing knowledge systems in land use and green area planning in San Juan. I propose a set of criteria for building just and effective knowledge-action systems for cities, including: context and inclusiveness, adaptability and reflexivity, and polycentricity. In this way, this study also makes theoretical contributions to the knowledge systems literature specifically, and urban sustainability in general.

The greatest challenge facing humanity in the twenty-first century is our ability to reconcile the capacity of natural systems to support continued improvement in human welfare around the globe. Over the last decade, the scientific community has attempted to formulate research agendas in response to what they view as the problems of sustainability. Perhaps the most prominent and wide-ranging of these efforts has been sustainability science, an interdisciplinary, problem-driven field that seeks to address fundamental questions on human-environment interactions. This project examines how sustainability scientists grapple with and bound the deeply social, political and normative dimensions of both characterizing and pursuing sustainability. Based on in-depth interviews with leading researchers and a content analysis of the relevant literature, this project first addresses three core questions: (1) how sustainability scientists define and bound sustainability; (2) how and why various research agendas are being constructed to address these notions of sustainability; (3) and how scientists see their research contributing to societal efforts to move towards sustainability. Based on these results, the project explores the tensions between scientific efforts to study and inform sustainability and social action. It discusses the implications of transforming sustainability into the subject of scientific analysis with a focus on the power of science to constrain discourse and the institutional and epistemological contexts that link knowledge to societal outcomes. Following this analysis, sustainability science is repositioned, borrowing Herbert Simon's concept, as a "science of design." Sustainability science has thus far been too focused on understanding the "problem-space"--addressing fundamental questions about coupled human-natural systems. A new set objectives and design principles are proposed that would move the field toward a more solutions-oriented approach and the enrichment of public reasoning and deliberation. Four new research streams that would situate sustainability science as a science of design are then discussed: creating desirable futures, socio-technical change, sustainability values, and social learning. The results serve as a foundation for a sustainability science that is evaluated on its ability to frame sustainability problems and solutions in ways that make them amenable to democratic and pragmatic social action.

This study investigates the vulnerability of subsistence agriculturalists to food shortfalls associated with dry periods. I approach this effort by evaluating prominent and often implicit conceptual models of vulnerability to dry periods used by archaeologists and other scholars investigating past human adaptations in dry climates. The conceptual models I evaluate rely on an assumption of regional-scale resource marginality and emphasize the contribution of demographic conditions (settlement population levels and watershed population density) and environmental conditions (settlement proximity to perennial rivers and annual precipitation levels) to vulnerability to dry periods. I evaluate the models and the spatial scales they might apply by identifying the extent to which these conditions influenced the relationship between dry-period severity and residential abandonment in central Arizona from A.D. 1200 to 1450. I use this long-term relationship as an indicator of potential vulnerability to dry periods. I use tree-ring precipitation and streamflow reconstructions to identify dry periods. Critically examining the relationship between precipitation conditions and residential abandonment potentially sparked by the risk of food shortfalls due to demographic and environmental conditions is a necessary step toward advancing understanding of the influences of changing climate conditions on human behavior. Results of this study support conceptual models that emphasize the contribution of high watershed population density and watershed-scale population-resource imbalances to relatively high vulnerability to dry periods. Models that emphasize the contribution of: (1) settlement population levels, (2) settlement locations distant from perennial rivers, (3) settlement locations in areas of low average annual precipitation; and (4) settlement-scale population-resource imbalances to relatively high vulnerability to dry periods are, however, not supported. Results also suggest that people living in watersheds with the greatest access to and availability of water were the most vulnerable to dry periods, or at least most likely to move when confronted with dry conditions. Thus, commonly held assumptions of differences in vulnerability due to settlement population levels and inherently water poor conditions are not supported. The assumption of regional-scale resource marginality and widespread vulnerability to dry periods in this region of the U.S. Southwest is also not consistently supported throughout the study area.