Ryan Holifield is an assistant professor in the Department of Geography at the University of Wisconsin, Milwaukee. His research focuses on the nexus between social justice and urban sustainability, with a particular interest in dimensions of environmental justice and injustice in the process of hazardous waste site remediation and risk assessment. Michael Porter is a doctoral candidate in the Department of Earth and Environmental Sciences at the Graduate Center of the City University of New York. His research explores the discourses of brownfields and environmental justice in the context of urban socio-spatial change. Gordon Walker is Chair of Environment, Risk and Justice in the Geography Division, Lancaster Environment Centre at Lancaster University, UK. His research focuses on the social and spatial dimensions of environmental and risk issues. He has investigated patterns of various forms of environmental inequality in the UK (air quality, flood risk, waste, green space) and explored the meanings and geographies of environmental justice in different settings. Current research is focusing on the social and justice dimensions of energy technologies and climate change adaptation and mitigation.