Amartya Sen and Martha Nussbaum have made major contributions to development studies and social philosophy, yet sustainability issues have largely remained outside their domain despite sustainability's significance and complex relation to their central value of freedom. This volume explores sustainability from a capabilities perspective, with the motif of human security, inviting a lively discussion within the human development family. After introducing the two approaches, authors conceptualize relationships between capabilities and the environment, examine the scientific and normative validity of environmental indicators and analyse intergenerational justice. Climate change is used to exemplify that a human security approach can add an explanatory ontology to the ethical criticisms of contemporary ways of life that champion consumerism. That ontology recognizes shared life experiences, problems and life challenges - a community of fate. The volume ends with a discussion of how the approaches can inform and sometimes critique the Sustainable Development Goals.