This article is based on a keynote presentation given at the 18th Congress of the International Ergonomics Association in Recife, Brazil, February 2012. It considers new, and not so new, approaches and practical roles for the emerging field of human factors/ergonomics (HFE) in sustainable development (SD).The material for this article was largely drawn from the literature in the fields of human development, sustainability, climate change mitigation and adaptation, and social/environmental impact assessment. Identifying the role of HFE in SD is not a simple one and from the outset is complicated by the widely differing ideas in the sustainability literature about what exactly it is we are hoping to sustain. Is it individual companies, business models, cultures, or the carrying capacity of our planet? Or combinations of these? For the purposes of this article, certain assumptions are made, and various emerging opportunities and responsibilities associated with our changing world of work are introduced. First, there are new versions of traditional tasks for us, such as working with the people and companies in the renewable energy sectors. Beyond this, however, it is suggested that there are emerging roles for HFE professionals in transdisciplinary work where we might play our part, for example, in tackling the twinned issues of climate change and human development in areas of significant poverty. In particular we have the tools and capabilities to help define and measure what groups have reason to value, and wish to sustain. It is suggested, that to do this effectively, however, will require a philosophical shift, or perhaps just a philosophical restatement at a collective level, regarding who and what we ultimately serve.