Using two reviews of the United Nations Decade on Education for Sustainable Development (DESD) and a special report on social learning–based ESD prepared for the end of the DESD conference as a backdrop (Wals, Review of contexts and structures for ESD. UNESCO, Paris, 2009a; Wals, J Educ Sustain Dev 3(2):195–204, 2009b; Wals, Shaping the education of tomorrow: 2012 full–length report on the UN Decade of Education for Sustainable Development. UNESCO, Paris, 2012.; Wals et al. Social learning–oriented ESD: meanings, challenges, practices and prospects for the post–DESD era. UNESCO, Paris, 2014) this chapter argues that, in order to address prevailing unsustainability, citizens, young and old, need to become active participants in transitions that break with hegemonic routines founded on untenable principles and values. A key learning challenge is that, although we have quite a good sense of what is ‘unsustainable’, we have little certainty about what in the end will prove to be sustainable. In fact we will never have such certainty. It can be argued that the essence of sustainably lies in the ability to respond, reflect, rethink and recalibrate, and not just once but periodically when changing circumstances demand us to do so. To complicate things further: how this is done and to what kind of society (school, neighbourhood, company, city, etc.) this will lead, will be different from place to place as no situation is identical. Sustainability as such is not a destiny or a way of behaving that can be transferred or trained but rather a capacity for critical thinking, reflexivity and transformation. The DESD reviews show that much ‘work’ is being done around the world under the umbrella of ESD but that this capacity is hardly emphasised or developed in practice. As such, ESD unwillingly runs the risk of replicating systems and lifestyles that are inherently unsustainable. This chapter will introduce social learning as a way to utilise diversity in generating creative routine–braking alternatives. Some concrete examples of social learning at the interface of school and community, at the interface of science and society, in the context of local and regional development and within policy making and governance are provided. Special attention is given to the problematic of assessing the impact of social learning.