Currently 23 cities exceed the 10 million inhabitants threshold. The number of worlds megacities is expected to grow to 39 in 2025 with 32 of these in emerging economies. While today cities cater for over half of the worlds population, they are facing ever increasing environmental problems. Whether or not an emerging megacity will be able to cope with expected climate change impacts and increased scarcity of natural or man-made resources depends on its capacity to change human behaviour in different areas of what a city constitutes. On-going research on various responses to anticipated climate change impacts on the emerging megacities aims to generate knowledge for an effective and feasible transition towards sustainable development. Where different disciplines and approaches seem to overwhelmingly agree is that mitigation and adaptation measures are urgently needed. This implies not only identifying available technological options but also exploring institutions defined as sets of rules and governance structures, i.e. those modes of organization that are necessary to put rules into practice. Thus, in order to arrive at feasible mitigation and adaptation measures, technical solutions and social construction need to be combined. This Emerging megacities series presents findings of current inter- and trans- disciplinary research on different topics concerning the sustainable growth of these rapidly expanding cities.