Book excerpt: In 2030, the world's population will be a staggering eight billion people. Of these, two-thirds will live in cities, and most will be poor. With limited resources, this uneven growth will be one of the greatest challenges faced by societies across the globe. Over the next years, city authorities, urban planners and designers, economists, and many others will have to join forces to avoid major social and economical catastrophes, working together to ensure these expanding megacities will remain habitable. To engage this international debate The Museum of Modern Art presents Uneven Growth, Tactical Urbanisms for Expanding Megacities, its third iteration in the 'Issues in Contemporary Architecture' series. Following the same model as the critically acclaimed Rising Currents: Projects for New York's Waterfront and Foreclosed: Rehousing the American Dream, Uneven Growth brings together an international group of scholars, practitioners, and experts of architecture and urbanism in a series of workshops, an exhibition, and a publication to focus on how emergent forms of tactical urbanism can address the increasing inequality of urban development around the globe. Featuring proposals for six global metropolises - New York, Mumbai, Rio de Janeiro, Istanbul, Hong Kong and Lagos - each developed by a team pairing local practitioners with international researchers, Uneven Growth documents the brainstorming sessions and workshops. Interviews with each team and essays by leading scholars on the issue make the publication a rich resource for students and professionals alike, and a catalyst for worldwide change.