By 2040, I imagine a world where sustainable urban life has become a reality. Cities are clean, green and energy efficient. Buildings use almost exclusively renewable energy, with electric or hydrogen-powered vehicles being the most used for transport. Urban spaces are full of community gardens, which not only provide food, but also strengthen community cohesion, and which people enjoy using. Waste is almost entirely recycled or composted and circular economy principles are applied at all levels. People are healthier because the air is clean and cities are designed to be easily walkable on foot or by bicycle. In this future, technology and human well-being go hand in hand: intelligent systems optimise energy use and urban planning prioritises human needs while respecting nature. People live in harmony with their environment and the effects of climate change have been minimised. This future would represent a world where sustainability is not a compromise but a natural part of everyday life.