What is the primary cause of increased sustainability in urban areas when integrating local food and energy production?

The main reason urban sustainability improves when cities grow their own food and energy is that everything stays closer to home, so the energy and food that travel are cut down. When farms, rooftop gardens, and micro‑plants are built right next to where people live, the miles that produce, transport, and heat food are shortened, which means less fuel is burned and fewer emissions are released. This local loop also keeps waste in the city’s own recycling and composting systems, so resources are reused and the city’s carbon footprint shrinks. For example, a neighborhood that installs solar panels on its schools and grows tomatoes in community gardens can power its own lights and cook its own meals, cutting the distance food travels from a distant farm and the energy needed to bring it in.