IUCN Issues Brief Cities and Nature

• Cities are home to 4.4 billion people — well over half of humanity. This figure is projected to reach 6.7 billion by 2050.
• Rapid and uncontrolled urbanisation brings dramatic environmental change, most often negative.
• Cities have ecological footprints that are orders of magnitude larger than their physical area, exerting heavy impacts also on distant peri-urban and rural ecosystems.
• Well-managed urban areas can support rich biodiversity, with many species rapidly adapting to the built environment. Green and blue infrastructure can also cost-effectively enhance the liveability, sustainability, and resilience of cities, but it suffers from chronic underinvestment.