World Cities Day, 31 October 2016

Biodiversity and associated ecosystem services are critical for the quality of life and the resilience of
cities. While cities occupy just 2 per cent of the Earth's surface, their inhabitants use 75 per cent of the
Earth’s natural resources. Cities draw on surrounding ecosystems for goods and services, and their
products and emissions can affect regional and even global ecosystems. Healthy ecosystems and
biodiversity are vital for cities to function properly. Ecosystems provide many kinds of services to the
city: provisioning of food, fibre and fuels; regulating through purification, detoxification, buffering of heat
islands and mitigation of droughts and floods; contributing to physical and mental health through exercise,
increasing real estate value due to valuation of green spaces, and enriching the spiritual, aesthetic and
social life of urban dwellers.