Today, 55% of the world's human population lives in urban areas. By 2030, up to 90% of the global human population will live in cities and the global population is expected to increase by 68% by 2050. Although land cover categorized as "urban" is a relatively small fraction of the total surface of the Earth, urban areas are major driving forces in global environmental change, habitat loss, threats to biodiversity, and the loss of terrestrial carbon stored in vegetation biomass. These and m...