Urban agriculture and sustainable cities.

Urban Farm DB summary

This text describes humanity's transformation into an urban species by the end of the 20th century, with large cities becoming the primary habitat. It notes that global urban populations expanded from 15% to 50% of the total population within one century, while the total population grew from 1.5 billion to nearly 6 billion. The text highlights the unprecedented size of modern cities, citing that by 1990, the 100 largest cities housed 540 million people.