San Francisco exists in a unique place on Earth. Our City's own nature and biodiversity, special in its own right, is no less important to global ecological sustainability than the rainforests of Brazil, Borneo, Burundi and British Columbia.
San Francisco is at the northern end of an environmentally diverse peninsula that harbors a phenomenal mosaic of natural habitats & ecological communities. Our ecological city has its own natural heritage - what remains despite intense urban development. The City abounds with diverse natural resources, including rare plant and wildlife habitats, unique geologic formations, lush natural seeps, rocky intertidal habitats, lakes, perennial springs and creeks.
Our local climate is called Mediterranean. Chile, South Africa, Southwest Australia and of course, the Mediterranean, all have similar climates, which are characterized by cool wet winters and dry hot summers. This description fits much of California, but here in San Francisco, our Mediterranean climate is locally moderated by our world famous fog, which creates a cool dry summer. Thus the average daily high temperature for San Francisco varies by less than 20 degrees Fahrenheit throughout the year.
San Francisco's ecology reflects diverse topography, local microclimates, and an active and diverse geologic history. San Francisco exists at a biogeographic crossroads - many species are at the southern limit of their ranges, while others are at the northern limit. We have native species that exist on several other continents, and most importantly, and most urgently, we have native plants and animals that live nowhere else on Earth!
Humans are part of the local ecology. From the indigenous ohlone who lived here sustainably for thousands of years to the competing human-environment approaches of modern capitalists and ecological restorationists, we are part of an everchanging local cultural ecology.