What these reports often seem to ignore is that there is still biodiversity within our cities--sometimes a lot of it. If the default assumption is "city bad, wilderness good", we're never going to make any progress, because short of an apocalyptic event cities are here to stay. What we should be focused on is making the cities we live in more sustainable and integrated with their ecosystems. Green roofs, urban parks, sustainable transportation networks, clean energy--there are plenty of avenues being explored today that are connecting our cities with nature. Cities should be a part of nature rather than apart from nature.
Thinking just of recognizable animals, typical cities have, what, rats, cats, starlings, house sparrows, rock doves, gulls, and not terribly much more. We can do better, but in general cities are not biodiversity hotspots.
