Following links from the Eco City 2008 site I have been browsing through the stunning environmental pictures of Gary Braash.  From his website:

Gary Braasch photographs environmental issues and conservation, nature, biodiversity, ecosystems, field science, and climate change in stock photos and assignments. Pictures of landscape, patterns, forests, Antarctica, the Arctic, global warming, cities and travel destinations are used by publications worldwide. Nature photos include flora and fauna, plants, animals, birds and insects. His photography grows from a deeply felt connection with nature and an ardent conservation ethic.

On landscape I see a resemblence to Galen Rowell but its the Cities and Environmental images that convey our impact on the earth.