A River Ran Through It is part of an environmental series called Footprints. It tackles major ecological issues using a conceptual style. This photo in particular deals with the theme of drought. Human actions are a major contributor to greenhouse gas emissions which subsequently contribute to the earth's rising temperatures. These rising temperatures then lead to a faster evaporation of ground water resulting in increased duration and expansion of dry areas. This process can destroy natural habitats and alter ecosystems that are vital to the entire food chain.