Geology is the science of the earth's composition, structure, origin, and evolution. It includes subjects as diverse as the origin of rocks and minerals, the migration of pollutants in ground water, and the evolution of life as recorded in fossils. <br><br>Geologists and geoscientists work in a variety of areas. In today's society, with concerns about the scarcity and conservation of natural resources, global climate change, and environmental pollution, many geologists are involved in devising sustainable approaches to energy development, to investigating and mitigating pollution, and to understanding and mitigating the effects of hazards, such as flooding, volcanic eruptions, earthquakes, and landslides.<br><br>Some geoscientists study the materials and fundamental processes of the solid earth while others investigate the effects of human influence upon the earth and provide the basic information needed to solve problems and establish rational policies for resource management, environmental protection, and public health, safety, and welfare. Geologists also study the history of the earth, including the fossilized rock record from which we can learn much about previous life forms, climates, and ecosystems. This knowledge is one of the fundamental tools for interpreting the magnitude and impact of modern day and future climate change.