Physical processes constantly change Earth's surface. Physical processes also interact with living things, creating and modifying Earth's ecosystems. Weather systems, ocean currents, volcanic activity, and tectonic plate movement affect the landscape and the organisms within it. At the same time, living things release and absorb gases, build and use soil, break down rocks, dam streams, and fill in lakes. These and many more activities make up the systems that shape Earth's geography.
Human activities shape Earth's surface.
Human settlements and structures are also part of Earth's surface. When people move from one place to another they often change the landscape as they go. In addition, people in different cultures interact with their environment in different ways. Human activities change the physical environment and ecosystems. In addition, human activities are influenced by the environment and by Earth's physical processes.