The Earth is made up of five interdependent spheres: the geosphere (lithosphere), hydrosphere, biosphere, cryosphere, and atmosphere. The spheres are so closely connected that a change in one sphere often results in a change in one or more of the other spheres. Changes that take place within an ecosystem are referred to as events. Events can occur naturally or they can be caused by humans. An event can cause changes to occur in one or more of the spheres or an event can be the effect of changes in one or more of Earth’s four spheres. This cause and effect relationship between an event and a sphere is called an interaction. Water in the lake seeps into the cliff walls behind the dam and becomes groundwater or evaporates into the air. Which spheres are interacting in this example? A) hydrosphere only
B) hydrosphere and atmosphere
C) biosphere, hydrosphere, and cryosphere
D) hydrosphere, geosphere, and atmosphere