Why does the hydrosphere include both the biosphere and atmosphere?

Hydrosphere causes erosion of geosphere through running water and precipitation. Biosphere breaks down rock of the geosphere (plant roots), but when it comes to soil, minerals of the geosphere feed the plants. Biosphere and atmosphere interact through animal and plant respiration of oxygen and carbon dioxide. The entire hydrosphere is involved in air pollution, whether it is exchange of pollutants between ground and surface waters and the atmosphere, the storage of potential air pollutants in clouds and soil water, or the release and the biota's uptake of water from the atmosphere