Like carbon, nitrogen has its own biogeochemical cycle, circulating through the atmosphere, lithosphere, and hydrosphere (Figure 5). ... In this symbiotic association, the bacteria become encased in nodules that grow on the roots of plants, through which nitrogen that has been fixed by the resident bacteria is obtained.
Examples would be: global warming, acid rain, air pollution, urban sprawl, waste disposal, ozone layer depletion, water pollution, climate change and many more affect every human, animal, and nation on this planet.
