2.3 Biogeochemical Cycles of the Green World (Planet Earth)
45
Human activities have been instrumental in alteration of the balance of the sulfur
cycle. The combustion of vast amounts of fossil fuels from coal leads to the release
of high quantities of hydrogen sulfide gas into the air (Haneklaus et al. 2003). When
rain combines with this gas, it creates acid rain, which can lead to environmental
deterioration by lowering the pH of lakes. It also leads to chemical degradation
of the built environment, especially buildings, by changing the appearance of
buildings. For instance, many of the marble monuments, including Washington’s
Lincoln Memorial, have suffered the disastrous effects of acid rain. These examples
highlight the various impacts of human activities on the environment.
Identify and explain the significance of the sulfur cycle. How is sulfur
dangerous to humans?
2.3.5 Phosphorus Cycle
The phosphorus cycle refers to the circulation of phosphorus in several forms (see
Fig. 2.9). Phosphorus is one of the scarcest of all elements recycled within the
biosphere. It is crucial for life since it enhances the transfer of energy and acts to
Fig. 2.9 The phosphorus cycle, Source: Encyclopædia Britannica (2012b)
45
Human activities have been instrumental in alteration of the balance of the sulfur
cycle. The combustion of vast amounts of fossil fuels from coal leads to the release
of high quantities of hydrogen sulfide gas into the air (Haneklaus et al. 2003). When
rain combines with this gas, it creates acid rain, which can lead to environmental
deterioration by lowering the pH of lakes. It also leads to chemical degradation
of the built environment, especially buildings, by changing the appearance of
buildings. For instance, many of the marble monuments, including Washington’s
Lincoln Memorial, have suffered the disastrous effects of acid rain. These examples
highlight the various impacts of human activities on the environment.
Identify and explain the significance of the sulfur cycle. How is sulfur
dangerous to humans?
2.3.5 Phosphorus Cycle
The phosphorus cycle refers to the circulation of phosphorus in several forms (see
Fig. 2.9). Phosphorus is one of the scarcest of all elements recycled within the
biosphere. It is crucial for life since it enhances the transfer of energy and acts to
Fig. 2.9 The phosphorus cycle, Source: Encyclopædia Britannica (2012b)