The Climate System: The Global Water Cycle

Water (H2O) is stored in different phases on the planet and passes from one phase to another through a cycled refered to as the global water cycle:

There are 16 main elements of the water cycle:
• Water storage in oceans
• Evaporation
• Sublimation
• Evapotranspiration
• Water in the atmosphere
• Condensation
• Precipitation
• Water storage in ice and snow
• Snowmelt runoff to streams
• Surface runoff
• Streamflow
• Freshwater storage
• Infiltration
• Ground-water storage
• Ground-water discharge
• Springs
• Global water distribution


• The water cycle plays an important role in regulating the earth climate

• Vise versa, a change in the climate system will significantly influence and modify the water cycle and how water is distributed on the planet

• The transport of atmospheric moisture from the oceans, which cover more than two-thirds of the globe, to the continents plays a vital role to balance the discharge from rivers and groundwater to the oceans8

• Water vapour is the most important of the greenhouse gases, in terms of its influence on the climate8

• By modifying the water cycle, we are also impacting global sea level. The main cause of sea level rise is due to thermal expansion of the water body as temperature rises. The second main cause of global sea level rise is ice melt from land ice

• There are also seasonal variations in sea level and during storm events as a result of change in atmospheric pressure

Source of Information : Climate Change: A Silent Threat by Sylvain Richer de Forges

The Climate System: The Global Water Cycle