Environment: Greenhouse Gases and Hydrological Cycles

Greenhouse gases emissions are a variety of gaseous compounds that are air pollutants, which include, but not limited to, carbon dioxide and chlorofluorocarbons. These gases act as a “lid” trapping energy from the sun and, preventing the heat from going back out into space so that the earth can cool.

Over the past century, humans have directly or indirectly contributed to the greenhouse effect through many of their economic and other activities such as agriculture practices and fire suppression. Other indirect contributions include fertilization, nitrogen deposition, and acid deposition, among others.

Scientists believe that since the temperature of the earth has increased by one Fahrenheit over the last one hundred years, these increases in temperatures could be made worse by more gases into the atmosphere. In this case, scientists expect an increase in the occurrence of various weather hazards such as heat waves, droughts, hurricanes, forest fires and floods, which they argue are already having an impact on the world’s climate.

Other major effects scientists are predicting of the climate change are rising sea levels from the polar sea melting, plants and animals that cannot cope with the climate change may die, and weather patterns will be more unpredictable hence the difficulty in farming.

The reaction towards carbon gas emissions is mixed in different societies. Climate scientists identifying global warming as the most important issue of our time, it has taken over twenty years for the problem to penetrate the public discourse in even the most superficial manner. Even as public concerns begin to arise, climate change remains low on the public list of priorities worldwide.

However, in a few countries, such as Japan among others in Europe, public overreaction has been observed with the public ordering shutdown of nuclear plants despite the heavy costs of alternative energies (John & Dryzek, 2011). Human activities that can negatively affect the hydrological cycle including, but not limited to, irrigation schemes, construction of dams and reservoirs, and City/urban infrastructure development.

Irrigation schemes: a dramatic example is what happened to the Aral Sea, located in Central Asia. In the 1960s, the two rivers that flowed into the sea were diverted by a series of dams and canals to create an irrigation system in the surrounding desert areas for agricultural purposes.

Precipitation was not enough to maintain the Aral Sea’s water supply. Over the years, about 70 percent of its volume of water has gradually evaporated. Ships and boats that once docked at fishing ports along the sea were abandoned as the water dried up. This example shows how humans can negatively affect the water cycle of the region.

Construction of dams and reservoirs: humans build this for water supply, hydroelectric power, flood control, and among other purposes. Evaporation rates are high in these large bodies of water, particularly in hot, arid areas.

This causes the water table to rise closer to the surface and prevents water from infiltrating the soil to refill aquifers or groundwater systems. Damming water also stops run-off continuing downstream and infiltrating aquifers and other catchment areas.

City/urban infrastructure development; since water cannot be soaked through paved bituminized surfaces in the city, there is wastage of water and interruptions of the water cycle. Proper drainage should be constructed to direct the runoff stormwater back to the water bodies to reduce the negative effect.

References

John, S &Dryzek, R 2011, The Oxford Handbook of Climate Change and Society. London: Oxford University Press.

Kabat, P 2010, Vegetation, Water, Humans and the Climate: A New Perspective on an Internactive System. Chicago: Springer.

R.I.C. Publications 2008, Planet Earth 2008: Earth Science for Sustainability. Newyork: R.I.C. Publications.

Rob Coppock, S 2004, Direct and Indirect Human Contributions to Terrestrial Carbon Fluxes: A Workshop Summary. Chicago: National Academies Press.

Tyson, P 2008, Global-Regional Linkages in the Earth System. Ohio: Springer.

United States, General Accounting Office 2013, Climate change selected nations’ reports on greenhouse gas emissions varied in their adherence to standards : report to congressional requesters. Washington: DIANE Publishing.

William Jury, H 2010, The Role of Science in Solving the Earth’s Emerging Water Problems. Chicago: National Academies Press.