Consequences of Global Warming

From Thermal-FluidsPedia

Jump to: navigation, search

There is considerable disagreement as to the severity of global warming and its long-term effects on the environment. Although environmentalists and the scientific community blame human greed and non-restricted use of fossil fuels, many politicians, oil companies, and even some researchers claim that the natural variations of solar activity have a much larger influence on climate change (1). However, this point of view is the clear minority, and many discard it purely as a political ploy to support the hidden agendas of special interest groups.

One thing that scientists agree on-- and data confirm-- is that global warming, whatever the cause, can lead to major changes in the regional climate, or local weather, increased frequency of extreme events, unprecedented hot summers, more intense heat waves, heavy rainfalls, and severe droughts (3 Among the potential consequences of global warming are:

1. The air temperature close to the earth’s surface increases, whereas the stratosphere cools. It is expected that, as a result of global warming, the earth will warm somewhere between 1.4-5.8°C by the end of the twenty-first century (4). The severity of the consequences can only be appreciated if we compare this to the last ice age, during which time the earth’s average surface temperature was only 5°C colder than it is today.

2. The ocean water gets warmer. Global warming also results in the warming of ocean waters and possibly even the collapse of the conveyor belt. The conveyor belt is a body of water that circulates between the Atlantic and Pacific oceans. It is shallowest in the Indian Ocean where the water is warmest. As water moves north it cools, becomes denser, and sinks to the bottom of the Atlantic near Greenland. The Gulf Stream is part of a conveyor belt in the south Atlantic that moves north, bringing mild weather to Europe; if weakened, it will cause the temperature in much of Europe to drop (5).

Warmer oceans also affect the diversity of marine life. As oceans warm, fish body temperatures, and with it metabolism and oxygen consumption rates, will rise. Unfortunately, the solubility of gases is reduced at higher temperatures and less oxygen is available, causing many species of fish to disappear. Higher temperatures also increase the rate at which organic waste decomposes, a process that competes for the dissolved oxygen and consequently, oxygen levels drop even further. Furthermore, water viscosity and density are reduced, causing increases in the rate of settlement of suspended particles in the water – possibly affecting aquatic food supplies (6). Finally, warmer oceans mean fewer nitrates, an important ingredient for the production of carbon-absorbing phytoplankton.

3. Ice caps in northern latitudes and Antarctica break up and melt. Rising temperatures cause the melting of glaciers, thus further reducing the fraction of sunlight that is reflected to the sky. A rise in sea level of only a few feet will bury many of the smaller Pacific islands underwater. In low lying countries, such as Bangladesh and the Netherlands, millions of people will be displaced. Many coastlines and beaches including some in the United States, Australia, and Europe, will also be lost. As a result, atmospheric temperature rises even further, causing more ice to melt (7).

4. The climate becomes even more unpredictable. Global warming does not mean all regions will experience warmer weather. As the upper layers of seawater warm, the intensity of hurricanes, typhoons, and tornadoes increases (8). The change in rainfall pattern will result in droughts in some regions and floods in others. Forests and other natural resources will suffer from changes in the climate.

5. Weather related diseases will increase. Global warming can dramatically increase pests and outbreaks of infectious diseases such as tuberculosis and malaria.

6. Agriculture will suffer. Salt water will damage much of the low-lying coasts and reduce farmland, thus affecting the grazing of farm animals and production of food. Drinking water will also be in short supply.

References

(1) See for example the article by Richard Lindzen in the Wall Street Journal, June 11, 2001

(2) Toossi Reza, "Energy and the Environment:Sources, technologies, and impacts", Verve Publishers, 2005

(3) NOAA web site: see <http://www.noaanews.noaa.gov/stories/s412.htm>, April 18, 2000

(4) Intergovernmental Panel on Climate Change, IPCC Working Group ,2001

(5) Scientists see threat of abrupt world climate,” Environmental News Network, December 13, 2001. Reuters article by Andrew Quinn, (http://www.enn.com/news/wire-stories/2001/12/12132001/reu_45873.asp)

(6) Hodges, L., Environmental Pollution, 2nd Ed., Holt, Rinehart and Winston, 1977. p.312.

(7) IPCC, Climate Change 1995: The Science of Climate Change, Oxford, Cambridge University Press, 1996.

(8) Recent studies suggest that much of the violent weather behaviors of the last decade, such as the 1991 cyclone in Bangladesh, 1992 floods in Pakistan, China, and Australia, and 1990-1995 El Nino and La Nina in the United States are related to global warming.

Further Reading

External Links