• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

1) Give information on the main source (naturally occurring/man made) of a selected gas.

Extracts from this document...

Introduction

1) Give information on the main source (naturally occurring/man made) of a selected gas.

Global warming, for almost a century, has been a very controversial issue. Scientists, determined to prove once and for all that man made sources are the main cause for global warming, have been surmounting more and more evidence to support this. The noticeable increase of late in the average temperature of our Earth has raised concerns. These concerns are regarding exactly what chemicals we should we using in our day to day lives. How are these chemicals, in the form of gases, causing global warming? Are they really enhancing the greenhouse effect? If so, how we can lessen the production and release of these harmful chemicals into our atmosphere? All these questions will be brushed over in this assignment.

There are quite a few chemicals that are considered influential in the greenhouse effect. These chemicals (which are all gaseous) include CO2 (carbon dioxide), CH4 (methane), N2O (nitrous oxide), Halocarbons (mainly chlorofluorocarbons or CFCs), and O3 (ozone).

The following table shows the sources of these gases and their relative effectiveness at trapping heat relative to CO2. CO2 is mainly responsible for the natural greenhouse effect, although events such as deforestation may now be pushing CO2 levels higher than normal.

Gas

Main Source

Heat trapping effectiveness compared with CO2

Overall Contribution to increased global warming

Life Span in the Atmosphere (years)

CO2

Combustion of fossil fuels and biomass

1

50%

2-30

CH4

Anaerobic decay of organic matter caused by intensive farming

30

18%

6-11

N2O

Artificial fertilizers and combustion of biomass

150

6%

120-150

O3

Secondary pollutant in photochemical smogs

2000

12%

-

CFCs

Refrigerant, propellant, foaming agents, solvent

10000 - 25000

14%

65-111

...read more.

Middle

The graph below shows the amount of CFC-11 in the atmosphere, measured in ppt (parts per trillion) and measured from various sites around the world over a period of time. As it can be seen, the amount of CFC-11 has jumped up tremendously from 1977 to 1990, where there was awareness for the dangers of CFC. This awareness unfortunately did not help stem the flow of CFC production. Obviously, the plateau of the amount of CFCs during the 1990s shows that there were steps taken to slow down the production of CFCs. In fact, the world’s goal is to stop producing these chemicals altogether.

image00.png

CFCs have many uses, and seem to make a great contribution to our society. But why do they seem to be a problem? They are not a problem down on the ground. They are essentially harmless substances, and are not a threat at all to humans directly. Even in our lower atmosphere, they are inert. But, when they reach the upper atmosphere, the events that take place there are what scientists are worried about. At this height, CFCs essentially play two roles in enhancing the greenhouse effect.

Firstly, CFCs physically trap heat extremely proficiently. Even at lower altitudes in the atmosphere, CFCs would collectively provide their own blanket over the Earth, which would in turn help to heat the planet up.

Secondly, CFCs chemically provide a hazard to our atmosphere.

...read more.

Conclusion

 [Internet]. Michael Pidwirny. Department of Geography, Okanagan University College.

Available:        http://www.physicalgeography.net/fundamentals/7h.html

[Accessed 11 Feburary 2005].

Neuss, G. 2001. Chemistry for the IB Diploma. Oxford: Oxford University Press.

Anon. n.d. Activity 2 – Global Warming. [Internet].

Available:        http://community.middlebury.edu/~rosenber/DR-personal-homepage/globalwarming/gwact2.html

[Accessed 11 Feburary 2005].

Elkins, J. 1996. Chlorofluorocarbons (CFCs). [Internet]. David E. Alexander and Rhodes W. Fairbridge. Kluwer Academic, Boston.

Available:         http://www.cmdl.noaa.gov/noah/publictn/elkins/cfcs.html

[Accessed 11 Feburary 2005].

Anon. 1999. CFCs and the Atmosphere. [Internet]. The National Asthma Council Australia. Melbourne.

Available:        http://www.nationalasthma.org.au/resources/cfc/cfcozone.html

http://www.nationalasthma.org.au/resources/cfc/cfc_trans.html

[Accessed 11 Feburary 2005].

Anon. n.d. Ozone Depleting Substances. [Internet]. Environment ACT. ACT.

Available:        http://www.environment.act.gov.au/corporate/contactus.html

[Accessed 11 Feburary 2005].

Xavier Tung. n.d. Chlorofluorocarbons. [Internet]. SKH Tsang Shiu Tim Secondary School. Hong Kong.

Available:        http://hk.geocities.com/xavier114fch/02/02i.htm

[Accessed 11 Feburary 2005].

Anon. n.d. Ozone. [Internet]. www.studyworld.com. Unknown Address.

Available:         

http://www.studyworld.com/newsite/ReportEssay/

Science/Earth%5COzone.htm

[Accessed 11 Feburary 2005].

Anon. n.d. The Ozone Hole: Ozone Destruction. [Internet]. The Ozone Hole Inc. Pennsylvania.

Available:         http://www.theozonehole.com/ozonedestruction.htm

[Accessed 11 Feburary 2005].

U.S Environmental Protection Agency. n.d. Ozone Science: The Facts Behind the Phaseout. [Internet]. EPA. Washington, D.C.

Available:         http://www.epa.gov/docs/ozone/science/sc_fact.html

[Accessed 11 Feburary 2005].

Anon. n.d. The Vienna Convention and the Montreal Protocol. [Internet]. United Nation Development Programme. New York.

Available:         http://www.undp.org/seed/eap/montreal/montreal.htm

[Accessed 11 Feburary 2005].

...read more.

This student written piece of work is one of many that can be found in our GCSE The Earth and Beyond section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE The Earth and Beyond essays

  1. Peer reviewed

    Global Warming - Is it man Made?

    This 'greenhouse effect' as it is known, heats the earth enough to cater for the needs of all of life on earth and has done for as long as life has been here. The reason global warming is deemed as such an issue is because the more of the gases

  2. Describe and explain the long-term effects of large-scale deforestation on the earth's atmosphere.

    Contained within the image are patches of deforestation in a distinctive "fishbone" of deforestation along roads. Forest fragments are isolated areas left by deforestation, where the plants and animals are cut off from the larger forest area. Regrowth-also called secondary forest-is abandoned farmland or timber cuts that are growing back to become forest.

  1. helium essay

    The U.S. Bureau of Mines has set the price of Grade A helium at $37.50/1000 ft3 in 1986. Properties Helium has the lowest melting point of any element and is widely used in cryogenic research because its boiling point is close to absolute zero.

  2. The greenhouse effect

    In 1987, the signing of the Montreal Protocol agreement by 46 nations established an immediate timetable for the global reduction of chlorofluorocarbon production and use. Since 1750, methane concentrations in the atmosphere have increased by more than 140 %. The primary sources for the additional methane added to the atmosphere (in order of importance)

  1. Greenhouse Effect.

    is the gas most significantly enhancing the greenhouse effect. Plant respiration and decomposition of organic material release more than 10 times the CO2 than released by human activities, but these releases have generally been in balance during the centuries leading up to the industrial revolution. Since the industrial revolution amounts have increased by 30%.

  2. What are stars made of?

    of our Sun, the gases of the outer layer are expelled, and then contract, so that the star becomes what it known as a white dwarf. However, if a star has a much greater mass than our Sun, the final stages of its giant star phase end in a supernova explosion.

  1. Victorian Press and the Working Classes

    It will also show how the chartists campaign began at this time within the pages of the Northern Star. Moving through to the 8th of January 1848 will give the papers a chance to move on to a different level.

  2. The Greenhouse Effect and the Ozone Layer.

    Many islands and coastal areas will be flooded, including Britain. Where will the animals and humans that live there go? So by now we can tell that it is the energy sector that contributes most to Global Warming. We could therefore reduce emissions by reducing the amount of energy that is consumed.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work