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

An Essay Upon Global Warming

Extracts from this document...

Introduction

20/04/07 Tim Lees 10AM An Essay Upon Global Warming Global Warming is defined by Encyclopaedia Britannica as 'potential increase in average global atmospheric temperatures resulting from the greenhouse effect.' This is, literally speaking, incorrect; literally, Global Warming means 'an increase in average global temperature', which could be for any number of reasons e.g. the sun increasing in size (bringing it closer to the earth and thus increasing the intensity of radiation reaching earth) and/or the sun increasing in temperature (a greater amount of radiation being emitted would result in a greater amount of radiation being received). However, in my opinion as a result of media attention, when we talk of global warming, we are usually talking about the greenhouse effect. The two potential issues mentioned above will almost certainly not become important for around a billion years, yet the greenhouse effect is, according to many scientists, already taking effect. Therefore, for us to be able to talk about global warming, it is important to have an understanding of the greenhouse effect. Electro-Magnetic-Radiation (EMR) is emitted by the sun, and contains light, as well as such things as infrared radiation and ultra-violet radiation. A small fraction of this radiation arrives at the earth's atmosphere, where some of it is absorbed, but in the most part it passes through to the surface of the earth. The molecules that make up the surface reflect much of this, but also absorb some. This increases the frequency of their vibrations; they are heated up. The heat dissipates out into the air around the surface and into the surrounding earth. Some of the energy is radiated back out; largely as infrared radiation because the particles don't get hot enough to emit much light but neither are they cool enough to emit micro or radio waves. ...read more.

Middle

So, is global warming taking place? Models have been produced to simulate the effect that greenhouse gasses will have upon the mean global temperature. The models described by the UN as 'generally accurate' in 1990 predicted that by 2000, the mean surface temperature should have increased by between 1.3 and 2.3�C since the late 19th century, with a higher figure for the northern hemisphere than the southern one. The currently observed warming is considerably lower. By 1995, (yes, it actually took them the best part of five years) the UN noticed that these models weren't so accurate, "unless a lower climate sensitivity is used". Also they said that "There is growing evidence that increases in sulphate aerosols are partially counteracting [the warming due to] increases in greenhouse gases." Sulphate aerosols are emitted when fossil fuels containing sulphur are burned. They are tiny dust particles that reflect away the sun's radiation before it can be absorbed by the surface. This reduces the amount of energy that can reach the surface, and so, even though a greater portion of energy received would be retained, less energy would be received. Because sulphate aerosols are usually produced along with greenhouse gasses, although in lesser amounts, it makes sense that they at least could be, counteracting global warming. So, global warming could be caused by greenhouse gasses, but, because of the sulphate aerosols that are being produced along with them, global warming is at least being slowed, if not halted. Another factor could be forests, which in the Northern hemisphere are believed to be absorbing up to 25% of the total emitted. In some forests, tree growth is abnormally fast, yet in others, tree growth is much slower than before. ...read more.

Conclusion

As the O-Zone hole increases in size, so more UV rays can pass through. This energy has to go somewhere, and I'll wager that the ice sheets are absorbing a fair portion of this radiation, and heating up along with it. A quasi-flaw with this suggestion is that the Southern O-Zone hole is considerably larger than the Northern hole, and the melting is presently worse in the Arctic. However, this is less of an issue than it may at first seem due to the fact that the Antarctic is considerably colder and much of the ice will have a higher melting point due to the reduced percentage in contact with the sea. Or perhaps this is all a load of rubbish and it's just a coincidence that the ice sheets are melting. In the 17th century, we know that people went ice-skating on the Thames. It seems unlikely that there was an unusually small amount of greenhouse gasses during this period, and so perhaps the earth just naturally changes in climate. The Thames hasn't frozen over to an extent that you could go ice-skating on it at all this century, not even during 1940. It is true that the hottest summers since records began were nearly all this decade, but records only began in 1880. Bearing in mind the possible number of combinations for the alignment of the poles on a given day in a year (1,690,052,000), 120 years worth of results is hardly going to help when determining what is going to occur at a time such as the one we are potentially facing; a time of climatic change. We must also bear in mind, however, that we may not be heading toward anything other than usual. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Physical Geography 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 Physical Geography essays

  1. Marked by a teacher

    Earthquakes in MEDC's and LEDC's

    4 star(s)

    As mentioned earlier, there were a great number of injured, homeless and jobless people. This caused widespread depression, which is understandable when the extended family set-up of households is examined. All in all, more than 87,000 people died and 138,000 were injured.

  2. Discuss what is global warming. And the effects that global warming gives and how ...

    Each time we burn gasoline, oil, coal, or even natural gas, more carbon dioxide is added to the atmosphere (Erandson 34).

  1. To what extent should Walton-on-the-naze be protected from the sea?

    Advantages: ?Low capital cost ?Stops wave energy in harmless way Disadvantages: ?High cost if rock armour isn't local material ?May disrupt Long-shore balance Is the protection successful? In this section I will be discussing how successful each type of protection there is at Walton.

  2. In this booklet I will be describing global warming, its effects, its causes, my ...

    How can we slow down the effects of global warming? To slow down global warming we must reduce the amounts of gas emissions which destroy the ozone layer, causing damage. To do this we first have to make people aware of the problem - this will be much harder to

  1. Physical Case Studies AQA Revision notes - Ice, rivers and volcanoes.

    This shortens the length of the river by cutting through the meander necks and thus increasing the speed of the river o Strengthening levees: concrete mattresses prevent erosion of levees o Soft Engineering Strategies- The River Quaggy, UK SE London.

  2. The Long Term Effects of Volcanic Eruptions

    Dust particles were carried 50 miles high into the stratosphere, where they were blown all over the world. For a full year after the event, only 87% of sunlight was able to shine through the particles in the atmosphere and reach earth.

  1. Global Warming Newspaper

    Doesn't Everyone want to stop Global Warming? After all the talk and proof of global warming happening fast, some people will Still deny the reality of it. They believe it is entirely the sun's fault as it is giving off more energy.

  2. Earthquakes and volcanoes research

    Today, earthquake monitoring instruments are installed all over places where there are fault zones and chances of an earthquake. From these instruments, scientists can learn building methods that endure what type of earthquakes that come by. Along with changing the way buildings are being built, constructing them in proper places is also very important.

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