Archive for April 6, 2008

The Greenhouse Effect

April 6, 2008 · Filed under The Greenhouse Effect

Greenhouse Effect Write-up

What is the “greenhouse effect”?

 

Let’s take a look at something smaller first: a greenhouse. We do not need greenhouses in Singapore, but temperate countries such as Canada do. This is because the climate in Singapore is naturally warm enough for plants to grow in abundance. Temperate countries that do not have this kind of warm climate all year round require greenhouses. Greenhouses are made of glass, and they can effectively trap enough thermal energy (heat) to stimulate the perfect conditions for the growth of plants.

 

How, then, does a greenhouse work?

 

The Sun’s heat passes through the glass roof of the greenhouse. The infra-red radiation given out by the plants and fittings inside the greenhouse, however, have a much longer wavelength than the heat waves from the Sun, and the glass prevents the transmission of longer wavelengths, hence effectively trapping the heat within the greenhouse. Due to this, the temperature inside the greenhouse rises over time. The “greenhouse effect” occurs in a similar manner.

 

The greenhouse effect is the process “in which the emission of infrared radiation by the atmosphere warms a planet’s surface” (Wikipedia, [website], available at http://en.wikipedia.org/wiki/Greenhouse_effect , 29th February, 2008). It was discovered in 1824, but only investigated quantitatively in 1896. It involves three main processes: the reflection, absorption and radiation of heat.

 

The Sun gives out infra-red radiation that passes through the Earth’s atmosphere. Some of it—approximately thirty percent—is reflected back into space, while the rest (about seventy percent) is absorbed by the Earth. This absorbed energy warms the surface of the Earth, and then is radiated back toward space. However, greenhouse gases in the atmosphere, namely methane, carbon dioxide, nitrous oxide, water vapor, ozone and halocarbons, prevent the transmission of longer wavelengths, just like the glass of the greenhouses. Since the returning infra-red radiation is of longer wavelength, the greenhouse gases in the atmosphere absorb most of this energy and fire it back at the Earth’s surface. In preventing the escape of heat, the Earth’s average temperature slowly rises.

 

Earth is not the only planet that experiences this process. Venus’s atmosphere is made up almost entirely of carbon dioxide (ninety-six percent), and the rest is made up of carbon monoxide, argon, sulfur dioxide, water vapor and nitrogen. Since carbon dioxide is a greenhouse gas, it traps the thermal energy that reaches the surface of Venus and prevents it from being transmitted back into space. Venus’s greenhouse effect has caused the planet’s surface and lower atmosphere to become one of the hottest places in the solar system.

 

To see how the enhanced greenhouse effect works and how it affects us, take a look at the post “The Enhanced Greenhouse Effect”.

 

 

  

For more information on some of the terms used in this entry, visit the category Glossary of Terms. 

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Prevention Efforts

April 6, 2008 · Filed under Prevention Efforts

Prevention Efforts Write-up

International/National: The Kyoto Protocol

The Kyoto Protocol is the first global legally binding contract that aims to reduce greenhouse gases. It is a protocol that aims to reduce the amount of greenhouse gases, hence preventing dangerous climate change, or more specifically, “to achieve stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system”. It was put forward by the international United Nations Framework Convention on Climate Change (UNFCCC), on 11 December 1997 at the 3rd Conference of Parties in Kyoto, but only entered into force almost 8 years later, on 16th February 2005. 175 parties have ratified the protocol as of November 2007. 137 developing countries such China and India have ratified the protocol but only monitor and report their emission of greenhouse gases; the other 36 have agreed to reduce their emissions by specified levels.

 

Each participating party or country is required to develop their own methods to meet their specified targets. For example, the European Union (EU) has set up a plan by which 12000 factories and power stations are given a carbon dioxide quota. If they exceed this amount, they will have to pay a financial penalty. This helps to keep the amount of carbon dioxide given out by industrial factories under control.

 

The protocol took seven years to come into force as many countries were reluctant to ratify it. In order for the protocol to come fully into force, the pact needed to be ratified by countries that contributed significant amounts of greenhouse gases—more specifically, countries that accounted for at least 55% of the 1990 carbon emissions. The United States and Australia were one of the few largest contributors of greenhouse gases at the time, but they both refused to ratify the protocol. The United States said that “signing up would ruin the US economy and [that] the pact wrongly [disregarded] developing countries”. The protocol only came into full force when Russia, another large gas polluter, became the first country to ratify the agreement, hence allowing the pact to move forward.

 

Australia initially refused to ratify the Kyoto Protocol as the Australian Prime Minister at the time, John Howard of the Liberal Party, felt that it would cost the Australians their jobs (countries with booming economies and large populations like China did not have any reduction obligations). He also claimed that Australia was doing enough to cut their emissions, as they had pledged $300 million to reduce their emissions over the course of three years.

 

However, Australia’s new government was formed by the Australian Labor Party after the election in November 2007. The new Prime Minister, Kevin Rudd, signed the instrument of ratification after his first day in office on 3 December 2007. It will take effect in March, 2008. Hence, Australia is now part of the Kyoto Protocol.

 

From 28th November to 9th December 2005, Montreal in Canada hosted the first ever meeting of all parties participating in the Kyoto Protocol. All representatives had different views about the best way to reduce the emission of greenhouse gases. The European Union confirmed the establishment of a China-EU partnership on climate change. They also discussed the following strategies: binding greenhouse gas emission targets, a global cap-and-trade system; adopting a pro-active approach to engage other main contributors of carbon emissions, particularly the US; and promoting research and innovation for other ways to generate energy, rather than burning fossil fuels.

 

INDIVIDUAL: LIFE AT HOME

We do not need to be political leaders or organizations to do our part in reducing the amount of greenhouse gases. Here are a few ways we can prevent the consequences of the enhanced greenhouse effect:

 

 

  1. Use recycled paper or use products that are manufactured from ecologically managed forests. According to the “Seventh Generation”, if every household in the United States replaced one roll of 1000 sheets of toilet with recycled toilet paper, they could save 373,000 trees, 155 million gallons of water, and avoid 62, 000 pounds of pollution. About 19 trees are used to make one ton of paper. Do the math and see just how much we can do to prevent the enhancement of the greenhouse effect as a nation 4 million strong!
  2. People running for elections should use email, radio and other media to campaign and stop using so many paper signs and flyers that use up our natural resources and then get left out and become pollution.

The following two suggestions will enable us to prevent deforestation, and to indirectly yet effectively prevent the enhancement of the greenhouse effect. The more trees we save, the more trees there will be to absorb carbon dioxide in the atmosphere for photosynthesis, and the level of this greenhouse gas in the air will not be so high.

  1. Send experts to talk about global warming in schools.
  2. At the end of each day’s weather forecast, report the level of carbon emissions levels today, or the comparative average temperatures (i.e., this year’s temperature as it compares to the past several years).

Education of both the younger generation and the general public is also important in moving toward a greener future. Allowing students to understand global warming is the first step to preventing it, and it would be very helpful for people to know how much carbon is emitted each day, so that they can work out for themselves the right way to lower carbon emissions.

  1. Use solar power in the day and use electricity at night if needed.
  2. If money permits, put light sensors in all office and school buildings so all lights go off when the rooms are empty.
  3. Replace incandescence light bulbs with fluorescence light bulbs.
  4. Unplug all electronics from the wall when they are not in use.
  5. Wait until you have a lot of clothes to wash before using the washing machine, so that you can wash all of them in one go instead of washing a few clothes many times.

Suggestions 5-9 help to reduce the amount of fossil fuels burnt in order to provide energy for electricity. Burning fossil fuels releases greenhouse gases, and is currently the primary way of generating electricity. However, countries such as Canada are beginning to rely more on other ways of generating energy, such as hydroelectricity.

 

 

 

For more information on some of the terms used in this entry, visit the category Glossary of Terms. 

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The Enhanced Greenhouse Effect

April 6, 2008 · Filed under The Enhanced Greenhouse Effect

Enhanced Greenhouse Effect Write-up

The greenhouse effect is the natural process of the warming of our Earth. However, the enhanced effect has the normal process tweaked. It is brought about by human activities, such as the burning of fossil fuels and clearing of forests.

 

The above activities cause greenhouse gases like methane (NH4), carbon dioxide (CO2) and nitrous oxide (N2O) to be released at a much higher rate. These gases are help to trap and retain heat on earth. However, as too much is produced at too quick a pace, excess amounts of heat energy are trapped, resulting in global warming.

 

From the last Ice age (around 10,000 years ago) to the end of the 18th century, the levels of greenhouse gases had remained rather constant. However, with the arrival of the industrial revolution, the situation changed. Workers were replaced with machines, and factories sprung up. Due to machines running on energy, the energy consumption rate experienced a huge growth. Burning of coal, a fossil fuel, was essential and this caused an increase in the emission of carbon dioxide. According to statistics, carbon dioxide contributed about 70% to the enhanced greenhouse effect.

 

The clearing and burning of vegetation also led to the high amount of carbon dioxide content. Plants make use of carbon dioxide for photosynthesis, and are thus referred to as greenhouse gas “sinks”. Over many years, forests build up a store of carbon within the trees, soil and fallen leaves. However, with activities like deforestation, much of this carbon is converted back to carbon dioxide through burning or decay.

 

As the enhanced greenhouse effect worsens, the Earth experiences much climate change, with effects varying around the globe. Global warming has a high possibility of causing irreversible and large changes. Some of these changes are a rise in temperature, flooding and extreme weather, mostly hazardous for organisms living on earth.

 

Effects of the Enhanced Greenhouse Effect

Why are these important people getting so worried about the greenhouse effect? The consequences of this process will not crash down on us for a long time, but unless we do something to prevent it from ever happening, it will be a dark future for man. The rise in the global average temperature will cause dangerous climatic changes all over the world. The ice caps in polar regions will begin to melt due to the rise in temperature, and the melting ice will become excess water. This will flow into oceans and seas, thus resulting in a rise in the sea levels. Millions of people in low-lying areas will be affected deeply. Tiny islands like the Maldives will perhaps even be submerged.

 

The need to prevent these deadly consequences grows stronger with each passing year. See the post “Prevention Efforts” to learn what governments and political leaders of different countries have done about it, on both national and international levels, and also how you can play your part at home.

 

 

For more information on some of the terms used in this entry, visit the category Glossary of Terms. 

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The Need for the Greenhouse Effect

April 6, 2008 · Filed under The Need for the Greenhouse Effect

 

The Need for the Greenhouse Effect Write-up

 

 

The greenhouse effect is one important difference that differentiates Earth from other planets in the solar system and makes life on Earth possible. It has a great impact on various aspects of life on Earth, ranging from the climate to the basic needs of living things.

 

Without the greenhouse effect, Earth would be much like Mars and too cold for life. The atmosphere of Mars is not thick enough to reflect sufficient heat back to the planet, resulting in a very low temperature on Mars. The same would happen on Earth without the greenhouse effect. The temperatures would be very low, and although people may be able to survive, animals and plants that cannot adapt to the low temperatures would not survive, and much-needed water would be frozen and difficult to obtain. Thus, without the greenhouse effect, it would be difficult to sustain life on Earth.

 

 

The greenhouse effect is vital to life on Earth for many reasons. Firstly, the greenhouse effect keeps the Earth’s temperature in a suitable range. During this process, the greenhouse gases in the atmosphere allow solar radiation from the sun to pass through and be absorbed by the Earth’s surface. At the same time, infra-red radiation emitted by the Earth’s surface is re-emitted back to Earth. Thus, greenhouse gases function as effective global insulators and keep the Earth warm in two ways, firstly by allowing solar radiation to pass through and warm the Earth, and secondly, by slowing the escape of heat. The greenhouse effect thus raises the average surface temperature of the Earth by about 33oC and keeps the Earth warm. With the greenhouse effect in place, the bodies of most living things are able to function normally at temperatures that are neither too hot nor too cold. The warmth that results from the greenhouse effect is not only a vital requirement for life on Earth, but also aids in satisfying another important need – water.

 

 

Temperature range provides water for life on Earth. As a result of the greenhouse effect, the temperature of the Earth falls between the freezing point of water and its boiling point, such that much of the water on Earth does not evaporate or freeze but remains accessible and usable to life on Earth. This satisfies the need of most living things for water.

 

Thus, by satisfying the vital needs of living things on Earth, the greenhouse effect aids in sustaining life. It provides the warmth and water required for life to flourish on Earth, and in effect sustaining our ecosystem and biosphere.

 

Another way in which the greenhouse effect affects life on Earth is through the role it plays in the Earth’s climate. By balancing the solar radiation absorbed from the sun with the infra-red radiation emitted by the Earth’s surface and atmosphere, the greenhouse effect keeps the Earth’s temperature in a stable state and prevents sudden and rapid heating or cooling. Thus, the incoming and outgoing radiation is well-balanced and the climate of the Earth is fairly regulated. The resultant warmth on Earth is also an important stimulus of its climate as it causes water to evaporate, condense and form rain, snow, sleet etc.

 

However, an enhancement of the greenhouse effect has dire consequences. An excess of greenhouse gases in the atmosphere will lead to what is known as the enhanced greenhouse effect. This will cause excessive heat to be trapped and absorbed, resulting in a dramatic increase in the average surface temperature of the Earth, a phenomenon known as global warming. Among other things, this will lead to many natural disasters such as droughts, floods etc. (To find out more, please refer to the report on the enhanced greenhouse effect.)

 

 

For more information on some of the terms used in this entry, visit the category Glossary of Terms.

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