Emissions Of Greenhouse Gases To The Levels example essay topic

Year 11 Senior Geography Essay - New South Wales, Australia. Mark: 20/20 (A). Global warming is the progressive gradual rise of the earth's surface temperature thought to be caused by the enhanced greenhouse effect and responsible for changes in global climate patterns. The greenhouse effect is a term used to describe the roles of water vapour, carbon dioxide, and other trace gases in keeping the Earth's surface warmer than it would be otherwise. The diagram below shows the greenhouse effect: These 'radiative ly active' gases are relatively transparent to incoming shortwave radiation, but are relatively opaque to outgoing long wave radiation. The latter radiation, which would otherwise escape to space, is trapped by these gases within the lower levels of the atmosphere.

The subsequent re radiation of some of the energy back to the surface maintains surface temperatures higher than they would be if the gases were absent. There is concern that increasing concentrations of greenhouse gases, including carbon dioxide, (the carbon dioxide emissions are primarily caused by the use of fossil fuels for energy) methane, and manmade chlorofluorocarbons, may enhance the greenhouse effect (this is called the enhanced greenhouse effect) and cause global warming. There are several important factors that have caused the increase in greenhouse gases over the past 200 years. Fossil fuels - coal, oil and natural gas - contain carbon.

When they are burnt as a source of energy, they release carbon dioxide. The global demand for energy, primarily from fossil fuels, has grown to an average annual rate of approximately two per cent for almost two centuries - although the demand for energy varies considerably over time and among different regions. The burning of fossil fuels on a global scale produces around 20 billion tonnes of carbon dioxide each year. About half of these emissions are absorbed by oceans and plants.

The rest stays in the atmosphere. Deforestation also contributes to increases in carbon dioxide, although on a much smaller scale, through the burning and decaying of vegetation. The reduction in vegetation also means that there are fewer plants to absorb the gas. Methane has various sources including herbivorous animals such as sheep and cattle that release it as a byproduct of digestion, rice paddies, land fills and forest fires. It can also enter the atmosphere from natural gas fields and coal mines. There are various sources of nitrous oxide including the use of fertilizers, the combustion of fossil fuels and motor vehicle emissions.

Chlorofluorocarbons and halons were invented in the 1920's as coolants. They have been used in refrigerators, air conditioners, plastic foams (bubbles) and aerosol cans. Water vapour is the most important greenhouse gas. Human activities are not directly changing the level of water vapour in the atmosphere.

However, increases in other greenhouse gases are likely to raise the earth's temperature and thus increase evaporation and therefore the level of water vapour. This would further increase global warming. There is an increasing body of evidence to suggest that global warming is taking place. Some examples include that temperature measurements taken in the traditional way - by thermometers in meteorological stations - show that the world warmed by about 0.5 degrees celsius during the twentieth century, 1995 was the world's hottest year since reliable records began around 140 years ago - prior to this 1990 was the hottest year, The Australian Bureau of Meteorology records show that Australia has been warming since the early 1950 by 0.1 degrees celsius to 0.2 celsius a decade, five Antarctic ice shelves have retreated dramatically over the past 50 years and others have broken up, at Macquarie Island just north of Antarctica sea temperatures have risen by more than 1 degree celsius since 1912, pine trees in northern Finland have taken root in tundra areas at the rate of about 40 metre's per year in an apparent response to warmer temperatures, tropical corals which are sensitive to water temperatures are beginning to suffer losses in many regions, Siberia is now warmer than at any time since the Middle Ages and the northern interior of India has been experiencing life-threatening heatwave conditions in consecutive years throughout the 1990's.

There are many possible impacts of global warming on a regional scale. These include that there could be an increase in the intensity and frequency of heavy rainfall in some regions, there could be a change in the frequency and intensity of natural disasters such as tropical cyclones and droughts, changes in temperature and the pattern and intensity of rainfall may affect the structure and functioning of ecosystems, the regional and subregion al changes in rainfall and temperature patterns may alter the production possibilities in some agricultural activities, the raising of global sea levels would increase the risk of flooding in low-lying coastal regions including small islands and human health could be affected by, for example, altering the incidence and range of insect-borne diseases like malaria, and, in Australia, Ross River Fever which seems to be sensitive to climatic change. Any policy designed to achieve a sustained reduction in greenhouse gas emissions would need to incorporate five key elements: an increase in the efficiency of energy production and use, a change from carbon-intensive fuels (such as coal) to nitrogen-intensive fuels (such as natural gas), encouragement of the development and use of solar energy and other carbon-free sources of energy, elimination of CFC production and the development of the technology required to 'recapture' those CFC's now in use and the reduction in the rate of deforestation. During the late 1980's and 1990's, several international conferences were held to discuss measures that could be directed at lessening the possible consequences of global warming: At the international conference (Toronto meeting, 1988) on the Changing Atmosphere, the proposal was made to reduce greenhouse gas emissions by the year 2005 to a level 20 per cent below the 1988 levels. This was recognised as an important first step that was considered to be achievable within 17 years. Even though there was agreement on the proposal, it was not considered to be binding on any country and individual nations were to take their own actions.

The United Nations Conference on Environmental and Development (UNWED), the Earth Summit, was held in 1992 in Rio De Janeiro, Brazil. The main aim was the stabilization of greenhouse gas concentrations in the atmosphere at a level which would prevent dangerous human-induced climatic change. This would ensure that future food production was not threatened and allow economic development to proceed in a sustainable manner. There were attempts to obtain agreement on the stabilization of greenhouse gases at 1990 levels by the year 2000. There was no agreement on this proposal. Instead, each country agreed to set its own goals.

The 1992 UN Framework Convention on Climate Change was signed by 154 countries as well as the European Union. Even so, the lack of commitment by nations to clear targets was seen as a major failure of the summit. The Berlin Conference on Climate Change, 1995 achieved only modest progress because negotiators failed to achieve an agreement to reduce emissions of greenhouse gases to the levels suggested. This was despite the arguments by the scientists, geographers, environmental organisations, and even the insurance industry, which was alarmed at the frequency and severity of weather-related disasters in recent years.

There were two reports presented at the Geneva Conference on Climate Change, 1996, that painted a grim picture for the future. The first, from the IPCC, argued that the evidence for human-induced climatic change has recently become stronger. The second, from the World Health Organisation (WHO), predicted that if global warming's proceeds, the impact on human health could be horrific. Even though there was widespread agreement at the convention on many issues, the conference, like its predecessors, failed to come up with legally binding targets for reduced emissions. Further discussion on these were postponed to the 1997 conference in Kyoto.

At the Kyoto Conference 1997, the Kyoto Protocol was adopted. Under the Protocol, which was adopted by consensus, industrialized countries have a legally binding commitment to reduce their collective greenhouse gas emissions by at least five per cent compared to 1990 levels by the period 2008-2012. We as a world community need to seriously do something drastic to slow down the process of global warming, otherwise we may find ourselves in a situation where we can't turn back the hands of time and we " re suffering because of Global warming. We need to make sure that future generations can live a happy and uncomplicated life; they shouldn't have to suffer from the impacts of Global warming that we (the current generation) have mostly caused.