Carbon dioxide comes from the burning of fossil fuels. Fossil fuels are needed to run cars, heat homes/businesses and power factories. Alternative sources of energy are always needed. Many countries have developed plants to utilise power from wind, wave, solar, hydroelectric, tidal, geothermal, ocean thermal energy, nuclear and biological energy sources. Despite the increase in alternative energy sources, fossil fuels are still widely used.
The impacts of global warming are varied throughout the planet. Worldwide temperature has risen an estimated 1 Degree Fahrenheit since the late 19th century. “For the earth on a whole, seven of the eight warmest years on record have occurred in the late 1980’s and 1990’s.” (Houghton, 1999). These increases may not seem like much but the consequence of have repercussions on vegetation, food chains, ice caps, climate and sea levels. Figure two below shows how global temperatures are continuing to increase.
(www.ncdc.noaa.gov)
This trend is set to continue as emissions of greenhouse gasses increase.
The projected warming could shift the ideal range for many North American forest species by about 300km to the north. If the climate changes slowly enough, warmer temperatures may enable trees to colonize north into areas that are currently too cold, at about the same rate as southern areas become to warm and dry for the species to survive. If the earth warms 2 degree Celsius in 100 years, the species would have to migrate about 2 miles every year. Trees whose seeds are spread by birds may be able to spread at this rate but wind and nut-baring trees may have problems. Other problems may arise if there are barriers to movement such as roads, cities, or poor soils.
Over the last 100 years it has been estimated that sea level has risen 10-25 cm. The problems of this are obvious. Many coastal locations would be lost to the rising sea level, coastal weathering would be increased and small islands are starting to disappear. The rise in sea level is due to glaciers melting. Half of humanity live within coastal zones around the world. “During the warm period before the onset of the last ice age, about 120,000 years ago, the global average temperature was warmer than today. Average sea level was about 5-6 metres higher than present.” (Houghton, 1999). If sea level was to reach this previous state the effects would be felt worldwide.
In the Netherlands, over 50% of land is below present sea level and is one of the most densely populated countries in the world. It is currently protected by dykes and sand dunes. In Netherlands alone, “It is estimated that an expenditure of about ten thousand million US dollars would be required for protection against a sea level rise of one metre” (Roan, 1998). This money would be needed to raise the dykes and sand dunes, and additional pumping will also be necessary to combat the incursion of salt water into freshwater aquifers.
As well as increasing the amount of sources of greenhouse gasses, humans also remove a major sink, the forest. A sink is a way of naturally removing harmful pollutants from the atmosphere. The process of photosynthesis in plants, simply explained, changes carbon dioxide into oxygen. When deforestation takes place it is removing a major sink and thus decreasing the amount of carbon dioxide removed.
Desertification is likely to intensify if global warming is amplified. The current rate of desertification is 0.1% of total dry lands per year. Global warming threatens 70% of all dry lands or 25% of the worlds total land area.
Hopes are being raised that this year’s earth summit meeting in Johannesburg for sustainable development will somehow combat global warming issues. Townsend, 2002, believes the earth summit will be “a glossy photo opportunity for the largest ever gathering of world leaders”. Townsend goes on to say, “Irony lies in the fact the earth summit could ultimately harm he earth it is trying to protect…its vast army of delegates…will create 500,000 tonnes of greenhouse effect gasses…the same amount as half a million Africans in one year.”
The earth’s greenhouse gasses have been increasing since the latter pat of the nineteenth century, largely as a result of human activity. Kemp, 1998, explains that, “The ultimate magnitude of the change is uncertain but it has the potential to cause large scale alterations to the natural environment and to global socio-economic and political systems” It is impossible to predict what will happen and when if the earth continues to heat up, but this assignment has outlined many of the predicted outcomes of a change in earth surface temperature.
Humans are responsible for realising more greenhouse gasses than natural resources and have destroyed many sinks. Human health is dependant on a good environment. Many of the factors that lead to deteriated environment also lead to poor health. Pollution of the atmosphere polluted or inadequate water supplies and poor soil all present dangers to human health. Global warming needs to be managed in order to prevent further effects to the atmosphere. Unfortunately it may be too late as the effects are often seen years after the cause in many environmental problems.
- Gribbin, John, (1990) Hot House earth; greenhouse effect and Gaia. Bantam press.
- Houghton, John, (1999) Global warming; the complete briefing, Lion press.
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Kemp, David D, (1998) Global environmental issues, 3rd edition. Routlage press.
- Roan, Sharon L, (1998) Ozone crisis. Wiley science editions.
- Townsend, Mark, September 2002, The state were in, Geographical magazine for the royal geographical society, volume 74, issue 9, page 16.
- Various, (2000) The New Oxford dictionary of English, Oxford publications.
- www.ncdc.noaa.gov, United States Climate centre information, accessed 06/08/2002.