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Global Warming

Global Warming. Global Warming [ref. pg 476 CSEC ; pg 216 WILSON ]. The greenhouse effect is a process where greenhouse gases found in the atmosphere absorbs thermal radiation from a planetary surface and then re-radiates the thermal radiation in all directions.

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Global Warming

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  1. Global Warming

  2. Global Warming[ref. pg 476 CSEC; pg 216 WILSON] • The greenhouse effect is a process where greenhouse gases found in the atmosphere absorbs thermal radiation from a planetary surface and then re-radiates the thermal radiation in all directions. • When it is re-radiated, some of it is radiated back to the back to the surface. This causes the average surface temperature to be higher than if it were heated directly by solar radiation. • Without the layer of gases present the atmosphere, the Earth’s average temperature would be -18 °C, making it uninhabitable.

  3. Global Warming • The term ‘greenhouse effect’ was named this because of the analogy to greenhouses because they are so similar since both limit the rate of thermal energy, however the mechanisms which the heat is contained is different. • Like a greenhouse, the gases allow the short wavelength radiation of the sun through but reflects the longer wavelength re-emitted by the Earth back hence trapping the thermal radiation and warming the Earth. • However, due to man burning fossil fuels and cutting away forests, the natural greenhouse effect has intensified which resulted in global warming.

  4. Long-Term Changes in Global Temperature [ref pg. 477 CSEC] • Since the early 20th century, Earth's mean surface temperature has increased by about 1°C - 3°C over the period 1906–2005. The rate of warming over that period was almost doubled (0.5 °C per decade). • It is believed that the rise in the average global temperature is caused by an increased amount of greenhouse gases in the atmosphere (i.e. global warming) • The warming of the climate system has impacted on the environment in many ways. It has caused an increase in global average air and ocean temperatures which led to the widespread melting of snow and ice and hence the rising of sea levels. • It has also caused the phenomena of climate change to occur which is expected to affect particular ecosystems such as coral reefs, tundra and mangroves. Climate change is expected to result in reduced diversity if ecosystems and the extinction of species.

  5. Causes of Global Warming [ref pg. 478 CSEC] • The fundamental cause of the greenhouse effect is greenhouse gases which absorb and emit radiation from the sun within the thermal infrared range. Some of these greenhouse gases include: WATER VAPOUR (which contributes about 36 – 70% to the greenhouse effect) CARBON DIOXIDE (which contributes about 9 – 26% to the greenhouse effect and is produced by the burning of fossil fuels and deforestation on a large scale) METHANE (which contributes about 4 – 9% to the greenhouse effect and is caused by the decaying of organic matter e.g. natural gas leaks) OZONE (which contributes about 3 – 7% to the greenhouse effect) • Clouds are a non-gas contributor to the greenhouse effect since it absorbs and emits the infrared radiation from the sun, therefore having an effect on the atmosphere’s radiative properties.

  6. Causes of Global Warming [ref pg. 216,217 WILSON] • Scientists report that they are over 90% positive that the source of it is the increased amount of greenhouse gases found in the atmosphere was brought about by human activities (e.g. the burning of fossil fuels; deforestation). • Nitrous Oxide is another greenhouse gas, however contributes to global warming on a smaller scale (5%). It is produced by the use of some chemical fertilizers and the burning of fossil fuels. • Even though CFCs are known for their major role in the depletion of the ozone, recent studies have suggested that they are in fact the key driver of global warming and may even play a more important role than carbon dioxide.

  7. Effects of Global Warming [ref pg. 479 CSEC] • Due to the rise in temperature, many changes have been occurring on our planet. Changes consequent to Global Warming are: ice glaciers are melting at a faster rate leaving animals such as penguins, polar bears and seals less places to surface. • The increase in temperature has caused an increased number of droughts, forest fires, intensity and number of storms, hurricanes and rainfall. As a result floods have also been on an increase. • Heat waves, fires, floods and droughts are on the increase in number and intensity in recent years. • Global Warming has disrupted the normal flow of the seasons which has caused some animals to become out of sync with each other causing some animals or plants which are dependent on other organisms to suffer and sometimes die.

  8. Effects of Global Warming • Global warming causes the penetration of the heat into the ocean which causes the thermal expansion of the water. This along with melting of glaciers and ice sheets can lead to a rise in sea level. • The rise in sea levels can be extremely bad for islands that are under sea level. Also the fresh water added by the glaciers is causing some fish to die due to the loss in the concentration of salt water. • This rise in sea level can hamper with factors such as currents, winds, and sides as well as with different rates of warming, the efficiency of ocean circulation, and regional and local atmosphere. • The rising in sea levels have caused things such as coastal erosion, saline intrusion and sea flooding. • Also, because of the location of many islands at near present sea level and their proximity to the coast, important infrastructure and major concentration of settlements are likely to be at risk.

  9. Solutions to Global Warming [ref pg. 483,484 CSEC] • Many developed and developing are aiming to less polluting and cleaner technologies. Using this technology helps mitigation and can possibly result in substantial reductions in carbon dioxide emissions. • Countries are now attempting to increase of renewable and energy efficiency and aiming for emissions reductions. • Some examples of this are expanding forests in order to remove larger amounts of carbon dioxide from the atmosphere, switching to renewable energy (e.g. solar, water and wind energy), using fossil fuels more adequately for electricity generation or industrial processes.

  10. Solutions to Global Warming • Measures can also be taken as an individual that we could do in our daily lives to help bring an end to global warming: • Reduce, reuse and recycle • Use less heat and air conditioning • Drive less and drive smart • Buy energy-efficient products • Use less hot water • Turn off any electrical appliances when not in use • Car pooling or riding a bike rather than driving in a car

  11. Case Study #1: The Bahamas • The Bahamas is comprised of 700 islands and islets and numerous cays. • Approximately 80 percent of the land area of the Bahamas is with 5 ft of the main sea level. • Andros island within the Bahamas is the largest of the 26 inhabited Bahamian islands and has a greater area than all the other 700 islands combined. However at high tide the island (Andros) is almost covered at high tide.

  12. Effects of Global Warming on The Bahamas • Originally the Bahamas have had problems with hurricanes and tropical storms. • Through global warming and climate change the major problem facing the Bahamas is rising sea level as the rise in the sea level there is a higher possibility of flooding. • Due to flooding there is an effect on housing but also the risk of contamination of fresh water reservoirs with can lead to malaria and dengue fever. • Due to erosion and inundation there will be a loss of beaches. • Salinization of freshwater aquifers. • There will be an increase in stress on the coastal ecosystem. • A high percentage of loss of amenities would jeopardize the viability and threaten the long term sustainability of the tourism industry.

  13. Effects of Global Warming on The Bahamas • Stemming from a sea level rise would be a loss of coastal lands, seasonal flooding and expansion of wetlands. • Changes in weather patterns caused by the changes in local and regional temperature regimes. • Due to the change in rainfall patterns will lead to uncertainties in crop production and possibly increased flooding. • There will be more frequent and more severe weather events such as drought and hurricanes due to the increase in temperatures.

  14. Effects of Global Warming the Bahamas (future impacts) • Coral reefs may get submerged, flooding of wetlands and coastal lowlands which may all be a result of the rise in sea level. • As a result of a rise in ocean temperatures and damage to coral reefs their will be a loss of marine biodiversity. • Their may be a loss of terrestrial biodiversity because of a rise in temperature and changes in seasonality of rainfall. • Loss of agriculture land and reduced agriculture productivity from salinity.

  15. The Bahamas’ Measures Taken to Reduce Impact • The Bahamas government took part in the United Nations Framework Convention on Climate Change signed in Rio de Janeiro in May 1992. • On April 9, 1999 the Bahamian government was the eighth country to accept the Kyoto Protocol which took effect on February 16, 2005 • The government of the Bahamas has prepared aNational Policy for Adaptations of Climate Change. It provides an assessment of the degree of vulnerability of The Bahamas to the projected impacts of climate change by sectors; of the capacity for adaptation to anthropogenic climate change.

  16. Case Study #2: Maldives • The nation of Maldives is located in the Indian Ocean, south-west of India. • It is made up of a double chain of 26 atolls which consists of 1,192 coral islands. • Covering about 90,000, it is considered to be one of the most dispersed countries in the world. • It is considered to be the lowest country on earth with its average ground level being 4ft 11in (1.5m) and highest natural ground level being only 7ft 10in (2.4m) above sea level. 80% of the Maldives islands are made up of coral islands which that are usually less than 1m above sea level.

  17. Effects of Global Warming on Maldives • Due to these conditions present throughout the islands and the fact that global sea levels are expected to continue to rise between 9 and 37 centimeters, Maldives has been ranked the 3rd most endangered country to flooding due to the rising sea levels caused by global warming. • According to Mohamed Nasheed, the previous president of Maldives, even if carbon emissions were to be eliminated this very day, there would be no effect on the earth for 60-70 years and if the carbon emissions continuing to rise at the rate at which they are currently, Maldives would be underwater in seven years.

  18. Effects of Global Warming on Maldives • In 2007, it was predicted by the Intergovernmental Panel that 200 of the inhabited islands of Maldives would have to be evacuated due to the upper limit of sea levels rising to 59cm by 2100. As a result of this, residents may have to move to countries such as Sri Lanka, Australia and India. • Powerful storms and higher sea surges also threaten the islands as they will further degrade the fragile island ecosystem. • This has caused beach erosion to become a serious problem especially as there are so many hotels and roads near the coastline. • The increase in global temperature has caused the sea waters there to be warmer and hence cause the bleaching of coral to occur.

  19. Maldives’ Measures Taken to Reduce Impact • After high tides flooded several islands, an ugly sea wall was built around the capital city, Male’ Hulhumale. This makes the island resistant to flooding, and was artificially constructed from sand dredged up from the ocean floor and dumped into a shallow lagoon. • In an effort to help bring an end to global warming, the nation intends to diminish greatly if not eliminate all use fossil fuels and hence all of its carbon emissions by the year 2020. • President Mohamed Nasheed plans to make the nation the world’s first carbon-neutral by 2020 by switching its source energy to renewable sources of energy such as solar and wind power.

  20. Maldives’ Measures Taken to Reduce Impact • This act was made in an attempt in order to raise awareness to the plight of the Maldives and to set an example that other less energy-integrated countries could follow. • President Nasheed was the subject of the film The Island President, which drew international attention to global warming and the fate of the Maldives.

  21. Group members • Élise Celestin • Analise Hosam • Anna Bethel • Kelsey Phillip • Keneisha Achap • Melissa Bradley

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