Global Warming and Ozone Depletion - PowerPoint PPT Presentation

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Global Warming and Ozone Depletion

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  1. Global Warming and Ozone Depletion

  2. Table of Contents Slides 3-8 Global Warming....... Ozone Depletion...... Slides 9-14

  3. What Causes Global Warming? - Global warming is the rise in average global temperature due to human activities, such as, the emissions of greenhouse gas pollution produced by the burning of fossil fuels and land-use changes like deforestation. Scientists predict that higher temperatures will probably be accompanied by an increase in extreme weather events like flooding and drought, as well as a rise in the global sea level.   - Light from the sun passes through the Earth's atmosphere and heats its surface. The Earth's surface then gives off heat, some of which is trapped in its atmosphere by a blanket of greenhouse gases rather than escaping into space, keeping the Earth warmer than it otherwise would be. Most of this greenhouse effect is natural, maintaining the Earth's average temperature at about 60 degrees Fahrenheit (15 degrees Celsius). Without the natural greenhouse effect, the Earth's average temperature would be closer to 0degrees Fahrenheit (-18 degrees Celsius). - Gases such as carbon dioxide, methane, nitrous oxide, and refrigerants create a greenhouse effect by trapping heat in the lower atmosphere. This makes the Earth warmer because the sun’s rays are allowed into the lower atmosphere but the heat from these rays isn’t able to escape.

  4. When And Where? • - Global warming is happening all over the world, all the time. • Changes in our climate are real and they are underway. But we can do something about it. The evidence that human-induced global warming is real is increasingly clear and compelling. • - Since the beginning of the 20th century, the mean surface temperature of the earth has increased by about 1.1º F (0.6°Celsius). • - Over the last 40 years, which is the period with most reliable data, the temperature increased by about 0.5 º F (0.2-0.3°Celsius). • - Warming in the 20th century is greater than at any time during the past 400-600 years.

  5. Occurences - Global warming is an increase in the average temperature of the earth's atmosphere, especially a sustained increase sufficient to cause climatic change so therefore it has and is occurring in the area of Windsor. - Recent examples of major occurrence in global warming were in Europe. In 2003 Europe received a massive heat wave. Scientists believed that the conclusion to this result is that climate change is now doubling the risk of major heat waves around the world. -Also, another example of global warming is that in the Arctic region, the ice is starting to melt rather quickly because the global warming is allowing the sun to give hotter rays onto the earth. -Like terrorism, global warming knows no boundaries. It can strike anywhere, in any form. It is not just a problem for the future. Global warming is already upon us.

  6. Potential for Destruction • Impacts from Global warming include sea level rise, more extreme weather events including heat waves, frosts, droughts, storms, extinction of species, loss of entire forests, marine life destruction • Some researchers believe that global warming is foreshadowing a coming ice-age. The last ice age occurred as the Earth's climate was warming. In the Arctic regions, more water would evaporate in summer, and fall onto the land as snow in winter. The winters would not be so warm as to melt all of this snow, thus glaciers would grow. Also, some carbon compounds released in the atmosphere may help prevent global warming. These particles reflects sunshine, which is redirected into space.

  7. Other Interesting Facts About Global Warming • The Kyoto Protocol is an amendment to the United Nations Framework Convention on Climate Change (UNFCCC), an international treaty on global warming. It also reaffirms sections of the UNFCCC. Countries which ratify this protocol commit to reduce their emissions of carbon dioxide and five other greenhouse gases, or engage in emissions trading if they maintain or increase emissions of these gases. A total of 141 countries have ratified the agreement. • Current estimates are that even if successfully and completely implemented, the Kyoto Protocol is predicted to reduce the average global temperature by somewhere between 0.02°C and 0.28°C by the year 2050 . • - using current and cutting-edge technology that will reduce our use of fossil fuels. By switching to energy efficient cars and trucks, and clean, renewable energy, we can curb global warming pollution, save consumers money and curtail our reliance on oil.

  8. Ozone Depletion

  9. What Causes Ozone Depletion • The ozone layer is located  above the troposphere in the stratosphere (10 km to about 50 km high). Stratospheric ozone is Earth’s natural protection for all life forms, shielding our planet from harmful  ultraviolet-B (UV-B) radiation. • UV-B radiation is harmful to humans, animals, and plant life. The  ozone layer is being destroyed by certain industrial chemicals including ozone depleting refrigerants, halons, and methyl bromide, a deadly pesticide used on crops. • Ozone depletion damage gets much worse when the stratosphere is very cold. This has been the case the past two years, causing extensive ozone depletion. This past winter, ozone depletion reached  the most severe levels ever recorded over the Northern Hemisphere. Western United States ozone levels also continue to drop 3-4 percent per decade.   • - Even if all of our efforts to stop harmful emissions are successful, the ozone layer is not expected to begin recovery  until around 2020 at the earliest.

  10. When and Where • Ozone depletion occurs in the stratosphere • It happens when the natural balance between the production and destruction of stratospheric ozone is tipped in favour of destruction

  11. Occurences Ozone depletion is presented throughout the whole stratosphere so therefore it has occurred in the area of Windsor. Recent example of its occurrence is in the arctic area. Severe depletion of the Arctic area was first discovered in the 1980’s. Arctic depletion is seasonal mainly occurring in the late winter and early spring. This resulted into the ozone hole in the sky.

  12. Potential for Destruction - The ozone helps get rid of the earth’s pollution but lately it has been letting the sun rays come onto the earth, causing UV radiation • (UV-B) radiation causes skin cancer, cataracts and immune suppression in both animals and humans.  UV-B also damages plants including hardwood forests, and phytoplankton • Skin Cancer Is Increasing • - There has been an 1,800 percent rise in malignant melanoma since 1930. • - One American dies of skin cancer every hour. • - One in five Americans develops skin cancer. • - People get 80 percent of their lifetime sun exposure by age 18.

  13. Other Facts - The Montreal Protocol on Substances That Deplete the Ozone Layer is a landmark international agreement designed to protect the stratospheric ozone layer. The treaty was originally signed in 1987 and substantially amended in 1990 and 1992. The Montreal Protocol stipulates that the production and consumption of compounds that deplete ozone in the stratosphere are to be phased out. • Solutions to the ozone layer depletion problem have been found but the ones that show the most promise are very expensive. The web site "The ozone Depletion Phenomenon" suggests in the article "solutions", "to build huge metal screens that float on helium balloons in the troposphere". • - They continue with "These screens will be electrified so that chlorine atoms will become negatively charged and unable to destroy ozone molecules". The also say that "In order for these screens to be effective the screens would have to be the size of a football field and a total of 8 screens would have to circle the earth".

  14. THE END!