Presentation on theme: "Climate Change Science 9.4 Standard Science 6.4 e Students know differences in pressure, heat, air movement and humidity results in a change in weather."— Presentation transcript:
Climate Change Ice ages- huge sheets of ice covered large parts of Earth’s surfaces. Ice sheets covered most of northern Erupoe and North America. It was 3 kilometers thick. The sheets melted and the rising oceans flooded coastal areas.
Global Warming Gradual increase in the temperature of Earth’s atmosphere Climate is changing because of Human activities.
Greenhouse Hypothesis The Earth’s gasses holds in heat from the sun. That’s why it if comfortable to be outside. Definition: gases in the atmosphere that trap energy are called greenhouse gases. Sunlight heats the soil, benches and pots. This in turns heats the greenhouse.
Greenhouse Hypothesis Gases: Carbon Dioxide Water Vapor Methane Increased carbon dioxide may cause global warming by trapping more heat in the atmosphere.
Changing levels of Carbon Dioxide Over the past 200 years, the level of carbon dioxide in the atmosphere has increased steadily. How do scientists know this? They measured the amount of carbon dioxide in air bubbles trapped in Antarctic ice. Gas bubbles in the ice provides sample of air from the time it was formed.
Climate Variation Hypothesis Satellite measures have shown that the amount of energy the sun produces increases and decreases slightly from year to year. Global warming's positive effects: Farmers can plant 2 crops instead of one Any plant can be farmed because it’s cooler
Global warmings’ negative effects: Higher temperatures cause evaporation from farmland. Dry soil blows away easily Warms up ocean water as well, which in turns creates hurricanes. It would also raise the sea level.
Ozone Depletion Ozone hole: a large area of reduced ozone Chemicals produced by humans have been damaging the ozone layer. Earth’s ozone layer filters harmful ultraviolet radiation from the sun.
Chlorofluorocarbons Definition: a major cause of ozone depletion is this group of compounds. (CFC’s) Use in air conditioners Refrigerators Cleaning electronic parts Aerosol spays Deodorants Scientists predict that banning the use of chlorofluorocarbons will gradually restore the ozone layer.
Results of Ozone Depletion A decrease in ozone depletion means an increate in the amount of ultraviolet radiation. The US and other countries have banned CFC’s. Ozone depletion affects the whole world. Production of this chemical has decreased over the years. Size of ozone hole is expected to shrink over time.
Modeling What are 3 possible effects of global warming? Do not just give me the answer. You need to find the page number. You need to give me the “Quote” straight out of the text that supports or answers this question. In other words: Not written in your own words
Checking for Understanding What is global warming? What effect have human activities had on the ozone layer? What are CFC’s?
Guided Practice Independent Practice Guided Practice Worksheet numbers 1-3. Stop! Have your work checked. Independent Practice- Workbook pages