Human Activities and Climate Change Climate Interactions Table of Contents Human Activities and Climate Change Ms. De Los Rios 6th Grade

Vocabulary 7.6 Ozone- A form of oxygen that has three oxygen atoms in each molecule instead of the usual two. Ozone Layer- The layer of the upper atmosphere that contains at higher concentration of ozone than the rest of the atmosphere. CFC’s (chlorofluorocarbons) Human-made gases containing chlorine and fluorine (CFC’s) that are the main cause of ozone depletion. Greenhouse Gases- Gases in the atmosphere that trap energy. Fossil Fuel- Coal, oil, or natural gas that forms over millions of years from the remains of ancient organisms, burned to release energy. Global Warming- A gradual increase in the average temp. of the atmosphere, thought to be caused by an increase in greenhouse gases from human activities.

How Does the Ozone Layer Protect Earth? Ozone is a form of oxygen that has three oxygen atoms in each molecule instead of the usual two. Ozone in the atmosphere absorbs some of the harmful radiation from the sun. The ozone layer is a layer of the upper atmosphere. It is about 15 to 30 kilometers above Earth’s surface. Sunburn It protects people from the effects of too much U.V. radiation. Eye disease

The Source of Ozone pg. 269 & 270 Ozone is constantly being made and destroyed as part of the ozone cycle. The amount of ozone in the ozone layer is decreasing, creating an ozone hole. Scientists determined that the major cause of the ozone hole is a group of gases called CFCs. What is CFCs, or chlorofluorocarbons???? CFCs are human-made gases that contain chlorine and fluorine. CFC’s block the cycle in which ozone molecules absorb U.V. radiation. Where is this gas found? CFCs were used in many household products. (AC, aerosol sprays, dry cleaning) Most uses of CFCs were banned in 2000. Scientists predict that if the ban on ozone-depleting substances is maintained, the ozone layer will gradually recover.

CFCs

Human Activities and Climate Change pg. 270 Ozone Hole The ozone hole (shown in blue) is over Antarctica. The hole has grown over time, but its size varies seasonally and from year to year. Mario José Molina and two other scientists won the Nobel Prize for Chemistry in 1995 for their theory that gases used in many household products help create the hole.

Ozone in the atmosphere is constantly being created and destroyed. Human Activities and Climate Change pg. 269 Ozone Cycle Ozone in the atmosphere is constantly being created and destroyed. Explain the ozone cycle in your own words. Then describe how ozone in the atmosphere protects life on Earth. ___________________________________________________________________________________________________________________________________________________________________________________________________________________

Greenhouse Effect pg. 271 Art in Motion- Pearson (r. 1P) The sun warms Earth’s surface, and the heat is radiated back through Earth’s atmosphere to space as infrared waves. The atmosphere keeps Earth’s surface warm through the greenhouse effect. Greenhouse gases such as carbon dioxide, methane, and water vapor absorb the heat leaving Earth’s surface. They make up only 1 percent of the atmosphere. Levels of Greenhouse Gases Many human activities are increasing the level of greenhouse gases in the atmosphere. This increase is causing global temperatures to rise.

Human Activities and Climate Change pg. 271 Figure 3 Greenhouse Effect Which word in the Word Bank completes each sentence? Then, describe how the structure of the atmosphere insulates Earth Through the greenhouse effect. _________________

Carbon Dioxide Levels pg. 272 Levels of Greenhouse Gases Many human activities are increasing the level of greenhouse gases in the atmosphere. This increase is causing global temperatures to rise. The most abundant greenhouse gas is carbon dioxide (CO2) Most of the carbon dioxide in the atmosphere was released by human beings burning fossil fuels (energy-rich substances formed from the remains of organisms.) Over the last 120 years, the average temperature of the troposphere has increased 0.7°C. This gradual increase in the temperature of Earth’s atmosphere is called global warming. Models of climate change predict that global temperatures will rise several degrees over the next hundred years.

Human Activities and Climate Change pg. 272 FIGURE 4 Carbon Dioxide Levels The graph shows the levels of carbon dioxide in the atmosphere over time. Describe what the level of Carbon dioxide was like 500 yrs. Ago? ______________________________ 2. When did the biggest increase in Carbon dioxide levels occur? Why? ____________________________

Effects of Global Warming The effects of global warming include melting glaciers, rising sea levels, drought, desertification, changes to the biosphere, and regional changes in temperature. Global temperature changes affect regions differently. Rising global temperatures cause some regions to get very warm and dry. Severe droughts cause some lands to become deserts and this process leads to food shortages. Rising temperatures cause sea levels to rise because of melting glaciers and they upset the balance of organisms in some ecosystems as organisms are forced to move to new locations to find familiar climates.

Human Activities and Climate Change pg. 273 FIGURE 5 Sea Level Rise The satellite image shows how sea level rise could affect the eastern United States. How would the sea level prediction shown affect the people in Florida and the rest of the eastern United States? ____________________________________________________________________________________________________________________________________________________________

Limiting Global pg. 274 Solutions for limiting global warming include: finding clean-renewable sources of energy (Solar, wind, hydroelectric, geothermal, nuclear, and tidal energy) being more energy-efficient Clean power plants, factories run on steam, people practice energy-efficient habits (turn off lights, public transportation) and removing carbon from fossil fuel emissions Developing technologies to remove carbon dioxide and buried them underground All of these solutions are designed to reduce greenhouse gas emissions. Interactive Art