Composition of the Atmosphere

Earth’s Atmosphere Consists Of: Nitrogen 2. Oxygen 3. Carbon Dioxide 4. Water Vapor 5. Other gases

Earth’s Composition Nitrogen Oxygen Makes up approximately 78% of the air we breath. Most abundant gas in the atmosphere. Occurs in all living things and makes up about 3% of the weight of the human body Second most abundant gas Plants and animals take in oxygen directly from the air (inhaling) and use it to release energy from food. Many process use oxygen. Fire uses oxygen to help it burn, Steel reacts with oxygen to cause rust.

Earth’s Composition Carbon Dioxide (CO2) Other Gases Makes up less than 1% of the atmosphere, but is essential to life. Plants use CO2 to produce food. Animal cells break down food and release CO2 as a waste product. When fuels like coal and gas are burned, CO2 is released, which increases the CO2 in the atmosphere. Oxygen and Nitrogen make up 99% of dry air. Argon makes up most of the other 1%. The remaining gases are called trace gases because there are only small amounts in the atmosphere.

Earth’s Composition Water Vapor Particles Air is not dry, air contains water vapor. Water vapor is water in the form of a gas. Weather cannot take place without water vapor. Clouds form when water vapor condenses out of the air to form tiny droplets of liquid water or crystals of ice. Pure air contains only gases. Our air is not pure. In the real world, air contains tiny particles of solid and liquid particles of dust, smoke, salt, and chemicals. You can see some of these particles, but most of them are too small to see.

GreenHouse Effect The atmosphere keeps Earth’s surface warm through a process called the greenhouse effect. The sun’s energy reaches the Earth. Earth’s surface is heated. Some heat is radiated into space. The heat easily passes through Nitrogen and Oxygen, however, greenhouse gases, such as water vapor, carbon dioxide, and methane absorb the heat leaving Earth’s surface. These gases radiate some energy back to Earth, trapping heat in the lower atmosphere.

GreenHouse Effect We need the greenhouse effect, but you can have too much of a good thing. Human activities increase the level of greenhouse gases in the atmosphere which causes global temperatures to rise.

GreenHouse Effect Carbon Dioxide Methane Most abundant greenhouse gas. Most comes from burning fossil fuels such as coal, petroleum, and gasoline. We use fossil fuels to generate electricity, heat homes, and power cars. Mining and the processing of coal and petroleum, livestock, agriculture, landfill use, and burning of biomass increases the amount of methane in the atmosphere.

Aerosols Aerosols are solid particles or liquid drops in gas. Can stay in the upper atmosphere for months or years. Scientists think aerosols reflect away some incoming solar radiation and lowers temperatures. The burning of fossil fuels and burning of biomass causes an increase in aerosols in the atmosphere

Global Warming Info Effects Over the last 120 years, the average temperature has increased 0.7 degrees Celsius or 33 degrees Fahrenheit. This gradual increase in the temperature of Earth’s atmosphere is called global warming. Increasing levels of greenhouse gases are causing global temperatures to rise more quickly. Melting Glaciers Rising Sea Levels Drought Desertification and Biosphere Changes Regional changes in temperature

What Can we do? Find clean and renewable energy resources Release very small amounts of greenhouse gases Examples: Solar, Wind, Hydroelectric, Geothermal, Nuclear, Tidal Be more energy efficient Electric Cars Turn off lights Don’t leave electronics on/plugged in when not needed Remove Carbon from Fossil Fuel Emissions Ethanol – additive to gas to make emissions cleaner Biodiesel – made from biomass (corn, wheat) or algae, doesn’t have to be added to gas