Learning Objectives: At the end of the class students will be able to. define air pollution explain the sources of air pollution understand the effects of air pollution like global warming acid rain and climatic change Have a clear understanding of actions to be taken to reduce and control air pollution. What is air pollution? What is air pollution? Air pollution is when unwanted chemicals, gasses, and particles enter the air and the atmosphere causing harm to animals and damaging the natural cycles of the Earth. Causes of Air Pollution Natural Causes of Air Pollution Some sources of air pollution come from nature. These include eruptions of volcanoes, dust storms, and forest fires. Human Causes of Air Pollution Human activity is a major cause of air pollution. Air pollution is caused by emissions from factories, power plants, cars, airplanes, chemicals, fumes from spray cans, and methane gas from landfills. Burning Fossil Fuels One of the ways that humans cause the most air pollution is by burning fossil fuels. Fossil fuels include coal, oil, and natural gas. When we burn fossil fuels this releases all sorts of gasses into the air causing air pollution such as smog. Burning of waste Open waste burning and organic waste in landfills release harmful dioxins, methane, and fine particulate matter like black carbon into the atmosphere. Pollution caused by industries Industries release a large amount of carbon monoxide, hydrocarbons, organic compounds, and chemicals into the air thereby depleting the quality of air. Effects of Air Pollution. Effects on the Environment Air pollution and the release of gasses into the atmosphere can have many negative effects on the environment. 1. Depletion of ozone layer. 2. Global warming Acid rains Climatic changes. What is ozone layer? The ozone layer helps protect us from harmful rays from the sun. It is getting damaged from air pollution such as methane gas from livestock and CFCs from spray cans. What happens if ozone layer is depleted? Earth's ozone layer, absorbs and blocks the majority of the sun's UV radiation. Without this barrier in place, all of the radiation would reach Earth, damaging the DNA of plants and animals resulting in skin cancers. Global Warming Global warming: The increase in Earth's average temperature over a long period of time due to increased green house effect. Greenhouse Gases The reason the Earth isn't a ball of frozen ice is because of greenhouse gases. Greenhouse gases act like insulation to keep the Earth warm. However, as more and more greenhouse gases get into the atmosphere, the Earth will start to grow warmer. The main greenhouse gases that keep the Earth warm are water vapor, carbon dioxide, and methane. What are green house gases Green house effect. Global warming In the past 100 years humans have been the cause of a significant increase in greenhouse gases in the atmosphere, especially carbon dioxide. Every time we drive our cars or use electricity, more carbon dioxide is released into the air. What is green house effect? Light from the sun passes through the atmosphere and is absorbed by the Earth’s surface, warming it. Greenhouse gases, like carbon dioxide, act like a blanket, trapping heat near the surface and raising the temperature. It is a natural process that warms the planet. But human activities are increasing the amount of greenhouse gases and trapping more heat. More heat trapped will result in increased temperatures. These increased temperatures result in global warming. Effects of global warming. Effect of global warming is felt on. Biodiversity: The increase of temperatures and the climate upheavals disturb the ecosystems, modify the conditions and cycles of plant reproduction. The scarcity of resources and climate change are changing life habits and migratory cycles of animals. Increase in sea levels On Oceans: Because of global warming, permafrost and ice are melting massively at the poles, increasing the sea level. Increase in sea levels can have devastating effects on coastal habitats. It can cause soil erosion, wetland flooding, aquifer and agricultural soil contamination with salt, and lost habitat for fish, birds, and plants. Climatic changes On climate: Global warming results in more droughts and heat waves, more precipitations, more natural disasters like floods, hurricanes, storms and wildfires, frost-free season, etc. On humans: Climate change is affecting the global economy. It is already shaking up social, health and geopolitical balances in many parts of the world. The scarcity of resources like food and energy gives rise to new conflicts. Rising sea levels and floods are causing population migration. Fog When warm moist air rapidly cools tiny droplets of water may form and stay suspended in the air. This is fog. Fog is sometimes called as low cloud.
