1 / 33

Chapter 20 Lecture Presentation

Chapter 20 Lecture Presentation. Preserving and Protecting Your Environment. Bursting with People: Measuring the Impact. Impact on other species Impact on our food supply Land degradation and contamination of drinking water Impact on energy conservation.

zia-talley
Download Presentation

Chapter 20 Lecture Presentation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chapter 20Lecture Presentation Preserving and Protecting Your Environment

  2. Bursting with People: Measuring the Impact • Impact on other species • Impact on our food supply • Land degradation and contamination of drinking water • Impact on energy conservation

  3. World Population Growth, 1950–2050 (Projected)

  4. World Liquid Fuel Consumption by Region and Country Group, 2007 and 2035 (Projected)

  5. Factors That Affect Population Growth • Total fertility rate is a measure of the hypothetical average of the number of children born to women between ages 15 to 44, given prevailing fertility and mortality rates. • In America, that rate is nearly 2 per woman, while in certain African countries and in the Middle East, the rate ranges from 5 to nearly 8.

  6. Different Nations, Different Growth Rates • India is expected to increase its population by 600 million by 2050, surpassing China. • In developing nations, large families occur because of • High infant mortality rates • Children being the family’s “social security” • Low education and economic status of women

  7. Selected Total Fertility Rates Worldwide, 2010

  8. Different Nations, Different Growth Rates • In wealthier nations,with the exception of the United States, population sizes are either static or declining. • The United States ranks 123rd out of 233 nations in population growth, adding 3 million people each year or 8,000 per day. • Although the United States represents only 5% of the world’s population, it consumes nearly 25% of total global resources.

  9. Zero Population Growth • Total zero population growth limits couples to two offspring. Once the parents die, these two children are their replacements, allowing the population to stabilize or even decrease. • There are over 20 countries with zero or negative population growth. • Education is the single largest contributor to zero population growth.

  10. Air Pollution • Air pollution is either naturally occurring or anthropogenic (caused by humans). • Components of air pollution • Sulfur dioxide, particulates, carbon monoxide, nitrogen dioxide, ground-level ozone, and lead. • Photochemical smog • Contains particulates and gases that form when oxygen-containing compounds of nitrogen and hydrocarbons react with sunlight.

  11. Air Quality Index • Like the weather, air quality changes day to day, hour to hour. • The Air Quality Index focuses on health effects that can occur within a few hours or days after a person breathes polluted air. • The scale runs from 0 to 500. When it rises above 100, it is considered unhealthy.

  12. Air Quality Index (AQI)

  13. Acid Deposition and Acid Rain • Acid deposition (acid rain) is precipitation that has fallen through acid air pollutants. • Acid pollutants are deposited in two ways: • Wet deposition: acidic rain, fog, and snow • Dry deposition: chemicals that are incorporated into dust or smoke before falling to the ground • Sources of acid deposition are mostly processes that burn fossil fuels. • Acid deposition damages lakes and ponds, kills trees, and causes human health effects.

  14. Indoor Air Pollution • Prevention of indoor air pollution • Source control • Ventilation improvements • Air cleaners • Environmental tobacco smoke is a form of indoor air pollution. • Home heating by woodstoves and oil- or gas-fired furnaces can emit particulates and carbon monoxide, respectively.

  15. Indoor Air Pollution • Asbestos, if disrupted, produces tiny fibers that become airborne. • Formaldehyde is contained in many home materials. • Radon seeps into homes through cracks and pipes. • Molds and fungi live both in and outdoors. • “Sick building syndrome” is primarily related to poor ventilation.

  16. Activity Break • Do you believe that if we do not change our current rate of population growth and our consumption of natural resources, we may face a situation where: • Electricity is available for only a few hours each day, so that you have to choose between using a refrigerator, TV, computer, or electric light? • Only limited amounts of gasoline are available for your car and there are shortages of grocery supplies?

  17. Ozone Layer Depletion • The ozone layer forms a protective layer in Earth’s stratosphere. • It protects the planet from ultraviolet B (UVB) radiation. • In the 1970s, it was discovered that chlorofluorocarbons (CFCs) contribute to the rapid depletion of the ozone layer. • Aerosol sprays containing CFCs were banned in the 1970s.

  18. Global Warming • Greenhouse gases • Carbon dioxide, CFCs, ground-level ozone, nitrous oxide, hydrocarbons, and methane form a gaseous layer that allows solar heat to pass through the atmosphere to Earth, but it also traps the heat and prevents it from escaping. • Kyoto Protocol • This is an international plan to reduce the human-made emissions responsible for climate change. It has been signed by more than 160 countries, including more than 30 industrialized nations. • This document, unsigned by the United States, would require us to reduce emissions by 33%.

  19. The Enhanced Greenhouse Effect

  20. Reducing Air Pollution and the Threat of Global Warming • Changes must occur in energy, transportation, and industrial practices. • Reducing consumption of fossil fuels in cars and shifting to alternate fuels, improving gas mileage, and using mass transportation are crucial to the reduction of air pollution. • In what ways can you reduce your carbon footprint?

  21. Water Pollution and Shortages • About 75% percent of Earth’s surface is covered with water; only 1 percent of this water is available for human use. • Water contamination • Point-source pollutants enter a waterway at a specific location. • Nonpoint-source pollutants consist of runoff and sedimentation.

  22. Water Pollution • Septic systems. • Landfills. • Gasoline and petroleum products. • Chemical contaminants designed to dissolve grease and oil. • Although polychlorinated biphenyls are now banned in the United States, some 500 million pounds have already been dumped into landfills and waterways. • Dioxins, commonly found in herbicides. • Pesticides. • Lead.

  23. Potential Sources of Groundwater Contamination

  24. Which Fish Is Safest to Eat? • What types of fish have high levels of mercury and should be avoided by children and pregnant women? • What types of fish are lower in mercury and are safer to eat? • What is the greatest health danger of consuming too much mercury in your diet?

  25. Land Pollution • Solid waste • Every day, 4 pounds of municipal solid waste per person is generated in the United States. • Although 90 percent of our trash is recyclable, only 26 percent is actually recycled. • Hazardous waste • The Superfund law was enacted in 1980 to provide money for the cleanup of hazardous chemical sites.

  26. What’s in Our Trash?

  27. Land Pollution • The number of landfills has decreased in the past decade, but their mass has increased. • As communities run out of disposal space, it is becoming more common to take garbage out to sea and dump it there, thus contaminating the ocean ecosystem.

  28. Land Pollution • Strategies to control waste: • Source reduction (waste prevention) • Recycling • Composting • Combustion with energy recovery

  29. How Much Do We Recycle?

  30. Crack Those Recycling Codes • Can you recycle on campus? Do you? • Were you aware of the Great Pacific Garbage Patch? In what way do you think it affects the environment? What should be done about it?

  31. Radiation • Nonionizing radiation: radio waves, TV signals, microwaves • Ionizing radiation: the sun, uranium • Radiation absorbed doses (RADs) • Electromagnetic fields (EMFs) • Nuclear power plants • Nuclear meltdown occurs when a nuclear reactor’s core temperature increases to melt both the nuclear fuel and the containment vessel that holds it. • At the nuclear power plant in Chernobyl, there was a reactor core fire and explosion.

More Related