1. Man Made Perils Examples Ozone Depletion Acid Rain Pollution
Man Made Perils/hazards - These are caused by human activity to the Earth. A hazard/peril is global when it impacts on earth’s life sustaining systems.
Examples
Ozone Depletion
Acid Rain
Pollution
Global Warming
Deforestation
Desertification
Nuclear threat
Species extinction/ loss of biodiversity
Genetic Erosion

2. Ozone Depletion
The ozone layer is a belt of naturally occurring ozone gas that sits 9.3 to 18.6 miles (15 to 30 kilometers) above Earth and serves as a shield from the harmful ultraviolet B radiation emitted by the sun.

3. What is ozone?
Ozone is a highly reactive molecule that contains three oxygen atoms. It is constantly being formed and broken down in the high atmosphere, 6.2 to 31 miles (10 to 50 kilometers) above Earth, in the region called the stratosphere

4. What are the effects of ozone depletion?
The ozone layer is deteriorating due to the release of pollution containing the chemicals chlorine and bromine. Such deterioration allows large amounts of ultraviolet B rays to reach Earth, which can cause skin cancer and cataracts in humans and harm animals as well.

5. How the ozone layer protects us

6. Illnesses in humans caused by overexposure to UVB rays
Skin Cancer
Cataracts
Suppressed immunity

7. Effects on the environment
Extra ultraviolet B radiation reaching Earth also inhibits the reproductive cycle of phytoplankton, single-celled organisms such as algae that make up the bottom rung of the food chain. Biologists fear that reductions in phytoplankton populations will in turn lower the populations of other animals. Researchers also have documented changes in the reproductive rates of young fish, shrimp, and crabs as well as frogs and salamanders exposed to excess ultraviolet B

9. How humans contribute to the problem:
Chlorofluorocarbons (CFCs), chemicals found mainly in spray aerosols heavily used by industrialized nations for much of the past 50 years, are the primary culprits in ozone layer breakdown. When CFCs reach the upper atmosphere, they are exposed to ultraviolet rays, which causes them to break down into substances that include chlorine. The chlorine reacts with the oxygen atoms in ozone and rips apart the ozone molecule.

10. Aerosol Cans One atom of chlorine can destroy more than a hundred thousand ozone molecules, according to the the U.S. Environmental Protection Agency.

11. Impact on the Arctic
The ozone layer above the Antarctic has been particularly impacted by pollution since the mid-1980s. This region’s low temperatures speed up the conversion of CFCs to chlorine. In the southern spring and summer, when the sun shines for long periods of the day, chlorine reacts with ultraviolet rays, destroying ozone on a massive scale, up to 65 percent. This is what some people erroneously refer to as the "ozone hole." In other regions, the ozone layer has deteriorated by about 20 percent.

12. More Developed Countries
About 90 percent of CFCs currently in the atmosphere were emitted by industrialized countries in the Northern Hemisphere, including the United States and Europe. These countries banned CFCs by 1996, and the amount of chlorine in the atmosphere is falling now. But scientists estimate it will take another 50 years for chlorine levels to return to their natural levels.

13. Pollution and Waste Disposal
Man Made Peril

14. Pollution
Any material produced by humans in quantity and disposed of in such a way that it interferes with the health of living organisms and with the natural environments and processes of Earth.

15. Types of pollutants
Persistent pollutants- materials that remain in the environment for many years without breaking down. Pesticides, heavy metals like lead
Non-persistent pollutants-biodegradable. Human waste, food

16. Air Pollution
Primary pollution- directly from industry, manufacturing, mining, refining or combustion
Carbon dioxide-released from burning fossil fuels
Carbon Monoxide-same as above (incomplete oxidation)
Hydrocarbons (automobile exhaust, smokestacks)
Particulates-smoke, dust, ash
Sulphur dioxide-burning FF that contain sulphur
Nitrogen oxides- from FF, creates smog

17. Secondary Air Pollution
Smog Acid Rain

18. Water Pollution Domestic Sewage Animal and human waste
Nitrogen and phosphate compounds
Agricultural runoff
Industrial wastes
Silt and sediment
Urban Runoff
Marine Discharges
Page 138- Animal and human waste comes from undigested food material often

19. The Hazards of Water Pollution
Disease-causing bacteria, viruses and protozoa found in animal and human waste can affect those drinking the water. Cholera, dysentery and hepatitis are known contaminants. Too much nitrogen and phosphorous in water causes excessive growth of algae, blocking light to deeper water. Sediment caused by erosion can suffocate fish, aquatic vegetation and other organisms.

20. Waste Disposal
How does Canada rank among other countries in terms of waste disposal?
t/municipal-waste-generation.aspx

21. Domestic Sewage
Halifax, NS (population 372,679) pumped untreated sewage into the harbour until 2008.
That’s anything that passes through toilets, sinks, bath and shower drains!
Other methods- “settling lagoons”, aeration (creates sludge which can be dried and used in compost and fertilizers)

22. Solid Waste Packaging, paper, metal, glass, styrofoam Goes to
Landfills
Incineration
Recycling

23. Hazardous and Toxic Wastes
Items that are explosive, flammable or other dangers such as poison
Issues
Storage (how long will containers last?)
Dumped in landfills (toxins leak into groundwater)
Incinerated (dangerous fumes, poisonous ash)
Ship to LLDCs????

24. Sydney Tar Ponds
Read case study on page 149 Questions 5, 7 and 8 on page 152