8.4.2:LE2 (Pollution): B-head – How Can Pollution in the Atmosphere Affect Land and Water?

Problems with air pollution become even greater when many pollutants fall to the ground with rain. These pollutants can include acid rain, particulates, volatile organic compounds (which, like benzene, can cause cancer), heavy metals, and radioactive isotopes. These pollutants can contaminate water supplies and soils, and can damage or kill wildlife. Fortunately, many of these pollutants can be eliminated or reduced through regulations or by changing industrial practices.

For example, when the U.S. and Soviet Union were actively testing nuclear weapons, significant amounts of radioactive isotopes fell across the land, contaminating food. Nuclear testing has been almost entirely eliminated around the world. As another example, lead used to be added to gasoline to improve engine performance. It was discovered that the lead washed into streams and lakes and was very harmful to life. The practice of adding lead to gasoline has now been almost entirely eliminated in most countries.

One of the most significant affects on land and water is from acid rain. When acid rain falls into a pond or a lake, it changes the conditions there. Many fish, particularly their eggs, cannot survive in more acidic water. When acid rain falls on plants, it can damage their leaves and stems. Acid rain that falls on the ground can also damage plants by affecting the nutrient levels in the soil. Whole forests have been destroyed by acid rain. Methods have been developed, however, where most of the nitrogen and sulfur oxides that contribute to acid rain are removed during the combustion process. Many lakes in the northeastern U.S. that were once too acidic for fish to survive have returned to healthy conditions.

Acid rain doesn’t just affect living things. The acid reacts with stone and metal in buildings and statutes. Statues and stonework damaged by acid rain may look as if they are melting, as seen the Figure XX [Use Figure 3 from IS-Ecology&Env p. 145]. Metal structures such as cars rust more quickly in areas with acid rain. These effects are not reversible and the damage can be costly. Even land erosion rates around the world have increased because of increased rain acidity. Humans are helping mountains erode at a faster rate!

One other important place where air pollution has caused an increase in acidity is the world’s ocean. Since the start of industrialization, the ocean’s acidity level has increased by 30%. The shells of most marine animals are made of a mineral called calcite that will dissolve in acid. The increased ocean acidity is therefore threatening many species of ocean animals, which will not be able to build their shells in the more acidic water. The reason for the increase in ocean acidity is the increase in carbon dioxide in the atmosphere. Humans release more than 30 billion tons of carbon dioxide into the atmosphere each year. About one quarter of this ends up going into the ocean.

Figures:1) Figure 3 from IS-Ecology&Env p. 145 [I also have some examples of acid rain on Cleopatra’s needle, behind the Metropolitan Museum of Art in NYC. This is a granite obelisk that was brought to NYC from Egypt in the mid-1800s. The east side is still readable, but the west side (facing New Jersey, where rain comes from!) is almost entirely obliterated. It stood unchanged in Egypt for millennia, but the hieroglyphs are almost obliterated in NYC in 150 years!]

East Side:

West Side:

2) A map of ocean acidification, such as:http://en.wikipedia.org/wiki/File:WOA05_GLODAP_del_pH_AYool.png

LE 1 Human Population and Resource Consumption

<I’ve picked up these two b heads from existing material. It is content light though, only about 6 paragraphs.>How Has the Human Population Grown Over Time? (about 2 pages)What Factors Allow the Human Population to Grow

Birth and Death RatesMedical Care and TechnologyPopulation Growth and Natural Resources

(new) What Factors May Limit Future Human Population Growth? (4 pages if needed)

Land AvailabilityFood AvailabilityWater Availability

<I’m reworking this B head from existing content> (about 2 pages)How Are Environmental Decisions Made?

Balancing Different NeedsTypes of Costs and Benefits

LE 3 Water Use

(new) Overuse of Freshwater (about 2 pages)Groundwater (aquifers and wells; look at how much water we rely on from the

ground for all uses)Surface Water (show aerial shots that show reduction in water levels over time;

look at how much water we use from the surface water for all uses.)

(new) How Can Human Impact on Freshwater Be Reduced? (about 2 pages) Water Conservation [Desalination (pick up some text and art from page 163, Ecology and the

Environment; add more info about how it is used for people in everyday life rather than just ships; decent lead in to the next B head)

<I’ve pulled together this B head from existing resources. It is 2 pages.>How Can Fisheries Be Managed for a Sustainable Yield? (pick up 106 & 107)

Fishing LimitsFishing MethodsAquaculture (merge the C heads from pp. 107 & 162) [Done]New Resources