Global Changes And Environmental Issues

Global Change

• Acid Rain - Acid rain is caused by the release of sulfur into the environment by coal burning power plants. The sulfur mixes with water vaop and creates sulfuric acid. When this sulfuric acid comes down as rain (or other forms of precipitation), it's called acid rain. Many living organisms are being hurt by this acid rain.
• The Ozone Hole - The Ozone Layer is the protective ozone that exists in the atmosphere surrounding the earth and allows life to exist on earth. Scientists have discovered that a hole is growing in our ozone layer. This hole, called the Ozone Hole, allows more ultraviolet radiation to reach earth. This ultraviolet radiation may lead to more cases of cataracts and cancer, especially skin cancer and eye cancer. CFCs (described in the next section) are the primary cause of this hole in our ozone layer.
• Chlorofluorocarbons - Chlorofluorocarbons (CFCs) are believed to be the primary cause of the ozone hole. They were invented in the 1920s and are used in aerosol spray cans, refrigerator and air conditioning coolants, and the making of stryofoam cups and containers (like what you may bring food home from a restaurant in!). The United States have now banned CFC's from being used in aerosol cans for this reason.
• Global Warming - Global Warming is an increase in the average temperatures on earth. It has been noted that as carbon dioxide in our atmosphere has increased, so have the temperatures on earth. Part of this increase in carbon dioxide comes from the burning of fossil fuels.
• Greenhouse Effect - Greenhouse gases (water vapor, CO2, methane, and nitrous oxide) trap heat within earth's atmosphere much like a greenhouse for plants traps heat inside it. We want heat on earth - we couldn't live without it - but we don't want TOO much! The increase in carbon dioxide in our atmosphere may be increasing the greenhouse effect thus leading to global warming.

The Effects of the Behavior of Humans On Earth's Ecosystems

Chemical Pollution, Loss of Resources, and Human Population Increase

• Biological Magnification Pesticides and other toxic chemicals can accumulate in the fatty tissues of animals. As these toxic chemicals move up the food chain, from one organism eating another, these chemicals become even more concentrated. This is what is meant by biological magnification.
• DDT - DDT is a pesticide that use to be widely used for the purpose of killing insects that may damage crops. It's use has now been restricted in the US. Why? Because it was harming our environment. DDT causes bird eggs to be very fragile and break easily. Because of DDT, many species of birds were declining in numbers, due to their problems with their eggshells.
• Extinction of Species In The Rain Forest - Did you know that we've already lost about half of our tropical rain forests? And more of rainforest are being destroyed every day. Rainforest land is being burned to create farmland or pastures for farm animals. In the process, many species of plants and animals are becoming extinct. It has been predicted that we may lose up to 1/5 of the species of plants and animals on earth. As you read this, keep in mind that everything on earth is connected. When even one species becomes extinct, the results can be far reaching, affecting so many other species as well. What if one or more of the species that are dying off hold the key for preventing or curing cancer?
• The Loss of Valuable Topsoil - Topsoil is the very rich, fertile layer of soil on the top of the ground. The world has lost about a third of it's topsoil since 1950 and is continuing to lose several centimeters of topsoil per decade. Certain agricultural practices allow rain and wind to wash the topsoil away.
• The Depletion and Pollution of Ground Water - Ground water is the the water that collects below the earth's surfaces, in the soil, rocks, and sediment. Ground water is the source of water in aquifers (porous rock reservoirs), springs, and wells. We are using water at a faster rate than it can seep into the aquifers. Also, ground water is being polluted by toxic chemicals and the disposal of chemical wastes.
• Increase in The Human Population - More people are being born than are dying each year. If we continue to increase in numbers at the rate we are currently doing, the population of humans on earth will have doubled from what it is now in just over 60 years. The human population is increasing the fastest in Asia, African, and Latin America. Yet, it's not expected that humans will continue multiplying at this rate. In fact, the rate has already begun declining.
  
  So what's the problem with having so many people on Earth? The more people on earth, the more resources we use, and the faster our resources get depleted. For how long can the earth support 6 billion people?

Solving Environmental Problems

1. Some sewage treatment facilities now remove chemicals in addition to bacteria.
2. "Scrubbers" are devices which reduce the sulfur emission pollutants from factory smokestacks. The "Clean Air Act of 1990" requires that these scrubbers be placed on power plant smokestacks.
3. In some cities, "carpool lanes" have been set aside for cars driving with more than one occupant in order to encourage people to ride together.
4. By law, cars must have catalytic converters in order to reduce the emissions they give off.
5. Reducing pollution costs money. (Paying for a scrubber on a smokestack costs more money than paying for a smokestack alone. Likewise, paying for a catalytic converter on a car costs more money than buying a car without one.) In order to help offset the increased expenses of reducing pollution, sometimes things which pollute the environment are taxed. An example is the gasoline tax.

5 Steps to Solving Environmental Problems Successfully

1. Assessment - The first step to solving environmental problems is assessment. Assessment includes collecting data and making a model.
2. Risk Analysis - During the second step to solving environmental problems, scientists predict what will happen (both positive and negative effects) if they implement various types of environmental interventions.
3. Public education - The third step is to inform the public about the various alternatives and their predicted results and costs.
4. Political Action - In the fourth step, the public votes (or may have their elected officials vote instead) on a plan.
5. Follow-through - The fifth step consists of monitoring the results over time. Has the plan been successful in helping the environment? Has it solved the environmental problem?