School Project on Energy Conservation
The following questions and answers on energy conservation are based on correspondence between Gabe Dodd of Farmington, Delaware and David Radcliff.
Gabe: What is energy?
David: Energy is the power that runs every thing from the human body to the space shuttle to electric leaf blowers.
Gabe: What are some major sources of energy?
David: Energy comes from many different sources. For instance, food is the energy the body needs. When we talk of energy conservation, we are usually thinking about the energy that powers our economy and provides for our lifestyles.
Fossil fuels (materials that were once organic matter, but have been turned into burnable fuels by pressures and processes within the earth) are a primary source of energy in our society. These energy sources include coal, petroleum and natural gas.
In terms of energy from fossil fuels in the world as a whole, 30 percent comes from coal, 42 percent from oil, and 28 percent from natural gas (reference: Earth Day Guide to Planet Repair, Dennis Hayes, Island Press, 2000, page 30).
Coal is a major source of energy worldwide, especially for energy production and in some cases home heating. It is the "dirtiest" of fuels, creating lots of pollution when burned. For one thing, it creates 2.37 pounds of CO2 for every kilowatt of electricity it creates--in other words, keeping a 100 watt bulb on for 10 hours=1 kilowatt=2.37 pounds of CO2, a major global warming gas. In addition, burning coal produces mercury pollution, which when it gets into the food chain can retard mental development in humans.
Petroleum is the energy that fuels much of global business and travel and supports our lifestyle (heating, cooling, cooking, etc.). It creates 2.14 pounds of CO2 per kilowatt.
Natural gas is the cleanest of the fossil fuels, but still creates global warming gases at a rate of 1.32 pounds per kilowatt.
Burning wood, which is how many people in the world cook their food and heat their homes, produces 2.59 tons of CO2 per cord (a cord is a stack of wood 4' x 4' x 8'). Cutting down trees for firewood is responsible for about half of the deforestation happening in the world. In our own society, 90 percent of the paper we use comes from virgin timber, rather than from recycled paper. All in all, the world is losing about 25 million acres of forest each year. Half the world's forests are already gone.
Nuclear energy is created by a controlled nuclear reaction in a nuclear power plant. The problem with nuclear energy is that even though it is relatively clean when created (although pouring millions of tons of concrete to build reactors has an environmental cost, since concrete production is a big polluter), the nuclear waste from the process is highly radioactive and must be buried somewhere or otherwise stored for thousands of years til it is no longer radioactive. So, in a sense when we use nuclear energy, we're passing on our problems to our children's children's children's children's children's…well, you get my drift.
Hydroelectric energy comes from damming rivers and using the energy of the water to turn turbines to generate electricity. This is "clean" too, except that building dams demands huge amounts of concrete, destroys river systems, disrupts or destroys fish populations, and affects people downstream who may have depended on the river for their livelihood.
Wind energy is created by using the wind to turn turbines to generate electricity. This is one of the cleanest forms of energy we now have available. The only limiting factor is living in an area where the wind is blowing constantly--or having some way to store the electricity for a calm day. Also, big oil companies and others may not like to see this kind of energy generation, as it is harder for them to control and make money from it.
Then there is the sun. The sun is actually responsible for just about all of the above, as it is what makes the weather change (wind), enables the hydrological cycle (rain and running water), and grew the plants that eventually over millions of years created the coal and oil. The sun can also be the source of energy by using solar panels to turn sunlight into electricity or directly warming homes by use of south-facing windows combined with good insulation.
Gabe: Why is it important to conserve energy?
David: There are lots of reasons to conserve energy in a world like ours.
Global warming is created by the emission of pollutants like carbon dioxide and methane, which go up into the atmosphere and form a kind of blanket around the earth. Scientists say that because of this "greenhouse effect," the earth will likely heat up by 3-7 degrees over the coming century. Global warming is already affecting the weather, causing more frequent and more severe storms, leading to the spread of disease. This happens in two ways: 1) disease carriers (bugs and viruses) can move into areas once too cold for them; 2) more severe storms cause flooding which affects clean water supplies and makes people ill. The World Health Organization reports that Global Warming will be responsible for 160,000 deaths in 2003. Global Warming is also affecting Arctic ecosystems--melting permafrost, which in turn releases even more greenhouse gases such as methane into the atmosphere. It is also melting Greenland at a rate of 51 billion cubic meters of water a year. If Greenland ever totally melts, it would raise global sea levels by as much as 23 feet. (State of the World 2001, Worldwatch Institute).
Energy conservation can also lead to a reduction in pollutants that go into the air, affecting human health. Air pollution will be the leading cause of death for 70,000 people in the United States this year, nearly twice as many as will die from car accidents (40,000).
Using less energy will also make our nation less dependent on oil from places like the Middle East, which could mean less military spending to support going to war for oil. (Americans take 60 car trips each week; if we gave up two of these, we wouldn't need any oil from Iraq [we have gotten about 3 percent of our oil from Iraq in the past]).
Conservation would also keep us from wanting to drill in places like the Arctic National Wildlife Refuge. Drilling there might affect the health of the Porcupine Caribou Herd, which in turn would affect the lives of the Gwich'in people who depend on the herd for survival.
Gabe: How much more energy does the United States use than other countries?
David: With about 4 percent of the world's population, we consume 24 percent of the world's energy, 25 percent of its fossil fuels, and emit 22 percent of the CO2. (E Magazine). In terms of petroleum consumption for transportation, we consume about 18 barrels per person per year, while in Europe or Japan the figure is 6 barrels per person per year (State of the World 2001, Worldwatch Institute). In an area like paper use, which is very energy intensive, the average American consumes 760 pounds of paper per year. This is roughly nine trees worth of paper (nine 40-foot tall trees about the width of telephone poles---Co-op America, WoodWise Consumer, 1998). The world average for paper consumption is about 100 pounds. People in the world's poorest areas consume less than two pounds per person per year. To produce a pound of paper that is made from trees (as opposed to recycled fiber) requires three and a half pounds of wood, 10 pounds of water, 10 btu's of energy, and creates a pound of solid waste and three pounds of CO2.
Gabe: What are the main uses of energy in the world?
David: Transportation consumes 25 percent of world energy use; heating and cooling buildings, 36 percent; industry, 40 percent.
Gabe: What are some ways to conserve energy?
David: Here are some areas in which any of us can conserve energy.
Advocacy - it is important to find ways to affect the wider community