We live in a world where environmental concerns are a growing topic. Reports of global warming, increasing incidents of droughts, heavy storms, floods and unpredictable weather plague our world today. Much of what we experience now is the result of human actions. The birth of industrialization has fostered our increasing dependency on energy. Since then, we heavily rely on energy to make our world go around. Energy has enabled us to enjoy what we have today - cars, airplanes, internet, air conditioning/heater and electricity.
But as we enjoy the convenience and luxury brought by energy in our daily lives, we are often unaware of its harmful effects in our environment. Our energy comes from fossil fuels combustion that mainly come from coal, oil and natural gas. Their combustion emits toxic gases that produce air pollution and damage the ecosystem. Coal and Natural Gas combustion is the primary culprit of greenhouse gas emissions. Oil spills contaminate the marine life and oil drilling harms the health of marine animals.
It is likely idealistic to think that we can go back to a simpler world where farmlands, grass, trees and fresher air fill our environment rather than tall buildings, factories, multiple freeways and numerous vehicles. But our actions can make a positive difference.
We can reduce our energy reliance by reducing our use of cars or choosing fuel efficient cars. We can limit our use of electricity by turning off lights, TVs, computers and other sources of energy unless they're absolutely needed. We can do all these simply yet great things as we continue to look for cleaner and renewable energy sources. For now, awareness on the basics of the energy that fuels our world are worth looking into and understanding, so we can take better choices and more responsible actions upon moving forward.
Fossil Fuels
The United States gets 84% of its total energy from oil, coal, and natural gas, all of which are fossil fuels. We depend on fossil fuels to heat our homes, run our vehicles, power industry and manufacturing, and provide us with electricity. Eventually, the degree to which we depend on fossil fuels will have to lessen as the planet’s known supplies diminish, the difficulty and cost of tapping remaining reserves increases, and the effect of their continued use on our planet grows more dire. But shifting to new energy sources will take time. In the meantime, what do we need to know about fossil fuels?COAL
In 2008, 49% of U.S. electricity came from coal, more than twice the contribution of either nuclear power or natural gas.
Importance:
America has plenty of coal. Its mines produced 1.2 billion tons in 2008, nearly all of its destined for electricity generation. That was a record year, but it barely scratched the surface of U.S. recoverable coal reserves, which are estimated at about 270 billion tons. More than one-fourth of the total known world coal reserves are located in the United States. Despite such coal riches, questions have recently been raised about how accessible these reserves truly are. The location, quality and recoverability of the coal could significantly impact these supply estimates and experts caution that the reserves should be analyzed more closely with these factors in mind.
Demand for Coal:
Demand for coal in the United States is projected to increase by 21% between now and 2030, propelled by the rising use of electricity and possibly the expanded use of still-developing technology that converts coal to liquid fuel. Most of the increased supply will probably come from western states, which now provide about six-tenths of the nation's coal. Wyoming alone accounted for 38% of all domestic coal mined in 2006.
- Of all the fossil-fuel sources, coal is the least expensive for its energy content, but it has negative environmental repercussions that go beyond combustion
- Burning coal in electric power plants is a major source of CO2 emissions
- Its use has repercussions on the environment beyond combustion
- Mining coal disturbs the land and modifies the chemistry of rainwater runoff, which affects stream and river water quality
- Coal-fired power plant emissions include oxides of nitrogen, sulfur dioxide, particulate matter, and heavy metals (such as mercury) that affect air quality and human health, often even hundreds of miles from the power plant
- In response to strict environmental laws, advanced coal—also known as “clean coal”—technologies are being developed to reduce harmful emissions and improve the efficiency of these plants
OIL
Almost two-thirds of the oil America uses is imported from a handful of nations.
Importance:
In 2008, the United States got 37% of its energy from petroleum, or oil, and experts project that demand for this fuel will stay strong over the next 20 years. U.S. domestic production of crude oil peaked around 1970 at about 9.5 million barrels per day and had declined to 5.1 million barrels per day by 2006. Today America imports almost two-thirds of its oil from a handful of nations. The EIA predicts that by 2030 U.S. production of oil will increase by a third, spurred by higher oil prices, while imports of foreign oil decline to 49% as a result of strides in vehicle efficiency and government requirements to increase the use of biofuels. But even this changing and hopeful trend can only go so far to address the enormous imbalance in U.S. demand and domestic supply of this crucial resource.
Demand for Oil:
Currently, total world consumption is approximately 85 million barrels per day, more than 19 million of which is used by the United States. The nation’s dependency on oil and the rapidly rising demand for oil in other countries, such as China and India, are heightening concern that we will reach a point where the oil supply can no longer be increased to meet projected demand. While this will certainly be true eventually, there is no consensus as to whether we are already entering that period or it is decades away. Pinning down an exact time frame is nearly impossible as estimates of the amount of “recoverable” oil available can change depending on new discoveries, technological developments, and price.
Environmental concerns about the impact of burning fossil fuels like oil and the security risks of depending heavily on foreign sources for our supply are leading to a reassessment of our oil consumption and a search for conventional oil alternatives. Much of this attention is focused on the transportation sector, which relies heavily on oil. Legislation such as the CAFE standards, which encourage manufacturers to develop more efficient vehicles, and research into new energy sources, such as biofuels, both aim to reduce our demand for oil.
NATURAL GAS
The United States imports less than 2% of its natural gas from outside North America. In 2008, 24% of the U.S. total energy supply came from natural gas.
Importance:
Natural gas is used to heat more than half the homes in the United States and is also a raw material in a variety of common products, such as paints, fertilizers, plastics, medicines, and antifreeze. Propane, which powers many kitchen stoves and outdoor grills as well as home heating systems, is derived from natural gas. Natural gas is also used to generate 21% of our electricity. (See Our Energy System for an overview of how natural gas is used in the United States.)
Natural gas is often described as “clean burning” because it produces fewer undesirable by-products than gasoline.
Demand for Natural Gas:
Natural gas provides 24% of our energy. Unlike oil, almost two-thirds of which is imported from foreign sources, our natural gas comes primarily from North America. The annual volume of consumption is projected to rise from 22.5 trillion cubic feet (tcf) in 2009 to about 23.5 tcf in 2030. New activity in Alaska will supply some of that, but most will likely come from the lower 48 states and the Gulf of Mexico. The nation imports less than 3% of its natural gas from outside North America, mostly in the form of liquefied natural gas, or gas cooled to its liquid phase for easier transportation. According to EIA, new estimates of unconventional domestic natural gas sources—primarily in natural gas shales—will result in a marked decrease in imports over the next two decades.
Environmental Effects:
- Like all fossil fuels, its combustion emits carbon dioxide, but at about half the rate of coal
- In natural gas combined cycle (NGCC) power plants, we now have technology that takes the waste heat from a natural gas turbine and uses it to power a steam turbine, resulting in a power plant that is as much as 60% efficient
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