General Idea about Global Warming
Global warming is the increase in average temperature of the oceans and atmosphere, both observed and predicted. The surface temperature of Earth depends on a balance of incoming and outgoing heat. When outgoing heat, or energy, exceeds incoming energy, an ice age occurs. Global warming results when incoming energy levels are greater than outgoing energy levels.
Causes of Global Warming
There are numerous causes of global warming, and scientists typically divide those causes into two primary groups: natural causes and man-made causes. While humans can do little to eradicate natural causes, it is possible to reduce or eliminate man-made causes.
Natural Causes of Global Warming
Natural causes have been contributing to global warming since before recorded history. Most experts do not believe that natural causes alone are substantial enough to result in the climate changes currently taking place on the planet.
Increased solar activity changes the Earth's solar radiation levels, thereby causing short-term warming cycles. Sunspots are dark patches on the sun's surface that block hot solar plasma. Although this blocking action might appear to reduce solar radiation, the opposite is true.
Permafrost, which is solid, frozen soil, constitutes about 25 percent of the land area in the Northern Hemisphere. Until recently, permafrost has locked carbon and methane beneath the surface of the planet. In some areas, permafrost is now emitting carbon, which could potentially accelerate the greenhouse effect and global warming.
Water vapor is increasing in the atmosphere due to carbon dioxide-induced warming. Approximately two-thirds of the heat trapped by greenhouses gases is contained in water vapor, and as the average temperature on the planet continues to rise, the amount of water vapor rises in turn.
Man-made (Anthropogenic) Causes
Most man-made causes of global warming result from an increase in greenhouse gases, which are gases that trap or absorb infrared radiation emitted from the planet.
Burning of Fossil Fuels
Carbon dioxide is the most significant cause of global warming, and most carbon dioxide emissions result from the burning of fossil fuels. Each time a fossil fuel burns, carbon dioxide levels in the atmosphere increase. Carbon dioxide absorbs infrared energy emitted from the earth, preventing it from returning to space.
Electricity Production: Electricity generation through the burning of fossil fuels accounts for 40 percent of carbon dioxide emissions in the United States. Coal is the largest producer of carbon dioxide emissions, giving off nearly twice as much carbon per energy unit as natural gas.
Automobiles: Carbon emissions from the burning of gasoline to power cars, trucks, and other methods of transportation are one of the leading global warming causes in the United States. Pollution created by cars and light trucks accounts for nearly one-third of American carbon emission, and emissions of carbon dioxide from airplanes is responsible for an additional 3.5 percent of global warming.
All living plants are capable of storing carbon, but as the number of plants on the planet declines, the amount of carbon dioxide free to build up in the atmosphere increases. Moreover, decaying plants give off stored carbon, thereby releasing a large abundance of carbon into the air during the clearing of forests or grasslands for building purposes.
As the population on Earth increases, food and housing demands also increase. Manure from cattle, a primary food source worldwide, contributes...