By the middle of the twenty first century, there is evidence that the Earth will be warmer than it has been at any time in human history, and quite possibly since the end of the dinosaurs, some 65 billion years ago. If we stay at the rate we our now (fossil fuel consumption / growth in population) then within the next two century the Earth's air might not be fit to breath. Many people in the world do not think that this is a major concern and that it is normal for the Earth's temperature to increase. However, if this temperature increase is put into perspective of several hundred years, there will be many devastating effects. This is why most scientists view global warming as a very serious and severe threat. Global warming does not require a reduction of the standard of living of people. However it does demand a rapid shift in the patterns of consumption of fuels such as oil, coal, and natural gas, to an economy more reliant on solar energy, hydrogen gas, wind biomass, and other renewable energy sources.
The term greenhouse effect is used to describe the increased warming of the Earth's surface and lower atmosphere due to increased levels of carbon dioxide and other atmospheric gases that absorb radiated energy in the atmosphere and then reradiate it back to the surface. But if it were not for the greenhouse effect, temperatures at the Earth's surface today would be much colder then they are now, and life as we know it could not exist. Scientists are now concerned that the greenhouse gases are being increased by human actions to levels that could be very harmful to life on Earth. Almost all specialists agree that without drastic steps to curb greenhouse gas emissions, the average global temperature will increase 1 to 3.5 degrees Celsius during the next century because effective levels of carbon dioxide are expected to double sometime between 2050 and 2100. Many of the greenhouse gases remain in the atmosphere for a long time, and because this happens their tendency to warm the Earth persist for periods that are much longer compared to human life spans. There are five naturally occurring atmospheric gases that have been responsible for the greenhouse effect. These gases are carbon dioxide, methane, ozone, nitrous oxide, and water vapor.
The main contributor to the greenhouse effect and global warming is carbon dioxide. The atmosphere contains over 700 billion tons of carbon in the form of carbon dioxide. Currently, humans burn more than 5 billion tons of fossil fuel carbon each year, all of it going into the atmosphere in the form of carbon dioxide or carbon monoxide. In addition, deforestation and subsequent burning and decay add another 1.5 billion tons. Scientists feel that about 40 percent of the carbon dioxide released into the atmosphere is taken up by the oceans or plant growth. The remaining 60 percent stays in the atmosphere, and is responsible for the .4 to .5 percent yearly growth in carbon dioxide concentrations.
Methane is also another major greenhouse gas that is growing significantly more and more each year. Methane is a gas that is naturally produced from decomposition of plant material and enteric fermentation in animals. Scientists say that the growth of methane is from a combination of increases in petroleum, natural gas, coal, rice farming, and increases in the population of domestic farm animals throughout the world. Nitrous oxide is just slightly increasing each year due to fossil fuel combustion and soil fertilization. Emissions from fossil fuel combustion also react to form ozone in the troposphere. Ozone acts like an infrared...