Global Warming

The scientific definition of Global warming is the worldwide warming of the atmosphere. Global warming has recently imposed a serious risk to our environment. The rising global temperatures are expected to raise sea levels due to the melting of ice caps, cause flooding in many low-lying areas of the world and change precipitation and other local climate conditions.

To understand global warming you have to first understand the greenhouse effect. The Greenhouse effect is a natural phenomenon that controls the balance of heat within the earth’s atmosphere. The process begins when the natural layers of gases in our atmosphere trap a small percentage of the sun’s radiation reflected from the earth’s surface. The energy from the sun drives the earth’s weather and climate and heat’s the earth’s surface. The earth then radiates the energy back into space. Without the greenhouse effect the average surface temperature of the world would be about -18 degrees Celsius. You can think of atmospheric greenhouse gas like the glass panels of greenhouse. It traps some of the outgoing energy and retains some of the heat.

Global warming is caused by an increase in the amount of carbon dioxide and other gases being released into the atmosphere by the burning of fossil fuels. These gases add to the natural greenhouse effect and in result cause global temperatures to rise. Combustion of fossil fuels and other human activities are the primary reason for the increased concentration of carbon dioxide. Fossil fuels are used to run cars, heat businesses, and power factories. Since the beginning of the industrial revolution atmospheric levels of carbon dioxide have increased nearly thirty percent.

Emission inventories account the amount of air pollutants discharged into the atmosphere. Inventories of natural and anthropogenic emissions are used by scientists as inputs as inputs to air quality models. Scientists have said that estimating the amount of future emissions is very difficult. Future emissions vary depending on demographic, economic, technological, policy, and institutional developments. Estimates of greenhouse gas emissions are presented in units of millions of metric tons of carbon equivalents. As an individual you can effect the emissions of about 4,800 pounds of carbon. You can help keep the emissions levels down by using less electricity in your home, lowering the production of waste, and personal transportation. Emission levels vary based on which country you live in. The United States currently emits more greenhouse gases per person than any other country.

There are many chemicals associated with the greenhouse gases. Carbon Dioxide is released into the atmosphere when solid waste, fossil fuels, and wood and wood products are burned. Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from the decomposition of organic wastes in solid waste landfills, and the raising of livestock. Nitrous Oxide is emitted during agricultural and industrial activities, also during the combustion of solid waste and fossil fuels. Very powerful greenhouse gases that are not naturally occurring include hydro fluro carbons, per fluro carbons, and sulfur hexafluoride, which are all generated in a variety of industrial processes. Each greenhouse gas differs in its ability to absorb heat in the atmosphere. HFCs and PFCs are the most heat absorbent. Methane traps over twenty one times more heat per molecule then carbon dioxide, while Nitrous Oxide absorbs two hundred and seventy times more heat per molecule then carbon dioxide.

Global warming mostly affects the world’s climate. The earth’s temperature has risen about one degree Fahrenheit in the past century. Land temperatures have increased about twice as fast as ocean temperatures. The twentieth centuries ten warmest years all occurred in the last fifteen years of the century. Nature and humans both effect the world’s temperature. It is recorded that most of the world’s warming over the last fifty years is attributable to human activities. These human activities have altered the chemical composition of the atmosphere through the buildup of greenhouse gases. Primarily these gases being: carbon dioxide, methane, and nitrous oxide. Global warming has occurred in both the northern and southern hemispheres and over all of the oceans. Global warming is further sustained by melting glaciers, decreased snow cover in the northern hemisphere, and even warming below ground.

As atmospheric levels of greenhouse gases continue to rise, scientists estimate average global temperatures will rise as a result. How much the temperatures will rise and how fast remain uncertain. This uncertainty results from greenhouse gas emissions, the possible cooling effect of atmospheric particles, and the climates response to changes in the atmosphere.