Global Waarming

Global Warming

Scientists, politicians, journalists, your neighbors today it seems that everyone is talking about global warming, but what is global warming? Well to understand what global warming is one has to understand what the greenhouse effect is. Earth receives energy from the sun in the form of short-wave radiation. About one-third of this incoming radiation is reflected back to space; the atmosphere absorbs the remainder, but oceans and lands absorb most of the radiation. The earth's surface becomes warm and as a result and emits long-wave radiation. The greenhouses gases (water vapor, carbon dioxide, ozone, methane, and nitrous oxide) trap and re-emit some of this long-wave radiation. This process is called the greenhouse effect, which causes the Earth to warm to an average temperature of 59 degrees Fahrenheit.1

Global warming is the increase of the Earth's average temperature, but what does global warming mean to us? It means a soggier, sicker, hungrier, and poorer world. As the plant warms the ice in the Arctic and in Greenland start to melt, causing sea levels to rise. Since warm water takes up more space than cold water, that means bad news, because a huge number of people live near the coasts, especially in tropical Asia. We are already seeing examples of direct effects of global warming (figure 1.1). The third hottest summer ever across North America was in 1988 and by the time it was done, corn and soybean yields had fallen by a quarter to a third. If the temperature stays hot enough for a week or two, corn can't pollinate and rice yields start to drop. The world already struggles to produce enough grain for a growing population, global warming is just going to make the situation worse. Global warming is damaging the welfare of the Earth's environment and that it's putting all of us in danger.2

What causes global warming? Many scientists agree that the increase of greenhouse gases into the atmosphere is because of human activities. Most of the greenhouse gases that come from human activity are because of the combustion of fossil fuels (coal, oil, and gas), deforestation and agricultural practices; beginning from the pre-Industrial Revolution. Carbon dioxide has gone up by about 30% (see figure 1.2), methane by more than a factor of two, and nitrous oxide by about 15%. The concentrations of greenhouses gases are higher now than at any other time period during the last 420,000 years. In addition, the combustion of fossil fuels has also caused the concentrations of sulfate aerosols to increase,