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Wednesday, April 25, 2012
Thursday, January 27, 2011
What is global Warming ?
The term "global warming" refers to the increase in the average temperature of global surface air and oceans since about 1950, and to continuing increases in those temperatures.
The global warming hypothesis originated in 1896 when Svante Arrhenius, a Swedish chemist, developed the theory that carbon dioxide emissions from the burning of fossil fuels would cause global temperatures to rise by trapping excess heat in the earth’s atmosphere. Arrhenius understood that the earth’s climate is heated by a process known as the greenhouse effect. While close to half the solar radiation reaching the earth’s surface is reflected back into space, the remainder is absorbed by land masses and oceans, warming the earth’s surface and atmosphere. This warming process radiates energy, most of which passes through the atmosphere and back into space. However, small concentrations of greenhouse gases like water vapor and carbon dioxide convert some of this energy to heat and either absorb it or reflect it back to the earth’s surface. These heat-trapping gases work much like a greenhouse: Sunlight passes through, but a certain amount of radiated heat remains trapped.
The greenhouse effect plays an essential role in preventing the planet from entering a perpetual ice age: Remove the greenhouse gases from the atmosphere and the earth’s temperature would plummet by around 60 degrees Fahrenheit (F). However, scientists who have elaborated on Arrhenius’s theory of global warming are concernced that increasing concentrations of greenhouse gases in the atmosphere are causing an unprecedented rise in global temperatures, with potentially harmful consequences for the environment and human health.
In 1988, the United Nations Environment Program and the World Meteorological Organization established the Intergovernmental Panel on Climate Change (IPCC), comprising more than two thousand scientists responsible for studying global warming’s potential impact on climate. According to the IPCC, the atmospheric concentration of carbon dioxide has increased by 31 percent, methane by 151 percent, and nitrous oxide by 17 percent since 1750. Over the twentieth century, the IPCC believes that global temperatures increased close to 0.5 degree Centigrade (C), the largest increase of any century during the past one thousand years. The 1990s, according to IPCC data, was the warmest decade recorded in the Northern Hemisphere since records were first taken in 1861, with 1998 the warmest year ever recorded.
Given this data, many scientists are convinced of a direct correlation between rising global temperatures and the emission of greenhouse gases stemming from human activities such as automobile use, the production of electricity from coal-fired power plants, and agricultural and deforestation practices. Concludes the IPCC in its Third Assessment Report, “The present carbon dioxide concentration has not been exceeded during the past 420,000 years and likely not during the past 20 million years. . . . In light of new evidence . . . most of the observed warming over the last 50 years is likely to have been due to the [human-induced] increase in greenhouse gas concentrations.”
Based on IPCC projections that global temperatures will increase by 2.5 to 10.4 degrees F between 1990 and 2100, scientists and environmentalists are predicting that global warming will have mostly negative consequences for the world’s climate. Kelly Reed of the environmental organization Greenpeace states that the “effects of global warming not only include rising global temperatures, but an increase in floods, droughts, wildfires, heat waves, intensified hurricanes and the spread of infectious disease.” Accordingly, those who share Reed’s view of global warming believe that the world’s governments must take immediate action to limit greenhouse gas emissions.
In response to these pressures, a growing band of skeptical scientists are questioning the validity of the global warming theory. According to these critics, the IPCC bases its predictions for rising global temperatures on faulty computer climate models, which exaggerate the climate’s response to carbon dioxide and other greenhouse gases while failing to accurately reproduce the motions of the atmosphere. Explains Richard L. Lindzen, a professor of meteorology at the Massachusetts Institute of Technology, “Present models have large errors . . . [and] are unable to calculate correctly either the present average temperature of the Earth or the temperature ranges from the equator to the poles. . . . Models . . . amplify the effects of increasing carbon dioxide.” Lindzen asserts that if models accurately represented the role of the major greenhouse gas—water vapor—in the climate system, they would predict a warming of no more than 1.7 degrees C if atmospheric carbon dioxide levels were doubled. This warming is significantly less than the 4 to 5 degrees C temperature increase forecasted by IPCC models under a doubling of atmospheric carbon dioxide.
Global warming skeptics also argue that natural climate fluctuation, not human activity, is responsible for the past century’s rising temperatures. According to S. Fred Singer, a professor of environmental sciences at the University of Virginia, the earth’s climate has never been steady and has continually warmed and cooled over the course of geologic time without any assistance from human activity. Says Singer, “The human component [in recent global warming] is thought to be quite small. . . . The climate cooled between 1940 and 1975, just as industrial activity grew rapidly after WWII. It has been difficult to reconcile this cooling with the observed increases in greenhouse gases.” Singer also argues that temperature observations since 1979 are in dispute: Surface readings with thermometers show a rise of about 0.1 degree C per decade, while data from satellites and balloon-borne radiosondes [miniature transmitters] show no warming—with possible indications of a slight cooling—in the lower atmosphere between 1979 and 1997. Until the science behind the global warming theory is more settled, Singer and other skeptical scientists advocate placing no limits on the consumption of fossil fuels.
Politicians, the media, big business, scientists, and environmentalists all play conflicting roles in the global warming debate as public policy collides head-on with special interests and a complex scientific theory. Global Warming: Opposing Viewpoints covers the debate with a wide range of opinions in the following chapters: Does Global Warming Pose a Serious Threat? What Causes Global Warming? What Will Be the Effects of Global Warming? Should Measures Be Taken to Combat Global Warming? This anthology examines the prominent viewpoints surrounding the global warming controversy.
What can we do to help our earth live longer?
1. Be A Vegetarian and Help Animals and Combat Climate Change. This is one of the problems that is causing global warming, you need seventeen more times more land to get the same amount of protein when you compare the livestock to soy bean, you need eight times more water to raise animals verses growing vegetables and grains and when you feed grains to animals as in America you only get back 10% of the calories and protein of livestock when you eat meat so a lot of good food is being wasted.
So this is the solution to world starvation, many people are dying, everyday children are dying because they lack food, 80-90% of all the grain grown in America is used to feed meat animals. So when you reduce meat production by 10% only, you would release enough grain to feed 60 million people just by a reduction of 10%. If people would consume only 50% they would release enough food to feed the entire developing world. So become a vegetarian and we can save the lives of so many people. We will have enough food for the whole world. Former UN Secretary General Kurt Waldheim, (21 December 1918 – 14 June 2007) said, “The food consumption of the rich countries is the key cause of hunger around the world.” Let’s do whatever we can to reduce global warming.
2. Pay attention to how you use water. The little things can make a big difference. Every time you turn off the water while you’re brushing your teeth, you’re doing something good. Got a leaky toilet? You might be wasting 200 gallons of water a day. Try drinking tap water instead of bottled water, so you aren’t wasting all that packaging as well. Wash your clothes in cold water when you can.
3. Leave your car at home. If you can stay off the road just two days a week, you’ll reduce greenhouse gas emissions by an average of 1,590 pounds per year. Combine your errands — hit the post office, grocery store and shoe repair place in one trip. It will save you gas and time. Walk or ride your bike to work, school and anywhere you can. You can reduce greenhouse gases while burning some calories and improving your health. If you can’t walk or bike, use mass transit or carpool. Every car not on the road makes
4. Recycle. You can help reduce pollution just by putting that soda can in a different bin. If you’re trying to choose between two products, pick the one with the least packaging. If an office building of 7,000 workersrecycled all of its office paper waste for a year, it would be the equivalent of taking almost 400 cars off the road.
5. Compost. Think about how much trash you make in a year. Reducing the amount of solid waste you produce in a year means taking up less space inlandfills, so your tax dollars can work somewhere else. Plus, compost makes a great natural fertilizer. Composting is easier than you think.
6. Change your light bulbs. Compact fluorescent light bulbs (CFLs) last 10 times longer than a standard bulb and use at least two-thirds less energy. If you’re shopping for new appliances or even home electronics, look for ENERGY STAR products, which have met EPA and U.S. Department of Energy guidelines for energy efficiency. In 2006, the ENERGY STAR program saved energy equivalent to taking 25 million cars off the road and saved Americans $14 billion in utility costs.
7. Make your home more energy efficient (and save money). Clean your air filters so your system doesn’t have to work overtime. Get a programmable thermostat so you aren’t wasting energy when you aren’t home. When you go to bed, reduce the thermostat setting — you won’t miss those extra degrees of heat orair conditioning while you’re asleep.
8. Maintain your car. Underinflated tires decrease fuel economy by up to three percent and lead to increased pollution and higher greenhouse gas emissions. Underinflation also increases tire wear, so it will save you money in the long run if you’re good about checking your tire pressure.
9. Drive smarter. Slow down — driving 60 miles per hour instead of 70 mph on the highway will save you up 4 miles per gallon. Accelerating and braking too hard can actually reduce your fuel economy, so take it easy on the brakes and gas pedal.
10.Turn off lights when you’re not in the room and unplug appliances when you’re not using them. It only takes a second to be environmentally conscious.
