29 May 2012
Global Warming: How Does it Really Happen?
Thank you everyone for attending today. My name is John Smith and I am majoring in Environmental Science at the Harvard. The University has asked me to conduct a presentation on global warming and the effects on the planet. Combining the knowledge gained through coursework and the research I have conducted, I will be presenting you with information on global warming and how global warming has been affecting the Earth well before humans could make an impact. Lets look at what global warming actually is. A definition of global warming pulled from dictionary.com defines global warming as, “an increase in the earth's average atmospheric temperature that causes corresponding changes in climate and that may result from the greenhouse effect” (Dictionary.com). Looking at the definition of global warming many may ask, well what is the greenhouse effect? The green house effect is, An atmospheric heating phenomenon, caused by short-wave solar radiation being readily transmitted inward through the earth's atmosphere but longer-wavelength heat radiation less readily transmitted outward, owing to its absorption by atmospheric carbon dioxide, water vapor, methane, and other gases; thus, the rising level of carbon dioxide is viewed with concern (Dictionary.com). After looking at that long and complex definition of greenhouse effect to try and understand global warming a little better, many of you are probably puzzled. To help you, here is a much simpler definition that you don’t need to be a scientist to understand; “Global warming is a significant increase in the Earth's climatic temperature over a relatively short period of time as a result of the activities of humans (Strickland, and Grabianowski). In this definition a relatively short period of time means, “an increase of 1 or more Celsius degrees in a period of one hundred to two hundred years would be considered global warming” (Strickland, and Grabianowski). Now that we have a definition that we understand, I’m going to enlighten all of you on some more details about global warming and why global warming is such a controversial topic. 27432004175760An illustration of the greenhouse effect for a better understanding of the process (“globalgreenhousewarming.com”). 00An illustration of the greenhouse effect for a better understanding of the process (“globalgreenhousewarming.com”). 2286000131826000An increase in the greenhouse effect is said to be causing global warming, the greenhouse effect is not bad though, as it is essential for our planet to survive, it keeps in the heat that warms the Earth. To help you understand the greenhouse effect I am going to give a simple explanation. When the Sun’s rays enter the atmosphere, about 70 percent of the energy stays on the planet, being absorbed by plants and water. The other 30 percent is reflected into space by reflective objects such as clouds, snow, and ice. All 70 percent of the energy doesn’t stay on Earth forever or else it would burn, the heat is radiated back into space by oceans and landmasses, but not all of the heat makes it to space, carbon dioxide, methane gas, and water vapor absorb it and then give off more energy. The heat that doesn’t make it out keeps the planet warmer than it is in outer space (Strickland, and Grabianowski). The concept of global warming and the greenhouse effect seem to make sense when you look at the gases being put into the air by nature and humans. The three substances that naturally occur to cause the greenhouse effect are carbon dioxide (CO2), nitrous oxide (NO2), and methane gas (Strickland, and Grabianowski). Carbon dioxide makes up less than 0.04 of the Earth’s atmosphere, which were put there thousands of years ago by volcanic vapors (Strickland, and Grabianowski). Today, humans are contributing to the amount of CO2 in the air resulting in an overall increase of carbon dioxide. Carbon dioxide is a big deal...
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