November 19, 2012
What Are The Causes and Effects of Global Warming? The summer of 2012 was one of the hottest summers, in the United States, on record. You would think the previous winter would have been one of the coldest on record, yet, in fact, it was one of the warmest. Up until fairly recent years, winters worldwide have been cold, sometimes in the extreme, and the summers have been hot, sometimes in the extreme. However, the winters have started to warm and the summers have increased in their extremely high temperatures. Such high temperatures are results from the warming of our planet. There are many factors that have aided and are aiding to this warming of the earth. There are facts, myths, beliefs, and doubts as to the reasons for this occurrence. One can make their own decision as to why global warming may be happening, but it can be hard to argue with scientific facts. Let us take a look at some of the factual causes and effects of global warming. How was global warming first seen? Scientists have made many advances over the years in monitoring the earth’s climate. They have been able to see the changes and compare data and find patterns. After seeing that temperatures have risen and become more extreme over the years, scientists have studied what could be causing these events. There are essentially three sources that could be responsible for the global warming that scientists see: the sun, the earth’s reflectivity, and greenhouse gases (Environmental Defense Fund). Increased output from the Sun might be to blame for 10 to 30 percent of global warming that has been measured in the past 20 years, according to a new report. Increased emissions of carbon dioxide and other heat-trapping gases still play a role, the scientists say (Britt). It is clear to see the effects warmth on melting glaciers and frozen ground disappearing at a much faster pace in the last 20 years than any other time before. Some think that the ozone layer is diminishing causing for less protection from the sun’s heat, yet, according to research from Columbia University, there have been errors in the interpretation of solar brightness. After the Columbia space shuttle disaster, satellites had a period of standstill from deployment. As a result, data was being received from less accurate satellites (Scafetta). Duke University examined solar changes over 22 years versus 11 years used in previous studies (Britt). Researchers state that maybe only about 10 to 30 percent of global surface warming from 1980-2002 has resulted from the sun (Britt). Loss of the earth’s reflectivity is apparent in the Northern Hemisphere. The part of the earth covered in snow and ice is called the cryosphere. Compared to 30 years ago, these areas of land are not cooling the earth as much. This occurrence is referred to as the ‘albedo decline.’ Karen Shell, atmospheric scientist, from Oregon State University doesn’t relate the albedo decline to global warming. Instead of being reflected back into the atmosphere, the energy of the sun is absorbed by the Earth, amplifying global warming. And while scientists have known for some time about this amplification effect, almost all the climate models Shell’s team examined underestimated the impact (Woollacott). Shell believes that 30 years isn’t enough time attribute the cryosphere’s decline to anthropgenic influence. However, she does agree that the decline is significant (Woollacott). It is arguable that greenhouse gases attribute most to global warming. Greenhouse gases are chemical compounds in the atmosphere that allow sunlight to freely enter the atmosphere. These gases absorb infrared radiation and reflect it back into space. The energy from the sun to the Earth should be the same as the energy reflected back to space and keep the earth’s temperature constant.