Global Warming Essay Example | Topics and Well Written Essays - 750 words - 3

Global Warming - Essay Example If the inactions of the past several decades is an indication, then the answer is no. Essentially, the greenhouse effect functions in the following manner. When sunlight pierces the atmosphere and hits the earth’s surface, not all of the sun’s solar energy is absorbed. Approximately a third of it is reflected back into space. Specific atmospheric gases serve in much the same way as does the glass of a greenhouse, thus the terminology. These gases allow sunlight to penetrate then trap some of the solar energy which heats the earth (Breuer, 1980). It is a delicate balance and because these greenhouse gases have been artificially augmented by man-made sources, more build up in the atmosphere has occurred thus trapping more of the sun’s energy and reflecting less back in to space. This occurrence is causing the earth to warm. Carbon Dioxide (CO2) is the most prevalent of the greenhouse gases. Trees absorb CO2 and when they die, CO2 is restored to the atmosphere. The clearing of forests by mass burning, which is happening at a phenomenal rate in the tropical rain forests, is decreasing the amount of CO2 that is absorbed and increasing the amount that is added to the atmosphere. CO2 supplies about half of the total gases that create the greenhouse effect (Breuer, 1980). Although deforestation is contributing heavily to the excess of CO2 in the atmosphere, a larger portion is caused by the burning of fossil fuels such as oil and coal. Fossil fuels are burned by factories, vehicles and electricity-producing power plants to name a few sources. Other greenhouse gases include methane, which is released when vegetation is burned during land clearing, during oil exploration activities and the coal-mining process; chlorofluorocarbons (CFCs), which is the substance that cools refrigerators and provides the propulsi on in aerosol cans and nitrous oxide (N2O) which is the lesser cause of CO2 (Breuer, 1980). It is generated from both

Final Project Statistics Example | Topics and Well Written Essays - 1000 words

Final - Statistics Project Example The interest of the study is to test if there is any significance difference between the energy intake before and after the exercise session. The most appropriate test for this study is the paired sample t-test. The test determines if there is significant difference between average values of measurements taken from a sampling unit under two different conditions (Park, 2009). The test is based on the paired difference between the two measurements. This is a two tailed test where both variables are dependent variables, i.e. pre and post-test variables. The power and post hoc testing for this study will be Bonferroni and Turkey’s test. Bonferoni is the simplest post hoc test because of its flexibility and ability to be used as correction test (Pavlidis, n.d). Bonferroni calculates the new pairwise alpha to be compared with the initial alpha . Bonferroni alpha is calculated as Pretessting and posttessting data both seem to be normally distributed. The conclusion is supported by Shapiro wilk test for normality. This test was chosen since it works best for a smaller samples size of less than 50. The results were as follows; From Shapiro wilk test, both pretesting and posttesting data was normally distributed. The significance values 0.803 and 0.712 are both greater than alpha 0.05. This test confirms that the data is appropriate for a paired t-test. In this study, there were 20 people whose energy intake was examined before and after going to the gym. The average energy intake before the exercise sessions was 6650.7 with a standard deviation of 1495.704 while the energy intake after the session was 5304 with a standard deviation of 1518.826. The last column gives the standard error of the mean for each of the test. This output also shows that there were 20 pairs of observation in the study. The correlation between variables in given in column three i.e . The fourth column shows the p value for the correlation coefficient. With an