QUESTION 1: Global warming and a possible cause (15 marks) Preamble In the last part of the 20th century, scientists developed the theory that the planet was warming and that the primary cause was the increasing amounts of atmospheric carbon dioxide (CO2), which are the product of burning oil, natural gas, and coal (fossil fuels). Although many climatologists believe in the so-called greenhouse effect, many others do not subscribe to this theory. Further, Earth's temperature has increased and decreased many times in its long history. We have had higher temperatures and we have had lower temperatures, including various ice ages. In fact, a period called the 'little ice age' ended around the middle to the end of the nineteenth century. Then the temperature rose until about 1940, at which point it decreased until 1975. In fact, a Newsweek article published 28 April 1975, discussed the possibility of global cooling, which seemed to be the consensus among scientists at the B. If the planet is warming, is there a human cause or is it natural fluctuation? C. If the planet 1s warming, is CO; the cause? In terms of data, the generally accepted procedure is to record monthly temperature anomalies. To do so, we calculate the average for each month over many years. We then calculate any deviations between the latest month's temperature reading and the monthly average calculated above. A positive anomaly would represent a month's temperature that is above the average. A negative anomaly indicates a month where the temperature is less than the average. PART 1A [2 + 4 = 6 marks] File GLOBALA xlsx contains the monthly temperature anomalies (C) from 1880 to 2020. Using the data answer the following: a. Considering the monthly temperature anomalies data over the data period 1880-2020, identify the data type and use an appropriate graphical technique to display the data. Discuss the trend in data and comment whether there 1s global warming. [Hint: Insert a trend line. ] b. Considering the population mean of the temperature anomalies (), test to show that, on average, there 1s global warming at the 5 percent level of significance. [Hint: Test whether the population mean of monthly temperature anomalies 1s positive (L > 0)]. PART 1B [1.5 + 1.5 + 1.5 + 1.5 = 6 marks] If the planet is warming, is there a human cause or is it natural fluctuation? We need to consider the temperature anomalies at various periods to consider this belief. File GLOBALB2.xlsx stores the data from 1941 to 1975, GLOBALB3.xlsx stores the data from 1976 to 1997 and GLOBALB4.xlsx stores the data from 1998 to 2020. Using these data answer the following: c. For each of the four time-period data, estimate the least squares line and the coefficient of determination. Report and interpret your findings. Has there been global warming in each of the four periods? PART 1C [2 + 1 =3 marks] If the planet is warming, is COz the cause? Data for CO; levels (ppm) in the atmosphere together with the temperature anomalies for March 1958 to August 2020 are stored in file GLOBALC xlsx. d. Use a graphical technique to determine whether there is a linear relationship between temperature anomalies and CO; levels. On the plot, insert the trend line and the coefficient of determination (R?). Comment on the fitness of the model. e. Using the estimated trend line equation, predict the temperature anomaly if the CO; level reaches 400ppm