### Climate Change

There have been many studies documenting that the average global temperature has been increasing over the last century. The consequence; of a continued rise in global temperature will be dire. Rising sea levels and an increased frequency of extreme weather events will affect billions of people. In this problem. we 11 study the relationship between average global temperature and several other factors. The file ClimateChange.csv, which is available in the Online Companion, contains climate data from May 1983 to December 2008. The variables are described in Table 22.2.

a) Start by splitting the dataset into a training set, consisting of observations up to and including 2006, and a testing set, consisting of observations after 2006. You will use the training set to build your model, and the testing set to evaluate the predictive ability of your model. Then, build a linear regression model to predict Temp, using all of the other variables as independent variables (except Year and Month). You should use the training set that you just created to build the model.

- i) What is the linear regression equation produced by your model?
- ii) Evaluate. the quality of the model. What is the .12 value?
**(***Note**that this is called ‘Multiple R-squared” in some software output,)*Which. independent variables are significant?