Data collected from around the globe show that the earth is getting warmer. The most common theory relates climate change to an increase in atmospheric levels of carbon dioxide (C02), a greenhouse gas. The mean annual CO2 concentration in the atmosphere (parts per million) is measured at the top of Mauna Loa in Hawaii (away from any local contaminants) and available at ftp://aftp.cmdl.noaa.gov /products/trends/co2/co2_ annmean_mlo.txt
The mean surface air temperature is recorded as the change in °C relative to a base period of 1951 to 1980. It is available at data.giss.nasa.gov/gistemp/graphs_v3/
Here are a scatterplot and regression for the years from 1970 to 2013:

a) Write the equation of the regression line.
b) Is there evidence of an association between C02 level and global temperature?
c) Do you think predictions made by this regression will be very accurate? Explain.
d) Does this regression prove that increasing C02 levels are causing global warming? Discuss.