The sea ice extent is the area of the ocean where at least 15% of the surface

Question:

The sea ice extent is the area of the ocean where at least 15% of the surface is frozen. The average sea ice extents (in million square kilometers) of the Northern Hemisphere are described by the time-series plots in Figs. 126 and 127 for the months of September in various years.
Fig. 126

Fig. 127

a. If an environmental group wants to emphasize how much the sea ice extent has decreased, which time-series plot would it display? Explain.
b. If an oil company wants to de-emphasize how much the sea ice extent has decreased, which time-series plot would it display? Explain.
c. From which time-series plot are you more likely to better estimate the sea ice extent in 2010? Explain. Estimate the sea ice extent in that year.
d. Estimate the change in the sea ice extent from 2000 to 2010. If the sea ice extent were to change that same amount from 2010 to 2020, what would be the sea ice extent in 2020? Do you have much faith that your result will turn out to be true? Explain.
e. The time-series plots describe the average sea ice extents in September, when the sea ice extents are the smallest. For the years 1980, 1990, 2000, 2010, and 2013, the average sea ice extents in March are larger than in September by approximately 9.4 million square kilometers. Construct a time-series plot that describes the average sea ice extents in March for the period 1980€“2013. Use scaling on the vertical axis that emphasizes the decrease in sea ice extent.