The CFCs Data

Download the CFCs data (plain text).

Chlorofluorocarbons (CFCs) are chemicals that were developed in the 1930’s and used as propellants in aerosol cans and for refrigeration. Because they were found to contribute to depletion of the ozone layer, their use has been phased out under the schedule agreed to by the 1987 Montreal Protocol.

The data in the data file CFCdata.txt were downloaded from the World Data Centre for Greenhouse Gases (external link is no longer valid). The data file contains the following variables:

• year
• month
• time — a numeric variable measuring month as fraction of a year
• cfc11 — the monthly mean atmospheric concentration of CFC-11 measured at the top of Mauna Loa in Hawaii

Read more about these data:

• D. Nelson (2009). Using Simple Linear Regression to Assess the Success of the Montreal Protocol in Reducing Atmospheric Chlorofluorocarbons. Journal of Statistics Education 17(2) (link to article, opens in new window)
• S.A. Khan, G. Chiu, and J.A. Dubin (2009). Atmospheric Concentration of Chlorofluorocarbons: Addressing the Global Concern with the Longitudinal Bent-Cable Model. Chance 22(3), 8-17.