FIGURE 1-2 



CONCENTRATIONS OF SELECTED GREENHOUSE GASES OVER TIME 



1. Carbon Dioxide 

 Concentration* 



a 

 o , 



2. Nitrous Oxide 

 Concentrations * 



1978 1977 1078 1970 



1 1 1 r 



4. Chlorof luorocarbon-1 2 



Concentrations 



1977 1978 1979 I960 1981 



4000 2000 



iOCJ TOO 100 100 200 



YEARS AGO 



1. Keeling, CD, R.B. Bacastow, and T.P. Whorf, 1982. Measurements of the Concentration of 

 Carbon Dioxide at Mauna Loa, Hawaii. Carbon Dioxide Review 1982, edited by W. Clark. New 

 York: Oxford University Press, 377-382. Unpublished data from NOAA after 1981. 



2. Weiss, R.F., 1981. 'The Temporal and Spatial Distribution of Tropospheric Nitrous Oxide. " 

 Journal of Geophysical Research. 86(C8):7185-95. 



3. Cunnold, DM., et al, 1983a. The Atmospheric Lifetime Experiment. 3. Lifetime Methodology 

 and Application to Three Years of CFCL3 Data. Journal of Geophysical Research. 

 88(C13):8401-8414. 



4. Cunnold, DM, et al., 1983b. The Atmospheric Lifetime Experiment. 4. Results for CF2CL2 

 Based on Three Years Data, Journal of Geophysical Research. 88(C13):8401-8414. 



5. Rasmussen, R.A., and M.A.K. Khalil, 1984. Atmospheric Methane in the Recent and Ancient 

 Atmospheres: Concentrations, Trends, and Interhemispheric Gradient, Journal of Geophysical 

 Research. 89(D7): 11599-605. 



