Figure 1.1

Figure 1.1. Variations in atmospheric composition over the last 200 years as deduced from analyses of trapped gases in Antarctic ice. The records show the rapid accumulation of two trace gas species in the atmosphere, largely as a consequence of increased emissions of these gases, related to increased world population (McEvedy and Jones, 1978). Also included are records of direct CO2 measurements, started in 1957 (Keeling et al., 1976). Note difference in levels relative to Figure 1.2. Data taken from Etheridge et al. (1992, 1996) for CO2 and CH4.