Figure 7. Future impact of CH₂Cl₂ growth on Antarctic column ozone and ozone trend from CCM simulations.

(a) Springtime mean column ozone decrease (DU) due to CH₂Cl₂ in the SH. (b) October mean Antarctic stratospheric ozone column (DU) relative to 1980. Results are shown for UMSLIMCAT run with CH₂Cl₂ growth Scenario 1 (blue, surface CH₂Cl₂ continues to increase at the mean rate observed over the 2004–2014 period) and without CH₂Cl₂ (black). While inter-annual variability is large, the two ozone time series are statistically different at the 95% significance level according to a Student’s t-test (P value=0.02). Ozone returns to the 1980 baseline in the year 2064 (without CH₂Cl₂) and in 2081 (Scenario 1).