Figure 1 shows the basic structure expected for the ozone response to decreasing chlorine from 2004 to 2017 as a function of latitude and altitude calculated in the Goddard 2D model. This result is the negative of the downward trends calculated for the mid 1970s through the mid 1990s during the period of chlorine increase. The most prominent feature in the figure is the increase of ozone in the upper stratosphere peaking in the 2-3 hPa pressure range. The maximum increase is at mid to high latitudes (~30-75°) in each hemisphere. In the lower stratospheric tropics we see a small region of negative trend. This is the reversal of "self-healing" that has been described for the earlier time period of the mid 1970s through mid 1990s. During that period, decreases in the ozone in the upper stratosphere allowed more UV radiation to penetrate to lower altitudes in the tropics thus increasing ozone production there. The other major feature of Figure 3 is the large increase in below about 50 hPa in the high southern latitudes. This represents the early stages of ozone hole recovery.

The upper stratospheric trend represents ozone increase due to the decrease in chlorine plus ozone increase due to cooling by increasing CO₂. CO₂ cools the stratosphere by radiating to space. The vibrational states of CO₂ are populated by collisions with other atmospheric molecules. The excited vibrational states can transition back to the ground state by emitting infrared radiation (primarily in the 15μ band). The radiation that is emitted downward will be reabsorbed in the denser atmosphere. The radiation emitted upward can escape into space representing a loss of energy and a cooling. This is different from the troposphere where the IR radiation is optically thick and the upward emitted radiation is also reabsorbed. Cooling of the upper stratosphere slows down the chemical reactions that destroy ozone leading to an increase in the ozone concentration.