Ozone: Deplete it and the Earth cools.

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The information about the ozone layer on wikipedia is a bit difficult to understand, but basically, "ozone warms the stratosphere by absorbing both infrared and ultraviolet radiation; thus ozone loss in that region should lead to cooling." - ucar

Although ozone depletion cools the Earth's surface, repairing stratospheric ozone is important to block harmful ultraviolet radiation. - spacetoday

Detail from wiki:

• The same CO₂ radiative forcing that produces near-surface global warming is expected to cool the stratosphere. This cooling, in turn, is expected to produce a relative increase in ozone (O₃) depletion and the frequency of ozone holes


• Conversely, ozone depletion represents a radiative forcing of the climate system. There are two opposing effects: Reduced ozone causes the stratosphere to absorb less solar radiation, thus cooling the stratosphere while warming the troposphere; the resulting colder stratosphere emits less long-wave radiation downward, thus cooling the troposphere. Overall, the cooling dominates; the IPCC concludes that "observed stratospheric O₃ losses over the past two decades have caused a negative forcing of the surface-troposphere system"^[37] of about −0.15 ± 0.10 watts per square meter (W/m²).^[38]

• One of the strongest predictions of the greenhouse effect theory is that the stratosphere will cool. Although this cooling has been observed, it is not trivial to separate the effects of changes in the concentration of greenhouse gases and ozone depletion since both will lead to cooling. However, this can be done by numerical stratospheric modeling. Results from the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory show that above 20 km (12.4 miles), the greenhouse gases dominate the cooling.^[39]

• Ozone depleting chemicals are also greenhouse gases. The increases in concentrations of these chemicals have produced 0.34 ± 0.03 W/m² of radiative forcing, corresponding to about 14% of the total radiative forcing from increases in the concentrations of well-mixed greenhouse gases.^[38]