How does the shrinking of the ozone layer increases the melting of the polar ice caps?
The ozone layer does not shrink, as twice a year it covers the entire Earth. Every year. The ozone layer thins, and it thins because the ozone layer warms just as all the rest of the planet. Ozone decays spontaneously, and does so faster when it is warmer. Also, a warmer troposphere lofts more water vapor, and water vapor is deadly to both the formation of ozone, and shortens ozone’s already short life. So the thinning of the ozone layer is just another symptom of warming in the troposphere, not the cause. The amount of “heat energy” represented by the UV-B solar component is insufficient to provide significant warming, in my opinion. Now consider that the south polar ice sheet got significantly larger under the ozone hole. Given that ozone is a greenhouse gas, it allows a more direct coupling between Earth’s surface and the 3K sink temperature of the Universe at large. So thinning ozone actually helps to cool Earth’s surface a bit. Of course, we’d be dead were it gone entirely…
