Today the ozone hole, which was first spotted 25 years ago, appears headed for a happy ending, thanks to unprecedented international action.

Could a similar effort rein in climate change? And is the closing ozone hole actually making global warming worse?

The ozone layer lies between about 9.3 and 18.6 miles (15 and 30 kilometers) above Earth's surface. This blanket of ozone, or O3, blocks most of the sun's high-frequency ultraviolet rays.

These UV rays can cause skin cancer and cataracts in humans, as well as reproductive problems in fish, crabs, frogs, and even in the single-celled phytoplankton at the bottom of the ocean food chain.

Ozone is created naturally when oxygen molecules (O2) high in the atmosphere get broken