Ozone Hole Recovery May Take Longer.

The eventual recovery of the gaping ozone hole over Antarctica, first discovered two decades ago, may take years longer than previously predicted, scientists reported Tuesday.

Researchers suspect that's because of all the older model refrigerators and car air-conditioning systems in the United States and Canada that are still releasing ozone-killing chemicals. Both countries curbed those chemicals in newer products.

If scientists are right, that means longer-term exposure to harmful ultraviolet radiation, which raises the risk of skin cancer and cataracts for people. Long-term UV exposure is bad for the biodiversity of the planet too.

Since the discovery of the ozone hole over the South Pole in the 1980s, satellites and ground stations have been monitoring it. Current computer models suggest the ozone hole should recover globally by 2040 or 2050, but Tuesday's analysis suggests the hole won't heal until about 2065.