Many scientists are devoting all their time to solving ozone layer depletion.
The problem with the ozone layer is that when certain chemicals, like chlorofluorocarbons, reach the stratosphere, they break down into chlorine and bromine, which react with the ozone and destroy it.
The plan is to somehow clean the stratosphere and get rid of these chemicals. For example, some scientists have suggested using giant lasers on top of mountains to basically break apart harmful chemicals before they reach the stratosphere.
However, research proves that this would be incredibly expensive, not to mention that the side effects aren't clear. Scrubbing out the chemicals this way might end up causing serious environmental problems.
It would be much easier to stop releasing harmful chemicals into the atmosphere in the first place. One chlorine molecule can break apart more than one hundred thousand ozone molecules. Why not keep it from getting there at all? If we stopped releasing harmful chemicals today, the ozone layer would probably be back at full strength by 2050.