The good news is that the ozone hole over Antarctica is slowly healing, thanks to controls on ozone-depleting substances that were once widely used in products such as refrigerators and aerosol cans. Stratospheric ozone protects us from harmful ultraviolet radiation that can cause problems such as skin cancer and crop damage.

As far as TV history goes, public service announcements will go down as a small but memorable slice of the great broadcast pie. The weeping Native American, brought to tears by the garbage strewn across his great country's highways. "Knowing is half the battle." "This is drugs; this is your brain on drugs." And so on.

Now, Al Gore and his Alliance for Climate Protection group have begun a privately funded PSA of their own with hopes of rallying the general public to the cause of preventing a global climate crisis.