Scientists recently reported that the ozone hole over Antarctica is showing signs of healing. This wonderful news comes almost 20 years after the Montreal Protocol banned the production and use of clorofluorocarbons (CFCs) in 1987. The decline means that CFCs are finally dropping in concentration in the atmosphere and are either breaking down high in the stratosphere or going into the ocean. Biologically inert, the CFCs in the ocean don’t harm any marine life, but they have proven very useful for oceanographers trying to understand circulation in the deep ocean.  Continue reading CFCs: Noxious for ozone, but luminescent for ocean currents →