Ozone-protection treaty had climate benefits, too, study says

The global treaty that headed off destruction of earth's protective ozone layer has also prevented major disruption of global rainfall patterns, according to a new study in the Journal of Climate.

The 1987 Montreal Protocol phased out the use of chloroflourocarbons, or CFCs, a class of chemicals that destroy ozone in the stratosphere, allowing more ultraviolet radiation to reach earth's surface. Though the treaty aimed to reverse ozone losses, the new research shows that it also protected the hydroclimate. The study says the treaty prevented ozone loss from disrupting atmospheric circulation, and kept CFCs, which are greenhouse gases, from warming the atmosphere and also disrupting atmospheric circulation. Had these effects taken hold, they would have combined to shift rainfall patterns in ways beyond those that may already be happening due to rising carbon dioxide in the air.