A NOAA study published in the journal Nature demonstrates a profound effect of the Montreal Protocol: as levels of ozone-depleting chemicals controlled by the intenational treaty declined, a poleward shift of summertime circulation patterns in the Southern Hemisphere halted.
Weather conditions were ripe for a big ozone hole this year. But declining levels of ozone-depleting chemicals kept it to near-average size.
Emissions of one of the chemicals most responsible for the Antarctic ozone hole are on the rise, despite an international treaty that required an end to its production in 2010, a new NOAA study shows.