ScienceNow: Climate change is bringing mixed news to the ozone layer. Thanks to increasing CO 2 concentrations and shifting air currents, the mid-northern hemisphere, including the United States, Canada, and Europe, will likely see its ozone restored ahead of schedule, according to a new study. Meanwhile, areas throughout the tropics and the mid-southern hemisphere, such as Australia, New Zealand, and Peru, may experience a delay in their ozone recovery.