Results of experiments conducted by the U.S. EPA and NOAA indicated that ozone precursor emissions (VOCs and NOx, primarily) from oil and gas development in the Uintah Basin in Utah were a primary factor in the increased ozone level (Utah Department of Environmental Quality 2013).
The report notes with "high confidence" that climate change will increase ozone levels, as rising temperatures and changes in atmospheric circulation affect local weather conditions.
Increasing ozone levels are also seen as a likely health problem.
It increases ozone pollution levels at the ground level (fueling the current epidemic of asthma and respiratory diseases).
Similarly, DHAR-overexpressing plants also showed an increased ozone tolerance with a higher level of photosynthetic activity despite exhibiting a larger stomatal area (Chen and Gallie 2005).
Los Angeles' recent record drought increased ozone pollution, the main ingredient in smog, to levels not seen in nearly a decade. .
Increasing temperature also contributed to increased ozone levels again, the more ozone there was to start with, the more was made.
Dynamical disturbance of the polar vortex from mid-spring increased Antarctic ozone levels in the latter part of the ozone hole's evolution and helped to limit the overall severity of depletion.
Increased fire byproducts in the stratosphere can increase ozone concentration beyond safe levels.
