EPA states in its regulatory impact analysis:
Climate change is expected to increase regional ozone pollution compared to what ozone levels would be in the absence of climate change, with associated risks in respiratory illnesses and premature death. In addition to human health effects, tropospheric ozone has significant adverse effects on crop yields, pasture and forest growth, and the composition of plant and animal species populations.
But EPA already separately regulates ozone and, in fact, will soon commence a rulemaking to tighten ozone standards. Moreover, this rulemaking will largely depend on EPA’s assertion that ozone causes premature death.