Ozone recovery may add 40% more warming than previously estimated, study finds

A University of Reading study projects that ozone changes could add about 0.27 watts per square meter of warming influence between 2015 and 2050, roughly 40% more than earlier estimates. That would make ozone the second-largest contributor to future warming after carbon dioxide. About half of the effect comes from recovery of the protective stratospheric ozone layer, the rest from rising ground-level ozone pollution in regions like India, Southeast Asia, and the Middle East. The finding does not undermine the Montreal Protocol. It does mean climate models need to account for ozone's dual role more carefully. The study used seven climate and chemistry models under a high-pollution scenario, and it shows that effective radiative forcing, which includes cloud and humidity feedbacks, gives a fuller picture than older metrics. For anyone tracking climate policy or carbon budgets, this shifts the expected warming trajectory and highlights why cutting ozone-forming pollutants like NOx and VOCs matters for both air quality and climate.