The prohibition of ozone-depleting substances like CFCs has facilitated the recovery of the ozone layer. However, when paired with rising air pollution levels, the heating effects of ozone are now expected to warm the planet by an additional 40% more than previously estimated.
Antarctica’s ozone hole in 2020. Image credit: ESA.
“CFCs and HCFCs are greenhouse gases contributing to global warming,” stated Professor Bill Collins of Reading University and his colleagues.
“Countries have banned these substances to protect the ozone layer, with hopes it will also mitigate climate change.”
“However, as the ozone layer continues to heal, the resulting warming could offset much of the climate benefits we expect from eliminating CFCs and HCFCs.”
“Efforts to reduce air pollution will limit ground-level ozone.”
“Still, the ozone layer will take decades to fully recover, irrespective of air quality policies, leading to unavoidable warming.”
“Safeguarding the ozone layer is vital for human health and skin cancer prevention.”
“It shields the Earth from harmful UV radiation that can affect humans, animals, and plants.”
“Yet, this study indicates that climate policies must be revised to consider the enhanced warming effects of ozone.”
The researchers utilized computer models to project atmospheric changes by the mid-century.
The models continued under a scenario of low pollution, where CFCs and HCFCs have been eliminated as per the Montreal Protocol (1987).
The results indicate that stopping the production of CFCs and HCFCs—primarily to defend the ozone layer—offers fewer climate advantages than previously thought.
Between 2015 and 2050, ozone is predicted to cause an excess warming of 0.27 watts per square meter (WM-2).
This value denotes the additional energy trapped per square meter of the Earth’s surface—carbon dioxide (which contributes 1.75 WM-2) will rank as the second-largest influence on future warming by 2050.
“Countries are making the right choice by continuing to ban CFCs and HCFCs that endanger the ozone layer globally,” stated Professor Collins.
“While this contributes to the restoration of the ozone layer, we’ve discovered that this recovery results in greater planetary warming than initially anticipated.”
“Ground-level ozone generated from vehicle emissions, industrial activities, and power plants also poses health risks and exacerbates global warming.”
The results were published in the journal Atmospheric Chemistry and Physics.
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WJ Collins et al. 2025. Climate forcing due to future ozone changes: Intercomparison of metrics and methods. Atmos. Chemistry. Phys 25, 9031-9060; doi: 10.5194/ACP-25-9031-2025
Source: www.sci.news
