Fixing the Ozone Layer May Cause More Global Warming Than We Thought

The ozone layer protects us from harmful UV rays that can cause skin cancer and damage crops. Repairing it is seen as a win for the environment. But new research shows surprising results; this recovery might also make global warming worse than expected.

A study led by scientists from the University of Reading has found that as the ozone layer continues to heal, it may actually trap more heat in the atmosphere, possibly leading to 40% more warming than earlier climate models predicted. The ozone layer blocks dangerous ultraviolet radiation. However, ozone is also a greenhouse gas, which means it can trap heat and contribute to global warming.

Under the 1987 Montreal Protocol, countries came together to ban harmful chemicals called CFCs and HCFCs, which were damaging the ozone layer. Due to this ban, the ozone layer is slowly recovering. But it also means there’s more ozone in the atmosphere, and therefore, more warming.

The study predicts that between 2015 and 2050, changes in ozone could lead to an extra 0.27 watts per square meter of heat being trapped near Earth's surface. For comparison, carbon dioxide (CO₂), the main cause of climate change, is expected to trap about 1.75 watts per square meter in the same time frame. That would make ozone the second-largest contributor to future warming after CO₂.

Air pollution is also a significant issue. Even if countries clean up air pollution, the ozone layer will keep healing for decades, and with it, some unavoidable warming. While protecting the ozone layer is still essential for health and safety, scientists say that climate policies need to be updated. They suggest we must now also factor in ozone’s growing role in global warming when planning for the future.