Ozone damage could have been detected decades earlier
A new study simulates that ozone depletion could have been detected as early as 1957 if modern satellite monitoring had existed then, suggesting earlier intervention might have been possible.
Scientists used a climate model incorporating ozone chemistry to simulate how ozone layer changes would have been detected if modern monitoring tools had been available in the 1950s. The model included greenhouse gas emissions, ozone-depleting pollutants, and natural events like volcanic eruptions.
The study found that a statistically significant ozone decline (at the 95% confidence level) would first have emerged in the upper stratosphere over the tropics in 1957. At that time, half to two-thirds of ozone-depleting chlorine in the atmosphere was still carbon tetrachloride rather than CFCs. In other regions, the signal would have appeared later — in the lower stratosphere, including over Antarctica, the ozone hole would have been detectable by 1976, a decade earlier than its actual discovery.
However, the researchers warn that current monitoring is at risk. The satellite measuring ozone at multiple stratospheric heights has been orbiting since 2004 and is far past its intended lifespan. Last year's White House budget proposal called for shutting it down. Without a replacement, detecting future small changes will become much harder.
