The Ozone Layer is Recovering, but... The Space Industry and Alternative Substances are Emerging as New Variables

The international community phased out ozone-depleting substances such as CFCs and HCFCs through the Montreal Protocol in 1987. The World Meteorological Organization (WMO) predicts that the ozone layer could recover to 1980s levels in most regions around 2040, in the Arctic by 2045, and in the Antarctic by 2066. In fact, positive changes have been observed in recent years, such as a reduction in the size and duration of the Antarctic ozone hole.

However, it is too early to be optimistic. Recent studies point out that aluminum oxide and black carbon generated during satellite launches and re-entry processes could accumulate in the stratosphere and delay the recovery of the ozone layer. The emergence of large-scale satellite constellations is becoming another environmental variable of the 'space age'. Wildfires and volcanic eruptions caused by climate change can also have significant short-term impacts on the ozone layer.

The issue of alternative substances has not been resolved either. After CFCs and HCFCs, HFCs became widely used, but they have a high global warming potential, exacerbating climate issues. The international community has agreed to reduce HFCs through the Kigali Amendment (Kigali Amendment, an international agreement adopted in 1987 aimed at reducing the production and consumption of ozone-depleting substances (CFCs, HCFCs, etc.)), and recently, low GWP alternatives such as HFOs, isobutane, ammonia, and CO₂ have emerged. However, practical challenges remain, such as flammability, toxicity, cost issues, and the burden of replacement for small and medium-sized enterprises.

Korea has also set a goal to significantly reduce HFC emissions by 2035. However, some HFCs are still on the rise, and institutional support and improvements in safety certification systems are urgent. Only through concurrent technological development, policy, and industry cooperation can a substantial transition be achieved.

The ozone layer is recovering, but there are still many challenges to be addressed. Whether we can overcome new threats and the limitations of alternative substances is once again putting international cooperation and scientific responses to the test.

Remaining Tasks and Questions

- How will the rapid growth of the space industry affect recovery scenarios?

- How will the ozone layer respond when natural phenomena like wildfires and volcanoes coincide with climate change?

- Until when and to what extent can alternative substances secure safety and economic viability?

- Is there no discrepancy between Korea's HFC emissions statistics and actual emissions?