Ozone depleting substances could have led to additional warming

Without the global ban on ozone-depleting substances, we would already be facing the reality of a ‘scorched earth,’ according to an international group of researchers.

Following the discovery of the ozone hole in 1985, in 1987 the Montreal Protocol led to the ban of various ozone-depleting substances, including CFCs.

According to researchers, without this ban, the planet’s critical ability to absorb carbon from the atmosphere would have been degraded.

If the ozone-destroying chemicals had been left unchecked then their continued and increased use would have contributed to global temperatures rising by an additional 2.5°C by the end of this century.

The modelling reveals:

Continued growth in CFCs would have led to a worldwide collapse in the ozone layer by the 2040s.
By 2100 there would have been 60% less ozone above the tropics. This depletion above the tropics would have been worse than was ever observed in the hole that formed above the Antarctic.
By 2050 the strength of the UV from the sun in the mid-latitudes, which includes most of Europe including the UK, the United States and Central Asia, would be stronger than the present-day tropics.
photo of outer space

Dr Paul Young, the lead author from Lancaster University, said: ‘Our new modelling tools have allowed us to investigate the scorched Earth that could have resulted without the Montreal Protocol’s ban on ozone-depleting substances.

‘A world where these chemicals increased and continued to strip away at our protective ozone layer would have been catastrophic for human health, but also for vegetation. The increased UV would have massively stunted the ability of plants to soak up carbon from the atmosphere, meaning higher CO2 levels and more global warming.

‘With our research, we can see that the Montreal Protocol’s successes extend beyond protecting humanity from increased UV to protecting the ability of plants and trees to absorb CO2. Although we can hope that we never would have reached the catastrophic world as we simulated, it does remind us of the importance of continuing to protect the ozone layer. Entirely conceivable threats to it still exist, such as from unregulated use of CFCs.’

Photo by NASA