Over a decade ago in 2010, a worldwide ban on chlorofluorocarbons (CFCs) came into effect. Their role in destroying the ozone layer had been known since the 80’s and in 1987 virtually every country in the world had signed the Montreal Protocol, agreeing to end the production of CFCs within the next 13 years.
In an encouraging sign that when we do decide to act on some of the damage that humanity does, the levels of CFC emissions went down, and the ozone layer began to repair itself. For the first few years after the ban the international agreement was actually working, there was a small but steady improvement and shrinking of the ozone layer hole we had created.
But data analysis showed that in 2013 something strange happened, the repair process slowed down and at the same time scientists observed a mysterious but very clear rise in the levels of trichlorofluoromethane (CFC-11) emissions.
Atmospheric measurements had made it possible to track the suspected rogue production of the chemicals to an area in eastern China. The Chinese government took notice and stepped up to end the illegal manufacturing pretty swiftly.
The truly encouraging thing is that, according to research by an international consortium of 12 institutions published last week in Nature, stopping this illicit production seems to have set the ozone layer recovery right back on track.
“The findings are very welcome news and hopefully mark an end to a disturbing period of apparent regulatory breaches,” said Luke Western from the University of Bristol, a co-lead author of one of the studies. “If the emissions had stayed at the significantly elevated levels we found, there could have been a delay, possibly of many years, in ozone layer recovery.”
There are a couple of lessons to take away from all of this.
The first is that our planet’s systems have a way of healing themselves if we stop doing more damage and let them.
The second is that there is a clear need for independent validation of international environmental agreements. Things have to be constantly measured so that we can pin down and act on any activities that violate those treaties.