Good environmental news! The 1987 ozone treaty had a surprising positive side effect

Generally speaking, you can have “good news” or “environmental news”. “Good environmental news” is a depressingly niche genre in our current (warming) climate, and you need a really “glass half full” attitude to see the upside of headlines like this.

With that in mind, I’m going to have to shift a gear for this piece: a new study published this week in Geophysical Research Letters reveals that the 30-year-old Montreal Protocol – a treaty adopted to restore the damaged ozone layer to its former glory by phasing out chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) – has helped us out in today’s battles against climate change.

That may be a surprising conclusion, given climate change wasn’t a huge concern 30 years ago, but because CFCs and HCFCs are also particularly harmful greenhouse gases – with the ability to trap heat on a scale thousands of times greater than carbon dioxide – cutting them out was hugely helpful for the battles of the future. As a result, the researchers think that between 2008 and 2014, phasing out CFCs and HCFCs saved the equivalent of 170 million tonnes of carbon emissions every year in the USA alone. That’s around half of the reductions achieved by all the other EPA climate regulations combined. A handy boost for a battle we’re doing our best to lose.

“We were surprised by the size of the decline, especially compared with other greenhouse gases,” said Lei Hu, lead author of the study. Better still, Hu believes that the benefits of the Montreal Protocol will get better over time. By 2025, her projections suggest that US greenhouse gas emissions will be reduced by the equivalent of 500 million tonnes of carbon dioxide, compared to 2005 levels – a reduction of around 10% compared to current CO2 emissions.

The problematic chemicals – previously used in refrigerants, foam blowing agents, aerosol propellants, fire retardants and solvents – were phased out in the US by the Clean Air Act, which saw CFC production and usage virtually vanish, while HCFC usage fell by 95%. A consequence of this has been the increased use of hydrofluorocarbons (HFCs, to add yet another acronym), and while these are comparatively ozone-friendly, some are potent greenhouse gases, undoing bits of the good work of the Montreal Protocol.

But the good news is that all countries adhering to the Montreal Protocol signed up to reduce HFC production and consumption last year too with the Kigali amendment. Under the terms of the legally binding amendment, rich countries will need to abandon HFCs by 2018, in a moment John Kerry called the “single most important step” in the fight against climate change.

Of course, this was back in 2016, before the then secretary of state knew that the USA would be taking another step – only this time backwards. When people voted for Donald Trump as the 45th president of the United States, they either didn’t know they were putting their faith in an anti-science climate-change denier, or they didn’t care. The consequences of this on the fate of the planet are quickly becoming apparent: the president has put a fellow climate-change denier in charge of the Environmental Protection Agency, pulled the US out of the Paris Climate Accord, and been instrumental in pushing the Doomsday Clock 30 seconds closer to midnight with talk of nuclear war with North Korea.

While that’s a depressing list of obstacles for the planet to overcome, the main take-home from this story is a rare glimmer of hope. Trump only has the White House keys for a maximum of three to seven more years – possibly even fewer. It’s taken us 30 years to see the real benefit of the Montreal Treaty, but just like Kyoto before it, it’s proven that we can achieve great things when we come together for a common good. One man, no matter how destructive, can only undo so much.