The Guardian view on climate change: good news – but not yet good enough
The Montreal protocol is the most successful environmental treaty in history, and arguably one of the most successful of any international pact. It phased out the gases that were destroying the ozone layer, averting potential catastrophe and healing the hole that human activities had opened in our protective layer. Unfortunately, it had a side-effect overlooked when it was signed in the 1980s: some of the chemicals substituted for the ozone-destroyers had an effect on the climate thousands of times higher than carbon dioxide. This month, world governments agreed to address that by eliminating the substitute chemicals called HFCs potentially reducing rising temperatures by as much as 0.5C in a relatively short time. Scientists put the safe limit on future rises at 2C above pre-industrial levels by the middle of this century: beyond that, catastrophic and irreversible climate changes are judged likely. So the reduction agreed under the Montreal protocol could have an enormous, and swift, impact. This is just the beginning of the good news. The International Civil Aviation Organisation agreed this month to measures to combat the impact of flying. Planes are not only a rising source of greenhouse gases, but also contribute through the vapour they produce, which coming at such high altitudes has a greater warming effect. This week, international shipping will debate similar rules to cut its impacts . This is a trillion-dollar business, and ships use particularly dirty fuel. Governments should take the simple measures needed. Altering the fuel to be less polluting, preventing outflow during shipping and harbourage, and improving monitoring to reduce emissions need not be costly and will be invaluable in the fight against marine and air pollution as well as climate change. These progressive moves, though belated and insufficient, must be welcomed. They represent an unprecedented run of helpful measures set out internationally since the Paris accord on climate change was signed last December . In further good news, the Paris accord itself has now been ratified, making it harder for future governments in any nation, and of any stripe, to unpick it. Supporters said Paris would unleash a slew of contributory measures that would help reverse the rising trend in greenhouse gases. Based on these conclusions, it looks as if they were right. Now the bad news. Last Tuesday, Nasa confirmed that September was the hottest on record, albeit by a small margin, making 11 out of the last 12 months record-breakers. This year is expected to set a new record as last year did , and 2014 before it. These results give the lie to climate sceptics claim that global warming has paused. The biggest obstacle to action on climate remains, as it has been for more than 20 years, the US political system. The US has led the world on other environmental reforms, but the Senate is, incredibly, threatening to block the improvements to the Montreal protocol, apparently from partisan spite, industry lobbying and climate denialism rather than any rational basis. And if Donald Trump were to win the White House, though polls now indicate that is unlikely , all bets on action on global warming would be off. He has declared himself a climate change denier and vowed to renege on the Paris agreement. Scientists say we have a rapidly closing window to reorient the worlds economies to a low-carbon future, just a few years before we are locked into dangerous levels of warming. In 1987, the Montreal protocol was agreed despite clamour from industry that phasing out these destructive gases would be technically impossible or economically catastrophic. Those voices were wrong: the change happened ahead of schedule, with no discernible economic effect. Multiple studies, not least the landmark 2006 Stern review , have shown that reducing greenhouse gases will have an economically beneficial effect. Industries such as coal can be compensated while others flourish, creating jobs and economic opportunity. To achieve what is needed before the window closes, we must recapture the sense of urgency that motivated the Montreal protocol. Then, a clear and imminent danger based on only two decades of scientific research, compared with more than 100 years of global warming led nations, even during the cold war, to come together to protect our planet. Climate change may be slow-burning compared with the ozone layers destruction, but it is no less threatening. Montreal should provide the template by which we tackle it.