Keep it in the ground: the Paris climate agreement is now official

Environment groups hail ‘momentous occasion’ but warn governments need to cut carbon emissions more steeply to avoid dangerous global warming

The French president and foreign minister, along with the UN secretary general and UN climate chief, celebrate agreeing the Paris climate change deal. Photograph: Francois Mori/AP

Friday 4 November 2016 

The significance of the Paris agreement coming into force today is easy to miss: it may seem like an anti-climax, given the travails that led up to its signing last December.

But the moment is of huge importance. This is the first time that a legally-binding agreement, signed by all of the world’s functioning governments, has laid down a commitment to limit the growth of greenhouse gases in the atmosphere with the goal of preventing global warming exceeding 2C above pre-industrial levels.

This figure was not plucked out of the increasingly carbon-rich air. It is the limit of what scientists regard as safety, beyond which climate change will run out of control, unstoppable in its damaging effects.

There are caveats. The Paris agreement is legally binding in forcing governments to accept and cater for the 2C limit. But the commitments on curbing greenhouse gas emissions in line with that goal are not legally binding. This means incoming governments can renege upon them. There are no sanctions for governments that flout the goals.

The outcome of the US presidential election will be key. Donald Trump, the Republican candidate whose polling has improved markedly in recent days, has vowed to cancel the US’s participation in the Paris agreement. Russia has also failed to ratify the agreement, along with several other nations. China has ratified, but if US participation is not forthcoming under a future Trump government, that may be off.

So while the agreement should be hailed as a massive and historic step forward in international efforts to avoid dangerous levels of global warming, it is potentially fragile.

Meanwhile, the signs of danger are growing increasingly strong. This year is almost certain, according to Nasa, to be the warmest on record, following last year’s record-setting temperatures. This gives the lie to the claims of warming-dismissers that the upward march of global temperatures has “paused”.

Next year may not set records, but the trend is clear. We are on a trajectory that may lead to warming that is unprecedented and potentially irreversible. While there are other encouraging signs - the growth in renewable energy use around the world, the small reductions in emissions in some major economies - we should be in no doubt. The real work of Paris remains to be done.

Fiona Harvey

Environment correspondent, The Guardian