US set to miss its emissions target under the Paris climate deal

The good news: the Paris climate agreement is likely to come into effect this year, earlier than expected.

But even if countries stick to their Paris targets it will not be nearly enough to limit warming to 2 °C. And the bad news is that the second biggest polluter, the US, is not on course to meet its target.

Although most countries have already signed the Paris agreement, it doesn’t take effect until at least 55 countries, accounting for 55 per of greenhouse gas emissions, individually approve it. It was feared this ratification process could drag on for years. The 1997 Kyoto protocol did not come into effect until 2005 (and was never ratified by the US).

However, 61 countries – accounting for 48 per cent of emissions, and including the two largest polluters, China and the US – have now ratified the Paris agreement, so it is already very close to coming into effect. Many other countries, including the UK, say they will ratify it before the end of the year.

Unfortunately, it has always been clear that the emissions cuts that countries have volunteered to make by 2030, as part of the Paris agreement, are not nearly enough to limit warming to 2 °C, let alone the aspirational 1.5 °C. And “coming into effect” does not mean much in practice as the entire agreement is essentially voluntary: countries are obliged to set targets under the treaty but not to meet them.

The agreement was designed this way this way to allow the US to ratify the agreement without a vote in the Republican-dominated Senate, where it would not pass.

Not on track

But the US is not on track to meet its promised emissions target, according to a study by Jeffery Greenblatt at the Lawrence Berkeley National Laboratory in California. The US is meant to cut its emissions by 2025 by nearly a third compared with the 2005 level of around 7000 million tonnes of carbon dioxide per year.

With the policies it has implemented so far, it might not even get close – it could miss the target by as much as 1800 million tonnes. And even if the US puts all its proposed policies into practice, it could still miss the target by up to 1600 million tonnes.

“I don’t think it matters if we miss the target by a little bit. It matters if we are far off,” Greenblatt says. “It’s very important for the US to set a precedent.”

So the US is going to have implement additional measures fast if it wants to do better. These could include a rapid phase-out of coal, encouraging public transport over private cars, reducing methane leaks from the oil and gas industry, and the use of slow-release fertilisers that produce less nitrous oxide – a potent greenhouse gas.

Greenblatt is optimistic about more action being taken, but much depends on the outcome of the US presidential election.

“It is of great concern that the Republican nominee for President has advocated U.S. withdrawal from the Paris Accord,” leading scientists wrote in an open letter last week. “The consequences of opting out of the global community would be severe and long-lasting – for our planet’s climate and for the international credibility of the United States.”

The scale of the challenge facing the world was highlighted last week, with the finding that the fossil fuel reserves we are already exploiting will emit enough CO₂ to take us past 2 °C.

In other words, untapped fossil fuel reserves must be left in the ground and all exploration should stop. But not a single country with fossil fuel reserves plans to leave them untapped.