Social Channels


  • Type

  • Topic

  • Sort

19 April 2016 12:15

Explainer: The adoption, signing and ratification of the UN climate deal

Sophie Yeo


Sophie Yeo

19.04.2016 | 12:15pm
COP21 ParisExplainer: The adoption, signing and ratification of the UN climate deal

Update 21/09/16 — At a ceremony in New York, 31 countries ratified the Paris Agreement, taking the total up to 60 countries responsible for 47.76% of global emissions. This means that the country threshold has now been passed. Another 14 countries representing 12.58% of emissions promised to complete ratification by the end of the year. The UK is among those that has now given its promise to ratify before the year is over.

Update 3/9/16 – The US and China have now ratified the Paris Agreement. This means that 26 parties have ratified in total, accounting for 39% of global emissions.

On 22 April, representatives from nearly 170 countries will travel to the UN headquarters in New York to sign the UN’s Paris agreement on climate change.

The deal was adopted after years of negotiations, when 195 countries finally reached a consensus on a set of principles and targets that will, it is hoped, see climate change limited to “well below” 2C.

The rapturous applause that greeted the final fall of the gavel on 12 December 2015 might have given the impression that the UN’s job was done.

But adopting the Paris text was only the first step. Before the deal comes into force, it needs to be signed and then ratified by the countries that want to be bound by it.


If adopting the Paris text was Step 1, then the signing ceremony taking place on Friday can be seen as Step 2(a).

Around 168 countries have said that they will attend the session in New York, with around 60 world leaders confirming they will sign in person.

Failure to show up at the ceremony this week does not mean that a nation has decided to abandon the deal.

In what could be considered Step 2(b), the agreement will remain open for signatures at the UN headquarters for a year after the ceremony, closing on 21 April 2017. It will still be possible to accede to the agreement after this date.


Step 3 is ratifying the deal. This can also take the form of “acceptance, approval or accession”, according to the legal text — subtly different processes that ultimately equate to ratification (for a full description of how they are different, see the UN’s treaty glossary).

This is a process that begins at the national level, as countries have to go through the constitutional and legislative procedures necessary to ratify the deal.
The Paris deal must be ratified by at least 55 countries representing at least 55% of total global emissions before it can enter into force. This threshold was negotiated furiously in the last few days of the negotiations in Paris.

The World Resources Institute, a Washington DC based think-tank, has created an interactive graphic illustrating how these thresholds could be crossed.

For example, if the US, China, India, EU, South Africa and the small island states ratify the deal, the thresholds would be reached.

The effort that needs to be invested in this process varies dramatically by country. Some nations, such as Fiji, Marshall Islands, Palau and the Maldives, have already ratified Paris in their home countries.

The Paris deal was also designed to avoid the need for Congressional approval in the US — which would have been almost impossible to win, given the current dominance of the Republican party in both the Senate and the House of Representatives.

US ratification is, therefore, expected to arrive swiftly on the back of its signature. Indeed, the US and China have jointly pledged to “take their respective domestic steps in order to join the agreement as early as possible this year”.

Other regions, such as the European Union, have lengthy bureaucratic processes to navigate, and so ratification is expected to come later. This is likely to have a knock-on effect on its 28 member states, which also have to ratify individually, regardless of what happens in Brussels. Eliza Northrop of the World Resources Institute, tells Carbon Brief:

“It is expected that each of the 28 member states will wait for the EU to [ratify], and either do it on the same day or shortly afterwards. Although this is not a legal requirement, rather [it is] precedent.”

Does signing equal ratification?

There are three stages on the journey towards entry into force, and countries do not always move in unison along this path — or even reach the final destination. While all countries formally adopted the deal in Paris, how many can be expected to actually translate this into ratification?

According to the Vienna Convention on the Law of Treaties, signing means that a country is “obliged to refrain from acts which would defeat the object and purpose of a treaty” — even if it has not ratified yet.

Todd Stern, who negotiated the Paris deal on behalf of the US, told reporters in February:

“A country’s not going to sign if they don’t intend to join. It can happen — a country can sign then run into some kind of a obstacle with respect to joining and so end up not joining, but I don’t think anybody signs without the intention of joining. So it’s a signal, it’s a very positive signal, that a country is going to be on board.”

This is a possibility of which the US has firsthand experience. It signed, but never ratified, the UN’s previous climate agreement, the Kyoto Protocol.

The potential for delay was brought into sharp relief recently by a leaked note written by the Third World Network, a Malaysian non-governmental organisation. Intended as a private policy document, it encouraged developing nations to hold off from signing the agreement in order to secure more leverage in future negotiations.


Two commentaries, published on Climate Home, have examined the historical precedents when it comes to persuading nations to sign and ratify UN climate treaties.

Nick Chan, an advisor to Palau at the UN climate talks, suggests that ratifying Paris may not be an easy ride, if the experiences of the Kyoto Protocol and its subsequent Doha Amendment are anything to go by.

Many countries refrained from ratifying the Kyoto Protocol for many years, he said. Some countries, such as Russia, used it to gain political leverage. Others were unwilling to be bound by an unfinished deal, and only ratified once all the rules had been elaborated. The Doha Amendment, which set climate targets for the period 2013 to 2020, has still not been ratified by enough countries to enter into force.

Michael Dobson, a former climate advisor to the Marshall Islands, paints a more optimistic view, suggesting that the low threshold for entry into force means no one country has power of veto over the Paris Agreement, and the commitment of China and the US makes success look likely.

Christiana Figueres, the executive secretary of the UN’s climate body, says she believes that the deal will enter into force by 2018 — something which could cause a legal headache, as it was initially envisaged that the agreement would begin in 2020. She says:

“It causes havoc, because in the meantime we have the Kyoto Protocol running, and the lawyers are very, very scared about this. But somehow we will lock all the lawyers in a room and have them fix that situation for us.”

Logistical difficulties

This isn’t the only logistical difficulty created by a potentially swift entry into force.

At Paris, countries set up a tight schedule of tasks that needed to be completed by a group christened the “Ad Hoc Working Group on the Paris Agreement” (APA), including drawing up rules on features of climate pledges, guidelines for transparency, and sources of input for the global stocktake.

Carbon Brief has looked at these tasks in detail. The UN has also drawn up a comprehensive list of 135 future tasks.

Many of these tasks need to be completed before entry into force, when the APA officially dies, to be replaced by the “Conference of the Parties serving as the meeting of the Parties to the Paris Agreement” (CMA), which is responsible for supervising the new deal.

Early entry into force could lead to the premature birth of the CMA. This would cause the APA to die with unfinished business, rather than coming to a peaceful end after a long and fruitful life, as was initially envisaged.

A recent UN information note clarified that, while the situation may be messy, the problem was not insurmountable. Its suggestions include reviving the APA to continue its original workplan, and extending the timeline of the CMA for adopting these extra rules and guidelines.

Main image: United Nations Building,the headquarters of the United Nations, in New York, Sep 27, 2015.
Sharelines from this story
  • Explainer: The adoption, signing and ratification of the UN climate deal - Carbon Brief
  • Around 155 countries have said that they will attend the Signing Ceremony of the Paris Agreement in New York

Expert analysis direct to your inbox.

Get a round-up of all the important articles and papers selected by Carbon Brief by email. Find out more about our newsletters here.