A “Legally Binding Treaty” or Not? The Wrong Question for Paris Climate Summit

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Both media and negotiators are spending an inordinate amount of time on whether the Paris climate summit starting this week should lead to a “legally binding treaty”. For the EU Commission, it “must be”. For US Secretary of State John Kerry “definitely not”.

For realist scholars of international relations this obsession is puzzling. In the absence of an international police force, why care about whether a commitment is legally binding? For international lawyers, in contrast, it seems to confirm the self-standing moral authority of their discipline. Why else would politicians hackle about bindingness?

The Paris red herring

Yet, “to treaty or not to treaty” is really not the question. Paris will certainly be a treaty and not be a treaty. As a matter of international law, Paris will undoubtedly result in a “treaty”. On the international plane, a text agreed upon by states constitutes a legally binding treaty unless the parties express an intention to the contrary, and this irrespective of the terminology used (treaty, convention, protocol etc.). All COP 21 participants seem to want a legally binding treaty in this sense including the US and China. This explains French President Hollande’s rebuke to Kerry that “if the agreement is not legally binding, there won’t be an agreement”.

As a matter of US constitutional law, in contrast, Paris will, with equal certainty, not result in a “treaty”. What international law classifies indistinctly as “treaties”, the US constitution subdivides in “treaties”, “congressional-executive agreements” and “presidential-executive agreements”, depending on an agreement’s specific content and who in the US can accept it, respectively, 2/3 of the US Senate, simple majority in both houses of Congress, the US President acting alone. Mustering a 2/3 majority for a climate change treaty in today’s Republican-controlled US senate is science fiction. Ergo, when you ask John Kerry, Paris will “definitely not” be a treaty. For others to insist that Paris be a treaty also in this US constitutional law sense would be counter-productive.

“Treaty or not” is a Paris red herring. It risks being used as a ploy to divert attention from the three questions that really matter.

The three questions that do matter

First, the substantive content and ambition of the deal, not only in terms of emission cuts (will the national climate action plans taken together limit temperature rises to 2 or 3.5 degrees Celsius?) but also financing and adaptation.

Second, far more important than whether a particular commitment is “legally binding” in the abstract, is the question of practical follow-up procedures: transparency, reporting, periodic reviews, mechanism to ratchet-up national action plans over time, sanctions, etc. There are plenty of international commitments that are “legally binding” but remain dead letter. Think of Syria or Ukraine but also of certain human rights, labor or environmental commitments. Conversely, a growing number of recently concluded agreements are not “legally binding” but extremely well implemented. Think of non-binding Financial Action Task Force (FATF) recommendations against money laundering (backed up by blacklisting non-complying countries), non-binding international health or technical standards (backed up by expert-accuracy and market forces) or new OECD tax avoidance rules (prominently supported by the G-20 but not as such binding).

Notwithstanding these realities, in a surprising number of settings – climate change but also the UN Human Rights Council currently working on a “legally binding instrument” on business and human rights or the UN General Assembly aiming for a “multilateral legal framework” for sovereign debt restructuring – the idea of a “binding treaty” continues to be portrayed as the holy grail, a silver bullet that will solve all problems. This is wrongheaded. Making something a “binding treaty” at the international level does not, as such, add much. Yet, it takes longer to negotiate and ratify, may reduce the level of ambition, sets the issue in stone and limits the parties involved to states.

Third, buy-in at the domestic level is more important than legal nature under international law. The real worry about not having a “binding treaty” is not so much fear of non-compliance. It is the risk of avoiding domestic control mechanisms: diplomats signing deals without the people’s support. In the US context, avoiding the 2/3 Senate majority rule can hardly be described as a “run on democracy”. Why should 1/3 of US senators be able to block a deal, and why should only the Senate, not the House, have a say? Adopting the Paris outcome as a “congressional-executive agreement”, the way 95% of binding agreements to which the US is a party have been adopted in the past, with a simple majority in both houses of Congress, is more, not less, democratic. Yet, in other instances, adopting non-binding rules at the international level that become de facto binding domestically without Parliamentary scrutiny is a problem. Many financial, health and tax rules referred to earlier have become binding in some way without domestic parliaments approving them. The challenge is therefore to construe innovative ways to ensure that international rules are supported and accountable to the people. Buy-in of non-state actors in the negotiation of the rules at the international level is one way. Making national climate action plans binding domestically, even if they may not be binding at the international level, is another. Binding commitments at the national, rather than international level, would not only come with more effective domestic back-up procedures (national courts and penalties). It would also trigger national legislative or administrative control mechanisms ensuring popular support. Surely, countries can change their domestic laws, but they can also un-sign or leave a binding treaty (the way George Bush un-signed Kyoto or Canada left Kyoto in 2012).

Variable geometry, not one-size-fits-all

If substantive ambition, practical follow-up procedures and domestic buy-in are the three core questions, for each, an important key to success will be variable geometry, not a one-size-fits-all approach.

Substantive commitments will need to be tailor-made to the specifics of each country, not the artificial bifurcation between developed and developing countries enshrined in the Kyoto Protocol. What really matters will be the decision on which commitments within the Paris treaty will be legally binding (e.g. using the word “shall”) or hortatory (using terms such as “should” or “strive”). Here as well, differences may be needed not only between provisions (e.g. emission cuts v. procedural commitments) but also between countries, some countries using the treaty as commitment device, others (such as the US?) using domestic law or binding review procedures to tie their hands. Variation will, finally, be key also to ensure popular support and domestic accountability of the Paris deal: in some countries, or for some provisions, ratification by parliament; for others, buy-in from non-state actors at the international level or control mechanisms under domestic legislative procedures or administrative law.

The best insurance policy to limit temperature rises to 2 degrees Celsius is not “a legally binding treaty”. Rather than spending their time on legal abstractions, Paris negotiators should focus their energy on substantive commitments and credible follow-up procedures at the international level, and maximizing domestic buy-in at home.

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Heiko says

December 4, 2015

Very good question. It would be only symbolic. And summum ius, summa iniuria anyway. We cant regulate all (and this applies also to the famous impunity gap IMHO).

Marty Lederman says

December 4, 2015

Thanks very much, Joost and Lilliana.

I'm not sure your principal premise is correct, however. To be sure, you're correct that "on the international plane, a text agreed upon by states constitutes a legally binding treaty unless the parties express an intention to the contrary." But this is critically dependent on the final condition -- "unless the parties express an intention to the contrary"; and the terminology used in the instrument certainly can be important indicia of such intent (although you're right that the title of the instrument is not likely to be determinative).

You write that "all COP 21 participants seem to want a legally binding treaty in this sense including the US and China." But that's not at all clear. There are many important provisions of the instrument that I imagine the U.S. executive will insist *not* be understood as binding as a matter of international law . . . because if they *were* binding, the U.S. Constitution would require the approval of either two-thirds of the Senate or of majorities of both houses of Congress--neither of which is in the cards these days--in order for the U.S. to ratify the treaty. This is one big reason the recent Joint Comprehensive Plan of Action regarding Iraq's nuclear capabilities was finalized as a nonbinding "political commitment," as I explain in the second half of this post:


The U.S. is likely to insist upon the same in Paris. That is to say: One shouldn't disaggregate the questions under U.S. constitutional law and international law, because the requirements of the former are likely to shape the parties' understanding of the application of the latter.

As to your third point, it looks fairly certain that there won't be legislative "buy in" in the U.S., at least not by either or both bodies of Congress if they continue to be Republican-controlled. (I'd very much like to be proven wrong on that; but I'm not holding my breath.) That's one big reason why the U.S. might insist that the agreement not be binding under international law.

Importantly, however, that does *not* mean the U.S. executive wouldn't comply with the terms of the agreement going forward -- merely that he or she would (almost certainly) do so without obtaining legislative approval. (I assume here that the President would have the domestic-law authority to comply--which probably means that the President would not give the U.S.'s assent in Paris to promise to do anything specific that is not already authorized under U.S. law.) As I wrote in that earlier post, political commitments, which are *very* common over the past century, are hardly worthless or unimportant, and they don't ordinarily go unheeded--"to the contrary, as Secretary of State Kissinger and State Legal Adviser Monroe Leigh explained to a Senate committee in 1975, such commitments are 'important statements of diplomatic policy [which] engage the good faith of the United States so long as the circumstances that gave rise to them continue,' even if 'they are not binding commitments of the United States.' Unless and until a party repudiates such a commitment, which it can do without legal penalty, it has in effect given its word of honor that it will comply with that commitment; and therefore, if it breaks that promise, it can be subject to costly political and diplomatic--but not legal--responses from other states. That's why the U.S., and other nations, rarely repudiate, or act in contravention of, such nonbinding agreements."

Joost Pauwelyn says

December 5, 2015

Thanks, Marty.

Our "premise" is that the Paris document will be a "treaty" under international law, not that all of the provisions in it will be legally binding (the same way that the WTO agreement is a treaty under international law but not all WTO provisions impose legally binding obligations, many are "should" or hortatory) - see the last part of our post: no one-size-fits-all. So on this we may agree.

You are also right that "binding or not", and what is agreed on, at the international level (e.g. procedural or not, within or beyond current US law?) will influence how the US must accept the instrument under US constitutional law.

Our core point is rather that this is a US problem of how the US must adopt the deal, with or without Congressional approval or done solely by the executive.

Other countries should not really worry about this. As you say, even a non-binding commitment by the US can have teeth (for us, it depends on the follow-up procedures, possible sanctions etc.).

On the contrary, for other countries to insist that all Paris commitments are "legally binding" would be counter-productive: it may make a deal impossible or if it were even concluded would make acceptance by the US (second largest emitter) impossible.

So climate supporters should actually cheer certain non-binding elements in a Paris deal, as this will facilitate US adoption, and may increase the ambition also of countries like China and India (assuming, always, that the follow-up procedures agreed upon are strong).

The real problem remains then: is it "democratic enough" for US voters that a Paris deal be adopted by the President acting alone. But that is a US problem, not a problem for France, China or other countries.

So in the end the choice may be between a strong climate deal (albeit with important non-binding elements) adopted by the US President acting alone, or a weak climate deal (but binding) adopted "more democratically" by Congress (if at all).

For a non-US climate supporter the former is obviously better; for a US climate sceptic, voting Republican, clearly the latter ...

Marty Lederman says

December 5, 2015

Thanks very much, Joost. Yes, I think we largely agree. I should have added the possibility that the U.S. might agree to join a document that is deemed a “treaty” under international law, as long as it does not require satisfaction of any substantive outcomes that are binding under international law. For example, as you suggest, if the operative provisions are merely hortatory, or even if they "require" states merely to "endeavor," or "make efforts," to reach certain goals, it might be the sort of thing the President can conclude unilaterally, without approval from the Senate or Congress.

The devil, as they say, will be in the details, which are still being negotiated; therefore I think it's a bit premature for we outsiders to presume anything in particular. There'll be time enough to untangle all of this when we have some text to evaluate.

Joost Pauwelyn says

December 9, 2015

As expected, COP21 draft released today http://unfccc.int/resource/docs/2015/cop21/eng/da01.pdf
includes a formal "Agreement" and a "Decision". The "Agreement" looks certainly like a "treaty" under international law with provisions on ratification, entry into force, withdrawal etc.

Interestingly, the "Agreement" includes the word "shall" 144 times; "should" only 27 times ... So there may be more "legally binding" provisions in there than is being reported. Articles to watch are Article 9 on Transparency and Article 11 on Implementation and Compliance. This is where I would expect a lot of the compliance pull to come from.

Marty Lederman says

December 14, 2015

Joost, Lilliana: Well, *that* was close!: