Climate Ambition or Green Protectionism? The EU’s CBAM at the WTO from a Global South Lens
On 1 January 2026 the European Union’s Carbon Border Adjustment Mechanism stopped being a reporting exercise and started costing money. Within three months, at the WTO’s Fourteenth Ministerial Conference in Yaoundé, India, China, Brazil and South Africa were calling it a trade barrier wearing a climate label. The conference closed without a ministerial statement. Russia had already asked the EU for consultations over the same measure. CBAM is no longer a Brussels policy debate. It is a WTO case waiting to be filed.
Here is what the mechanism does. Under Regulation (EU) 2023/956, part of the EU’s Fit for 55 package, an importer bringing steel, cement, aluminium, fertiliser, electricity or hydrogen into the EU must buy certificates covering the carbon emitted in making those goods. Each certificate is priced off the EU Emissions Trading System. Article 9 of the Regulation then lets the importer deduct any carbon price already paid where the goods were produced. That deduction is the EU’s entire answer to the fairness objection. It is also where the trouble starts.
Most of the criticism from developing countries runs like this: CBAM discriminates, therefore CBAM breaks WTO law. I think that gets the case backwards. The discrimination arguments are correct, and they will decide nothing, because Article XX of the GATT exists precisely to excuse discrimination carried out for the environment. The place CBAM should lose is a single paragraph sitting at the top of Article XX, known as the chapeau. It says that an environmental measure cannot be applied in a way that amounts to “arbitrary or unjustifiable discrimination between countries where the same conditions prevail” or to “a disguised restriction on international trade.” CBAM fails that test, on grounds the Appellate Body spelled out in 1996 and again in 1998. And the EU is in no position to object to the test, because it wrote those same words into the UN climate convention.
The arguments everyone leads with
Article I:1 of the GATT, the most-favoured-nation rule, says that any advantage the EU gives to goods from one country must go “immediately and unconditionally” to like goods from every other country. Article 9 gives an advantage, namely a smaller CBAM bill. It attaches that advantage to a policy choice made by the exporting government. Chinese steel arrives with a national emissions trading scheme behind it and a deduction available. Indian steel arrives with neither. The test in Article 9 never mentions origin, but it sorts by origin, and in EC – Seal Products the Appellate Body confirmed that Article I:1 catches that sort of hidden discrimination too.
National treatment under Article III is a shorter point. Steel is steel. Physical properties, end uses and tariff classification are what decide whether two goods are “like”, and carbon intensity is a fact about how a good was made rather than about the good itself. If dirty steel and clean steel are like products, charging them differently engages Article III:2. The EU has a reply to this, and I take it seriously further down. My point for now is narrower. The delegations at Yaoundé were probably right about discrimination, and being right about it will not win them the case.
Nor will CBAM fall at the next stage. Article XX(g) covers measures relating to the conservation of exhaustible natural resources, provided they come alongside restrictions on domestic production. A stable climate fits comfortably inside that phrase on the reading the Appellate Body gave it in the Shrimp case. And the domestic-restriction condition is met almost too neatly, because CBAM only exists at all as a companion to the ETS. On XX(g), the EU wins. Everything therefore turns on the chapeau.
Where CBAM actually breaks
In United States – Shrimp, the United States banned shrimp imports from any country that did not require its trawlers to fit turtle excluder devices. The measure cleared Article XX(g) and then died at the chapeau. The Appellate Body’s first objection was rigidity. Washington had demanded that other countries adopt essentially the same regulatory programme as its own, rather than one that worked comparably well, and had forced a single policy design onto states in very different situations.
Article 9 does the same thing. CBAM recognises one instrument and one only: an explicit price, paid, per tonne. India’s energy-efficiency trading under the Perform, Achieve and Trade scheme earns nothing. Renewable purchase obligations earn nothing. A mandated coal phase-down earns nothing. A regulation that keeps a tonne of carbon dioxide out of the air just as effectively as a fifty-euro allowance is, in CBAM’s arithmetic, worth zero. The EU has not simply failed to accommodate different national circumstances. It has built a mechanism that cannot see them.
What makes this hard to defend is that the cure has been sitting on the shelf for twenty-five years. When the United States redrafted its shrimp measure, the change it made was to accept foreign programmes that were comparable in effectiveness rather than identical in form, and on that basis the compliance proceedings in 2001 let the measure stand. Brussels had a working template and chose not to use it.
The second objection is procedural, and here the EU has no answer at all. In United States – Gasoline, the Appellate Body faulted the United States for never exploring cooperative arrangements with Venezuela and Brazil before imposing its clean-air baselines. In Shrimp it went further. Washington had negotiated a turtle conservation treaty with one group of countries while offering the Asian complainants nothing comparable, and that asymmetry, negotiating seriously with some and not with others, was itself unjustifiable discrimination. Serious negotiation across the board is a legal requirement of the chapeau, not a diplomatic courtesy. CBAM was passed through the EU’s own internal legislative procedure. There is no CBAM equivalent of that turtle treaty, no equivalence talks with the BASIC economies, no offer to link the mechanism to Article 6 of the Paris Agreement. The Commission consulted third countries. It did not negotiate with them.
My third objection is about the money, and I put it last because it is the weakest of the three. Brazil – Retreaded Tyres holds that discrimination turns arbitrary or unjustifiable when the reason given for it has no rational connection to what the measure is supposed to achieve. CBAM is supposed to stop carbon leakage, which is a global objective, since a tonne emitted in Bhilai warms the same planet as a tonne emitted in Duisburg. Its proceeds go to the EU budget. Nothing in the chapeau requires revenue sharing, and a panel could fairly say that how a member spends its own receipts is not discrimination between countries at all. So I would not lead with this. But a scheme that sends the whole cost abroad and keeps the whole revenue at home invites an obvious inference about what the design is for, and “disguised restriction on international trade” is where the chapeau puts that inference.
The best defence the EU has
The strongest reply to all of this is not an Article XX reply. It is that CBAM never breaches Article III to begin with. Article II:2(a) of the GATT lets a member charge an import an amount equivalent to an internal tax levied “in respect of an article from which the imported product has been manufactured or produced in whole or in part.” If CBAM is simply the ETS collected at the border, the entire Article XX question disappears.
The problem is that this route has been doubtful since 1970. The GATT Working Party on Border Tax Adjustments separated taxes levied directly on products, which can be adjusted at the border, from taxes not levied directly on products, which cannot, and left the awkward middle category of hidden taxes on inputs unresolved. The 1987 GATT panel in US – Superfund allowed adjustment for a tax on feedstock chemicals, but those chemicals were physically inside the imported substance. Carbon is not inside a tonne of steel. It is released while the steel is being made, and then it is gone. More than fifty years after the Working Party reported, no adopted ruling has held that a charge based on how something was produced can be adjusted at the border. CBAM asks a panel to be the first.
The EU wrote the rule it is now breaking
Which brings the argument back to the chapeau, and to a sentence the EU cannot disown. Article 3.5 of the UN Framework Convention on Climate Change provides that measures taken to combat climate change, including unilateral ones, “should not constitute a means of arbitrary or unjustifiable discrimination or a disguised restriction on international trade.” That is not a paraphrase of the chapeau. It is the chapeau, copied into a climate treaty the European Union has ratified, and Article 31(3)(c) of the Vienna Convention makes it available to a WTO panel as a rule of international law applicable between the parties. Article 2(2) of the Paris Agreement points the same way, committing its parties to implementation that reflects common but differentiated responsibilities “in the light of different national circumstances.”
So the Global South does not have to persuade a panel to smuggle climate justice into trade law. The EU already carried trade law’s non-discrimination rule into climate law, and it now has to live underneath it.
One amendment would fix most of this. Rewrite Article 9 so that it credits foreign climate regulation that is comparable in effectiveness, not merely carbon prices actually paid. That is the concession the United States made in 2001 to save its own measure, and it cost Washington nothing environmentally. Until Brussels makes it, the fair description of CBAM is neither climate ambition nor green protectionism. It is a well-meant measure built on a design the Appellate Body condemned in 1998, defended by a Union that helped draft the words it is breaking.
