What Mexico signed: agreements that bind and agreements that guide

Bajío Ventures · October 2026 · From commitment to project, 3 of 6

Mexico signs almost everything. The useful question for a project developer is not what Mexico signed. It is which of the signed texts can become a requirement, an amparo (constitutional injunction suit) or a condition set by the customer. This note separates three levels: treaties that bind, political commitments that guide, and trade rules that carry a cost.

In this series: 1. The MDGs · 2. The SDGs four years from 2030 · 3. What Mexico signed (this post) · 4. What the federal government is doing · 5. The Bajío states · 6. What Bajío Ventures can do

First, the hierarchy

A ratified treaty is Mexican law. Since the 2011 constitutional reform, the human rights contained in treaties form, together with the Constitution, the standard against which any act of authority is reviewed. The Supreme Court established this in binding precedent (jurisprudencia) P./J. 20/2014. The rights to a healthy environment, to information and to consultation have effect through this rule.

The 2030 Agenda, the Millennium Declaration and the declarations of the climate summits are different. They are resolutions and political commitments. Nobody can sue on them. They guide plans, budgets and, more and more, the conditions of finance.

Level 1: treaties that bind

Treaty	Ratified by Mexico	In force	What it requires
UN Framework Convention on Climate Change	11 Mar 1993	21 Mar 1994	Emissions inventories and reports
Kyoto Protocol	7 Sep 2000	16 Feb 2005	No quantitative target for Mexico
Paris Agreement	21 Sep 2016	4 Nov 2016	Submit, update and report a nationally determined contribution (NDC)
Montreal Protocol	31 Mar 1988	1 Jan 1989	Eliminate ozone-depleting substances
Kigali Amendment	25 Sep 2018	1 Jan 2019	Phase down the HFCs used in refrigeration and air conditioning
Convention on Biological Diversity	11 Mar 1993	29 Dec 1993	Conservation and sustainable use
Basel, Stockholm and Minamata Conventions	1991, 2003, 2015	1992, 2004, 2017	Hazardous waste, persistent pollutants, mercury
Escazú Agreement	22 Jan 2021	22 Apr 2021	Environmental information, participation and justice; protection of environmental defenders
ILO Convention 169	5 Sep 1990	5 Sep 1991	Consultation of indigenous peoples
High Seas Treaty (BBNJ)	22 Sep 2025	17 Jan 2026	Marine biodiversity beyond national jurisdiction

Dates from the United Nations Treaty Collection; the dates for ILO Convention 169 come from the ILO register.

Paris and NDC 3.0

The Paris Agreement makes the procedure binding: submit a contribution, update it every five years and report. The figures in the contribution are not enforceable before an international court. They are the reference for everything else.

Mexico has submitted four versions. The 2015 version offered to cut emissions by 22% against a business-as-usual scenario. The 2020 update kept the figure with a higher baseline; a collegiate court suspended it in 2021 at the request of Greenpeace, and the suspension was lifted in December 2022. The November 2022 version raised the figure to 35% unconditional by 2030.

The NDC 3.0, presented at COP30 in Belém in November 2025, changes the format. For the first time the target is absolute:

• 2035, unconditional: between 364 and 404 million tonnes of CO₂ equivalent, net.
• 2035, with international finance: between 332 and 363 million.
• Net zero emissions in 2050.
• Methane: 30% less by 2030.
• Clean electricity: 38.5% in 2030 and 43.3% in 2035.
• A dedicated component on loss and damage, and the target to conserve 30% of the territory by 2030.

Climate Action Tracker rates the package as “highly insufficient” (February 2026): the target improved, and the policies in force do not reach it.

Escazú

The Escazú Agreement is the treaty that affects projects most. It makes three things mandatory: to provide environmental information without asking for a reason, to open participation from the early stages of a permit, and to guarantee access to justice. Who can challenge a project is still under discussion. In May 2026, according to a column in Diario de Yucatán, the Supreme Court recognised the standing of Maya residents of three communities to challenge a state rule on pig farms. In the opposite direction, the October 2025 reform of the Amparo Law requires a legal injury that is “real and differentiated from the rest of the people”. The tension between the two rules will be resolved case by case.

Convention 169 and consultation

Mexico ratified Convention 169 in 1990. The reform of Article 2 of the Constitution of 30 September 2024 took it further. It recognises indigenous and Afro-Mexican peoples as subjects of public law. It requires consultation before measures with significant impacts. It provides that, if the beneficiary is a private party, that party pays the cost of the consultation and grants a fair and equitable benefit.

The electricity sector already has this in its rules. The Regulations of the Electricity Sector Law (3 October 2025) require authorisation of the social impact statement before construction starts, with a plan for social management and shared benefits. We give the detail in Three environmental and social changes for energy projects.

Level 2: commitments that guide

These are declarations. They do not bind, but they appear in plans and in the questions that banks ask.

• Global Methane Pledge (COP26, 2021): cut global methane emissions by 30% by 2030.
• Glasgow Declaration on Forests (2021): Mexico joined at the last moment.
• Zero-emission vehicles declaration (2021): 100% of new cars and vans with zero emissions by 2040.
• Powering Past Coal Alliance: Mexico has been a member since 2017 and has no federal phase-out plan.
• Tripling renewables and doubling efficiency (COP28, 2023): Mexico is among the 133 signatory countries.
• Kunming-Montreal Framework (2022): conserve at least 30% of land and sea area by 2030.
• 2030 Agenda, Sendai Framework, Addis Ababa Action Agenda, New Urban Agenda, Sevilla Commitment.

The next meeting is COP31, in Antalya, Turkey, from 9 to 20 November 2026.

Level 3: trade that carries a cost

This is the level with the fastest consequences for a plant in the Bajío.

USMCA. Chapter 24 prohibits a failure to enforce environmental law, in a sustained or recurring way, in a manner that affects trade or investment between the partners. It is subject to dispute settlement panels. The treaty also has a rapid response labour mechanism that acts plant by plant. The list of the United States Trade Representative recorded 49 cases at the end of September 2026. By our count, 19 correspond to plants in the five states that this series reviews: seven in Guanajuato, four in Querétaro, four in San Luis Potosí, two in Aguascalientes and two in Jalisco.

In the joint review of 1 July 2026, the United States did not confirm the 16-year extension of the treaty. The USMCA remains in force until 2036, with annual reviews.

European Union. The Modernised Global Agreement was signed in Mexico City on 22 May 2026 and the European Parliament approved it on 8 July. Its chapter on trade and sustainable development contains, in the words of the Council of the EU, binding commitments on labour rights, environmental protection and climate action. At the time of writing, we had not located the approval of the Mexican Senate.

CBAM. The EU carbon border adjustment mechanism entered its definitive phase on 1 January 2026 for cement, iron and steel, aluminium, fertilisers, electricity and hydrogen. The legal obligation falls on the European importer. The practical burden falls on the producer: to supply verified data on the emissions embedded in the product. The sale of certificates starts in February 2027 and the first annual declaration, on 2026 imports, is due on 30 September 2027.

Reporting. International sustainability standards are now a local rule. The CNBV, Mexico’s banking and securities regulator, requires listed issuers to report under IFRS S1 and S2 from financial year 2025. For private companies that apply Mexican financial reporting standards, the Mexican sustainability standards NIS A-1 and B-1 ask for 30 basic indicators — 16 environmental, 6 social and 8 governance — covering financial year 2025, which is disclosed in 2026.

What it means for a project

If the project…	What applies	In practice
Needs an environmental permit	Escazú	Public information and early participation; more actors with the capacity to challenge
Is in or near indigenous territory	Convention 169 and Article 2	Prior consultation, cost paid by the developer, shared benefit
Is electricity generation or transmission	Regulations of the Electricity Sector Law	Social impact authorised before construction starts
Uses refrigerants	Kigali	HFC phase-down schedule
Sells steel, aluminium or cement to European customers	CBAM	Verified emissions data per product
Supplies a listed issuer or a company that applies NIS	IFRS S1/S2, NIS	They will ask you for your emissions, including electricity consumption
Exports to the United States	USMCA, chapters 23 and 24	Labour and environmental compliance that can be verified plant by plant

The takeaway

1. What binds fastest is not the climate treaty. It is the customer, the bank and the customs office. A mid-sized plant in the Bajío will feel the CBAM and the NIS before the NDC.

2. Consultation and information are no longer a final formality. With Escazú and Article 2, a project that informs late is open to challenge. The cost of doing it well at the start is lower than the cost of an amparo in the middle of construction.

3. The 2035 target needs projects. Between 364 and 404 million tonnes is a national figure. It is met or missed in decisions at regional scale: what is connected, what generates heat, how freight moves. What the federal government is doing to get there is the subject of the next post.

This note is for information only and is not legal or investment advice. The ratification status and the rules cited change; check the version in force before you make decisions.

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Sources: UN — Treaty Collection, chapter XXVII · UNAM, Cuestiones Constitucionales — binding precedent P./J. 20/2014 · UNFCCC — Mexico’s NDC, 2022 update · Climate Case Chart — Greenpeace v. INECC · La Jornada — NDC 3.0 at COP30, 18 Nov 2025 · Expansión — NDC 3.0 targets, 20 Nov 2025 · Gaceta Parlamentaria, 9 Sep 2026 · Climate Action Tracker — Mexico · Galicia Abogados — Escazú Agreement · Diario de Yucatán — column “Derecho a demandar”, 7 Jun 2026 · Senate — decree reforming Article 2 · Holland & Knight — Regulations of the Electricity Sector Law · Crónica — forests declaration · Mexico Business News — zero-emission vehicles · IEA — Mexico in the Powering Past Coal Alliance · COP28 — renewables and efficiency pledge · CBD — target 3 of the Kunming-Montreal Framework · UN — the road to COP31 · USTR — USMCA, chapter 24 · USTR — rapid response labour mechanism · White & Case — USMCA joint review, Jul 2026 · Council of the EU — agreements with Mexico, 11 May 2026 · La Jornada — European Parliament, 8 Jul 2026 · European Commission — CBAM · Taylor Wessing — changes to the CBAM, Oct 2025 · KPMG — CNBV rule, Jan 2025 · Forvis Mazars — NIS in 2026

Bajío Ventures — a Mexican energy-infrastructure investment group based in Guanajuato: capital, a data platform on the region’s industrial base, and a German industrial channel, with its own advisory presence in Berlin.