Mexico Defends Sonora Train Amid Environmental Controversy

The federal government has rejected the complaint admitted by the Commission for Environmental Cooperation of North America (CEC) regarding alleged environmental violations in the construction of the Sonora Train. Officials argue that the project complies with environmental regulations and that its implementation will strengthen trade relations between Mexico and the United States in a sustainable manner.  

On Oct. 2, 2024, the Center for Biological Diversity (CBD) and the Mexican Center for Environmental Law (CEMDA) submitted a petition to the CEC, claiming that Mexican environmental authorities failed to enforce environmental legislation concerning the assessment of the Sonora Train’s environmental impacts.  

The organizations state that the train’s construction was not subjected to a proper environmental impact assessment (EIA), which is required for this type of infrastructure project, thereby violating national environmental laws. They argue that the Ministry of the Environment and Natural Resources (SEMARNAT) granted the project’s environmental permit in August 2024, despite construction having begun in September 2023, leading to significant deforestation. Moreover, they highlight that the project cuts through a natural protected area called Rancho El Aribabi.  

Alejandro Olivera, Mexico Representative, CBD, explained that the project poses a threat to endangered species such as the jaguar, ocelot, and black bear. He emphasized that the train, along with the border wall, creates a major obstacle and danger to the migration of these species. Additionally, he noted that the project endangers the Sonoran mud turtle, an endemic species in the region.  

According to the petitioners, by failing to comply with Mexican regulations, which require environmental impact assessment information to be publicly available, authorities are concealing the construction’s environmental impacts, making legal action to halt the project more difficult. “It feels like we are fighting a ghost train because we have nothing to hold onto legally, there are no documents, no executive project, and no environmental impact statement,” said Mirna Manteca, Co-Director of the Northwest Mexico Program, Wildlands Network.  

Mexico’s Official Position on the Complaint

In response to the complaint, SEMARNAT, as the responsible authority, informed the trinational body that the project’s environmental impacts are neither severe nor irreversible and that mitigation and compensation measures were included in the project’s final approval.  

The construction of the Sonora Train began with a provisional authorization granted under an executive order by former President Andrés Manuel López Obrador, which declared his administration’s strategic projects to be matters of national security and public interest. This order allowed projects like the Mayan Train and other flagship initiatives to proceed without waiting for environmental impact statements and other required licenses and permits.  

The order was published in the Official Gazette of the Federation in November 2021. Although Mexico’s Supreme Court later ruled it invalid on May 18, 2023, it was still considered valid for the Sonora Train’s provisional authorization since it was granted on May 12, just days before the Court’s decision.  

The government also stated that the area known as El Aribabi no longer holds the status of Voluntary Conservation Area (ADVC), following the early cancellation of the corresponding certificates. Furthermore, officials pointed out that this cancellation was confirmed by the Northeast and Upper Gulf of California Regional Directorate, one of the nine administrative offices of the National Commission of Natural Protected Areas (CONANP).  

SEMARNAT emphasized that the actions of the competent authorities have been transparent, diligent, and aligned with the principles of legality and good faith governing such procedures. In this regard, officials stated that the commission had improperly admitted the petition to review the project's environmental compliance. According to the Mexican government, this mistake undermines the certainty and balance of the petition mechanism, as it allows cases that, in their view, do not meet the requirements, setting a precedent that contradicts legal principles and threatens the validity of this trilateral mechanism.  

The government maintained that it is enforcing environmental laws under a shared vision with North America. Additionally, it asserted that the project will improve connectivity, reduce logistics costs, optimize supply chains, and contribute to more sustainable trade, aligning with USMCA’s environmental protection commitments.  

“Currently, much of Mexico-Unite States trade relies on road transportation, which generates high CO₂ emissions and a heavy dependence on diesel. Modernizing the railway system will allow a significant portion of these operations to transition to a more efficient and less polluting mode of transport,” the agency noted. The CEC will now review the Mexican government’s report and determine whether to recommend opening a factual record on the case.