The term “twin transition” first echoed through the halls of the European Parliament in 2019, during Ursula von der Leyen’s inaugural speech as President of the European Commission.Footnote ¹ On that occasion, von der Leyden suggested: “we should harness this transformative power of the twin digital and climate transition to strengthen our own industrial base and innovation potential.”Footnote ² The idea quickly took root. By 2020, the European Commission had woven the concept into its EU Industrial Strategy,Footnote ³ while the Council adopted it to describe the synergy between the European Digital Strategy and the Green Deal.Footnote ⁴ The twin transition swiftly took hold among EU policymakers becoming a guiding mantra – a shorthand for a future where sustainability and digitalisation reinforce each other.

Yet, beneath the surface of this shared language lies a fundamental ambiguity. What does the twin transition truly mean? Is it a unified transformation, where digital and green goals merge into a single, harmonious process? Or is it merely a parallel journey, with two distinct but loosely connected revolutions unfolding side by side? The lack of clarity is striking: official documents employ the term with considerable flexibility, thereby exposing not a consensus on its definition, but rather a persistent ambiguity regarding its scope and application. The stakes, however, are anything but abstract. The twin transition’s implications directly shape EU regulatory frameworks and policy implementation across multiple domains – demanding more than just semantic coherence.Footnote ⁵

Yet, despite this urgency, the integration of the digital and green transitions remains largely absent from binding regulatory frameworks. Digital laws rarely acknowledge the green agenda, and even when they do, the connection is superficial – often confined to non-binding documents that lack teeth.Footnote ⁶ The EU AI Act may represent an exception, though its environmental provisions arrived late and remain underdeveloped.Footnote ⁷ The message is clear: while the twin transition may sound like a guiding star, its path is still uncharted.

This special issue seeks to illuminate that path – or at least to examine the extent to which uncertainties in the relationship between digital and green transitions persist within the EU policy and regulatory framework, and how these challenges are addressed. After all, the twin transition promises to bundle two monumental shifts into one, but in doing so, it also risks oversimplifying their inherent tensions. Without concrete strategies to reconcile competing objectives, the concept may well prove little more than empty rhetoric. Greening and digitalisation are undeniable priorities, but their coupling demands policy and regulatory clarity – or, at the very least, coherence.

That is why, in this special issue, our aim is twofold. A first set of contributions dissects the twin transition’s ambiguities in the EU governance and confronts its contradictions directly. A second set examines the uncertainties introduced by the twin transition in selected areas of EU regulation, exploring how these challenges can be addressed through targeted legal solutions. Together, these analyses bridge the gap between ambition and policy and regulatory action – revealing how the twin transition is taking shape in EU law, moving beyond vision to tangible implementation.

In the first set of contributions, De Hert and Hinrichs investigate whether the EU’s twin transition operates as a seamless, unified strategy.Footnote ⁸ Their analysis centres on comparing the regulatory instruments shaping each domain. The findings reveal a stark divergence: digital policy leans heavily on highly harmonised hard-law instruments, while environmental and climate governance employs a more hybrid approach, weaving together binding obligations with funding-based and programmatic measures that allow for national discretion. These contrasting regulatory approaches extend into enforcement, where environmental law turns to criminal penalties to drive compliance, whereas digital regulation typically relies predominantly on administrative oversight. The authors conclude by advocating cross-domain dialogue so that regulators can share and refine tools for making the twin transition not just coherent, but genuinely effective.

Aude-Solveig Epstein critically argues in her piece that EU law is not yet capable of delivering a meaningful “twin transition.”Footnote ⁹ While environmental law has supported the datafication of the environment and the expansion of digital infrastructures, it remains ineffective in addressing their environmental harms and may even facilitate their growth. At the same time, echoing Griffin and Fornasari’sFootnote ¹⁰ argument in this same special issue, Epstein argues that the EU’s reliance on corporate actors and disclosure-based governance weakens accountability and environmental protection, as companies largely control what environmental data is shared, potentially skewing policymaking. The article convincingly demonstrates that these limitations demonstrate that existing environmental law is insufficient to address the ecological impacts of digitalisation. A fundamental transformation that moves beyond self-regulation and transparency frameworks towards rules focused on concrete environmental outcomes and systemic change is therefore needed. Epstein concluded by suggesting a move from data governance to environmental governance, whereby policymakers promote democratic deliberation about what data is necessary and adopt a restrained, purposeful approach to data generation.

Lastly, Quintavalla, Celeste and Perez Victorio explore the extent to which national AI strategies of the twenty seven member states of the EU reflect concerns associated with the twin transition.Footnote ¹¹ In fact, the authors argue that the push towards the twin transition at the EU level should also be tested at the national level where each member state designs its own national AI agenda. Yet, the findings expose a troubling fragmentation: strategies vary widely in how they prioritise the environmental dimension, from proactive integration of sustainability principles to outright neglect. These inconsistencies eventually undermine the uniform application of the twin transition within the EU, revealing a patchwork of approaches that risk diluting its ambitions. The authors thus contend that soft-law harmonisation alone is insufficient to bridge these divides and they call for a more proactive and binding EU role.

In the second set of contributions, Griffin and Fornasari, Footnote ¹² with reference to the Digital Services Act and the Corporate Sustainability Due Diligence Directive, argue that the regulation of environmental and human rights impacts effectively delegates the management of risks to large corporations in the service of multiple public values. This regulatory model prioritises procedural compliance over substantive outcomes and creates practical challenges for both public and private enforcement aimed at ensuring corporate accountability. The article’s central claim is that such an approach ultimately shields corporate freedom: it relies on technocratic modes of governance and, by reframing structural harms as manageable business risks, externalises the inherent consequences of certain corporate models.

Jansen and van de SandenFootnote ¹³ explore the complex interplay of legally binding ESG reporting obligations under EU law. In this context, (semi-)centralised ESG data-sharing arrangements have emerged as a response to the challenges posed by compliance with a multiplicity of reporting requirements. While such arrangements can help reduce unnecessary burdens and improve efficiency, they also raise significant competition law concerns. Drawing on competition law, the article proposes a set of safeguards to ensure that these mechanisms operate without distorting competition. In particular, the authors, inspired by recent Dutch banking practice, examine two possible models for data-sharing arrangements: enhanced collaboration among firms within the same sector and the creation of centralised sustainability data-sharing platforms.

Lastly, Cordova’s work delves into the complex relationship between digitalisation and environmental sustainability within the EU’s energy transition, with a particular focus on the interplay between the right to energy and the right to data protection and privacy.Footnote ¹⁴ The study explores how digital innovations – such as smart grids, AI-driven energy management systems, IoT devices and big data analytics – are reshaping access to energy while simultaneously introducing pressing questions about privacy, consumer rights and regulatory compliance. A central argument in the research is that the EU’s twin transition gives rise to significant tensions, particularly in balancing GDPR’s data minimisation principle with the operational needs of smart grids and meters and the GDPR’s strict consent requirements with the lack of transparency for consumers regarding how their data is collected and utilised in smart energy ecosystems. Cordova ultimately calls for a coherent regulatory framework that ensures digitalisation and energy sustainability evolve in alignment with existing legal standards. Without such a balance, the energy transition risks exacerbating inequalities or, worse, undermining fundamental freedoms.

The special issue closes with Angiolini’s afterword. The afterword offers a curated analysis of the articles of this special issue and advances a methodology for developing a coherent legal framework for the regulation of the intersections between the two transitions.