Stop Ecocide International has led the push to criminalize ecocide in recent years.10 The organization set its goal to create a definition of ecocide that would be legally and politically workable, prioritizing criminalizing behavior during peacetime, for adoption as a fifth core crime under the Rome Statute; twelve international law lawyers with diverse disciplinary backgrounds came together as the IEP to do so.11 Over the course of several months, the IEP produced a draft definition that states:

For the purpose of this Statute, “ecocide” means unlawful or wanton acts committed with knowledge that there is a substantial likelihood of severe and either widespread or long-term damage to the environment being caused by those acts.12

This definition is accompanied by sub-definitions of each threshold term, which I examine in greater detail in Section II.

While not its explicit goal, the IEP structured its definition around the goal of maximizing political feasibility instead of legal clarity. They explain that they had a pragmatic approach, in which they selected language that would appear familiar to States Parties and remain within the boundaries of concepts already used in international law.13 This resulted in the avoidance of scientific formulations and technical thresholds.14 The IEP also rejected an enumerated list of underlying acts.15 The IEP concedes that while such a list could have provided clearer guidance, they feared it would be under-inclusive and inevitably imply that whatever environmentally destructive conduct not listed was permissible.16 The IEP viewed the flexible and inclusive definition to be more palatable to States Parties, but the reality is the definition is plagued by vagueness.

II. Vagueness Flaws within the IEP’s Ecocide Definition

The IEP’s ecocide definition17 depends almost entirely on qualitative descriptors that lack objective boundaries. The result is that each threshold relies on concepts that invite wide interpretive discretion and require prosecutors and judges to make precise analyses regarding scientific conditions, complex environmental impact, and socio-economic tradeoffs.18 These terms function as the core limits of criminal liability, yet the IEP confirms that none of them is quantitatively defined and all depend on context-specific assessments using “best available science” on a case-by-case basis.19 This commitment to flexibility manifests most clearly in the ambiguity that surrounds terms like wanton, severe, widespread, and long-term.

Walking through this analysis with a real-world example highlights the vagueness issue that is pervasive in the IEP’s definition of ecocide. The Nam Theun 2 Hydropower Project in Laos (NT2) was constructed in 2010 and created a 1070-megawatt hydropower station.20 At the time of construction, NT2 represented 42% of the entire country’s electricity generation capacity.21 The project was said to be accompanied by a reduction in the poverty rate, a resettlement of a rural population on the Nakai Plateau to modernized living situations, and a campaign to protect local vulnerable species by stakeholders; the reality is that these advances are overstated and the impact of NT2 has been negative when viewing the situation through an ecocide lens.22 The construction of the dam led to the forced displacement of over six thousand indigenous residents and inundation of forests; long-term ecological disruption, including the loss of forest land, decline in aquatic biodiversity, and water-quality degradation also followed.23 NT2 shows how even a heavily researched, deeply disruptive project can reasonably fall on either side of each threshold, demonstrating the instability of a definition that provides no objective way to draw the line.

A. “Wanton”

The IEP defines wanton as:

[R]eckless disregard for damage which would be clearly excessive in relation to the social and economic benefits anticipated.24

A central problem with the definition is that there is no baseline for determining when environmental damage becomes “clearly excessive in relation to the social and economic benefits anticipated,” as there is no guideline as to whether the cost-benefit analysis should be financial, ecological, social, or a hybrid of the three.25 When applying this analysis to NT2, some questions arise: Excessive in relation to what? National electrification goals?26 The long-term survival of the river ecosystem the dam would destroy?27 The populations displaced by development?28 Without providing some guideline on how to prioritize certain comparison points, the proportionality inquiry loses all bounds, and two prosecutors could reach entirely different conclusions regarding the same inquiry.

Furthermore, the uncertainty surrounding “social and economic benefits” only worsens when considering the different viewpoints and goals of countries in the Global North and countries in the Global South. The IEP does explicitly note that they approached this very portion of the definition sensitively towards Global South development concerns.29 It is no question that they are aware of and sympathize with the fact that some environmentally harmful projects may deliver substantial infrastructure benefits in less-industrialized states.30 But the same question remains: Whose benefits matter more? A national government seeking industrialization may evaluate benefits differently from a local community facing displacement, a corporation pursuing investment returns, or the broader public that bears long-term ecological loss—all of these are situations that have occurred along with the construction of NT2.31 This distributive problem is foundational; decisions about benefit often reflect power asymmetries rather than shared interests, making it unclear whose perspective the proportionality test is meant to reflect.32 Under the IEP’s formulation, NT2 could be treated as wanton in one jurisdiction and permissible in another. While not the goal, the wanton element can expose the Global South to greater scrutiny because large, environmentally invasive projects are completed at a greater rate by industrializing countries, which is precisely where the balancing test comes in.

A proportionality test is not new to the Rome Statute. Article 8(2)(b)(iv) already requires weighing environmental harm against “concrete and direct overall military advantage.”33 While a proportionality test regardless of its variables does invite some ambiguity and vagueness, the concept of military advantage has been well defined in international humanitarian law and is substantially more determinate than other forms of justification.34 Article 8(2)(b)(iv) only applies to individuals engaging in war, whether that be combatants, commanders, or decision-makers—a much more limited group compared to the crime of ecocide. Furthermore, environmental harm in armed conflict is usually tied to discrete and attributable attacks, making the proportionality assessment more concrete. For example, in the 1991 Gulf War, retreating Iraqi forces intentionally set fire to hundreds of Kuwaiti oil wells.35 This produced massive atmospheric pollution clearly identifiable as the result of a single military operation, making weighing the direct military advantage against the environmental harm more workable.36

By contrast, the IEP’s use of proportionality in the ecocide definition operates in peacetime and asks decision-makers to assess malleable and subjective “social and economic benefits,” meaning the structural features that make proportionality workable in armed conflict, like discrete attacks and identifiable decision makers, do not apply.37 As a result, the IEP’s proportionality test is far more indeterminate and unstable.

B. “Severe”

The IEP defines severe as:

[D]amage which involves very serious adverse changes, disruption or harm to any element of the environment, including grave impacts on human life or natural, cultural or economic resources.38

What does “very serious” mean under the IEP’s definition of severe? The IEP offers no objective metric or baseline, which could have included the number of species extinguished or affected, the amount of greenhouse gas emissions released, the percentage of population displaced, and countless more.39 Instead, it uses broad and open-ended terminology such as “very serious” and “any element to the environment.”40 Who gets to decide when damage crosses from significant to very serious? Scientists? Judges? Local communities? The Prosecutor? The IEP suggests that the “best available science” should inform this determination, but the meaning of scientific severity itself shifts across disciplines, locales, and through time.41

Consider the NT2 situation. The dam floods a river valley and clears a wide swath of forest and displaces the small upstream, indigenous community.42 Would the depletion of a small forest, potentially ruining a local ecosystem for decades, count as “very serious”? Or would the loss of the small community’s ancestral lands? Different evaluators could arrive at entirely different answers.

The breadth of the phrase “any element of the environment” further compounds the uncertainty built into the definition of severe.43 By its terms, the provision sweeps in everything from microbial life to deep sea ecosystems to atmospheric processes, and even outer space.44 This universal scope means that severity would be assessed across environmental contexts that radically differ in scale, function, and scientific measurability. In the NT2 situation, the ICC would be forced to decide whether the alteration of fish stocks,45 significant changes to the river’s characteristics,46 or the displacement of a small community47 should matter most for determining severity. Prosecutors and judges could correctly elevate entirely different ecological or social impacts when evaluating the same project, creating uncertainty in what harms are acceptable when developers conduct risk assessments.

C. “Widespread”

The IEP defines widespread as:

[D]amage which extends beyond a limited geographic area, crosses state boundaries, or is suffered by an entire ecosystem or species or a large number of human beings.48

The issue with the IEP’s definition of widespread lies mainly in its first alternative, “beyond a limited geographic area,” partly because its open phrasing could allow even modest geographic impacts to qualify.49 The deeper issue is that without any metric for what counts as a limited area or a large number of people, the definition provides no coherent or principled boundary for prosecutors or judges to apply. The elasticity of the standard creates a risk of inconsistent charging decisions: the same magnitude of harm could be treated as widespread in a small island state but not in a geographically large state, purely by virtue of differing scales instead of any principled legal distinction.

The IEP avoided numerical thresholds deliberately because of past iterations’ attempts at using any quantifiable criteria when describing the term widespread.50 Both ENMOD and API define their focused geographical scope as several hundred square kilometers and thousands of square kilometers, respectively.51 As such, both were criticized for being under-inclusive and inapplicable as environmental science advanced.52 The IEP desired to do away with the restrictions and use their current formula for the term widespread. Unfortunately, without any measurement anchor, coupled with the lack of underlying acts to form a reference, the threshold would become more difficult to apply.

A further conceptual difficulty is that the term widespread gestures toward a scale of harm that justifies elevating conduct to the level of an international crime, yet the definition never explains what makes environmental damage internationally significant rather than merely serious at the domestic level.53 International crimes traditionally derive their legitimacy from interests so substantial that they implicate the global community.54 But under the IEP’s formulation, even damage confined entirely within one state could be labeled widespread without any requirement that the harm transcend borders, disrupt regional ecological systems, or otherwise rise to a level of international concern. The IEP’s definition blurs the line between serious national environmental harm and conduct that truly warrants international criminalization by leaving this connection unstated.

The situation caused by NT2’s construction again illustrates this instability. NT2 caused riverbank erosion far from the dam itself at the Boua Khai, Nasong, and Dan Pak Xe villages.55 Furthermore, it has altered migratory patterns of aquatic species, which affects local river-dependent communities’ sources of food and can have implications spanning hundreds of kilometers.56 But the IEP’s definition of widespread makes one pause and consider how far these effects must travel before they are enough for criminal investigation. If NT2’s impacts were confined to one river valley but reshape the local ecology, would that be enough? The widespread threshold risks becoming a discretionary judgment tool instead of a solid legal standard, which would produce inconsistent outcomes.

D. “Long-Term”

The IEP defines long-term as:

[D]amage which is irreversible or which cannot be redressed through natural recovery within a reasonable period of time.57

The IEP’s definition of long-term once again departs from prior international instruments but does not replace their quantitative guidance with any objective metric. ENMOD interpreted long-lasting to mean “several months or a season,” while API treated long-term as environmental harm persisting for “decades.”58 The IEP rejects these approaches as either too short or too long.59 However, prosecutors and judges have no temporal baselines or examples of underlying acts they can use to determine when exactly ecological harms rises to the level of ecocide.

The central question becomes how decision-makers decide what makes a period of time “reasonable,” as different organisms and natural processes can recover from damage and disruption on dramatically different timescales. As discussed, NT2 has destroyed swaths of forests and altered migration routes, which could take decades and years, respectively, to correct.60 Under the IEP’s formulation, the Prosecutor has no principled way to decide which of these recovery scales should matter. Should long-term turn on the slowest ecological process, as the damage would last longer; or the fastest, in which the recovery is more observable to litigate? The assessment becomes highly dependent on which temporal baseline the evaluator happens to prioritize.

The IEP’s alternative threshold of “irreversible damage” raises a different set of problems. Very little in the natural world is truly irreversible in a scientific sense; ecological systems may recover only over centuries but technically remain capable of recovery.61 If “irreversible” is interpreted narrowly, few cases will satisfy it; if it’s interpreted functionally, as in effectively irreversible within human timescales, the term becomes indistinguishable from the undefined “reasonable period of time” standard. The IEP allows prosecution without waiting for any recovery period to manifest, meaning that “long-term” harm must be inferred prospectively through predictive ecological modeling.62 This sort of modeling magnifies scientific uncertainty and places significant weight on expert judgment in an area where natural recovery trajectories are inherently contested.

The IEP’s use of these threshold terms, “wanton,” “severe,” “widespread,” and “long-term,” transforms their definition of ecocide to one that is far too flexible and vague, functioning only based on varying scientific assumptions and the evaluator’s own value judgments. NT2 shows that even a well-documented and deeply disruptive project can fall on either side of every threshold, depending on who is applying them and how. This is the structural flaw of the IEP’s approach, leading to questions about legality, notice, consistency, and selective enforcement that must be addressed prior to the IEP’s definition becoming an addition to the Rome Statute.

III. The IEP’s Definition in Comparative Perspective

A clearer picture of the IEP’s drafting choices emerges when they are placed alongside existing approaches to defining international crimes, as well as the domestic ecocide statutes that predate the IEP’s work. The crimes already included in the Rome Statute are just as complex as ecocide but have far greater specificity; this is seen through the enumeration of underlying acts and attachment of various contextual thresholds.63 Domestic ecocide statutes follow the IEP’s vague formulations, leading to the lack of any real enforcement on a national level.64 These comparisons highlight that the IEP’s vague approach to ecocide is a sharp departure from international criminal law drafting traditions, and raise questions regarding its workability at the ICC.

A central way that the Rome Statute achieves determinacy is by enumerating underlying acts and then attaching contextual elements. This structure is used for crimes against humanity and war crimes, creating foreseeability about what conduct may trigger liability.65 When comparing the IEP’s definition of ecocide, its open-textured approach stands in sharp contrast to the Rome Statute’s current format. The ecocide definition contains no list of prohibited facts, leaving the crime defined only by the threshold adjectives described above.66 This choice only expands discretion by removing the anchor of defined underlying acts, and causes the IEP’s definition to be far too ambiguous.

Domestic ecocide provisions in countries such as Armenia, Ukraine, Belarus, Kazakhstan, and Georgia show a similar preference for open-textured formulations that do not rely on clearly delimited conduct.67 These codes typically criminalize “mass destruction of flora or fauna” or “pollution of the atmosphere, land or water resources” combined with “other acts” that have caused or are capable of causing an “ecological catastrophe” or “environmental disaster,” without specifying how likely the catastrophe must be or what kinds of projects fall within the category.68 In practice, these provisions gesture toward very high levels of harm but leave both the underlying conduct and the required risk level largely undefined, which mirrors the IEP’s preference for broad harm terms and a proportionality test instead of numerically anchored thresholds.69 The fact that there appear to be no reported convictions under any domestic ecocide offense suggests that such vagueness may undermine their practical enforceability, regardless of their expressive ambition.70

The Rome Statute has built-in protections against crimes defined too vaguely. Article 22(2) states that if the definition of a crime is ambiguous, that ambiguity will be interpreted in favor of the individual being investigated, prosecuted, or convicted.71 The IEP’s deliberately flexible standards for the terms “wanton,” “severe,” “widespread,” and “long-term” risk being construed in the light more favorable to the accused, further undermining workability because of Article 22(2). Article 22(2) ensures that crimes are defined with sufficient precision, so individuals can foresee what conduct is criminal.72 With the IEP’s campaign to add ecocide to the Rome Statute creating a buzz about expressive legislation normalizing the prosecution of environmental crimes, Article 22(2) puts overly symbolic, vague criminal provisions at risk for undermining legality.73

IV. Why Vagueness in the Ecocide Definition Must be Limited

If ecocide is going to be added to the Rome Statute, the definition has to work as a criminal prohibition. As it stands today, the IEP’s version does not. Its vagueness creates predictable problems: people cannot tell in advance what conduct is covered and enforcement risks become uneven. The ICC’s credibility depends on avoiding standards that are this open to interpretation.

Vagueness raises concerns about selective or uneven enforcement. Flexible thresholds inevitably leave room for political judgment about which states, industries, and projects warrant investigation.74 This has already proven to be an issue for the ICC, as that risk has not fallen evenly. The ICC faces a history of criticism for geographically uneven enforcement, with the vast majority of defendants being from Africa.75 This trend will continue with ecocide if the definition remains in its current form. Many states in the Global South depend on environmentally intensive development pathways to expand electrification, agriculture, mining, and basic infrastructure; these activities would be more readily framed as ecocidal under an open-textured standard.76 By contrast, major corporate actors headquartered in wealthier states may be structurally insulated from prosecutorial focus, even when engaging in similarly harmful conduct abroad.77

Another issue is notice. The IEP’s definition provides no stable way to predict when development or resource-extraction amounts to ecocide.78 Many projects, such as dams, pipelines, large-scale agriculture, and mining all routinely produce environmental risks or impacts that could be characterized as severe, widespread, or long-term depending on which scientific baselines or community perspectives are used.79 Without objective thresholds, or at least defined underlying acts, it is extremely difficult for decision-makers to be able to decide whether their lawful acts are in fact wanton under the definition’s given test before beginning a project.80 A definition this open-textured does not give fair warning of what is criminal, leaving the risk that actors only discover the boundaries after an investigation commences.

A further consequence of this indeterminacy is that the definition offers weak, and potentially negative, deterrence value. Effective deterrence depends on actors being able to identify ex ante when their conduct crosses the line into criminality.81 Yet, under the IEP’s formulation of ecocide, many large-scale development projects can be plausibly framed as falling within a grey zone, where reasonable experts might disagree about whether the environmental risks create a “substantial likelihood” of severe harm.82 Because the definition leaves core elements open to broad, subjective interpretation by design, project planners cannot reliably distinguish lawful development from criminal conduct in advance. Vagueness may be tolerable elsewhere in the Rome Statute, but where the explicit aim of the amendment is deterrence and norm creation, a standard this fluid is unlikely to influence conduct in the manner its drafters intend.83

Commentators often defend ecocide as valuable primarily for its expressive or symbolic force, but symbolism sits uneasily within the Rome Statute’s legality framework.84 Criminalization cannot rest on open-textured moral messaging, as Article 22, discussed above, requires that crimes be drafted with precision, applied narrowly, and construed in favor of the accused.85 It has not been the Court’s general practice to create norms, but to enforce them.86 The ICC and the Rome Statute were created on the premise of enforcing crimes that have had international usage, not enlisting a small group of scholars to decide what the world should prosecute next.87 With legitimacy already posing an issue for the ICC today, a symbolic and vague crime that lacks teeth could make matters worse.

The ICC’s chronic resource constraints cannot be ignored. The Court currently operates with limited investigative capacity, a divided judiciary, and significant pressure to prioritize a handful of cases at a time.88 Furthermore, the ICC has only handed out eleven convictions in its two decades of existence.89 A crime built around open-textured ecological thresholds would require significant scientific input and substantial fact-development to establish all of the elements.90 That reality is hard to expect from an institution that struggles to manage its existing docket. When the legal standards are unclear, more expert evidence, scientific modeling, and litigation are needed just to determine whether conduct falls within the Statute.91 A definition this indeterminate risks diverting scarce resources into threshold litigation, which would reduce time and capacity available for existing prosecutions and potential situations to be investigated.

An issue building from the previous is the question as to whether the ICC is the correct avenue to determine the scientific scope of the IEP’s ecocide definition.92 ICC judges come from criminal law, international criminal law, and human rights backgrounds.93 Currently, there are no judges presiding over the ICC with any type of scientific experience, let alone ecological scientific expertise.94 As discussed in previous sections, the questions of whether environmental harm rises to the levels of wanton, severe, widespread, and long-term is a complicated scientific inquiry that requires balancing complex environmental variables.95 ICC judges, then, will likely have to rely on experts to understand the environmental matters brought before them in the absence of clear statutory metrics. With this, it is likely that divergent interpretations across cases will result along with significant pressure on the ICC’s already limited resources.

The shortcomings in the IEP’s draft definition do not mean that ecocide is an unworkable project. The fact is that environmental harm is an inherently complex discipline for the ICC to expand into. For the IEP’s definition of ecocide to operate within the ICC’s framework, there must be more solid guidelines, balanced with some flexibility, to account for this complexity. Some flexibility is unavoidable in capturing diverse ecological contexts. However, clarity and foreseeability are paramount in criminal law, and they are needed for the Court to be able to target the most heinous environmental crimes.

V. Ways to Improve the IEP’s Ecocide Definition

The purpose of this section is to propose modifications to the definition of ecocide that would be workable for the ICC in practice. Some degree of vagueness is both inevitable and valuable in environmental law, given that ecological harm is highly contextual and scientific knowledge evolves over time.96 But the IEP’s version pushes flexibility beyond what criminal statutes can support. A more functional approach would be to preserve necessary interpretive space while introducing targeted precision where the current draft is most unstable. This includes revising the threshold terms to give clearer anchors, removing the wanton element altogether, and adding a set of enumerated categories of conduct, paired with a catch-all clause, to guide prosecutors and judges without freezing the definition in outdated scientific assumptions.

The definition of ecocide should aim for a balance between flexibility and rigidity and should not contain strict boundaries. Currently, the definition fails at distinguishing between localized ecological disruption and the type of large-scale harm that would justify international criminalization.97 A workable definition must preserve some room to account for context while still drawing principled lines. This way, ecocide does not become a general environmental offense and maintains the IEP’s vision of encompassing the worst ecological harms.98

A. Removing “Wanton” and the Proportionality Test

The wanton element should be removed because it cannot be meaningfully refined. As discussed above, the proportionality test it introduces is inherently unstable. No amount of drafting precision can resolve the subjectivity baked into that comparison without elevating some interests while excluding others that may be equally relevant.99

The proportionality test also runs against the core purpose of ecocide as a crime centered on protecting the environment from human-caused destruction.100 The very act of weighing environmental harm against “social and economic benefits” serves to enforce that the IEP’s version of ecocide will not prioritize ecological integrity, but human interests.101 Corporations already conduct cost-benefit analyses when deciding whether or not environmentally harmful activities would nevertheless be outweighed by economic benefit.102 Embedding the same exact logic into the definition of ecocide could reproduce the structural incentives that permit ecosystem destruction in the first place, and turn the ICC into a forum of subjective justifications.

Jojo Mehta, the chair of Stop Ecocide International, has stated that the crime of ecocide is meant to protect the environment from corporate activities, including large-scale deforestation in the Amazon and drilling in the Arctic.103 However, as stated, these acts are already justified through cost-benefit balancing frameworks. This means that the very harms ecocide proponents seek to curtail could still fall outside liability, especially where the acts are lawful and carried out for ostensibly essential purposes, such as agriculture or industrial expansion.104 If there is to be a meaningful boundary beyond which no claimed lawful benefit can justify environmental destruction, the wanton element cannot remain. A proportionality test would reintroduce the same justificatory logic that ecocide is meant to disrupt.

Although the IEP’s definition should not rely on open-textured standards, some flexibility can come from the structure of the Rome Statute itself. Article 53(1)–(2) allow the Prosecutor to decline to open or pursue an investigation where there is “no reasonable basis” to proceed, considering whether the investigation would “serve the interests of justice.”105 This institutional design already enables the Office of the Prosecutor to filter out matters that do not reflect the gravity, scale, or normative significance required for ICC intervention.106 Furthermore, Article 17 enables the Court to determine that a case is inadmissible where there is not “sufficient gravity to justify further action.”107 In a way, the Court’s built-in discretion removes the need for ecocide’s proportionality test because its screening already provides a mechanism for excluding cases that fall below the intuitive threshold of ecocide even under a clearer, more determinate definition.

B. Adding Enumerated Acts

Introducing enumerated categories of underlying conduct would give the ecocide definition a baseline structure that the current IEP draft lacks.108 The purpose of this is to provide clear starting points that will guide prosecutors and judges towards the types of environmental harm that should warrant international criminal attention. Similar to Articles 7 and 8, these categories would operate as illustrative anchors while still leaving room for a catch-all provision to capture functionally comparable conduct.109 By doing so, the addition of ecocide to the Rome Statute will carry substantially less risk of arbitrary or politically skewed enforcement identified earlier because decision-makers would no longer be required to infer the boundaries of the crime solely from qualitative thresholds. It would also give the ICC, an institution without inherent scientific or ecological expertise, a reference framework for identifying serious environmental harms without reinventing the analysis in every case.

A functioning enumerated-acts section would draw on existing models that organize ecocidal conduct into coherent categories without attempting an exhaustive list. Several proposals already demonstrate how this can be done. The Promise Institute’s draft110 offers broad, ecologically grounded categories, including large-scale destruction of habitats or ecosystems; despoliation of biological resources that threatens biodiversity; introduction of harmful quantities of pollutants into air, water, or soil; illegal trafficking in hazardous waste; industrial activities involving ozone-depleting substances or persistent organic pollutants; destruction or large-scale taking of protected species; and conduct that significantly contributes to dangerous anthropogenic interference with the climate system.111 The Promise Institute follows the list with a catch-all phrase for similar acts.112 Matthew Gillett, an international lawyer with extensive experience working with the ICC and other international courts,113 has a similar approach in his own ecocide definition.114 These models make the concept of ecocide much more understandable and foreseeable, a benefit both for the ICC itself and for decision-makers that will be subject to the law.

C. Improving “Severe,” “Widespread,” and “Long-term”

As stated in the previous section, the goal is not to replace the IEP’s flexible thresholds with rigid numerical mandates. The IEP is correct that strict quantitative triggers, like fixed geographic sizes or recovery-time benchmarks, would risk excluding situations that plainly merit international concern, such as the collapse of a small but culturally and ecologically vital habitat.115 However, the IEP’s definitions of severe, widespread, and long-term need to have more guidance to limit open-ended interpretations. Modest refinements to the threshold terms along with the addition of enumerated categories of ecocidal conduct would provide the Court and decision-makers with concrete reference points. Prosecutors and judges would be able to assess whether a particular harm is comparable in scale or character to the listed categories, giving the threshold terms more functional meaning.

The threshold for severe should be reformulated so that it provides clearer guidance than the IEP’s current open-textured phrase “very serious adverse changes,” but without collapsing into rigid numerical benchmarks. A revised definition should tie severe to categories of ecologically significant harm drawn from established international environmental law practice. Incorporating an enumerated list paired with a catch-all clause for functionally comparable harms would create a structured way to evaluate severity across ecological contexts.116 This is a practice already followed by the Rome Statute in Article 7, where a catch-all phrase extends the crimes against humanity definition beyond enumerated acts, permitting inclusion of additional conduct only where it is comparable in nature and gravity, or, in other words, severity, to the listed acts.117

A revised widespread threshold should supply guidance on when geographically limited harm confined in one country is serious enough to become internationally significant. While the IEP was correct to deviate from ENMOD and API’s strict metrics, there needs to be additional guardrails as to when harm “extends beyond a limited geographic area,” even when all consequences are confined in a single state.118 By interpreting widespread through the newly-added enumerated acts, similarly to severe, prosecutors and judges would have structured benchmarks for assessing scale adequately.

A revised understanding of long-term should likewise offer clearer guideposts without returning to ENMOD or API’s rigid temporal baselines. But the current formulation, “irreversible or not redressable within a reasonable period of time,” still leaves prosecutors and judges without any principled way to evaluate duration.119 Almost all ecosystems are technically capable of recovery over long enough horizons, making irreversibility a flawed benchmark.120 Interpreting irreversible should therefore be explicitly limited to genuinely permanent alterations, such as ecological loss rendered non-recoverable by physical conversion of land or the total extinction of a species, not to muddle the distinction between “irreversible” and “reasonable period of time.” Like widespread and severe, decision-makers can also assess whether the temporal dimension of the harm resembles the kind of degradation captured in the listed categories.

A simple way to make this framework explicit is to include a clarifying clause, similar to Gillett’s in his formulation, stating that the “severe, widespread, and/or long-term nature of the harm may be established on the totality of the conduct at issue, which may include multiple underlying acts.”121 This way, it is made clear that the Court can and should use the enumerated acts as a guide to assess whether a situation matches each threshold.

The revised definition of ecocide supplies the predictability and coherence that the IEP’s version lacks by combining modest definitional adjustments with enumerated categories of conduct and reliance on existing prosecutorial filters. Together, these recommendations demonstrate that clarity is achievable without sacrificing ecological nuance.

VI. Conclusion

There is no question that the law should respond to the accelerating scale of human-driven environmental destruction, and criminalizing ecocide reflects that.122 But elevating ecocide to the level of genocide, crimes against humanity, war crimes, and aggression requires more than this moral force. For ecocide to be added to the Rome Statute, there must be fair notice, limited ambiguity, and it must be applied consistently by an institution with limited resources and no inherent scientific expertise. The IEP’s draft definition has been a positive development, as it has successfully reignited the debate over ecocide and brought it to the forefront of international criminal discourse.123 However, its inherent flaws, including vagueness, unbounded proportionality analysis, and lack of defined enumerated acts, makes it far too indeterminate to deter harmful conduct, too vulnerable to selective enforcement, and too unstable to uphold the ICC’s legitimacy.

The analysis throughout this comment shows that modest but targeted revisions, including removing the wanton element, refining threshold terms, and grounding the definition in enumerated categories of ecologically significant conduct, can bring clarity and structure. These adjustments preserve necessary flexibility while simultaneously ensuring that individual liability rests on principled boundaries.

If ecocide is to serve as a meaningful constraint on the gravest environmental harms, its definition must be more than symbolic. It must be able to guide conduct and withstand legal scrutiny. A revised, more determinate definition would honor the moral ambition of the ecocide movement while ensuring that its legal expression is capable of achieving the protective purpose at which it aims.

Endnotes — (click the footnote reference number, or ↩ symbol, to return to location in text).

1. 1.

   Rachel Killean & Damien Short, Scoping a Domestic Legal Framework for Ecocide in Scotland, ERCS (Mar. 2024), available online. ↩

2. 2.

   Anna Jenkin, The Case for an International Crime of Ecocide, 26 NZJEL 221, 226 (Jan. 2022), available online. ↩

3. 3.

   Hannibal Travis, Ecocide: A Brief History of an Explosive Concept, CJEL (Jan. 8, 2016), available online. ↩

4. 4.

   About—Ecocide Law, Stop Ecocide International, available online (last visited Nov. 30, 2025). ↩

5. 5.

   Legal Definition, Stop Ecocide International, available online (last visited Dec. 1, 2025). ↩

6. 6.

   Jenkin, supra note 2, at 226. ↩

7. 7.

   Simone Scriven, The Birth and Rise of “Ecocide”, Delacorte Review (Jul. 18, 2023), available online. ↩

8. 8.

   See generally Elizabeth Maruma Mrema, Carl Bruch & Jordan Diamond et al., Protecting the Environment During Armed Conflict: An Inventory and Analysis of International Law, UNEP (Nov. 2009), available online. ↩

9. 9.

   Rome Statute of the International Criminal Court, Adopted by the United Nations Diplomatic Conference of Plenipotentiaries on the Establishment of an International Criminal Court, Jul. 17, 1998, U.N. Doc. A/CONF.183/9, as amended [hereinafter Rome Statute], 8(2)(b)(iv), available online. ↩

10. 10.

    Milena Sterio, Crimes Against the Environment, Ecocide, and the International Criminal Court, 56 Case W. Res. J. Int’l L. 223, 224 (2024), available online. ↩

11. 11.

    Id. ↩

12. 12.

    Legal Definition, supra note 5. ↩

13. 13.

    Stop Ecocide Foundation, Independent Expert Panel for the Legal Definition of Ecocide: Commentary & Core Text (Jun. 2021) [hereinafter Core Text], available online. ↩

14. 14.

    Id. ↩

15. 15.

    Matthew Gillett, A Tale of Two Definitions: Fortifying Four Key Elements of the Proposed Crime of Ecocide, Part I, Opinio Juris (Jun. 20, 2023), available online. ↩

16. 16.

    Christina Voigt, «Ecocide» as an International Crime: Personal Reflections on Options and Choices, EJIL Talk (Jul. 3, 2021), available online

    (“An alternative would have been to provide a catalogue of various acts […] there was fear that it would be too limiting […] potentially carrying the notion of “justifying” acts that are not explicitly listed.”). ↩

17. 17.

    Legal Definition, supra note 5. ↩

18. 18.

    See Adam Branch & Liana Minkova, Ecocide, the Anthropocene, and the International Criminal Court, 37 Ethics & Int’l Aff. 51, 58 (2023), available online, doi. ↩

19. 19.

    Voigt, supra note 16. ↩

20. 20.

    The World Bank, Nam Theun 2: Powering the Next Generation (Oct. 23, 2019), available online. ↩

21. 21.

    Id. ↩

22. 22.

    Id.; see also Bruce Shoemaker & William Robichaud eds., Dead in the Water: Global Lessons from the World Bank’s Model Hydropower Project in Laos (UW Press, 2018), paywall. ↩

23. 23.

    See Bounsouk Souksavath & Mikiyasu Nakayama, Reconstruction of the Livelihood of Resettlers from the Nam Theun 2 Hydropower Project in Laos, 1 Int’l J. Water Resources Dev. 71 (2012), paywall, doi; see broadly Shoemaker & Robichaud, supra note 22. ↩

24. 24.

    Legal Definition, supra note 5. ↩

25. 25.

    Core Text, supra note 13; see Eoin Jackson, Analysing the Conclusions of the Independent Expert Panel for the Legal Definition of Ecocide—The Pragmatic Approach to International Environmental Crime, UCD (Jul. 15, 2021), available online. ↩

26. 26.

    The World Bank, Nam Theun 2 Project Overview (Nov. 27, 2019), available online. ↩

27. 27.

    Bruce Shoemaker & William Robichaud, Briefing Paper: Dead in the Water: Global Lessons from the World Bank’s Model Hydropower Project in Laos 6 (2018), available online. ↩

28. 28.

    Id. at 4. ↩

29. 29.

    Voigt, supra note 16. ↩

30. 30.

    Elliot Winter, Stop Ecocide International’s Blueprint for Ecocide Is Compromised by Anthropocentrism: A New Architect Must Be Found, 57 Israel L. Rev. 175, 184–85 (2024), available online, doi. ↩

31. 31.

    See broadly Shoemaker & Robichaud, supra note 27

    (discussing the overall impact of the Nam Theun 2 Hydropower Project in Laos). ↩

32. 32.

    Clara Ellenbeck, Ecocide: A Critical and Constructive Approach to Establishing a Fifth Crime Against Peace, 42 Ariz. J. Int’l & Comp. L. 1, 16 (2025), available online, archived. ↩

33. 33.

    Rome Statute, supra note 9, at Art. 8(2)(b)(iv). ↩

34. 34.

    Robert D. Sloane, Puzzles of Proportion and the “Reasonable Military Commander”: Reflections on the Law Ethics and Geopolitics of Proportionality, 6 NSJ 299, 302 (Jun. 2, 2015), available online, archived. ↩

35. 35.

    Richard D. Small, Environmental Impact of Fires in Kuwait, 350 Nature 11 (Mar. 7, 1991), paywall, doi. ↩

36. 36.

    Id. ↩

37. 37.

    About—Ecocide Law, supra note 4. ↩

38. 38.

    Core Text, supra note 13. ↩

39. 39.

    Avidan Kent & Cherie Leman-Richardson, An International Crime of Ecocide: Prospects and Difficulties, Trends (May 10, 2022), available online. ↩

40. 40.

    Id. ↩

41. 41.

    Voigt, supra note 16. ↩

42. 42.

    Sanita Auttopakorn, Nam Theun 2: World Bank Withdrawal Leaves Major Concerns Over Project Outcomes, Int’l Rivers (Jun. 19, 2018), available online

    (“[Nam Theun 2 hydropower dam in Laos] led to the involuntary resettlement of 6200 indigenous peoples, and to widespread impacts to downstream communities.”).

    See also Thayer Scudder, A Retrospective Analysis of Laos’s Nam Theun 2 Dam, 36 Int’l J. Water Resources Dev. 351, 362–63 (2019), paywall, doi

    (describing the lack of improvement efforts to the damaged forest near the Nam Theun 2 hydropower dam). ↩

43. 43.

    Core Text, supra note 13. ↩

44. 44.

    Id.

    (“The reference to ‘any element of the environment’ is intended to make it clear that it is enough to affect any element encompassed by the definition of the environment, that is, ‘the earth, its biosphere, cryosphere, lithosphere, hydrosphere and atmosphere, as well as outer space’ ”). ↩

45. 45.

    Shoemaker & Robichaud, supra note 22, at 188. ↩

46. 46.

    Id. at 187. ↩

47. 47.

    Scudder, supra note 42, at 354. ↩

48. 48.

    Core Text, supra note 13. ↩

49. 49.

    Id. ↩

50. 50.

    Id. ↩

51. 51.

    Matthew Gillett, Georgia Moloney & Anne-Lise Chaber, Proving Ecocide: The Plight of Pangolins as a Case Study for Fusing Ecological Science with International Law, 25 Int’l Crim. L. Rev. 1, 27 (Mar. 5, 2025), available online. ↩

52. 52.

    See Joanna Jarose, A Sleeping Giant? The ENMOD Convention as a Limit on Intentional Environmental Harm in Armed Conflict and Beyond, 118 Am. J. Int’l L. 469, 481 (Oct. 17, 2024), available online, doi; Ellenbeck, supra note 32, at 22. ↩

53. 53.

    Ellenbeck, supra note 32, at 22

    (noting scholars such as Markus Wagner question whether certain intrastate environmental harms rise to the level of an international crime). ↩

54. 54.

    Rome Statute, supra note 9, at Art. 1. ↩

55. 55.

    Mekong Watch & International Rivers, Nam Theun 2 Hydropower Project, Lao P.D.R.: Field Report 7 (Jun. 18, 2018), available online. ↩

56. 56.

    Shoemaker & Robichaud, supra note 22, at 188. ↩

57. 57.

    Core Text, supra note 13. ↩

58. 58.

    Anastacia Greene, The Campaign to Make Ecocide an International Crime: Quixotic Quest or Moral Imperative?, 30 Fordham Envtl. L. Rev. 1, 5 (2019), available online; Gillett, Moloney & Chaber, supra note 51, at 27–28. ↩

59. 59.

    Core Text, supra note 13. ↩

60. 60.

    See, e.g., Tim McNulty, What the River Teaches: Ten Years After Dam Removal on the Elwha River, Rewilding Inst. (Jul. 30, 2024), available online; see also Lourens Poorter et al., Multidimensional Tropical Forest Recovery, 374 Science 1370 (Dec. 9, 2021), paywall, doi

    (finding that tropical forests can recover full plant species diversity in twenty-five to sixty years and that it takes up to a century to recover the full biomass of a mature forest). ↩

61. 61.

    Carl Schleussner & Ansa Heyl, Glaciers Will Take Centuries to Recover Even If Global Warming is Reversed, IIASA (May 19, 2025), available online. ↩

62. 62.

    Core Text, supra note 13. ↩

63. 63.

    See broadly Rome Statute, supra note 9, at Art. 8. ↩

64. 64.

    Killean & Short, supra note 1, at 34–41

    (listing domestic ecocide legislation). ↩

65. 65.

    See broadly Rome Statute, supra note 9, at Arts. 7 & 8. ↩

66. 66.

    Matthew Gillett, “Human, All Too Human”: The Anthropocentricisation of Ecocide, Int’l J. of Hum. Rts. (Sep. 18, 2025), available online, doi. ↩

67. 67.

    Killean & Short, supra note 1, at 34–37. ↩

68. 68.

    See, e.g., id.

    (surveying broad formulations in domestic ecocide statutes, including Criminal Codes of Belarus Art. 131, Armenia Art. 282, Russia Art. 358, and similar provisions in Moldova, Ukraine, Georgia, Kazakhstan, Kyrgyzstan, and Tajikistan). ↩

69. 69.

    Core Text, supra note 13. ↩

70. 70.

    Killean & Short, supra note 1, at 19. ↩

71. 71.

    Rome Statute, supra note 9, at Art. 22(2). ↩

72. 72.

    Caroline Davidson, How to Read International Criminal Law: Strict Construction and the Rome Statute of the International Criminal Court, 91 St. John’s L. Rev. 37, 56 (2017), available online. ↩

73. 73.

    Darryl Robinson, Ecocide—Puzzles and Possibilities, 20 J. Int’l Crim. Just. 313, 319 (May 27, 2022), available online, doi. ↩

74. 74.

    See Alexander K.A. Greenawalt, Justice Without Politics? Prosecutorial Discretion and the International Criminal Court, 39 N.Y.U. J. Int’l L. & Pol. 583, 586 (Mar. 21, 2007), available online. ↩

75. 75.

    Melissa Hendrickse, Amnesty Int’l, A Chance for Africa to Counter the Pitfalls of International Criminal Justice? (Apr. 22, 2024), available online

    (“Out of the 54 individuals indicted by the ICC to date [of this comment], 47 are African.”). ↩

76. 76.

    Rebecca Hamilton, Ecocide and the Atrocity Aesthetic, 37 Temp. Int’l & Comp. L.J. 123, 127–28 (2023), available online. ↩

77. 77.

    Oscar Van den Heede, Ecocide as a Fifth Core Crime in the Rome Statute, 55 N.Y.U. J. Int’l L. & Pol. 435, 442 (May 2023), available online

    (discussing the ICC’s lack of personal jurisdiction over corporations). ↩

78. 78.

    See Michael Karnavas, Ecocide: Environmental Crime of Crimes or Ill-Conceived Concept?, Opinio Juris (Jul. 29, 2021), available online. ↩

79. 79.

    See, e.g., Ricardo Gabbay Souza, Ana Mariele Domingues, Anna Spindlegger, Claudia Mair-Bauernfeind & Florian Part, Review of the Current Knowledge and Identified Gaps in Assessing the Social and Environmental Impacts of Mining Processes in the Lithium Triangle, 53 SPC 40 (Jan. 2025), available online, doi

    (discussing the high ecological risk lithium mining, mainly for lithium-ion batteries, posed in South America).

    See also David Tilman, Global Environmental Impacts of Agricultural Expansion: The Need for Sustainable and Efficient Practices, 96 PNAS 5995 (May 25, 1999), available online, doi

    (describing agricultural food production’s detrimental environmental impacts on terrestrial and aquatic ecosystems). ↩

80. 80.

    See Ellenbeck, supra note 32, at 16. ↩

81. 81.

    See Hyeran Jo & Beth A. Simmons, Can the International Criminal Court Deter Atrocity?, 70 Int’l Org. 443 (Jul. 8, 2016), paywall, doi, earlier version (Mar. 7, 2016) available online.

    (discussing the deterrent effects of the ICC).

    See also William A. Schabas, An Introduction to the International Criminal Court 57 (2007)

    (discussing the importance of deterrence to the ICC). ↩

82. 82.

    See, e.g., Aud Tennøy, Jens Kværner & Karl Idar Gjerstad, Uncertainty in Environmental Impact Assessment Predictions: The Need for Better Communication and More Transparency, 24 IAPA 45 (2006), available online, doi

    (studying the inherent uncertainty in environmental impact assessments). ↩

83. 83.

    About—Ecocide Law, supra note 4

    (“Ecocide law will help to create a healthy societal taboo around mass damage to nature.”). ↩

84. 84.

    Philippe Sands & Catherine Savard, Criminalising Ecocide, BMJ (Aug. 20, 2025), available online, doi. ↩

85. 85.

    Rome Statute, supra note 9, at Art. 22. ↩

86. 86.

    Robinson, supra note 73, at 322–24

    (affirming that criminal law is not a suitable tool for complex societal reform, especially in international criminal law, since it is meant to cover crimes that are already condemned by broad moral consensus).

    Id.

    (“Strategically, if states have refused to adopt a proposition in in the softer realm of state responsibility, it is not plausible to expect that they will suddenly embrace it for the first time in the narrower field of serious international crime.”). ↩

87. 87.

    See id. ↩

88. 88.

    Douglas Guilfoyle, This is Not Fine: The International Criminal Court is in Trouble, Part III, EJIL Talk (Mar. 25, 2019), available online, archived. ↩

89. 89.

    Stephanie van den Berg, What is the International Criminal Court?, Reuters, Apr. 2, 2025, available online. ↩

90. 90.

    Van den Heede, supra note 77, at 441. ↩

91. 91.

    See id. ↩

92. 92.

    Id. at 440. ↩

93. 93.

    Karnavas, supra note 78. ↩

94. 94.

    Current Judges, ICC, available online (last visited Dec. 3, 2025). ↩

95. 95.

    Van den Heede, supra note 77, at 441. ↩

96. 96.

    Catherine Savard, What Mens Rea for Ecocide in the Rome Statute?, Int’l J. of Hum. Rts. 4–5 (forthcoming 2025), available online, doi. ↩

97. 97.

    Ellenbeck, supra note 32. ↩

98. 98.

    About—Ecocide Law, supra note 4

    (“Ecocide refers only to the very worst harms, usually on a major industrial scale or impacting a huge area.”). ↩

99. 99.

    See Ellenbeck, supra note 32, at 14. ↩

100. 100.

     Id. at 16. ↩

101. 101.

     Rachel Killean & Damien Short, A Critical Defence of the Crime of Ecocide, Envtl. Pol. 6 (Apr. 2025), available online, doi. ↩

102. 102.

     Polly Higgins, Eradicating Ecocide: Laws and Governance to Stop the Destruction of the Planet at XVI (2d ed. 2015), excerpt available online. ↩

103. 103.

     Jojo Mehta & Julia Jackson, Editorial, To Stop Climate Disaster, Make Ecocide an International Crime. It’s the Only Way, The Guardian, Feb. 24, 2021, available online. ↩

104. 104.

     See Kevin Jon Heller, Skeptical Thoughts on the Proposed Crime of “Ecocide” (That Isn’t), Opinio Juris (Jun. 23, 2021), available online. ↩

105. 105.

     Rome Statute, supra note 9, at Art. 53. ↩

106. 106.

     Brian D. Lepard, How Should the ICC Prosecutor Exercise His or Her Discretion? The Role of Fundamental Ethical Principles, 43 John Marshall L. Rev. 553, 554–55 (2010), available online. ↩

107. 107.

     Rome Statute, supra note 9, at Art. 17(1)(d). ↩

108. 108.

     Gillett, supra note 66, at 13; see also Killean & Short, Critical Defence, supra note 101. ↩

109. 109.

     See broadly, Rome Statute, supra note 9, at Arts. 7 & 8. ↩

110. 110.

     Promise Institute for Human Rights, Proposed Definition of Ecocide (Apr. 9, 2021), available online. ↩

111. 111.

     Id. ↩

112. 112.

     Id. ↩

113. 113.

     Dr. Matthew Gillett, Profile, U. Essex, available online (last visited Dec. 5, 2025); Gillett, Moloney & Chaber, supra note 51. ↩

114. 114.

     Gillett, Moloney & Chaber, supra note 51, at 23–25. ↩

115. 115.

     Kate Mackintosh, Ecocide is the Missing Crime, Icarus Complex (Oct. 22, 2025), available online. ↩

116. 116.

     Gillett, supra note 66, at 13. ↩

117. 117.

     Rome Statute, supra note 9, at Art. 7(1)(k). ↩

118. 118.

     Core Text, supra note 13. ↩

119. 119.

     Id. ↩

120. 120.

     See supra note 59. ↩

121. 121.

     See Gillett, Moloney & Chaber, supra note 51, at 25. ↩

122. 122.

     See Travis, supra note 3. ↩

123. 123.

     About—Ecocide Law, supra note 4. ↩