We have clustered the lessons learnt into four categories—lessons from negotiations, treaty and agreement proliferation and fragmentation, lessons on agreement design (output), and lessons from implementation (outcome and impact).
Treaty and agreement negotiation and innovations
States as sovereign actors come together to negotiate solutions or agreements to their common problems. The reasons (drivers) why countries negotiate with each other are embedded at national and international levels and, hence, it is important to understand the role of these reasons at both levels. These reasons are linked to actors (e.g. their economic, environmental and political interests as well as their capacity) and to the context (e.g. the level of development, availability of technology, expectations of conflict or cooperation with other states), which are dynamically intertwined (Karlsson-Vinkhuyzen et al., 2022; Petersson & Stoett, 2022; Mirumachi & Hurlbert, 2022; Pouw et al., 2022). For example, the economic interests of the timber industry and fossil fuel industry have played a key role in shaping the framing of the Kyoto Protocol (Petersson & Stoett, 2022) and the Paris Agreement on Climate Change—the latter, for instance, does not even mention fossil fuels.
The diversity of interests could stand in the way of reaching an agreement. Hence, leadership from credible and accountable leaders is needed to mobilize countries to adopt international agreements; thus understanding when, why and under what conditions countries want to lead is important; but equally—laggards slow down the process and hence it is also important to understand why they do so (Karlsson-Vinkhuyzen et al., 2022, Kalfagianni & Young, 2022). The motivation of actors who negotiate on behalf of countries to become agents (whether as leaders or laggards) depends on their (nation’s) motivations which can range from their own narrow short term interests (e.g. energy security, economic growth, trade, technology transfer or the protection of particular economic sectors) to a concern for addressing issues that are important for humans, humanity and the planet. Often a dominant motivation for action is dissatisfaction about: the state of the environment and its impacts on humans, trade subsidies, and/or lack of access to new knowledge. Another motivating factor is the emotions (e.g. influenced by iconic photos and reports) which influence the desire to lead, especially when linked to actors’/nations’ dominant values and interests (Karlsson-Vinkhuyzen et al., 2022). Laggards are motivated more by the fear that they may lose in the short term from international negotiation and by the powerful economic interests of “small, medium-sized and especially multinational corporations whose business model is built on letting society bear the financial and non-financial costs of environmental externalities/pollution and their employees who stand to lose their jobs due to outsourcing or changes in business models” (Karlsson-Vinkhuyzen et al., 2022). However, behavioural changes and rising fuel costs may also lead to a larger group of the public to protest against taking on more serious international obligations.
The role of the US is particularly important. While it needs international law to protect its multinationals, and its trade and investment interests, it tends to be a laggard in entering international environmental agreements (e.g. the US has not signed the UN Convention on the Law of the Sea; the UN Convention on Biological Diversity; the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal; the Stockholm Convention on Persistent Organic Pollutants; and some related human rights agreements). On the one hand, it has access to massive knowledge because of its impressive scientific sector; on the other hand, domestic politics, the polarization between the positions of Democrats and Republicans, senate filibuster and two-third majority rules, and backlash against the UN, among other factors such as the unwillingness to change lifestyles, have influenced its role in international environmental agreements. Its tendency to use non-ratification and moving in and out of agreements (e.g. it never ratified the Kyoto Protocol to the Climate Change Convention and in regard to the Paris Agreement, the US accepted it by executive order, then withdrew, then once again re-joined) has left a mark on global treaty negotiations, undermining the success of this instrument. The EU plays a more consistent leadership role although it is less able to mobilize and influence other countries because of its own cumbersome internal politics. Nevertheless, there are examples where it has played the role of bridge builder (Petersson & Stoett, 2022). However, in relation to agreements on fisheries, neither the US nor the EU are willing to push for change as the current situation suits the interests of their fisheries (Petersson & Stoett, 2022).
Among the G77 and China, China has moved from being a cautious actor characterised by incoherence between domestic and international action, to show some degree of leadership ambition in environmental agreements. While least developed countries and small island states have made their case in many treaty negotiations, evolving from actor to agent, their influence on policy design has been limited (e.g. on loss and damage and reducing emissions from deforestation and forest degradation (REDD)). These developing country coalitions have, however, become unstable and this affects their agency both in relation to climate change and in relation to the work of the World Commission on Dams (Karlsson-Vinkhuyzen et al., 2022).
Non-state actors such as NGOs and businesses have been participating more often in international regimes. To some extent they provide new information and support for (or opposition to) governments and demand increased transparency. To some extent, they themselves can take action at the domestic level to influence national-level decision making (i.e. the two-level game theory) or work with governments and other stakeholders to implement policies and reforms at the national level. There is growing evidence that feedback loops between the domestic and international levels could enhance the effectiveness of action. This has been encouraged through the recognition of the UN special groups since 1992. Over the years, the views of youth and indigenous communities have been increasingly presented at the domestic level and acknowledged at international negotiations through greater procedural legitimacy and input legitimacy. However, these have had a limited influence on the outputs, often becoming part of a mere ticking-the-box exercise (Mirumachi & Hurlbert, 2022). NGOs and the business sector, on the other hand, have been more influential when they have sought to identify solutions to promote implementation. However, in the process, ideas such as market mechanisms have received greater inclusion in the agreements as compared to the ideas of youth and indigenous communities—this also affects the ability to implement these agreements (Karlsson-Vinkhuyzen et al., 2022). Where large multinationals are afraid to lose out from reputation damage, they may be susceptible to pressure from NGOs (Pouw et al., 2022); although this fear has not made a major dent on the large energy multinationals.
All this reflects the role of various forms of bargaining power which play a key role in shaping the outcomes of international negotiations. The water literature more explicitly talks in terms of hydro-hegemony—on how power influences the framing of water problems, water sharing and the instruments for managing water (Mirumachi & Hurlbert, 2022); the literature on climate change and the other regimes also discuss the influence of power in terms of the knowledge of the powerful scholars (Karlsson-Vinkhuyzen et al., 2022), powerful countries and powerful actors (Pattberg et al., 2022) in shaping agreements; while scholars do not talk of climate hegemony, they do talk of climate injustice (Pattberg et al., 2022; Gupta et al., 2022). When powerful states, actors and knowledge systems come together, it is easier to promote a neo-liberal story calling for a pragmatic as opposed to a principled approach, the use of more market mechanisms, reducing the role of the state in favour of other actors, reducing the role of joint action in favour of voluntary measures, and by promoting the views of the most powerful actors (domestic and international) at the cost of other knowledges (Karlsson-Vinkhuyzen et al., 2022). This has led to the rise of WTO disputes, e.g. on renewable energy subsidies (Van de Graaf & Van Asselt, 2017) and court cases around these various issues which focus on enhancing at least elements of the legal justice narrative and holding actors accountable (Karlsson-Vinkhuyzen et al., 2022; Moynihan & Magsig, 2020).
Such power often plays out within the changing North–South dynamics in international treaty negotiation (Petersson & Stoett, 2022; Gupta et al., 2022). Simply put, countries are in different stages of economic development. Within the UN, there has long been conflict between these countries in terms of whether the global North was trying to prevent the development of the global South through, e.g. trade, investment and other economic law instruments. This led to the adoption of the UN Declaration on the Right to Development in 1986. This did not entirely end the controversy—as there is conflict regarding whether this is a right of individuals or that of states. Nevertheless, in the environmental arena, first comers to development create an environmental problem, recognize the problem, and then make rules that may stand in the way of latecomers to development to use their own resources (e.g. deforest to make space for cities or agriculture; use fossil energy; water for hydroelectricity). In the Climate Change Convention, this right was reworded as the right to promote sustainable development, undermining its very meaning. Nevertheless, it has been included in the Paris Agreement and Agenda 2030, and this may lie at the heart of the call for ‘full permanent sovereignty’. In many ways, this principle has been exercised by the US in full with regard to global environmental treaties where it has refused to ratify these agreements as mentioned above.
Against the background of a range of domestic and international reasons for countries to participate in international treaties, it is important to recognize the procedural design innovations that have emerged over the years. These include: (a) encouraging meetings of the parties even before a treaty enters into force (e.g. the Intergovernmental Negotiating Committee meetings in the climate change regime); (b) designing a Convention with follow-up Protocols (now used in many environmental agreements enabling follow-up Protocols to get like-minded countries to move together); (c) setting standards in meetings of the Conference of the Parties which can be adopted by parties and do not need ratification—or what some refer to as the rise in global administrative law; (d) enabling consensus building around interpreting articles in an agreement after it has been designed to enable flexibility (Sand & McGee, 2022); and (e) breaking rigid coalitions by requiring developing and developed countries to share negotiation seats as was undertaken within the negotiations on the 2030 Agenda; (f) stocktaking of the science; and (g) enabling wide participation, including crowd sourcing (Chasek & Wagner, 2016). Treaty secretariats and chairs of meetings are increasingly taking a leadership role in some of these innovations (Karlsson-Vinkhuyzen et al., 2022). Nevertheless, procedural efforts to enhance participation as a ticking-the-box exercise may undermine the legitimacy and equity of such processes. The securitization of some issues has also led to a suspension of procedural legitimacy in some regimes (Mirumachi & Hurlbert, 2022). Some of these measures go beyond what is generally acceptable in treaty negotiation but could be justified by the concept of limited territorial sovereignty. However, there is a healthy debate among legal scholars about whether and to what extent such observed innovations may affect the legal system.
A number of papers focus also on the rise of transnational actors and transnational governance systems as both try to address the limitations of interstate agreements as well as bypass the legitimacy and legality of this system. Such governance systems address these limitations by mobilizing many actors to take and demand action, by avoiding the deadlocks that often take place in the interstate system, and demonstrating the need felt by many actors to go ‘beyond the state’ (Pattberg et al., 2022; Karlsson-Vinkhuyzen et al., 2022). Having said that, many of these actions that aim at being efficient and effective, often end up sacrificing equity and justice issues, not least because they bypass the legitimacy and legality of the system (Pattberg et al., 2022; Sand & McGee, 2022).
Treaty proliferation, congestion and fragmentation
Whether it is due to the success of the treaty process, or due to the appeal of ‘treaty shopping’/forum shopping/forum shifting and avoiding a comprehensive agreement, the international arena is now congested with agreements from bilateral through to global levels, often addressing each issue individually (e.g. mercury), and using a set of inconsistent principles and instruments to address related problems. Those who wanted a number of bilateral and bottom-up approaches were afraid that global solutions and uniform approaches would not succeed (Pouw et al., 2022). However, these bottom-up approaches have also failed to meet quantitative targets, although they have mobilized other actors. Most of these agreements address the symptoms of the problems, with very few addressing the underlying drivers that have led to the creation of these problems; for example, the systemic underlying challenges including the economic, trade and investment system and gross inequality (Petersson & Stoett, 2022; Gupta et al., 2022).
Such congestion in treaties is also referred to in many ways, including as treaty complexes (Kalfagianni & Young, 2022; Pattberg et al., 2022). The congestion and fragmentation in treaties lead to treaty fatigue, but also to greater coherence or contradiction between the agreements. For example, the Montreal Protocol on Ozone Depleting Substances allowed the emission of CFC substitutes that had a high greenhouse gas potential. While both the climate convention and the International Maritime Organization have looked at emissions from international shipping, they were unable to resolve their differences (Hackmann, 2012, cited by Elsässer et al., 2022).
Treaty fragmentation may be more economically costly because ambitious climate targets then have to be achieved by fewer actors or emission reductions cannot occur where they are cheapest (Hof et al. 2009: 58; Pattberg et al., 2022; Pouw et al., 2022). However, while effectiveness increases by increasing the size of the coalition, the larger the coalition, the more unstable and unwieldy it becomes (Pouw et al., 2022). At the same time, such treaty fragmentation often reflects normative conflicts between actors. The US initiated the Asia–Pacific Partnership on Clean Development and Climate (APP) in competition with the Kyoto Protocol and its requirement that the industrialized countries should reduce their emissions. The APP eventually failed but also showed how such initiatives are often taken to undermine the legitimacy and equity aspects of existing regimes (Pattberg et al., 2022). Coordination between the climate regime and the forest regime failed as the climate regime focused on forests as carbon sinks and not on their role in biodiversity; while the forest and biodiversity regimes could reach coherence because of their mutually supporting definitions (Petersson & Stoett, 2022). Such fragmentation can exacerbate existing injustices (Okereke 2018; cited in Pattberg et al., 2022) by allowing forum shopping or shifting. Beyond such fragmentation within the environmental regimes, there is a growing conflict with the trade and investment regimes. Court cases on human rights reveal the clash between the human right to water and contract/investment law (Mirumachi & Hurlbert, 2022). Biodiversity regimes are also unable to cope with trade regimes: “the CBD (which does not include the United States as a formal party) does not even have Observer status at the World Trade Organization, despite the centrality of the Sanitary and Phyto-Sanitary Agreement to the fight against invasive alien species (the FAO’s International Plant Protection Convention does, however)” (Petersson & Stoett, 2022).
The interactions between these different regimes can reflect embeddedness (when one is embedded in another), nesting (when one is related to a broader regime); clustering (when one is clustered with another and coordinated); and overlap (when they cover similar issues). The causal interactions between these regimes can be cognitive-based (when the influence of knowledge, ideas and norms is discernible), commitment-based (when the commitments in one regime influence that in another—output level), behaviour-based (when the behaviours of actors in both regimes are influenced—outcome level); and impact-based (when actions in one regime influence the impacts in another) (Elsässer et al., 2022). Regimes learn from each other as, for example, with the ‘CBD-ification’ of older conservation agreements; notions developed within the CBD were then applied within other conservation agreements. This demonstrates cognitive learning. However, as biodiversity issues are less salient, the impacts they may have on other types of regimes may be marginal (Petersson & Stoett, 2022).
Innovation to address treaty congestion and fragmentation include: (a) treaty orchestration; (b) memoranda of understanding between treaties; (c) thematic clustering; (d) joint liaison groups; (e) coordination and integration through meta governance—e.g. through UN Water; (f) multi-stakeholder partnerships playing a ‘bridge’ role; and (g) initiatives by treaty secretariats (Sand & McGee, 2022; Pattberg et al., 2022; Petersson & Stoett, 2022). These are attempts at interplay management and have predominantly led to mutual learning, some efficiency improvements and increased coherence. Secretariats play a dominant role here, especially when “state preferences are weak and/or their expertise enjoys low substitutability” (Elsässer et al., 2022). Such innovations can be fruitful in that the interactions between the Paris Agreement on Climate Change, the Kigali Amendment to the Montreal Protocol on Ozone Depleting Substance and the Carbon Offsetting and Reduction Scheme for International Aviation have shown that “equal stringency reinforced cooperative fragmentation” (Pattberg et al., 2022).
Treaty design: goals, principles, rules and approaches
The toolkit of treaty design, as opposed to the negotiation and interpretation processes discussed above, has expanded from rules-based governance to include goals, principles and hybrid approaches. This enlarged toolkit offers more opportunities for addressing global problems as one can tailor-make the tools to fit the situation (Kalfagianni & Young, 2022).
In terms of the nature of agreements, there is emphasis on both legally binding agreements, soft law, and something in between. While legally binding agreements reduce the risk of free riders, such agreements are often either harder to negotiate or include indeterminate language. Soft law agreements, being non-binding, provide greater scope for highlighting the needed changes and allow all actors including non-state actors to play a key role. A good example of this is the 2030 Agenda which appears to have mobilized a vast range of actors. The Paris Agreement is something in between—while being legally binding, the choice of ‘Agreement’ in the title and the lack of specific targets for countries within the document enabled the US to ratify, withdraw the ratification, and then again decide to ratify, without consulting the senate. This rise of soft law approaches and hybrid modalities is a key innovation in environmental agreements (Sand & McGee, 2022).
In terms of the content, most agreements have been relatively narrowly focused and rule-based. However, the Millennium Development Goals initiated some goal-based governance, but only included environmental issues based on limited indicators. The 2030 Agenda made more significant strides in goal-based governance which also aimed to create a comprehensive and systemic approach to addressing environmental issues (Kalfagianni & Young, 2022). This also led to delegating responsibility to states to come up with appropriate standards (Sand & McGee, 2022) and attention to interactions across domains.
While principles have been highly contested in different treaty regimes, the Rio Principles on Environment and Development provided a reasonably comprehensive soft law menu of values that could be incorporated by states. Water law has seen a profusion of principles being developed which include principles on not causing harm to others, equitable utilization and the recognition of the human rights to water and sanitation. Despite this impressive menu of principles, bargaining power/hydro-hegemony plays a key role in resisting the adoption, interpretation and implementation of many of these principles (Mirumachi and Hurlbert, this issue). For example, at times the polluter pays principle has been shelved in favour of cost-sharing principles as in the Rhine Chloride case (Mirumachi & Hurlbert, 2022).
Treaty design includes a range of collaborative instruments including targets and timetables, technology development and/or transfer, capacity building, financial assistance, and market-based mechanisms. Targets and timetables are a key feature of many treaties including those on climate, biodiversity and water. The design of such targets and timetables has been the subject of many papers. While ostensibly these targets aim at addressing the problem within a time schedule and allocating responsibility between states, power struggles have either led to such targets being poorly articulated (e.g. in the Climate Convention), or being left to bottom-up voluntary commitments (e.g. in the Paris Agreement) sacrificing equity concerns (Gupta et al., 2022). Many national and international agreements emphasize technology development and/or transfer. However, while such technologies can play a key role in enhancing efficiencies, the focus on using these technologies for augmenting supply (e.g. the supply of water or renewable energy), as opposed to reducing demand, may lead to technological lock-in that will be difficult to reverse as we reach planetary boundaries (Mirumachi & Hurlbert, 2022). This insight may also be relevant for capacity-building efforts. Moreover, the unwillingness of states to promote less dependence on fossil fuels has also led to risky technologies being promoted such as geo-engineering and negative emissions technologies, often also justified by arguments that this addresses equity concerns (Pattberg et al., 2022).
Financial aid to countries with economies in transition and developing countries has often been seen as a way to enhance treaty implementation. The provision of such assistance has been shown to be effective in public goods provision, given the difference in costs with low-cost countries (Pouw et al., 2022). Moreover, financial assistance through the Global Environment Facility (GEF) has been effective in creating awareness on climate change and biodiversity (Pouw et al., 2022), but whether the GEF projects in themselves have been effective has not been systematically analysed. Much of the literature also discusses that technology transfer and financial assistance have scarcely been in line with what has been promised in the agreements. For example, the Paris Agreement promise to raise USD 100 billion from 2020 onwards to help finance the climate actions of developing countries is a broken promise, as an article in Nature reveals.Footnote 1
Instead, there has been considerable focus on market-based mechanisms, especially since the 1990s. This has been most prominent in the climate change regime with its focus on joint implementation, the clean development mechanism (CDM), emissions trading and reducing emissions from deforestation, and forest degradation (REDD). Many of these instruments looked good on paper, but as Kalfagianni & Young (2022) note, the second best instruments may often have a better result. This may be because, in the development of such instruments, the key actors concerned may be inadequately heard: for example, in the REDD instrument—the voices of the powerful industry and economic actors drowned those of the indigenous people and local communities who have long been protecting these resources, to the detriment of a successfully designed instrument (Karlsson-Vinkhuyzen et al., 2022). REDD, in addition, has many design flaws (e.g. the potential for leakage, unproven additionality; perverse incentives, etc.). Similarly, while the CDM did take off because of the cost-effectiveness it embodied (Pouw et al., 2022), it was facilitated by a wide range of stakeholder networks and was relatively efficient as a project-based instrument (Karlsson-Vinkhuyzen et al., 2022), neither the CDM nor emissions trading nor joint implementation mobilized the necessary changes and instead postponed the need for action in the industrialized countries. Within the EU, the internal trading system was initially weak because of the low emission caps, but since 2013, it has been more stable in reducing the rate of growth of emissions (Pouw et al., 2022). Nevertheless, this does not mean that this will work in other national contexts or at the global level.
Many agreements promote public–private partnerships. While these ostensibly optimize the strengths of both public and private actors, they can also have serious challenges that have been highlighted in the broader literature. INEA has highlighted that the success of such partnerships depends on how the contract has been designed, whether there is a functioning legal system, the relationship with contract and investment law, and often aid or government funding (Mirumachi & Hurlbert, 2022). Such agreements run the risk of lack of affordability for the poor and, hence, low-cost recovery by the companies (Pouw et al., 2022) as well as poor financing of wastewater systems. The rise of re-municipalization of water services in many Western countries reveals the shortcoming of using this instrument, especially in relation to public goods.
Governments can phase out perverse subsidies or promote subsidies to change behaviour. A special issue examined the key elements of success and failure in regards to energy subsidies at the intersection of climate, energy and trade governance. Overall, it concluded that a consensus definition of “energy subsidy” is missing, methods for measurement usually take a price-gap or inventory approach, and that renewable energy support is continuously challenged (Van de Graaf & Van Asselt, 2017, 321). Proposals for reform (e.g. by the G20) call for action by those who usually establish energy subsidies, i.e. national or sub-national governments, but increasingly also by other actors in the “regime complex” (p. 324). While the G20, the World Trade Organization (WTO), and the Climate Change regime can play an important role in signalling energy subsidy reform needs, steering away from financial investments from fossil fuels, and prohibiting the most environmentally harmful fossil fuel subsidies (De Bièvre et al., 2017), other international government organizations can play an accompanying role in implementation. Kalimo et al. (2017) proposed a less important role for the WTO adjudication process in deciding about value reconciliation, arguing that member states themselves should develop rules and regulations to balance economic and environmental values under the WTO Agreement on Subsidies and Countervailing Measures.
Agreements also need to embody elements that ensure adaptability to new circumstances. Adaptive treaties are critical for addressing the uncertainty in complex environmental problems (Kalfagianni & Young, 2022; Mirumachi & Hurlbert, 2022). In fact, many (e.g. water) treaties will have to be renegotiated in order to address the impacts of climate change on these treaties (Mirumachi & Hurlbert, 2022). Policy mixes need to ensure that the sum total of the different instruments address the various dimensions of the problem (Mirumachi & Hurlbert, 2022).
A key question in treaty design is how just and equitable are these agreements. While in the early 2000s justice issues were scarcely covered or subsumed under a behavioural approach within new institutionalist scholarship within INEA, they were later covered under access and allocation issues; and since 2015 there is a more open discussion on justice issues. While equity principles have been a cornerstone of international law, parties have selectively adopted these principles in agreements and also selectively implemented them. For example, despite the adoption of the common but differentiated responsibilities and respective capabilities principle, there has been a shift from top-down to bottom-up voluntary targets in the climate regime in a post-equity approach (Pattberg et al., 2022; Gupta et al. 2022). In the world of bilateral and transboundary water agreements, agreements have often excluded the equity issue of local actors which may exacerbate impacts on the environment as well as on local people; permits given to big actors may exclude small ones but may not prevent them from using the water they need, and papers argue that equity issues need to be accounted for in the ways water problems are to be addressed (Mirumachi & Hurlbert, 2022). What becomes evident is that although justice norms should enable a critique or reinterpretation of text, in practice procedural justice is relatively easier to achieve (although it may become a ticking-the-box exercise) than substantive justice in issues such as climate change. Three discourses appear to be emerging—corrective justice, justice issues in the energy transition, and justice in relation to adaptation. They show that market mechanisms may have an impact on justice and such mechanisms are not spontaneous but have been created. Papers also argue that one may need to go beyond holding some states responsible to holding key actors responsible for their emissions (Sand & McGee, 2022; Gupta et al., 2022).
Some papers have discussed the conflict between efficiency, effectiveness and equity/justice. While some suggest that efficiency and equity can be enhanced through global market mechanisms, others have argued against it. There has also been debate about whether environmental agreements should address prioritizing environmental issues over equity (e.g. Verbruggen cited in Pouw et al., 2022; Vellinga et al., and Keohane cited in Pattberg et al., 2022) or not. The adoption of the 2030 Agenda recognizes the indivisibility of goals and that neither should be prioritized over the other. The mood in scholarship has also changed worldwide as evinced by debates in other journals (e.g. Global Environmental Change, Third World Quarterly). The rise in youth and social movements and court cases also demonstrate the growing demand for justice (Pattberg et al., 2022; Gupta et al., 2022). Some see the idea that effectiveness can be achieved without equity as wishful thinking. Achieving environmental goals without equitable approaches is unlikely; achieving access without fair allocation is also likely to fail. This is because environmental treaties need to address the underlying drivers of environmental problems, and not just the symptoms (Pattberg et al., 2022; Gupta et al., 2022).
Treaty implementation: vertical interaction
Lessons learnt on treaty implementation show that treaties may succeed if one assesses implementation in terms of mobilizing actors and coalitions, political parties, public opinion, sub-national entities, media coverage and initiatives and the engagement of bottom-up actors who then may mobilize their transnational partners (Pattberg et al., 2022; Karlsson-Vinkhuyzen et al., 2022). Justice and equity issues in biodiversity regimes have been difficult to implement: benefit-sharing mechanisms have been poorly implemented, subject to elite capture and disempowerment of local people (Petersson & Stoett, 2022). This has also been the case in the climate change regime where technology transfer and finance has been low, while in target setting and implementation equity issues have been sacrificed (Pattberg et al., 2022; Gupta et al., 2022). Empirical measurement of treaty implementation tends to be dismal in showing the actual achievement of the end goals of a treaty and breaking the negative trends (Pattberg et al., 2022). None of the Biodiversity targets for 2020 were achieved; nor was access and benefit-sharing as designed in the agreement achieved (Petersson & Stoett, 2022). Most studies focus on hypothetical results—what would happen if the goals are achieved; but few actually trace the specific implementation of treaty measures. Institutionalized uncertainty affects treaty implementation (Petersson & Stoett, 2022). Clearly, national and sub-national dynamics play a key role in influencing treaty implementation (Karlsson-Vinkhuyzen et al., 2022). Such mobilization and dynamics should ultimately influence states to commit to action under international law. In fact, if the implementation is viewed as having output legitimacy this can provide positive reinforcement by ensuring that social actors agree to participate in the process (Karlsson-Vinkhuyzen et al., 2022). Costs and perceptions of costs play a role in influencing implementation. The fall in the costs of renewable energy has made it more attractive to implement. The availability of zero-carbon technologies and finance also increases the likelihood of action. At the same time, the high costs and other barriers of technologies including trade barriers and intellectual property rights also influence the willingness to act (Karlsson-Vinkhuyzen et al., 2022). In terms of reporting on implementation, industrialized countries are less likely to mention the actions and initiatives of non-state and sub-national actors than developing countries. Thus implementation may be difficult, but may still meet some criteria of effectiveness (Petersson & Stoett, 2022). Compliance mechanisms differ from regime to regime, but in general, are able to mobilize action but not always ensure implementation. Some innovations here include the EU issuing a warning to South Korea on non-compliance with fisheries law, which was more effective than listing its vessels as Illegal, Unregulated and Unreported fishing vessels under the Convention on the Conservation of Antarctic Marine Living Resources, which is relatively less known and has less impact (Petersson & Stoett, 2022). The challenge is the lack of data and lack of resources to conduct quality comparative research on what policy mixes work, where and under what circumstances.