Abstract
Air pollution is a major environmental problem, yet existing international legal responses fall short of adequately addressing the problem on a global scale. This article investigates if and how the Sustainable Development Goals (SDGs) fill the current legal and regulatory gap, and whether they can contribute to problem-solving. The SDGs do not have a separate goal that covers addressing poor air quality in its scope; however, they include several targets and indicators specific to the problem. The SDG framework is still far from offering a comprehensive approach to air pollution. Nonetheless, even in this limited capacity, the SDGs contribute meaningfully to legal responses to air pollution. First, the SDGs frame air pollution as a global development concern, given its impacts on health, the environment and economy worldwide. Second, the SDG framework proposes relatively precise targets and indicators on air quality that are globally applicable, which is significant given the absence of a global legal agreement on preventing air pollution. Third, the SDGs exhibit strong transnational legal characteristics and broadly define their norm addressees, thereby opening opportunities for a range of actors - nation-states, international organizations, and various stakeholders - to foster multi-stakeholder, multi-level cooperation to implement the Goals. Thus, the SDGs lay an important foundation for addressing air pollution on a global level and can contribute to further legal developments. As discussions about the SDGs’ post-2030 future are already underway, it is vital to establish a more systematic approach to air pollution in the subsequent framework, recognizing its complex linkages with other environmental issues and its relevance to overall sustainable development.
Keywords
Introduction
Air pollution is a major global environmental problem, with various adverse effects on health, the environment, the economy and, more generally, on the stability of the Earth system, and threatens planetary integrity. 1 Air pollution is estimated to lead to millions of premature deaths annually 2 and has been described by the World Health Organization (WHO) as ‘one of the greatest environmental risks to health’. 3
The issue of air pollution is therefore a matter of global concern necessitating a strong international legal response. Yet, at present, international environmental law in this domain is inadequate to the challenge. There is no global treaty on air pollution, while existing regional arrangements concern only transboundary air pollution and have significant shortcomings limiting their effectiveness. 4
The Sustainable Development Goals (SDGs) were adopted by the United Nations (UN) General Assembly in 2015 5 and have emerged as a meta-framework to guide the world towards a more sustainable economy, society and environment. Midway through, their implementation and post-2030 future have been actively debated. 6 Given the detrimental impact of air pollution on sustainable development, it is important to consider whether and how the SDGs can contribute to problem-solving on a global scale.
Research Framework
Prior assessment carried out by Lode et al in 2016 concluded that the SDG framework ‘constitutes an important contribution to international (hard) law focusing on the atmosphere’ primarily for their capacity to measure global progress on air quality through indicators. 7 Several other authors have examined the substantive links between the SDGs and air pollution, 8 yet they have not addressed the legal dimensions. A comprehensive assessment of how the SDGs contribute to international legal norms addressing air pollution is therefore still missing.
Through the analysis of legal sources and norms, and policy documents, and engagement with relevant scholarship, this article shows how the SDGs complement existing international legal frameworks and norms to address polluted air. The scope of the article is on conventional air pollutants including particular matter (PM), sulphur dioxide and other aerosols and gases. 9
In its assessment of SDGs’ contribution to addressing air pollution globally, this paper focuses on the following analytical categories: (1) legal framing of the problem, (2) normative determinacy, and (3) norm addressees. This analytical framework partly borrows from Brölmann's evaluation of how SDG6 on clean water and sanitation advances international water law, 10 which also inspired this work in the first place. 11 On the legal framing of the problem, the article discusses how the SDGs problematise air pollution in terms of its nature, causes, impacts and solutions. Normative determinacy refers to the extent to which the SDG framework prescribes conduct or outcomes relating to air quality. 12 The category of norm addressees asks whom the SDGs are oriented at, how the SDGs allocate authority and whether this deviates or not from the current sovereign-territorial paradigm of international law. 13
The article contributes to the literature on the law and governance of air pollution and the scholarship on the SDGs, particularly as concerns their relationship with international (environmental) law.
The article first explains the state of the air pollution problem globally, its impacts on health and the environment, and interlinkages with development and climate change (3). It then outlines how air pollution is currently addressed in international law (4) and establishes the legal nature of the SDGs as soft law with strong transnational characteristics (5). The article continues with the analysis of how the SDGs address the problem of air pollution across its Goals, targets and indicators (6). The discussion section that follows this contains an analysis of how the SDG framework complements international legal responses to air pollution and contribute to problem-solving (7). The article's findings are summarised in the conclusions (8).
The State of the Problem of Air Pollution
Air pollution is a complex mixture of particles and gases, including PM, nitrogen dioxide, sulphur dioxide, ozone, and carbon monoxide. 14 Exposure to indoor and outdoor air pollution contributes to millions of premature deaths annually, estimated at 8.1 million in 2021. 15 In addition to premature mortality, air pollution is a contributing factor in various acute and chronic diseases especially cardiovascular and respiratory diseases. 16 Air pollution also results in economic losses and reduced crop yield, thereby affecting food security.
The problem is widespread: 99% of the world's population live in areas with air pollution exceeding WHO limits. 17 It is estimated that nearly 90% of all air-pollution-related deaths occur in low and middle-income countries, in particular in South-East Asia and Western Pacific regions, 18 with the most vulnerable populations – women, children and the elderly – being most at risk. 19
There are strong interlinkages between air pollution and development issues 20 : for example, the use of solid fuels for cooking demonstrates a lack of electricity access. 21 Additionally, air pollution warms the climate through black carbon, tropospheric ozone and methane – collectively known as short-lived climate pollutants (SLCPs).
Air Pollution in International Law
Air pollution is not governed by a central treaty or a custodian international organisation. Instead, there is a heavily fragmented patchwork of rules and principles of general international law, regional agreements, relevant rules under international treaty regimes and international bodies, case law, and various inter/transnational institutions and networks. International legal norms predominantly address air pollution in a transboundary context; however, there are also (soft) norms that go beyond transboundary air pollution in addressing air quality globally or aiming at reductions of specific SLCPs.
Transboundary Air Pollution
Transboundary air pollution was one of the early environmental problems addressed by international law, and as such related norms are well-developed. 22 International legal norms relating to transboundary air pollution are positioned within the field of international (environmental) law and therefore operate under such rules and principles as state sovereignty, a no-harm rule and state responsibility, prevention, 23 the duty to conduct environmental impact assessments, the precautionary approach, and the concept of sustainable development, among others. 24
Substantive norms under international law primarily address transboundary air pollution through a network of regional treaties and soft law frameworks. 25 These agreements include the Convention on Long-Range Transboundary Air Pollution (CLRTAP) 26 and its Gothenburg Protocol to Abate Acidification, Eutrophication and Ground-level Ozone (Gothenburg Protocol), 27 the Association of Southeast Asian Nations Agreement on Transboundary Haze Pollution 28 and the Malé Declaration on Control and Prevention of Air Pollution and its likely Transboundary Effects for South Asia. 29 There are also three agreements on air pollution in Africa: the 2008 Eastern Africa Regional Framework Agreement on Air Pollution 30 , the 2008 Southern African Development Community Regional Policy Framework on Air Pollution 31 and the 2009 West and Central Africa Regional Framework Agreement on Air Pollution. 32 In addition, there are several regional networks focusing on air pollution, such as the Asia and the Pacific Clean Air Partnership, 33 the Acid Deposition Monitoring Network in East Asia, 34 and the Intergovernmental Network on Air Pollution for Latin America and the Caribbean. 35
At first glance, this network of regional agreements and networks on transboundary air pollution appears to have good geographic coverage. In practice, regional approaches vary greatly in terms of their legally binding nature, effectiveness, coverage of pollutants, sources of pollution, policy approaches, and implementation mechanisms.
Beyond Transboundary Air Pollution
While there is no treaty or other legal framework on air pollution with global reach, a more global approach to improving air quality has recently been advocated by the UN Environment Programme (UNEP). 36 This approach includes knowledge assessments, cooperation initiatives, and capacity-building activities. For instance, in 2023 UNEP developed a guide on ambient air quality legislation to assist national governments, 37 and in 2024 the UN Environmental Assembly agreed to establish a cooperation network across international organizations on air quality. 38
The WHO Member States have also acknowledged the need for a global response to air pollution, considering it as a risk factor for noncommunicable diseases. 39 The WHO's work on standards, for instance the WHO Global Air Quality Guidelines of 2021, 40 is important for air quality governance. Such standards have a non-binding nature: ‘the guidelines are not intended to be taken as recommendations for air quality standards per se, but rather as a rigorous scientific tool that can be used by regulatory authorities as a basis for setting standards’. 41 Despite lack of bindingness, these guidelines ‘have progressively acquired more normative strength’ 42 through the impacts on domestic air quality standards, litigation and legal rights. 43
Growing attention has also been paid at the international level to SLCPs – primarily, black carbon and methane emissions – under the Gothenburg Protocol and the Paris Agreement 44 as well as soft law documents such as the Arctic Council's Framework for Action on Enhanced Black Carbon and Methane Emission Reductions 45 and the Global Methane Pledge, 46 and the Climate and Clean Air Coalition (CCAC), a network organisation. 47 Overall, however, SLCPs are not addressed comprehensively in international legal instruments, and instead the governance responses are fragmented across types of pollutants and geographic coverage. 48
To sum up, air pollution is not covered by a global treaty. Instead, there exists a highly fragmented network of regional agreements on transboundary air pollution, with uneven geographic coverage and varying substantive scope. International organisations and transnational partnerships play a key role in the global governance of air pollution.
Positioning of the SDGs in International Law
Scope and Implementation Structure
The SDGs were agreed in 2015 by the UN General Assembly after a three-year process of intergovernmental negotiations and multi-stakeholder consultations. 49 They are to be achieved by 2030 and replace the Millennium Development Goals developed in 2001. The SDGs comprise 17 goals and 169 targets, 50 and achievement of the targets is monitored by reference to a set of 230 indicators. 51 The Agenda is often described as exemplifying a broader shift towards governance by goal-setting, or the growing prominence of metrics as pointers of effectiveness. 52 The SDGs themselves are highly aspirational and expressed in vague language. The associated targets are characterised by greater specificity but many of them still leave significant scope for interpretation. 53
At UN level, the SDGs are supported by the High-Level Political Forum under the auspices of the UN Economic and Social Council and the UN General Assembly to provide ‘political leadership, guidance and recommendations’ for implementing the 2030 Agenda as well as follow up and review. 54 States report on national progress towards the achievement of the SDGs through Voluntary National Reviews: by late 2024, most of them had undertaken at least two of these reviews. 55
In their substance, the SDGs take an ambitious approach to defining the global agenda for all aspects of sustainable development – economic, environmental and social. Commentators described them as ‘bold’ in character, holistic in approach, and transformative in scope. 56 At the same time, the framing and scope of the Goals did not escape criticism for their roots in neoliberal thinking and their emphasis on economic growth while ignoring the structural inequalities embedded in the global economic and financial system. 57
The 2030 Agenda also emphasises universality, as the SDGs should be implemented by all countries; the SDGs’ interconnectedness and indivisibility; and broad inclusion (‘no one should be left behind’). 58 Some scholars suggest that the SDG framework in its people-centred approach ‘normatively expresses an innovative and bold cosmopolitan understanding of sustainable development’ 59 recognising individuals as the benchmark while states and other relevant actors are expected to act in their interest. 60 In other words, the framework provides a notably broad interpretation of its beneficiaries.
Despite the people-centred approach, respect for national sovereignty and national ownership of the development agenda are highlighted throughout the document: ‘every State has, and shall freely exercise, full permanent sovereignty over all its wealth, natural resources and economic activity’. 61 Furthermore, each government sets ‘its own national targets guided by the global level of ambition but taking into account national circumstances’. 62 The follow up to and review of progress towards the implementation of SDGs are also state-driven at the national, regional and global levels. 63
Legal Nature
The SDGs were developed in the framework of the UN and adopted by the UN General Assembly. The SDGs do not generate obligations under international law as they were expressed in a resolution by the UN General Assembly, which has no legally binding force in relation to states. 64 The Goals have been described as lying at the lowest end of the hard-to-soft law continuum and characterized by a low degree of legalisation. 65 Some even suggest that the SDGs are situated in ‘an arena of contested legality’ and ‘are not only explicitly political, they are, more specifically and overtly, non-legal’. 66
This does not, however, mean the SDG framework cannot have a normative influence. In the context of international environmental law, the problem-solving capacity of norms is of greater importance than the legal form in which they are conveyed. 67 In fact, some of the past resolutions of the UN General Assembly, such as the Rio Declaration on Environment and Development, and the Millennium Development Goals have had a significant normative impact on the relevant international and domestic law. 68
The SDGs and their targets are clearly imbued with a degree of ‘oughtness’ and are supported by a transparency and accountability system through regular national reporting and review. It is therefore a normative framework with the expectations of state ‘adherence’ 69 to the Goals. It is not entirely voluntary for states whether or not to participate in the implementation of the SDGs, 70 and, despite the lack of enforcement mechanisms, more than four hundred Voluntary National Reviews have been submitted by countries as of July 2025. 71
Agenda 2030 is also explicit about its linkages to international law: not only was the document was ‘guided by the purposes and principles of the Charter of the United Nations, including full respect for international law’, 72 but many SDG targets are also consistent with the existing norms of international law, for instance international marine law and international biodiversity law. 73 It is also ‘to be implemented in a manner that is consistent with the rights and obligations of states under international law’. 74 This demonstrates ‘the intention to join goals and the law together’ for the effective implementation of the Agenda 2030. 75
Consequently, many commentators agree on SDGs being a form of soft law, as they have ‘the intent to lay down legally relevant normative expectations’. 76 As such, they influence the interpretation and application of existing rules and norms of international law, and can, in principle, even transform into binding norms. 77 In particular, the SDG framework is important for interpreting the scope and contents of the principle of sustainable development, 78 which is a recognised principle of international environmental law. 79 Legal implications have also been discussed for international water law 80 and law concerning access to clean energy. 81 Regarding the effects of SDGs on domestic jurisdictions, there is also evidence of the integration of SDGs into national and sub-national governance frameworks, for instance in Sweden, Scotland, and Norway. 82 The SDGs’ legal effects are therefore ‘not negligible’. 83
This shows that the literature converges on the legal nature of SDGs as a soft law framework that can have important ‘normative consequences for the progressive development of international law’ by clarifying existing rules and norms in various fields of international law. 84 Although the full normative effect of the SDGs on international and domestic jurisdictions is still to be ascertained, the SDG framework already provides ‘a more consolidated perspective on international development law that is currently missing.’ 85
Transnational Characteristics of the SDGs
Relevant to the focus of the article on air pollution, the SDG framework also exhibits strong characteristics of transnational law, 86 reflecting novel processes in public international law that increasingly emphasise law-making beyond states. 87 International law – in its Westphalian paradigm – is traditionally understood as a legal order regulating relations between sovereign nation-states while matters that arise within states are subject to national law. 88 Globalisation processes have altered this conventional system and resulted in the expansion of norms and norm-making outside the interstate arenas. Nation-states are still central to international law but are no longer the sole definers of its boundaries and contents.
Transnational law, as one of conceptual approaches to describe such expansion of law-making actors, departs from the formalistic division of law into international-national binary towards a broader understanding of law beyond borders – one that considers ‘the relevance of decentred normative practices and processes, and of non-state actors, in the production and consolidation of law’. 89
Transnational law characteristics of the SDGs are evident both in the process of their development and in their norm addressees.
Although the SDGs were developed in the framework of the UN and adopted by the UN General Assembly – in an analogous manner to traditional international law-making – the process differed from other multilateral negotiations in important ways. These include not only various innovative negotiation formats 90 but also an unprecedented degree of stakeholder participation. 91 The Open Working Group on SDGs charged with the negotiation task was mandated to ensure ‘an inclusive and transparent intergovernmental process’ and be ‘open to all stakeholders’. 92 Accordingly, an ambitious program of open-ended dialogues with civil society, interest groups, business, and others was conducted, including national and global consultations, large-scale global surveys, and e-discussions. 93
Furthermore, the SDGs are inclusive in terms of their addressees as they refer to ‘all parties and all stakeholders’ who ‘acting in collaborative partnership, will implement’ the SDGs. 94 The SDG framework does not, therefore, place the responsibility for realising the SDGs and targets only on nation-states, even though, as mentioned above, it repeatedly acknowledges national sovereignty and national ownership of the development agenda, and considers follow-up and review as ‘the primary responsibility’ of governments. Moreover, the SDGs and their targets explicitly highlight the importance of stakeholders in implementing Agenda 2030 (e.g., targets 17.16 and 17.17 on multi-stakeholder partnerships). The SDG framework also explicitly addresses the private sector 95 and more specifically, in relation to air pollution, SDG 11 refers to a subnational actor – cities, indicating the multilevel nature of SDG governance. In addition, Agenda 2030 document establishes a multi-stakeholder forum on science, technology, and innovation to inform the work of the High-Level Political Forum. 96
Having established that the SDG framework is a form of soft law with legal impacts and strong transnational characteristics, we now turn to discussing the extent to which the SDGs address the problem of air pollution.
SDGs and Air Pollution Linkages
Air pollution is not mentioned in any of the SDGs but it is referenced in targets and indicators under SDG3 on Health, SDG11 on Cities and SDG12 Sustainable consumption and production, 97 as summarised in Table 1. 98
Direct Treatment of Air Pollution in the SDGs.
On SDG3, the target focuses on reducing the impact from outdoor and indoor air pollution on public health. Its scope addresses air pollution as a whole, rather than focusing on a single air pollutant, 99 which indicates a more holistic approach to the problem.
On SDG11, the target focuses on improving air quality in cities where the progress is measured in terms of annual mean levels of particulate matter (e.g., PM2.5 and PM10). Pollution by particular matter and its components is indeed among the most important worldwide, and most urban areas – home to over half of the world's population – exceed the WHO guidelines for particular matter concentrations. 100 At the international level, particular matter pollution is regulated only in parts of the Northern Hemisphere through emissions reduction targets contained in Gothenburg Protocol to CLRTAP. Against this background, the inclusion of the indicator focusing on particular matter pollution in the SDG framework is significant. 101
Finally, on SDG 12, target 12.4 focuses on addressing the drivers of air pollution in the chemicals and waste sectors. The target has a systemic approach in aiming at the environmentally sound management of chemicals and wastes to reduce all types of their releases, including to air.
The substantive linkages between sustainable development and clean air however go beyond the three cases where air pollution is directly referenced in the SDG framework. These connections involve both synergies and trade-offs. Table 2 summarises the key substantive linkages between sustainable development and air pollution, and how the SDGs address them – mostly indirectly.
Linkages Between SDGs and Air Pollution. a
aThe table draws on the evaluations by Elder and Zusman, 2016, and Longhurst et al, 2018, but differentiates between (1) substantive linkages and (2) their operationalisation in the SDG framework, as well as adds new analysis.
The table demonstrates multifaceted, complex linkages between the SDGs. 102 Air pollution hinders the achievement of all SDGs in some way. 103 On the other side, achieving SDG7 ‘Affordable and clean energy’, SDG9 ‘Industry, innovation and infrastructure’, and SDG12 ‘Responsible consumption and production’, as well SDG8 ‘Decent work and economic growth’, and SDG13 ‘Climate action’ can lead to structural economic changes and therefore address the sources of air emissions. SDG3 ‘Good health and well-being’ and SDG11 ‘Sustainable cities and communities’, as well as SDG2 ‘Zero hunger’, SDG6 ‘Clean water and sanitation’, SDG14 ‘Life below water’, and SDG15 ‘Life on land’ can minimise negative impacts of air pollution on human health, agriculture and ecosystems. SDG4 ‘Quality education’, SDG16 ‘Peace, justice and strong institutions’, and SDG17 ‘Partnerships for the Goals’ contribute to developing strong processes and policies to address air pollution.
Although all SDGs are connected to the problem of air pollution in one or another way, it appears that some SDGs are particularly important for improving air quality. This concerns SDG7 as relating to clean energy and SDG9 concerning sustainable industrialisation and infrastructure: progress on these Goals is crucial for solving the problem of air pollution. 104
The comprehensive nature of the SDG framework also enables managing potential trade-offs. Achieving certain development objectives can lead to increased air pollution: for instance, enhancing energy access and economic growth, if conducted unsustainably, can result in worsened air quality. 105 In this respect, ensuring balanced progress on SDG9 ‘Industry, innovation and infrastructure’ and SDG 12 ‘Responsible consumption and production’ can help prevent such negative outcomes.
Although the SDG framework addresses air pollution to some extent, there are clear limitations to its approach. Most importantly, it does not treat air pollution systematically. 106 For instance, the target to improve air quality in cities under SDG11 only refers to particular matter pollution. This ignores other important pollutants and goes against the more integrated, multipollutant approach advocated by air pollution scientists and experts. 107 Further, the Goal only covers cities and ignores rural areas. 108 Consequently, pollution from the use of coal and biomass in open cooking and heating, which takes places both in urban and rural areas and is estimated to lead to from 2.6 to 3.8 million premature deaths annually, 109 is not fully captured. Similarly, air pollution resulting from agriculture is not covered.
Concerning SDG3 on Health, the relevant indicator has a limited focus on mortality from air pollution only and does not include other impacts on public health such as morbidity. 110 Here, UNEP for instance highlights that ‘the estimates of premature deaths underestimate the total number of individuals affected’ and that air pollution has potential health effects on everyone breathing in air. 111
Also, the SDG framework does not address linkages between air quality and other policy issues in a systematic way, for instance making no mention of SLCPs. 112 This is also reflected in the system of indicators: progress on the above-mentioned target 9.4 to upgrade infrastructure and industries for better sustainability is measured by one indicator only, which covers climate impacts (CO2 emission per unit of value added) and makes no reference to associated emissions of air pollutants. Lack of consideration of linkages can lead to losing significant co-benefits of integrated policies 113 and even unintended consequences where achievement of one target is associated with failure on another target. 114
Current Legal Responses to Air Pollution: Complementarity of the SDGs
Although the SDGs do not address air pollution systematically, there are still several ways in which they complement international legal frameworks and norms addressing the air pollution problem. This section unpacks the contribution of the SDGs across the analytical categories outlined in the introduction: (1) legal framing of the problem, (2) norm determinacy, (3) norm addressees.
Legal Framing of the Problem
First, the SDGs offer a broader
In international law, air pollution is problematised when it leads to transboundary harm. It is accordingly a matter to be addressed by (sovereign) nations: those affected by pollution and those responsible for it. This problem-framing is reflected in the existing network of regional treaties and soft law frameworks on transboundary air pollution. Under such framing, responsibility lies with individual nation states, and problem-solving takes place in accordance with the rules and principles of international law such as state sovereignty, state responsibility, and the no-harm rule. Therefore, if the sources and harms of air pollution are confined within national borders, international law – under its sovereign-territorial paradigm – would consider this as a matter of national jurisdiction.
In contrast, the SDG framework considers air quality through the lens of sustainable development, which some describe as a ‘cosmopolitan understanding.’ 116 It presents clean air as an important determinant of health, for instance by highlighting the public health impacts of air pollution (target 3.9) and underscoring the importance of achieving good urban air quality (target 11.6). Related to this, the WHO serves as the custodian agency responsible for monitoring progress toward clean air targets under the SDGs. Notably, SDG Indicator 7.1.2 ‘Proportion of population with primary reliance on clean fuels and technology’ for SDG 7 ‘Affordable and clean energy’ is considered primarily from an air quality perspective, and therefore also falls under the WHO's reporting responsibility.
By considering air pollution as part of the global development agenda, the SDG framework also promises a more holistic approach to air pollution through addressing not only end emissions but the very sources of air pollution. 117 Many of the SDGs promote a systemic transformation of energy systems, industry and infrastructure towards better sustainability, which will in turn lead to a less polluting economy overall. The COVID-19 pandemic starkly demonstrated how reductions in economic activity can lead to significant improvements in air quality, 118 albeit at considerable social and economic cost. In contrast, air pollution policies often follow a reactive approach where the focus lies on emissions that have already occurred and their effects. Accordingly, they typically contain end-of-pipe measures, as this is assumed to be more cost-effective than addressing structural changes to energy systems and the economy. 119 The SDGs take an entirely different approach.
Indeed, the link between clean air and the wider development agenda is also acknowledged in several Voluntary National Reviews: notably, Mongolia's Voluntary National Review report devotes an entire chapter to air pollution, emphasizing that it is ‘an example of a complex, multifaceted development challenge that would benefit from cross-sectoral coordination and multi-stakeholder partnerships through a sustainable development lens.’ 120
Air pollution – to the extent it is addressed - is thus framed in the SDGs as requiring a coordinated global response, given its negative impacts on the achievement of global goals for sustainable development. By establishing global targets on air quality, the SDGs effectively frame air pollution as a global policy problem and not just a local or regional one. The territorial factor –whether the sources and impacts of air pollution lie within or beyond national borders – is not important in problematizing air pollution from a global sustainable development perspective. To be clear, as noted in Section 4, the implementation of the SDGs is still state-driven. At the same time, in terms of responsibility, such framing places less emphasis on nation-states compared to the transboundary pollution framing under international law.
Norm Determinacy
Concerning
The degree of norm precision can be analyzed in terms of how well the norm defines ‘the addressee (who), the substance (what), and the timeline (by when)’. 121 Both targets 3.9 and 11.6 aim at reductions of adverse health and environmental impacts, respectively (in case of 3.9 – substantial reductions), and therefore their substance is worded in a concrete way. The two targets are also bound in temporal terms: both should be achieved by 2030. The related indicators are expressed in a quantified way: for example, progress on urban air quality is measured in terms of annual mean levels of fine particulate matter (indicator 11.6.2), while progress on the health impacts of pollution is measured in mortality rate attributed to household and ambient air pollution (3.9.1). Significantly, the targets focus on the end goal, on what is to be achieved by countries, and not on the process by which this goal is to be achieved. This supports the point made by Brölmann 122 that the SDG targets are closer in nature to obligations of result than to the obligations of conduct that are widespread in international law.
Global applicability of SDG targets on air pollution is important from the perspectives of both generating global data on air quality 123 and supporting developing countries in strengthening their monitoring capacities and policy responses. According to UNEP, most countries conduct monitoring of air quality sporadically, if at all, which limits understanding of adverse effects of air pollution and impedes development of effective responses. 124 The problem is particularly acute for low- and middle-income countries. 125 Here, global targets on reducing health impacts of air pollution and on urban air quality can facilitate domestic action as well as international capacity building activities and financial assistance to improve availability of data. For instance, the WHO has already been engaging in work to promote better monitoring and reporting on air quality worldwide in the context of its custodial responsibilities on SDG air quality targets. 126 In addition, the SDG targets can facilitate a wider adoption of national ambient air quality standards, which provide an essential framework for harmonisation of policies and legislation. Globally, only 63% of all countries have embedded such air quality standards in their legislation. 127
Norm Addressees
The SDG framework defines its
Concerning duty-bearers, although the reporting and review process remains state-driven, the broad wording of the SDG framework - ‘[a]ll countries and all stakeholders [..] will implement this plan’ 132 - suggests that responsibility for achieving the Goals is shared not only by states but also by a wide range of relevant stakeholders.
The transnational elements of the SDG framework are important for addressing the complex linkages between air pollution and sustainable development. In particular, the emphasis on sub-national actors such as cities under Goal 11is crucial for improving urban air quality. By involving actors beyond national governments, the framework facilitates ‘a more multi-level, multi-actor, multi-agenda and multi-sector approach’ to implementing the SDGs. 133 In its inclusive approach, the SDG framework fosters new, innovative partnerships across all levels of governance. 134 The early assessments have already demonstrated a certain impact of the SDGs on cities and regional governments. 135 Indeed, by 2024, more than 270 cities and subnational governments have engaged in the process of preparing Voluntary Local Review reports on the achievement of the SDGs, which mirror Voluntary National Reviews. 136 This has been a bottom-up initiative which is not formally a part of the review and follow-up architecture of the SDG framework. Transnational actor networks such as C40 Cities Climate Leadership Group are important for air quality governance and already active in supporting cities worldwide in improving their air quality. 137 Beyond cities, broader partnerships have emerged to advance the air quality agenda in the context of the SDGs. One example is the BreatheLife campaign, led by the WHO, UNEP and CCAC, with the aim to commit national and sub-national governments to achieving WHO Air Quality Guidelines to halve the number of deaths from air pollution by 2030. 138 The campaign was launched in 2016 and now covers 79 cities, regions and countries. The WHO's work on air quality agenda has advanced in 2025 with a voluntary commitment by governments to cut health impacts from air pollution by 50% by 2040. 139 This demonstrates that broad coalitions of international organisations, transnational networks, and philanthropies have mobilised around the global air quality agenda in the context of the SDGs.
Conclusions
This article provided a comprehensive assessment of how the SDG framework complements international legal frameworks and norms on air pollution, and thereby contributes to problem-solving.
The article outlined the existing approaches to air pollution in international law, concluding that air pollution is not governed by a globally applicable treaty but rather by a fragmented network of regional agreements and cooperation mechanisms on transboundary air pollution.
The article then demonstrated that the SDG framework is a form of soft law with legal impacts and strong transnational characteristics. It then explained that, while the SDG framework does not provide a comprehensive approach to air pollution, it does directly integrate air quality into several of its targets and indicators: in relation to reducing the health impacts of outdoor and indoor air pollution (3.9), improving air quality in cities (11.6), and air releases from chemicals and waste (12.4). More broadly, there are complex multifaceted linkages between all SDGs and air quality.
The article then discussed how the SDGs complement existing international legal responses to air pollution and can contribute to addressing this problem. First, the SDGs offer a broad legal framing of air pollution as a global issue, given its impacts on global health and development. Second, the SDG framework proposes relatively precise targets and indicators that are globally applicable, which is important given the lack of a global legal instrument on air quality. Third, the SDG framework defines its norm addressees in broad terms. This creates an opportunity for all actors – nation states, international organisations, and various stakeholders – to emphasise the need to tackle the air pollution problem, incorporate related policies into national development priorities, and develop multi-stakeholder, multi-level cooperative approaches.
Air pollution is a major environmental issue that threatens sustainable development and planetary integrity, and global cooperation efforts are required to mitigate it. Although the overall impact of the SDGs remains unclear, 140 including on the development, interpretation and application of law, the SDG framework nonetheless provides a valuable foundation for tackling air pollution globally and, in this way, can inspire further legal change. As discussions on the future of the SDGs beyond 2030 are already underway, attention should be paid to developing a more systematic approach to air pollution in the next framework, recognizing its complex linkages with other environmental problems and overall sustainable development.
Footnotes
Acknowledgements
The author wishes to thank Eric Zusman for their useful comments on earlier drafts of this paper.
Funding
Research for this article was funded by the Research Council of Finland (355184).
Declaration of Conflicting Interests
The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.