Strategies, Policies, and Recommendations for Reducing Air Pollution in the Indian Himalayan Region

Abstract

The Indian Himalayan Region is an important ecological location, but it is now suffering from serious air pollution due to activities like vehicular emissions, industrial activities, biomass burning, and regional atmospheric circulation, which have led to increased air pollution and threatened ecosystems, human health, and the climate. This paper employs qualitative document analysis through reviews of the national climate policies, institutional frameworks, state documents, and technology-based solutions. It concludes that despite comprehensive national policies, many gaps exist between the policy design and ground-level implementation. Our findings reveal three critical governance gaps: (i) altitude-specific regulatory failures in vehicular emission standards, (ii) Institutional fragmentation limiting enforcement capacity, particularly for diffuse sources, (iii) economic barriers preventing sustained adoption of clean fuels despite subsidy programs. According to this research, we propose a three-pillar framework integrating (i) investment in sustainable technology and green infrastructure, (ii) strengthening institutions and policies, and (iii) fostering behavioral change and public awareness. The study contributes to the limited literature on region-specific air quality governance and offers a strategic framework to support climate resilience in the Himalayas.

1. Introduction

Mountains cover around 24% of the Earth’s land surface and host a wide array of biodiversity [1]. The Himalayas provide hundreds of millions of people living there with freshwater and other facilities. The Himalayas are among the youngest, largest, and highest mountains in the world and extend across seven countries, namely India, China, Pakistan, Myanmar, Nepal, Afghanistan, and Bhutan. The Indian Himalayan Region (IHR) serves as a water tower for South Asia by fulfilling ecosystem services to over 240 million inhabitants and 1.65 billion people in downstream [2]. However, the region is facing challenges due to climate change, unsustainable land use, natural hazards, unplanned development, and socioeconomic dynamics, all of which require urgent attention from the scientific community and policymakers to prevent long-term negative consequences [3].

The IHR is a distinct geographical entity, comprising several environmental, cultural, and social frameworks. The region makes up 18% of India’s total land area and has a total geographic area of about 591,000 sq km [4]. The IHR covers 13 states and union territories, namely Arunachal Pradesh, Assam, Himachal Pradesh, Jammu and Kashmir, Ladakh, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura, Uttarakhand, and West Bengal [1]. Figure 1 shows the geographical extent of the Indian Himalayan Region, comprising 13 states and union territories. It is of world importance because of the geo-climatic roles of the cryosphere and river basins, which feed various civilizations. The region is already experiencing long-term problems such as resource depletion, ecological imbalance, and economic unsustainability due to altered demographic patterns, globalized economy, and risk of climate change [5].

Air pollution is becoming an increasing threat to the Himalayan Region. The air pollution in the region comes from various factors like the confluence of local emissions and transboundary transport from the Indo-Gangetic Plain [6]. It contributes 30–45% of wintertime particulate matter concentrations at southern Himalayan sites [7,8]. This transboundary flux, combined with unique topographic features like deep valleys and temperature inversions, creates a condition where pollutants are trapped for long, thereby prolonging exposure and increasing health risks [7,8,9,10]. The annual PM_2.5 levels exceed both National Ambient Air Quality Standards (40 μg/m³) and World Health Organization guidelines (5 μg/m³) by factors of 3–8 across multiple IHR cities [11,12,13,14]. Household biomass burning remains a predominant contributor to indoor air pollution, particularly impacting vulnerable populations [15]. Beyond domestic sources, urbanization, industrial expansion, and increased vehicular traffic contribute to ambient concentrations of particulate matter (PM_2.5 and PM₁₀), nitrogen oxides (NOx), sulfur dioxide (SO₂), and ozone (O₃) [7,8,16,17]. Both natural and human-induced forest fires exacerbate seasonal air quality issues, releasing substantial pollutants into the atmosphere. These emissions compromise air quality and have adverse effects on human health, ecosystems, monsoon patterns, water supply, agriculture, and livelihoods [18]. The deposition of Black Carbon (BC) from sources such as forest fires and incomplete combustion increases glacial melting. It is an environmental impact that is often beyond the reach of traditional air quality laws. Recent discussions highlight that the region is highly vulnerable to air pollution from both internal and external sources, particularly in the Indo-Gangetic Plains, where numerous rural areas face serious problems [19]. The consequences include increased risks of respiratory and cardiovascular diseases, morbidity and mortality, and adverse effects on regional climate patterns, glacier health, and agricultural productivity [20]. Addressing air pollution in this region is therefore imperative for environmental sustainability and public health, as the region is delicate and undergoing rapid transformation [21].

Rapid urbanization and infrastructural development, including road construction and housing, intensify local emissions. Economic development initiatives relating to hydropower, tourism, and small-scale industries also contribute to the air pollution burden. These activities, while driving economic growth, require careful environmental impact assessments and sustainable planning to mitigate deterioration in air quality [3,17].

IHR sustains nearly 50 million inhabitants through water, energy, and ecosystem services [22]. This creates a high-stakes policy paradox, as it is simultaneously exposed to local emissions magnified by valley meteorology, winter inversions, and transboundary pollutant transport from adjacent airsheds, which combine to create hazardous episodic and chronic exposure. Despite India’s comprehensive air quality policy framework, many gaps remain between policy intentions and ground-level implementation. This paper addresses the need to assess mitigation policies. Many studies have analyzed air pollution in the Himalayas, but most remain incomplete, focusing either on technological interventions or on policy initiatives in isolation [7,8,21].

This paper seeks to fill these gaps by providing a methodological evaluation of environmental statutes, understanding the pollution control mechanisms in place in the IHR, identifying their limitations, and proposing strategic pathways for improved implementation. We address three questions: Do good policies on paper translate into weak outcomes in practice in mountain regions? What intervention packages are most likely to provide climate benefits? What is the role of a stringent, comprehensive, and integrated policy assessment in controlling air quality in this region? It assesses the effectiveness of India’s policies, identifies significant institutional, technological, and behavioural barriers, and proposes an integrated framework combining policy, technology, and community interventions. Through this multisectoral synthesis, the paper provides an understanding of air quality governance in IHR and proposes a strategic roadmap for long-term emission reduction in the region. This research improves mountain governance by providing comprehensive, region-specific insights into policy effectiveness and by developing a replicable analytical framework for similar vulnerable mountains. It moves beyond descriptive policy to explain why well-designed regulations often underperform in high altitude settings. This paper also seeks to demonstrate that effective IHR air quality management requires national coordination rather than state-based approaches, and proposes an outcome-focused, altitude-adaptive governance framework that can be transferred to other similar vulnerable mountain regions.

2. Literature Review

2.1. Temporal and Spatial Patterns of Air Pollution in the IHR

Direct observational studies show that trans-Himalayan valleys can act as pathways for pollutant transport, and multi-year measurements document seasonal cycles that are consistent with regional transport and valley winds [23]. During winter months (December to February), particulate matter concentrations such as PM₁₀ and PM_2.5 tend to peak in some regions due to temperature inversions, increased biomass burning, and stagnant atmospheric conditions. In contrast, during the summer monsoon period (June to August), aerosol concentrations rise due to agricultural residue burning, enhanced vehicular activity, and regional transport [21,24]. The southern boundary of the Himalayas experiences constant winter fog, haze episodes, visibility, and increased accumulation of pollutants linked to IGP [25]. In winter, due to temperature inversion, pollutants from heating fires, agricultural activities, and biomass burning are trapped below the warmer layer, resulting in thick, dense haze visible in satellite images [26]. This condition is aggravated by the use of biofuel for heating and biomass burning, leading to higher levels of carbonaceous aerosols, as well as sulfates and nitrates, in that area [27,28]. According to climate models, up to 20% of glacial melting occurs through aerosol absorption [19], and the region’s annual rainfall is disrupted [29]. These disruptions have serious environmental and socioeconomic consequences, including impacts on water supply, agriculture, and ecosystem resilience [30,31]. The diurnal variations are similar in valleys and on plains; the morning and evening peaks are mainly due to human activity and meteorology. During these times, pollution levels are elevated, and the ozone layer reaches its peak in the middle of the day and is reduced at night by titration with nitric oxide and dry deposition. Interestingly, at high altitudes, the pattern is different: pollution from lower elevations is carried upward during the afternoon, increasing particulate matter concentrations that remain high due to the absence of ozone depletion at night [32]. Regional haze and persistent winter fog in the southern Himalayan regions reflect an interaction of emissions, weather patterns, and boundary-layer physics. The assessment reports show that winter haze and fog have increased across the IGP, reducing visibility and degrading air quality in the southern mountains [8,22]. The Himalayan snow studies show that black carbon in snow measurably reduces albedo and can shift melt timing from days to weeks under realistic concentration conditions [33]. Air pollution in the IHR has been summarized in Figure 2 and has many sources of emission, including vehicles, industries, biomass burning, and transboundary flows from the Indo-Gangetic Plains. The figure illustrates how these pollutants are moved around complex atmospheric routes and eventually lead to environmental, climatic, and health effects in the region. The assessment further synthesizes evidence that air pollutants within and near the region can amplify cryosphere impacts and influence regional rainfall distribution but emphasizes complex interactions that should not be reduced to single deterministic percentages without context. This supports the fact that IHR air quality cannot be managed effectively using only city- or state-bound controls, because a good portion of the load is transported across administrative boundaries.

This is now also reflected in high-level regional thinking, as evidenced by recent multi-country, multi-sector synthesis work on the Indo-Gangetic Plains and Himalayan foothills. It emphasizes coordinated, evidence-based approaches and regional cooperation, treating the region as a connected airshed. For formal South Asian cooperation, existing mechanisms include the Malé Declaration process under the South Asia Co-operative Environment Programme, ICIMOD’s Knowledge Platforms, and the SAARC Environment Framework [34].

2.2. Policy and Regulatory Framework

India’s air quality governance operates through multiple legislative instruments. The Air (Prevention and Control of Pollution) Act, 1981, led to the creation of SPCBs (State Pollution Control Boards) with powers to set emission standards, monitor sources, and prosecute environmental offences. The Environment (Protection) Act, 1986, grants broad rule-making power to the central government, enabling specific rules like Hazardous Waste Rules, 1989, and Plastic Waste Management Rules, 2016. The Motor Vehicles Act, 1988, determines and authorizes fuel-quality and emission standards [35]. The National Green Tribunal (NGT) provides environmental dispute resolution and compliance enforcement. National Ambient Air Quality Standards (NAAQS) define permissible pollutant concentrations. At the same time, at the program level, NCAP (National Clean Air Programme) has evolved from an initial objective of 20–30% to a 40% PM₁₀ reduction or meeting the national annual PM₁₀ standard (60 µg/m³) by 2025–26 and reduction in particulate matter in non-attainment cities by 2026 [36]. The same reporting describes operational features that matter for evaluation—Continuous Ambient Air Quality Monitoring Systems (CAAQMS), city action plans, and the PRANA portal (Portal for Regulation of Air-Pollution in Non-Attainment cities) used to monitor implementation.

The NAAQS of India specify annual standards, including PM_2.5 = 40 µg/m³ and PM₁₀ = 60 µg/m³ [37]. The WHO Global Air Quality Guidelines of 2021 are substantially more stringent, with an annual mean PM_2.5 level of 5 µg/m³ and annual mean PM₁₀ level of 15 µg/m³, and emphasize that adverse health effects are evident at lower concentrations than previously understood [14]. This standards gap should be used analytically by the agencies as it provides a basis for defining health and regulatory compliance targets. The MoEFCC (Ministry of Environment, Forests & Climate Change, India) itself emphasizes that monitoring and evaluation depend on CAAQMS and harmonized datasets. It is an area where the Himalayan assessment also calls for instrument comparability, validated databases, and vertical profiling to understand mountain pollution [38].

IHR states show varied policy adoption and enforcement. Among the states of IHR, Himachal Pradesh implemented the Air Act earliest in 1981, followed by the introduction of ambient air-quality monitoring in 1986. It also introduced lead-free petrol, Bharat Stage (BS) Norms, and stringent controls on stone crushers and cement plants [16,21,39]. Later, Uttarakhand adopted the Air Act in 2002 and has since implemented NCAP for its non-attainment cities, Kashipur and Rishikesh [40]. The state has introduced green taxes on diesel vehicles, banned 15-year-old vehicles, and promoted ropeways and electric mobility [21,22]. The state has also worked diligently to implement the Pradhan Mantri Ujjwala Yojana (PMUY), which has increased LPG coverage in rural households to 88%, reducing indoor air pollution [41].

Sikkim pioneered environmental legislation among the IHR states in the 1990s. It was also the first state to ban firecrackers and agricultural waste burning in 2014, and converted all farmlands to certified organic, thus eliminating chemical pesticides to increase air quality [42,43]. These measures address pollution from waste burning, chemicals, and fireworks and reduce chemical emissions. Jammu and Kashmir and Ladakh have no separate air act. As there are no region-specific approaches to the implementation of Air Act, central environmental laws became directly applicable to Jammu and Kashmir and Ladakh after Section-370 was revoked in 2019 [44]. These places do have local regulations and policies governing tourism, including caps on vehicle numbers in sensitive areas such as Gulmarg. Several northeastern Himalayan states, such as Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, and Assam, implemented the Air Act through SPCBs and established State-Level climate change initiatives focusing on clean energy and air quality monitoring [45].

Despite these frameworks, IHR faces monitoring deficiencies because state-level regulatory maturity is unevenly distributed: states such as Himachal Pradesh and Sikkim exhibit a relatively active approach to environmental governance, while other Himalayan states rely heavily on national-level regulations and make minimal adaptations. More importantly, the majority of policy reviews are conducted based on the intent of their regulations rather than implementation outcome, which provides little information on how terrain, institutional capacity, and socioeconomic limitations can influence actual effectiveness.

3. Methodology

The study follows a qualitative data analysis approach to systematically examine national and state-level air quality policies, regulatory frameworks, technological interventions, and programme initiatives implemented across the IHR. We performed a scoping review using the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis)-aligned systematic scoping review (PRISMA-ScR) methodology [46]. It was used to map and synthesize peer-reviewed evidence and authoritative reports on air pollution drivers, impacts, and governance interventions in IHR and its connected literature. The IHR air quality literature encompasses atmospheric chemistry, public health, energy economics, forest ecology, transport engineering, and public policy, making a rigid meta-analytic approach methodologically unsuitable. We, therefore, adopted a structured narrative synthesis approach that preserves contextual nuance while maintaining systematic transparency.

The methodology integrates structured document collection, thematic, and cross-sectoral synthesis. This study follows a three-stage research design, which includes (i) Document Identification, (ii) Document selection and Screening, and (iii) Cross-Sectoral Synthesis and Framework Development. The policy and regulatory documents reviewed key policy frameworks such as the National Action Plan on Climate Change (NAPCC), legal texts and India’s Nationally Determined Contributions (NDCs), NAAQS, Motor Vehicle Act, Environment Protection Act, Air Act, Solid Waste Management Rules, Plastic Waste Management Rules, Hazardous Waste Rules, State level policies, and national missions. Case studies of climate action projects were also examined to understand the governance structures and strategies that help achieve climate goals in the region. It further referred to various technological interventions, including Central Pollution Control Board (CPCB) and State Pollution Control Board (SPCB) annual reports, Ministry of Power and Ministry of Renewable Energy reports, NITI Aayog energy transition reports, and NCAP city-level action plans. Then, peer- reviewed academic literature from 2000–2025 were retrieved from databases like Scopus and Google Scholar for broad coverage supplemented by targeted retrieval of high-authority grey literature using keyword combinations such as “Air Pollution Himalayas”, IHR policy analysis”, “Black carbon Himalayas”, “Mountain air quality monitoring”, “Schemes IHR”, “Policies of mountains”, “Biomass Burning in Indian Himalaya”, and “Clean Cooking Transition”. The screening and extraction were guided by a pre-specified template, including pollutant metrics; site characteristics, including elevation, source attribution, seasonality, policy mechanism, implementation barriers, and reported effect sizes, wherever available. Finally, the relevant articles were filtered, read, thoroughly considered, and added to this study. We included empirical studies and official reports that reported measurable air-quality outcomes, evidence, or evaluated policy instruments relevant to the region. The studies were included if they focused on IHR states or high-altitude regions of India, were published in peer-reviewed journals, government reports, or policy documents, and addressed air quality, pollution sources, health impacts, or policy interventions.

The studies were excluded if they focused solely on plains or non-mountain regions, lacked empirical data or policy analysis, were duplicate publications, conference abstracts without full text, or were not in English. We excluded opinion pieces and sources without reproducible methods or traceable datasets. To avoid an arbitrary narrative review, the full keywords, the screening counts, and reasons for exclusion are reported in a PRISMA flow diagram (Figure 3). A total of 2181 documents published by 30 September 2025 were initially identified. After screening and relevance assessment, 84 documents were included in the final analysis. This article synthesizes and critically compares existing evidence rather than reporting new experimental measurements. Various sectoral interventions are assessed based on implementation effectiveness, contextual suitability, and governance constraints.

4. Thematic Synthesis

4.1. Policy Framework Assessment

As discussed earlier, IHR states derive their regulatory authority from national statutes to set emissions standards, monitor sources, and prosecute violations. When comparing air quality management policies across the Himalayan states of India, significant differences emerge in regulatory maturity, enforcement, and outcomes. The key policy tools used by individual states or union territories, their fundamental strengths, and the long-standing implementation gaps that are pulling down the effective air pollution control are summarized in

Table 1. Comparative Analysis of Air Quality Management Policies and Gaps in the Indian Himalayan Region.

State/UT	Major Policies	Strengths	Implementation Gaps
Himachal Pradesh	Air Act of 1981, BS norms, stone crusher regulations	Early monitoring, industry-specific controls	Informal units evading enforcement
Uttarakhand	NCAP, Green tax, EV policy of 2025	Mobility reforms, LPG uptake	Biomass dependence during winter
Sikkim	Waste burning ban, organic agriculture	Strong environmental leadership	Limited industrial regulation
Ladakh	EV Policy of 2022, national laws	Tourism vehicle caps	Harsh terrain, limited monitoring
J&K	NCAP, vehicle caps in tourist zones	Central law harmonization	Weak enforcement post-reorganization
North-Eastern States	Climate cells, forest programs	Strong potential for RE	Dispersed settlements hinder monitoring

. As shown in Table 1, states such as Himachal Pradesh and Sikkim have stronger policy frameworks, while certain regions continue to face constraints in enforcement and monitoring.

4.2. Sectoral Analysis and Implementation Gaps

4.2.1. Vehicular Emissions

The transport sector is the major contributor to air pollution in IHR due to rapid motorization, rugged terrain, and the persistence of ageing vehicle fleets. The initiatives taken by governments to curb vehicular pollution rely heavily on strengthening fuel standards, installing retrofit technologies, and establishing stricter inspection regimes. This includes the use of catalytic converters and Euro-equivalent BS norms. India has enforced advanced policy programs such as the passenger vehicle emission standards BS-6 and the comprehensive fuel economy standards for new vehicles [42,47]. The Government has also tried to improve diesel control under these standards to mitigate emissions from the newest vehicle fleets. However, their effectiveness declines substantially under high-altitude operating conditions. Reduced oxygen availability, cold-start emissions, heavy work on steep slopes, and altitude-induced combustion inefficiencies collectively undermine the performance of emission controls in mountainous environments [39,48]. The regulatory focus on new vehicles in the IHR states is not meeting the targeted approach toward cleaner air, as they suffer from a high density of old, poorly maintained vehicles that often operate on adulterated fuel [49]. As a result, it requires concentrated efforts on the inspection and maintenance of the current fleet, explicitly targeting the small fraction of designated super-emitting cars, which account for almost half of total vehicular emissions. The regulatory gains achieved at the manufacturing stage fail to translate into proportional improvements in ambient air quality [50].

4.2.2. Advancing Electric Mobility

In recent developments, the Government has launched various initiatives to promote electric vehicles (EVs), as they are associated with lower air pollution by eliminating tailpipe emissions. In 2024, the Government initiated a central policy spindle with the launch of the PM Electric Drive Revolution in the Innovative Vehicle Enhancement Scheme [51]. This framework was notified in March 2024 and allocates ₹2000 crore for the installation of public charging stations in India [52]. The environmentally sensitive zones, such as Himachal Pradesh, Uttarakhand, and Sikkim, are targeted for enhanced EV production and infrastructure development, which is expected to promote electric mobility in the region. Some states in the region have also formulated dedicated EV policies. Ladakh enacted the Ladakh Electric Vehicle and Allied Infrastructure Policy in 2022, which aims to promote, adopt, and incentivize charging infrastructure and to increase research and development in the specific sector [53]. Himachal Pradesh also adopted an Electric Vehicle Policy in 2022, targeting Shimla, Baddi, Dharamshala, and Mandi as model cities ready for the adoption of electric mobility [54]. There is also a Uttarakhand EV Policy, 2025, which seeks investment in local manufacturing, battery production, and charging infrastructure to make the state a key player in cleaner transportation and improved air quality. The other states have not undertaken any explicit action to enhance this step locally [55]. These should be used to reduce tailpipe emissions but cannot be used in isolation as a PM reduction strategy, since road wear, resuspended dust, and tire wear remain contributors to PM₁₀ [35,39,50,51]. Road dust resuspension is often the most significant non-exhaust PM₁₀ fraction across regions, and heavier battery EVs can reduce PM₁₀ only marginally while potentially increasing PM_2.5 under some scenarios [50,56,57]. Hence, the EV policy must be paired with non-exhaust mitigation measures such as road-surface management, weight control, tire material standards, and braking-profile optimization. Experimental results indicate that regenerative braking can drastically reduce brake-wear particles under specific operating modes, providing a concrete design-and-enforcement lever specifically relevant to steep slope mountain driving [58].

4.2.3. Inspection, Maintenance, and Management of End-of-Life Vehicles

A legislative initiative was made with the notification of the End-of-Life Vehicles (ELV) Rules, 2025. These rules burden producers through Extended Producer Responsibility, holding vehicle manufacturers responsible for the environmentally sound management and recycling of vehicles at the end of their operational life [59]. This policy covers all types of vehicles, including those used for transportation and non-transportation, and sets specific recycling targets.

The ELV framework is essential in states like Himachal Pradesh, Uttarakhand, Jammu and Kashmir, and Ladakh, which have high concentrations of old commercial fleets due to extended vehicle use cycles. The strengthening of inspection and maintenance frameworks and the operationalization of these regulations are paramount due to the complex topography, which is confined by valleys, experiences temperature inversions and has limited atmospheric dispersal, thereby contributing to the accumulation of emissions in these areas [7,8]. The older vehicles are in poor condition and are grossly under-maintained, contributing to localized pollution burdens. The implementation of inspection and maintenance regimes serves to identify and regulate high-emitting vehicles. These rules complement each other in a way that manufacturers ensure production, dismantling, and recycling of vehicles at the end of their operational life and regular inspection of old vehicles in these states

In the Himalayas, effective implementation of ELV Rules is supported by accessible inspection infrastructure and enforcement capacity. It has the potential to yield substantial reductions in localized PM and NOx concentrations, particularly in narrow valleys and urban centers prone to pollutant trapping. However, without parallel investments in inspection capacity, transport access to authorized scrappage facilities, and economic incentives for fleet replacement, the emission-reduction potential of the ELV framework is likely to remain under-realized. Thus, these measures have implications for mitigating vehicular pollution in the region by facilitating systematic removal, replacement, or recycling of end-of-life vehicles, which are among the highest contributors to particulate matter (PM) and NOx emissions.

4.2.4. Implementation Challenges: High-Altitude Performance Degradation

The uniform national standards do not adequately address the challenges of high altitude. National policies fail since engine performance and emissions degrade significantly on steep inclines and at high altitudes [60]. Additionally, the deployment of advanced emission-control technologies, such as diesel particulate filters, is hampered by supply chain constraints. They only operate effectively with ultra-low sulfur diesel fuel, ideally with a concentration below 50 ppm, which is rarely available in many parts of the region [61]. The deficiency in the fuel supply chain that renders advanced pollution-control systems functionally obsolete in new vehicles is the continued use of high-sulfur fuel. IHR has high concentrations of poorly maintained, aging vehicles operating on adulterated fuel. The policy focuses on new-vehicle standards, neglecting the existing fleet, which is responsible for the majority of emissions.

Despite national infrastructure plans, the physical barriers to EV adoption and the clarity around cleaner air remain in question. EVs are known to reduce tailpipe emissions but still contribute to air pollution through non-exhaust emissions like tire and brake wear [56,57,60]. The challenge, which also adds to doubt about the promotion of EVs, is that if the electricity used to charge the battery comes from burning fossil fuels, then it offers less advantage over conventional methods, and net emissions reduction is diminished. EVs in this region are also hampered by a lack of charging infrastructure in remote areas and by performance limitations on steep terrain. The national policies on these vehicles have ignored the area’s geographical challenges. Thus, EV transitions must be coupled with the expansion of clean energy and region-specific mobility planning. According to the policy effectiveness assessment, vehicular emissions are only partially effective due to a mismatch between standard regulations and the realities of high altitude, insufficient development of the clean-fuel supply chain, and a lack of policy ambition for EV infrastructure.

4.3. Industrial Emissions and Regulatory Measures

In India, the industrial sector accounts for over 98 per cent of CO₂ emissions, with over 90 per cent concentrated in four primary sub-sectors: metals, minerals, machinery, and rubber and plastics, predominantly associated with fossil fuel burning [62]. According to the 5th Assessment Report of the Intergovernmental Panel on Climate Change, Earth’s temperature is steadily increasing due to the proliferation of anthropogenic activities, resulting in increased concentrations of GHGs in the atmosphere and thereby impacting both natural and human systems [63]. The adoption of energy-efficient technologies, optimizing production processes, investing in renewable energy, adopting cleaner technologies, implementing pollution control measures, and promoting sustainable practices can minimize environmental impact in the Himalayan region [62,64].

Industrial emissions’ regulatory interventions have produced measurable but uneven improvements in air quality across the IHR. The states such as Himachal Pradesh and Uttarakhand, where cement production, hydropower tunnelling, stone crushing, and small-scale manufacturing are prominent, show reductions in localized particulate matter (PM_2.5 and PM₁₀) concentrations in zones where pollution control devices such as electrostatic precipitators, bag filters, and continuous emission monitoring systems have been implemented [16,64]. Uttarakhand has contributed to improved compliance with consent-to-operate norms under the Air Act and the imposition of green taxes, thereby reducing fugitive emissions from major industries.

However, overall air quality remains low due to the persistent dominance of unregulated and semi-regulated sources of emissions. In several states, including Jammu and Kashmir, Himachal Pradesh, and Uttarakhand, many construction-based dust, informal brick kilns, roadside stone crushers, and hot mix plants continue to generate particulate matter [7,8,65,66]. Their frequent relocation to riverbeds or remote valleys enables them to bypass monitoring, thereby weakening the air-quality improvements offered by the CPCB reforms of 2025. As people are still dependent on brick houses, there are still plenty of brick kilns. The brick kilns remain a significant emitter of PM, Black Carbon, SO₂, and NO₂ [11,67]. Although India has taken steps to promote Zig-Zag Kiln Technology and has revised particulate standards, adoption in this region remains incomplete.

The cumulative effect of high-altitude topography and wintertime inversions on ambient air quality remains modest due to the small industrial base in certain states, such as Sikkim; however, persistent biomass burning, transport emissions, and construction dust, overshadow the benefits of industrial energy-efficiency improvements [68].

Industrial decarbonization strategies such as Carbon Capture and Utilization (CCU) offer long-term potential to reduce CO₂ emissions. However, their direct impact on air pollutants such as PM, SO₂, and NO_x will remain limited unless paired with broader controls on process emissions and fugitive dust from small-scale units and construction-led pollution [11,69,70]. Initiatives such as financial incentives for emission reduction, capital subsidies for adopting new technology, and financial assistance for improving efficiency and achieving certification can be taken in order to prevent emissions from the MSME (Micro, Small & Medium Enterprises) sector of the Himalayan Region, which in turn will help them to contribute to a more sustainable and resilient region [71]. According to the policy effectiveness assessment, industrial emission controls are moderately adequate in large, registered units but fail to address dispersed and mobile pollution sources, informal-sector emissions, small-scale units below regulatory thresholds, and topographical pollution accumulation.

4.4. Renewable Energy Transition

Electricity generation accounts for around 40 per cent of total emissions in India [72]. This is primarily because of the extensive use of coal in industry, which accounts for over 70 per cent of electricity generation, 50 per cent of installed capacity, and the majority of sectoral emissions. Renewable energy presently accounts for about 48 per cent of the industry’s total installed capacity, including hydropower [72]. While hydroelectric power plants exist in the Himalayas, thermal power plants fueled by coal in neighboring states such as Punjab, Uttar Pradesh, Bihar, Assam, and Haryana have a direct impact on the Himalayas [73]. The states in the Himalayas have immense hydropower potential, as they rely on hydropower due to the abundant rivers. Hydropower projects like Tehri in Uttarakhand and Nathpa Jhakri in Himachal Pradesh have lower operational emissions than coal. However, backup diesel generators common in remote northeastern states, where power supply is erratic, contribute immensely to emissions [74]. Policies that encourage renewable energy need to be promoted to reduce emissions in IHR. These include Sikkim’s renewable energy programmes that promote micro hydel and solar projects, and Uttarakhand and Arunachal Pradesh investment in off-grid solar and small hydropower plants [75]. National Solar Mission, National Wind Energy Mission, National Hydro Power Mission, Smart Grid Project, Clean Energy Corridor, etc., collectively aim to increase the share of renewable energy in the Himalayan region’s energy mix, decrease dependence on fossil fuels, and help in mitigating the environmental impacts of power generation [76].

India has updated its NDCs, aiming to achieve 50 per cent of its total installed electric power capacity from non-fossil fuel sources by 2030 [77]. This goal will be supported by technology transfer and accessible international financing, including support from the Green Climate Fund. This initiative will help lower emissions and facilitate a shift towards cleaner, greener energy sources. The remote locations of IHR often pose challenges for achieving large-scale grid connectivity. Renewable energy systems such as solar microgrids and biogas plants play a critical role in reducing pollutants in the power sector [78].

4.4.1. Special Small-Hydro Policy for North-East India

The Ministry of New and Renewable Energy announced a region-specific initiative in 2025: the imminent rollout of a Special Small-Hydro Policy for the Northeastern states of India. This policy targets states having remote areas, hilly terrain, and river networks, such as Arunachal Pradesh, Assam, Meghalaya, Nagaland, Sikkim, and Tripura [79].

The policy represents a strategic move to develop small hydropower to diversify the renewable mix beyond solar and wind [79]. The region has an estimated renewable energy potential of 22 GW, but only 5.1 GW has been installed so far. The policy is designed to unlock new project pipelines by providing financing models and central support, making small-hydro projects more financially practical and quicker to operate [80]. This strategy directly addresses energy access and connectivity issues in regions that often struggle to connect to the large-scale grid, thereby supporting regional self-reliance and reducing reliance on fossil fuels, which are among the leading sources of particulate matter.

4.4.2. Decentralized Energy Systems: Solar Microgrids, Off-Grid Solar, and the Green Energy Corridor

It has been observed that remote Himalayan settlements cannot be built without solar microgrids and biogas plants. Due to the isolation of these sites and the risks associated with creating extensive grid connectivity in the IHR, government actions make the provision of decentralized renewable energy systems paramount [81]. States like Sikkim, Uttarakhand, and Arunachal Pradesh in the IHR have specific programs promoting micro-hydel, off-grid solar, and small hydro projects [75,76,78]. This strategy can be used to replace fossil-fuel-powered generation with renewable sources, thereby avoiding the emission of dangerous air pollutants.

The Green Energy Corridor aims to interconnect the scattered sources of renewable energy across the Himalayas to the national grid. The infrastructure project enables the supply of consistent, uninterrupted electricity through a hybrid renewable energy system combining solar and wind power [76,82]. The ministry has also initiated the Biogas program, which promotes the use of decentralized renewable energy sources and encourages biogas as a power source.

4.4.3. Mitigating Local Pollutants from Backup Diesel Generators

Diesel generators also harm air quality by emitting several air pollutants, including particulate matter, nitrogen dioxide, sulfur dioxide, carbon monoxide, and greenhouse gases [74,83]. They are found in remote areas of Northeastern states where power supply is sporadic. To minimize the use of these generators, the Government has launched rural electrification schemes such as the Deen Dayal Upadhyaya Gram Jyoti Yojana (DDUGJY), which improves grid supply and reduces the need for diesel generators [84]. Reducing the use of these generators directly reduces nitrogen oxide and particulate matter emissions in villages and small towns.

According to the policy effectiveness assessment, power sector policies are promising, evidenced by substantial renewable capacity additions, diesel generator displacement in improved grid areas, and decentralized solutions for off-grid locations. However, there are still some challenges, such as continued reliance on coal, environmental concerns about small-hydro projects, and financing gaps [80].

4.5. Domestic or Household-Level Combustion

Despite improved electricity access, many households in the region depend on biomass as a primary and secondary fuel during harsh winters due to financial constraints and cultural practices [15]. To minimize the use of fuelwood, the Pradhan Mantri Ujjwala Yojana (PMUY), implemented by the central Government, provides subsidized LPG connections to rural households and has significantly expanded LPG coverage [71,85]. In waste management, the Swachh Bharat Mission has focused on infrastructure but failed to curb open burning, a significant source of dioxins and particulate matter. Municipal bylaws prohibiting this act are rarely enforced. Another important policy lever is increasing access to solar power to supply household lighting and small-scale electricity needs, thereby addressing poverty and development issues in rural set-up [86]. The solar home system and microgrids are decentralized energy solutions that are clean and reduce reliance on kerosene lamps, a significant source of pollution.

Studies on household air pollution in developing nations have mainly concentrated on the efforts to upgrade cooking stoves to make them more fuel-efficient and reduce emissions [87]. Although these stoves can have a positive health impact, reduce climate change, and be economically viable, intervention programs like the Kyoto Protocol have been unsuccessful, and locals often fail to adopt them [88]. The introduction of more efficient stoves in some households has made the region more comfortable, but it does not guarantee adequate indoor air quality or health benefits [87,89].

4.5.1. Clean Cooking Fuel Transition

In the Himalayan states, the combustion of biomass for cooking and heating remains a significant contributor to both indoor and outdoor air pollution [15]. Household transition from biomass to cleaner fuels such as LPG, biogas, and electricity is more advantageous, as seen in certain nations where these resources are readily available, and has been ranked among the most effective measures to reduce emissions [71,89,90]. The PMUY provides subsidized LPG connections to rural households and has significantly expanded LPG coverage. This highlights that although the initial rollout is often successful, relapses occur as refill rates decline dramatically after the initial free cylinder. This decline is explained by affordability constraints, especially for poor households during harsh winters, when heating demand is highest [85]. As a result, many households revert to using biomass as a primary or secondary fuel source, creating a cycle of pollutants that regulatory structures have not yet fully addressed. This creates a persistent emission baseline that is addressed primarily through regulatory law. Subsidies, microfinance options, low-interest loans, other financing, and marketing can facilitate households’ transition to clean fuels [85].

4.5.2. Biogas as a Cleaner Alternative

To counter economic dependence on biomass, efforts to subsidize clean substitutes have been increasing [90]. A state like Sikkim has been actively discouraging the use of firewood by promoting LPG and subsidizing biogas production. This initiative works by providing improved financial support to adopt clean fuels. The programme will establish biogas plants to provide clean cooking gas, lighting, and power solutions, thereby cutting greenhouse gas emissions [91]. A characteristic feature of this programme is the increased Capital Financial Assistance to the Northeastern Region and other hilly states. Special incentives, such as the establishment of cattle-dung-based biogas plants with sanitary toilets and incentives for biogas-based generator sets, are also provided [89,90,91].

This means that the issue of its long-term performance in the IHR can be directly addressed through such limited, region-specific financial aid. The Biogas Programme encourages the development of a strong, clean energy supply chain that is less reliant on remote and centralized LPG supplies by fully subsidizing the decentralized production of clean fuel using local resources, thereby increasing the likelihood of lasting adoption and emission reductions. Increased funding mechanisms, including micro-financing options and low-rate loans, can also help fund the switch to clean fuels [86,90].

4.5.3. Improved Cookstoves in the IHR

Although the substitution of the current fuels with cleaner alternatives like LPG or electricity is generally seen as a more beneficial intervention than an increase in the efficiency of the stoves, the advocacy of the use of energy-efficient chullahs still happens to remain a strategically significant intervention, especially in places where the use of biomass is a traditional practice. In the Northeast, where slash-and-burn cultivation is common, states have introduced alternative livelihoods and energy-efficient chullahs through the National Mission for Clean Cooking. Research into improved cooking stoves continues to focus on enhancing fuel efficiency and pollutant reduction for health benefits and mitigating climate impacts [71,87].

The household sector policies show limited sustained effectiveness, with PMUY’s high initial adoption but poor retention due to economic barriers. Biogas programmes were only successful when adequately supported. The improved cookstoves are also insufficient without fuel switching, and prohibitions on waste burning have been poorly enforced. Biogas subsidies can be augmented by the implementation of a voluntary climate change mitigation strategy established by the parties to the United Nations Framework Convention on Climate Change, known as REDD+ schemes.

4.6. Integrated Management of Diffuse Sources

4.6.1. Curbing Agricultural Stubble and Waste Burning

Although crop residue burning is less prevalent in the mountainous IHR states than in the plains, emissions from orchard pruning, winter heating, and shifting cultivation remain significant. State governments have enacted outright bans, such as Sikkim’s 2014 ban on burning agricultural waste, leaves, and garbage, and Himachal Pradesh’s prohibition on open burning [43,92]. Central policy, guided by the Commission for Air Quality Management and the National Policy for Management of Crop Residue, 2014, specifies that stubble burning must be eliminated via in situ methods and promotes environment-friendly agricultural practices [93]. To create an economic incentive for managing agricultural residue, the Ministry of Petroleum and Natural Gas implemented a policy requiring a 7% blend of biomass pellets derived from agro-residue with coal for co-firing in coal-based power plants, facilitating pollution reduction while decreasing coal consumption [93].

4.6.2. Agroforestry and Sustainable Farming Schemes

The state forest departments in Assam and Tripura provide financial incentives to replace slash-and-burn farming with agroforestry and terraced agriculture. Combination techniques, including agroforestry (where trees absorb carbon) and organic farming (where no artificial agrochemicals are used), are strengthened to enhance soil carbon fixation and reduce emissions [94,95]. In addition, the Government is actively pursuing measures to reduce methane emissions from diesel-powered irrigation pumps, pioneering solar-powered pumps [96]. Such integrated approaches avoid synthetic chemicals, increasing carbon sequestration and reducing emissions. The Kisan Urja Suraksha Evam Utthaan Mahabhiyan scheme is one of the most extensive national programs that supports the implementation of Solar Irrigation Pumps in the region, simultaneously reducing greenhouse gas emissions and air pollutants [97].

4.6.3. Forest Fire Prevention

Forest fires are another significant contributor to black carbon, along with particulate matter, but the policy turnaround has placed greater emphasis on firefighting than on preventive measures. This approach does not account for fundamental drivers, such as the large mass of dry pine needles that form a significant fuel load, nor does it consider the market value of this biomass [98]. In the past, no filling policy model has led to a pine needle market or to the institutionalization of controlled burning as a regulatory component of forest management. Such a lack is essential, as the black carbon released by such conflagrations accelerates glacier melting. This disastrous climate effect has not yet received the attention it deserves under standard air-quality laws [99]. To promote proactive prevention, the Government has launched a data-focused program to identify fire-prone areas in Himachal Pradesh, Uttarakhand, Jammu and Kashmir, and Ladakh. The project uses advanced variables to categorize areas into discrete risk categories, and this point of interest shows a strong relationship with the actual fire findings. The cartography of these danger areas was completed and provides the spatial information needed to shift the focus of the policies [100]. As a result, the identification of these results preconditions central government to impose preventive measures, such as the creation of economic markets for pine needles or the introduction of well-thought-out controlled-burning initiatives, which will be the way to limit the excessive accumulation of black carbon on the alpine ice sheets [99].

4.6.4. Municipal Waste Management and Open Burning Prohibition

Management of solid waste in the IHR relies on open burning, a significant source of dioxin and particulate emissions. Though the Swachh Bharat Mission has focused more on infrastructure development, it has not largely prevented this open-burning habit [101]. The municipal bylaws that ban the practice are rarely enforced due to logistical reasons. The policy still lacks support for decentralized, climate-responsive waste management. In the case of settlements (large or small) distributed across the Himalayas, community-based composting would be a more appropriate option than centralized processing plants. However, policy funding for such decentralized systems remains insufficient [45,101].

The diffuse source policies show emerging but incomplete effectiveness, as agricultural burning is moderately effective where enforced, agroforestry incentives are gaining traction, and forest fire prevention remains reactive and not proactive. In order to incorporate the various drivers, effects, and policy actions discussed in the present work, an integrated air quality monitoring and policy implementation framework and its impacts in IHR are summarized in Figure 4. The figure highlights linkages between emission sources, the atmospheric amplifying factors, the impacts, and the mitigation strategies in line with the national policies and Sustainable Development Goals. To assess the feasibility of air pollution control initiatives, a sectoral overview of the policy interventions implemented in the region, including their effectiveness ratings and constraints about their usefulness is summarized in

Table 2. Evaluation of effectiveness of Sectoral Interventions for Air Pollution Control in the Indian Himalayan Region.

Sector	Policy Intervention	Effectiveness Rating	Primary Barriers
Vehicular	BS-VI Standards	Limited	Altitude degradation, fuel quality gaps
Vehicular	EV Promotion	Emerging	Infrastructure, costs, cold climate
Vehicular	ELV Rules 2025	Too early to assess	Implementation pending
Industrial	Emission Standards	Moderate	Informal sector, enforcement gaps
Industrial	Technology Mandates	Moderate	Capital costs, mobile sources
Power	Renewable Expansion	Promising	Grid integration, financing
Power	Small Hydro Policy	Too early to assess	Implementation pending
Household	PMUY	Limited	Refill affordability
Household	Biogas Programme	Effective	Upfront costs, technical support needs
Household	Clean Cookstoves	Limited	Incomplete fuel switching
Agricultural	Burning Bans	Moderate	Enforcement capacity
Agricultural	Agroforestry Incentives	Emerging	Slow adoption rate
Diffuse	Forest Fire Prevention	Limited	Reactive approach, no fuel management
Diffuse	Waste Management	Limited	Open burning continues

.

4.6.5. Transboundary Pollution Governance

As discussed in the above sections, air pollution in the IHR cannot be addressed solely through domestic policies, as transport from the IGP and other South Asian regions contributes to PM_2.5 concentrations and affects air quality [22,23,24,25]. Thus, it requires mechanisms to coordinate across jurisdictions, and some international frameworks have been established to improve the region’s quality. India, along with Bangladesh, Bhutan, Maldives, Nepal, Pakistan, and Sri Lanka, is a signatory to the Malé Declaration, which is facilitated by the South Asia Co-operative Environment Programme [34]. The Malé Declaration establishes regional monitoring networks and facilitates data sharing but lacks binding emission reduction targets or enforcement mechanisms. As of 2026, only 15 monitoring sites under the Malé network are operational across all signatory countries, none of which are in high-altitude IHR zones [102]. ICIMOD knowledge platform functions as a knowledge broker without regulatory authority, and its recommendations remain advisory rather than binding on member states [103]. It is the International Centre that coordinates regional science-policy dialogue through initiatives like the Atmosphere Initiative and the Hindu Kush Himalaya Monitoring and Assessment Programme (HIMAP) [104]. HIMAP is a landmark programme, which synthesizes evidence on transboundary pollution impacts on the cryosphere, agriculture, and health [104].

The South Asian Association for Regional Cooperation (SAARC) adopted an Environment Action Plan in 1997, and a Convention on Cooperation on Environment in 2010, but implementation has been limited by geopolitical tensions and the absence of a supranational enforcement capacity [105,106]. No SAARC-led initiatives specifically target Himalayan airshed management. Despite recognition of transboundary pollution, several gaps exist, such as the absence of bilateral air quality agreements among the Indian Himalayan neighbors, whereas the European Union has cross-boundary framework on air quality.

5. Conclusions

The governmental policy of air quality management in the IHR is shifting from a national regulatory model to state-specific restrictions and opportunities. The period is characterized by various policy milestones designed with the intention of institutionalizing sustainability across sectors.

The analysis presented in the study confirms that even though India has indeed come to a point where the country has strong national strategies to manage air-quality issues, institutional fragmentation, incompatibilities between technology, inadequate enforcement of the law, and poor community engagement limit the effectiveness of the strategies in the region. To reduce the impact of air pollution in the Himalayas and its socio-financial consequences, a multidimensional intervention is required that involves investing in sustainable technologies and green infrastructure, building institutions and policies, and promoting behavioral change and widespread awareness to minimize its effects. This paper aimed to understand sectoral policies, identify weaknesses, and develop a roadmap. It is intended for state pollution control boards and related departments in IHR states, national programme designers seeking airshed policy, and researchers building integrated mountain monitoring and policy-evaluation systems. Air pollution has continued to put pressure on the Indian Himalayas, but the country now requires a strategic plan to avoid predicaments. It requires a shift from city-bounded plans to airshed governance, and from input-focused policies to outcome-verified implementation. This area needs to emphasize the implementation of sustainable technologies and electricity in residential areas, farming, industry, and transport. The move will improve air quality, sustainability, and economic development. The presence of national agencies encompassing Government, industry, civil society, and local communities needs to intervene and establish strong institutions to support stronger policies, backed by laws that can be easily implemented.

6. Recommendations and Strategic Framework

Addressing air quality deterioration in the IHR requires a detailed and multisectoral approach. Although the Government of India has initiated policy reforms, technological innovation, and institutional strengthening, substantial work remains to translate these policy intentions into measurable improvements in air quality. The literature and analysis conducted in this study show that air pollution mitigation rests on three independent pillars: altitude-specific technology interventions, strong institutions and regulatory coherence, and public behavioral change.

Structural transformations in the energy and transportation sectors are crucial. Reducing emissions from these sectors can yield immediate reductions in short-lived climate pollutants and greenhouse gases [107]. India’s growth in renewable energy capacity, such as solar, wind, and hydropower, has been facilitated by enabling policies, including feed-in tariffs, competitive auctions, and enhanced private investment. The declining cost of renewable energy relative to thermal power further supports the long-term goal of clean energy transition [108]. The rapid urbanization and motorization in the Himalayas have significantly exacerbated air quality deterioration [109].

To combat this crisis, we propose a three-part avoid-shift-improve mobility strategy.

• Avoid: We must avoid the unnecessary need to travel by carefully planning our cities.
• Shift: We must encourage people to shift to greener modes of transport, such as public transport and non-motorized mobility.
• Improve: We must improve the development of cleaner vehicles, cleaner fuels, and electric mobility.

These concepts are reflected in initiatives such as the Jawaharlal Nehru National Urban Renewal Mission (NNURM), which improves public transport infrastructure [110], and the latest standard, Bharat Stage (BS) VI, which mandates strict limits on nitrogen oxides, particulate matter, and other vehicle emissions [111]. The Motor Vehicles Act, 1988 (Amended in 2019), regulates vehicular emissions and mandates compliance with emission standards for all vehicles.

The establishment of India’s carbon market will also broaden the policy toolkit, supplementing the currently prioritized approach of improving energy efficiency across many businesses and activities. The Energy Conservation (Amendment) Bill, 2022, authorizes the national Government to establish India’s carbon credit trading scheme. The Carbon Credit Trading Scheme was officially launched in India in 2023. The Government must promote demand generation in targeted sectors, including mandates for the utilization of green hydrogen in industries such as fertilizer, steel, and petrochemicals, as well as in transportation. Green hydrogen may also be utilized to meet Renewable Purchase Obligations under the Green Open Access Rules 2022, which could help Himalayan states transition toward cleaner industrial processes, reduce emissions, and contribute to global climate goals.

Finally, community-level participation remains essential. Local people can engage at the individual level through afforestation or agroforestry activities, planting trees on their land, or participating in community-based reforestation efforts. They can also engage others; organizing local environmental awareness programs can help spread knowledge about emission-reduction strategies and the importance of conserving air quality. Increased public awareness of the health risks associated with emissions from rubbish incineration may promote alternate disposal methods such as composting, particularly in less populated regions [87]. Encouraging source segregation of waste and promoting recycling initiatives can reduce the need for open waste combustion. In many metropolitan regions, this resolution resides in municipal solid waste collection. To translate legislative will into concrete air quality gains in the IHR, this study recommends the following:

(a) Implement Altitude-Specific Vehicular Standards and Fuel Supply Chains: The current BS-VI standards assume sea-level operating conditions and are not altitude-specific. It needs a specific subcategory within the BS framework that requires engine calibration certification for altitudes above 2000 m. High-sulfur diesel undermines soot-control performance, and diesel particulate filter (DPF) systems are typically matched to ultra-low sulfur diesel, making it consistent with BS-VI fuel quality, which is a prerequisite for mountain transport emission reductions [112]. Modified emission testing protocols are also required for high altitudes. It should also promote the mandatory use of ultra-low sulfur diesel along key transport corridors. The consistent use of BS-VI standards, relying on technologies like DPFs, is inconsistent with the IHR’s environment and supply chain. Within the framework of BS, a specific regulatory subcategory is required for high-altitude zones that require engine adjustment and certification, accounting for performance degradation on steep inclines. Simultaneously, it is essential to guarantee the dedicated provision, and implementation of low-sulfur fuel in key transport corridors within the region to facilitate the effective functioning of installed pollution control devices.

(b) Increase SPCB Capacity and Decentralized Enforcement: The current SPCB operating system is limited to enforcing regulations on a large number of small, scattered polluters, especially stone crushers and hot mix plants, which operate below the EIA threshold and avoid inspection. Specialized funding should be directed to support SPCB’s technical capacity by purchasing mobile monitoring labs, drones for surveillance, and technical personnel specialized in high-altitude logistics. This will enable proper implementation of the Air Act and the Environment Protection Act against non-compliant small-scale industries.

(c) Secure Sustainable Clean Fuel Availability through Financial Restructuring: PMUY has been undermining long-term emission-reduction targets due to high LPG user turnover driven by refill costs, leading to continued fuel stacking and, in turn, household emissions of PM and black carbon despite nominal LPG access. It should be measured by sustained use, not just by connection coverage. When considering the area’s low-income residents, the PMUY model should be modified to include a subsidized or free fuel-refill feature based on specific air quality requirements or low-income status. This financial guarantee, coupled with the decentralized clean energy supply promoted by the MNRE Biogas Programme, will create a more robust clean energy ecosystem that is less vulnerable to economic fluctuations. This gap can be structurally amplified in mountainous areas by higher last-mile delivery costs, low consumer density, rugged terrain, and affordability constraints.

(d) Integrate Forest Fire Prevention and Air Quality with Climate Policies: The enormous BC concentrations from forest fires and pine needles pose a threat to ice caps, but this policy remains separate from air quality legislation. The spatial data from the Fire Risk Zone Identification must be immediately integrated into state forest action plans. Policy should create a viable, regulated economic market for pine needle biomass utilization. Institutionally, the region suffers from ambiguous mandates, overlapping authorities, and weak coordination among pollution control boards, municipalities, forest departments, and state agencies. Strengthening institutional capacity and establishing region-specific governance mechanisms for air quality management are essential. Although India has enacted stringent measures for PM_2.5 nationwide [113], the unique challenges of the region, like its scattered settlements, difficult terrain, and climate, make it necessary for tailored frameworks.