Research area: Environmental Governance and Policy

“Stabilising” the Climate, but for Whom? Reflections from Reykjavík, and Questions for India

In mid-October, I spent two days in Reykjavík at the Global Risk and Stabilization Summit at the invitation of Renaissance Philanthropy. It brought together scientists, funders, entrepreneurs, policymakers, and a handful of representatives (primarily researchers) from the Global South to discuss catastrophic climate risks and what the emerging field of climate stabilisation could do about them. 

I went in with more questions than answers. I wasn’t sure if these interventions could be governed thoughtfully, or whether the people who would bear their risks the most would have any say. I went, however, because these questions will hit places like India the hardest, and because the conversations about them are largely being shaped in the Global North. This blog is a collection of personal reflections, and SFC’s work in this regard is anchored by my colleagues Arunesh Karkun and Himanshu Pabreja, whose thoughtful inquiry helped us enter this space.

The conversations were anchored around the belief that the world is on course for around 3°C of warming. The recently released emissions gap report pegs future warming within this century at 2.6°C, but global investment banks are already stress-testing for a 3°C world. Emissions mitigation and carbon removal, speakers argued, will not be sufficient to pull us out of this trajectory, and adaptation can only confer a level of security from climate risks before it becomes economically unviable. What was needed, they said, was the development of a further category of response — deliberate interventions in the Earth system such as reflecting sunlight and refreezing glaciers — to be developed now, so they are ready if they are ever needed to stabilise the Earth’s climate.

Why India is already in this conversation

India has more reasons than most to pay attention. Aerosols, the fine particles that make up much of our air pollution, already shape our climate by scattering sunlight and altering clouds, thereby reducing the warming over the country that climate change would otherwise cause. One study argues that over the Indo-Gangetic plain, the impact of aerosol loading may contribute to a 0.5-1℃ reduction in temperatures, and another documented the increase in warming during COVID-19 lockdowns. The Economist has glibly described the trade-off between increased warming and 1.67 million deaths from air pollution as “choking less and frying more”. 

There is no scenario in which the public health emergency of air pollution is an acceptable price to mitigate additional warming. What the debate does show, however, is that decisions on air quality are also decisions about climate change. Rejecting the false dichotomy between “choking” and “frying” would mean recognising that cleaning up the air and reducing emissions are both necessary for India to meet its development goals. 

However,  India has, in effect, already traded away cleaner air for other priorities, though not for climate reasons. Sulphur dioxide limits for coal power plants, notified in 2015 with a 2017 deadline, were extended four times; in July 2025, about 78% of units were exempted outright, and another 11% may be exempted case by case. This kicks the can down the road. It accepts the health burden of sulphate air pollution (the primary focus of the 2015 standards) as the price of cheap power to fuel development, a false trade-off, given the rapidly declining price of electricity generated from renewable sources and the rising cost of coal power. It also defers rather than avoids the question of what happens to warming when India’s air does get cleaner.

Internationally, including at the summit, India’s decarbonisation and pollution abatement policies are increasingly viewed as a source of future regional warming that needs to be accounted for, although estimates of what the aerosol cleanup would contribute to global temperatures are uncertain. 

Unplanned experiments

The world has also recently run an unplanned experiment on this. In 2020, the International Maritime Organization cut the sulphur levels allowed in shipping fuel from 3.5% to 0.5%, and the clouds over busy shipping lanes, especially in the Pacific, became less reflective. How much this has added to warming is still to be fully understood. One modelling study puts it at just under 0.05°C over the decade; a preprint still under review argues that models underestimate the effect two- to four-fold; and research presented at the summit suggested it brought warming forward by as much as a decade.

Either way, aerosols act as a lever on global temperatures. Remove them, and warming is unmasked; disperse them into the stratosphere at scale, and the planet cools. This is the physical basis of stratospheric aerosol injection, one of the foundational pillars of a stabilisation strategy. 

The Government of India has taken notice, aided by international academics engaged in this field. NITI Aayog’s Annual Report for 2025–26 announced a working group to evaluate the science, risks, and governance of solar radiation modification and recommend measures for India’s preparedness. That is welcome, but two features stand out. Its scope is solar radiation modification alone, not the wider set of interventions, including glacier and marine cloud brightening, which would be of significance for India. Its membership and terms of reference have not been made public, so we do not officially know who, and on what terms, is shaping India’s first official thinking on a subject with consequences for every farmer who depends on the monsoon, and every Indian downstream of their harvest. There is also little evidence, global or Indian, on what decoupling CO2 from temperature, or changing the quality of sunlight, would mean for biodiversity, carbon sinks, and ecosystems.

A field in a hurry

Three things stood out about the conversations in Reykjavík.

First, this is a field preparing to grow, and fast. The aim is to grow from roughly a thousand people currently to 5 or 10 thousand in a decade, with dedicated journals, patient capital, and institutional funding. Philanthropic money is already flowing, and national programmes are following, most prominently the UK Advanced Research and Invention Agency’s £56.8 million programme.

The field also wants a permanent place in climate policy, as a third pillar alongside mitigation and adaptation. The field’s leaders point to the history of adaptation, which was once dismissed as a distraction from cutting emissions, or carbon dioxide removal (CDR), which was viewed as a moral hazard. Yet the IPCC now considers removal as unavoidable for reaching net-zero and adaptation as integral to climate-resilient development. The analogy is instructive but imperfect. Adaptation changes human systems, largely within the borders of those who choose it, and CDR acts on the carbon cycle rather than climate as a whole. These interventions, on the other hand, change the climate itself, including for people who had no say in them.

Second, the field is more candid about its science than its pitch suggests, and that deserves credit. Researchers were clear that stratospheric aerosol injection is a family of designs, differing in where, when, how high, and how much material is injected, and that models assess strategies against particular baselines, not “the effects” of the technology. As one presentation put it, models cannot predict governance or human behaviour at all. Several scientists also argued for stronger governance of their own work, in a room where a common view was that the field already faces too much scrutiny and too little work on the ground.

Third, governance was named the biggest challenge, yet discussions stayed abstract, and implementers engaged only minimally. The most concrete proposals were a coalition of first-mover countries setting collective norms among themselves. Some argued that  seeking global consensus at a time of geopolitical fissures amounts to a de facto ban. Platforms such as the new Solar Geoengineering Research Governance Platform are building useful tools for responsible research: charters, disclosure, and independent review. But, as far as I am aware, there is no parallel effort to examine whether such research is politically viable, that is, whether governments and publics in the places that would bear the consequences would accept it. Even the most developed research roadmaps, modelled on the phased go/no-go gates of clinical trials, leave open the most important question – who sets the criteria for passing each gate, and whether the countries that would live with the consequences have any say in them.

Is it really “stabilisation”?

The summit’s own vocabulary also deserves scrutiny. Stabilisation is an appealing word. It evokes a patient in an emergency room, stabilised before the underlying illness is treated (an analogy often used at the conference). But it names an intended outcome rather than an action, and so builds success into the term.

More importantly, it raises the question of for whom are we stabilising? Interventions such as stratospheric aerosol injection would, at best, be designed to hold global average temperature at some level, perhaps 1.5°C or 2°C above pre-industrial averages. In temperate, wealthy countries, that might feel like stability. For much of the Global South, already living with deadlier heat, more erratic monsoons, and more frequent extremes at today’s temperatures, locking in that level of warming is not stability. It is the continuation of harm under a reassuring name. Urgency without clarity can also foster poorly thought-through policies developed with insufficient consultation that could prove detrimental.

Holding the global mean steady also says little about regional climates. In idealised simulations at the Indian Institute of Science, injecting aerosols at 15°N, one of the most efficient latitudes for cooling the planet, cut Indian summer monsoon rainfall by about 21%, and at 30°N by about 29%. Subsequent work found that tilting the aerosol load toward the Northern Hemisphere pushes the tropical rain belt south, with northern monsoon rainfall falling about 7% for every 0.1 of imbalance in aerosol optical depth. 

Farmers working in a rice paddy field in Tarapith, West Bengal, India, during the day.
Solar radiation modification will have consequences for every farmer who depends on the monsoon, and every Indian downstream of their harvest. Credit: Dibakar Roy, Pexels.

Every choice – the season, latitude, altitude – with respect to injection comes with trade-offs, with each design serving some regions’ priorities over others’. We may stabilise the world on average, but destabilise the most densely populated regions as a result. Stabilisation in this context would also speak only to global temperatures, ignoring several other planetary boundary thresholds we are currently pushing. 

For these reasons, an alternate term proposed at the conference – Earth system interventions – may work better. It describes what is being done, a deliberate intervention in the Earth’s systems, without presuming that it works in a positive direction or deciding whom it works for.

What the field gets right about risk

The summit was at its best when it was communicating risk. Speakers were explicit about the limits of what they knew. Climate models, several said, project the floor of plausible change, not the ceiling. Tipping points were discussed system by system, with candour that the frame fits some systems better than others and that timing is the largest uncertainty, and the wide ranges on thresholds were stated rather than brushed aside. Risk was also translated into terms decision-makers already use, from financial exposure to national security.

That contrasts with much of the wider domestic discussion of tipping points, including around UNEP’s recent Limiting Overshoot report. Overshooting 1.5°C  brings tipping points closer, and regional disasters are already manifesting that reality in South Asia. Yet, discourse around what has to be done is still either anchored around global carbon budgets and the space within it that India needs to develop, or on building adaptation capabilities for risks that we haven’t yet begun to quantify.  

Balancing development and climate goals is vital, but treating overshoot as something to be settled at the negotiating table or simply adapted around understates the risks it carries. Identifying  the Earth systems most at risk for India, stating the confidence intervals around those risks, and being clear about what we do and don’t know would be a first step in working out what overshoot means for our development trajectory.

The same honesty should apply to the urgency on display at the summit. Uncertainty about when thresholds are crossed cuts both ways. It is a reason to take the risks seriously, not a reason to cut short deliberation about interventions whose own risks are still poorly understood.

The questions facing India

For India, the immediate questions are less about whether interventions should ever be deployed than about what must be in place before a research agenda takes shape. Here are a few that we believe are essential:

1. Who is framing the questions?
India needs to know what interventions would mean for the monsoon, for heat, for Himalayan glaciers, and for its crops. There is no guarantee that research funded and designed elsewhere will ask those questions.

2. What capabilities do we have?
Intervention scenarios are entering mainstream climate modelling: a stratospheric aerosol experiment is now a Fast Track experiment for the next round of model intercomparison, CMIP7. Whether India can say anything credible about what such trajectories mean for its own national context depends on regional modelling, computing, and observation capacity that has to be built now. These capabilities also extend to whether India could even detect an intervention deployed by someone else, beyond its borders, and trace its effects on our own weather.

3. Who holds the authority?
No agency in India has a clear mandate over Earth system interventions. There is no route to permit, condition, or refuse an outdoor experiment, and while NITI Aayog can advise, it has no legal foundation to permit. On the international stage, holding non-Indian actors accountable for impacts on India would require developing a novel mechanism of the sort that lacks a clear precedent. Authority also has to last. Any deployment to stabilise temperatures could run for decades, and stopping abruptly could bring termination shock. Whatever India builds will have to outlive many governments, including the one that sets it up.

4. Who gives consent?
India’s experience with agricultural technologies shows that expert backing and approval at the Union government level do not amount to public acceptance. Agriculture and water are state subjects under the Constitution, so even if the Union holds formal jurisdiction over international negotiations on Global South coalitions,  any credible process will have to run through the states, not around them. These processes will also have to include relevant civil society stakeholders and community-based organisations. Informed consent is also feasible only in the context where everybody has access to appropriate information on costs and benefits, impacts, and uncertainties. Information asymmetry would further weaken the basis for any consent taken in this regard. 

5. Whose costs count?
A utilitarian would ask whether solar radiation modification’s total benefits to India, chiefly relief from extreme heat for its enormous workforce, outweigh its total harm. A Rawlsian would instead focus on how you would compensate the worst off; the farmer whose crop fails due to a weaker monsoon, or a downstream state suffering water shortages due to a decline in rainfed river water. In that context, compensation becomes a precondition, rather than an afterthought. India already faces a $1.8 billion per year crop insurance outlay to bolster a flailing agricultural sector. Making up for losses that could be blamed on intervention(s), climate change or natural variability would be far harder. Which moral test India applies will decide what costs it accounts for before saying yes.

6. How transparent should the State be?
Who advises the government, with what affiliations and funding, under what terms of reference, and with what public input? Disclosing the composition and mandate of the NITI Aayog working group would be a simple first step; a public register of research and outdoor activity would be another. A 2023 IISc-led survey of Indian experts found strong support for transparency, public consultation, disclosure of research, and an interministerial oversight committee.

Choices for the Global South

These questions are not India’s alone. Across the Global South, three choices are coming into view.

The first is between participation and observation. Being invited into the room is not the same as having the research capacity to challenge what is said in it. Institutions in the Global South received about $3.5 million of tracked funding for solar radiation modification research through 2024, around 2% of the total. Without capacity, participation risks being seen as an endorsement.

The second is timing. Coalitions of the Willing are being proposed. Joining early offers influence, but building positions independently first offers leverage. African environment ministers, taking no view of the position they reached, have shown that a region can set its own terms on its own timetable as they reaffirmed their rejection of stratospheric aerosol injection and called for a non-use agreement in 2025.

The third is honesty about differences. Interventions would produce winners and losers within the Global South, not just between the South and the North. Modelling suggests, for instance, that cooling the tropics could shift malaria risk between Global South regions rather than simply reduce it. “The Global South” will not speak with one voice, and should not be expected to.

Where I’ve landed for now

I went to Reykjavík with the hunch that these were interventions we didn’t currently have the capability to govern, and so probably shouldn’t engage in. What I learned left me more concerned than before about the governance gaps, and more certain that India needs to build its own research and regulatory capabilities to take an informed global stance on the subject. The money and momentum behind this field will ensure that India will have to take a view on whether we want to engage or not, and the question is whether we do so with a fuller understanding of the implications for our people and economy. 

That takes more than just research capacity. It takes institutions that can permit, refuse and monitor activity at home; processes that facilitate informed consent for states, farmers and communities before decisions are made; and sustained dialogue with other countries in the Global South that share our exposure, so that questions like detection and accountability aren’t left to those who would deploy. All of this would enable us to take a considered view on what next steps to take.

What comes next

We at SFC aim to take these questions forward, starting with an issue brief on what India would need in place with respect to capabilities, institutions, and law, before an Earth system interventions research agenda takes shape. 

We do not yet have the answers, and we are wary of anyone who claims to. But choices about who asks the questions, who funds the answers, and who gets to say no are being made now, often by default. We would rather have India make them deliberately, and welcome the conversation.

The author would like to thank Arunesh Karkun and Himanshu Pabreja for their comments that strengthened this piece.

Caught in the Crossfire: Himalayan Glaciers at the Confluence of Air Pollution and Climate Change

Himalayan glaciers are melting faster than ever. Over the past three decades, glacier area in the Hindu Kush Himalayan region has reduced by 12%, with a 5% reduction between 2010 and 2020 alone. It is now widely understood that glaciers are melting faster than they can be formed due to increasing greenhouse gas emissions. However, climate change isn’t the only environmental threat to glaciers – emissions of heat-absorbing air pollutants such as black carbon are accelerating their melting. A 2021 study in the Drass Basin in the Indian Himalayas found that glaciers closer to a national highway were melting faster than those farther away, largely owing to pollution from vehicular traffic. In this context, air pollution is exacerbating the impacts of climate change.

How does air pollution contribute to the melting of glaciers?

Air pollutants are made up of solids, liquids or gases suspended in the air. Solid and liquid pollutants suspended in the air are known as aerosols, while gases are known as gaseous pollutants. These pollutants can play a key role in regulating the temperature in the atmosphere. Some pollutants reflect solar radiation away from Earth and cool the atmosphere, while others absorb the radiation, and heat the atmosphere. As a result, emissions of heat-absorbing aerosols such as black carbon can further increase temperatures in an atmosphere already being warmed by greenhouse gases. A byproduct of incomplete combustion, black carbon is often found in diesel vehicle exhaust, smoke from cookstoves, brick kilns and wood burning – all prevalent sources of pollution in the Himalayas. 

Black carbon contributes to accelerated glacier melting through two channels: increased atmospheric warming and reduced albedo. The first occurs when black carbon in the air absorbs solar radiation and converts it into heat, thereby warming the surrounding air. The second occurs when the solid black carbon particles get deposited on glaciers and darken their surface. As a result, the albedo of the glacier, i.e. the ability of the surface to reflect sunlight away reduces, leading the glacier to absorb more solar energy and melt faster. This is evidenced by the fact that the Himalayas are already warming faster than the global average.

Risks posed by accelerated glacier melt

The consequences of accelerated glacier melt are manifold. In the short term, as the structural integrity of the glacier and the underlying mountain is compromised, the risk of disasters such as landslides increases, as seen in the recent Nepal flood calamity. Similarly, the risk of Glacial Lake Outburst Floods (GLOFs) also rises as glacial meltwater accumulates in lakes, posing a major threat to downstream communities. Given the dynamic nature of glacial lakes, the National Disaster Management Authority has been working with the government to set up monitoring and GLOF Early Warning Systems.

Rise in water level in the lake formed underneath the Drang-Drung Glacier in Ladakh between July 2019 (left) and July 2026 (right). Images: Annanya Mahajan and Anhad Mahajan

As these freshwater stores deplete faster than they can be replenished, increased glacier melt has water-supply implications for millions. In the short run, faster melting will mean more water flowing into rivers — but this is a sign of reserves being drawn down, not a lasting gain. Once glaciers shrink past a critical point, meltwater contribution permanently declines, leaving downstream communities with less water than before. 

Water supply will also be affected by changing monsoon patterns, partly due to rising concentrations of black carbon in the atmosphere. This has far-reaching impacts on agriculture, tourism and hydropower generation, all critical economic activities for both mountainous regions and the plains. This places a unique responsibility on mountain states to make development decisions that safeguard these glaciers to protect those downstream, whose lives and livelihoods depend on the rivers originating from these states. Himachal Pradesh has taken on this role of ‘guardian of natural resources’ in its 2025 climate-sensitive human development report.

How can we protect our glaciers from pollutants such as black carbon?

The good news is that black carbon is a short-lived pollutant, meaning that unlike greenhouse gases, it doesn’t stay in the atmosphere for long durations. If we start taking action to control its emissions, we will see quick results. 

Existing solutions to curb black carbon emissions, such as adoption of cleaner cooking fuels such as LPG and renewably generated electric cooking or transitioning towards low-emission brick kilns, have the technical potential to achieve an 80% reduction in black carbon levels by 2030, relative to 2010. Because this heat-absorbing aerosol has far-reaching warming impacts in the Himalayas, even small reductions in its concentration can yield enormous benefits for the region. Tackling this pollutant offers a unique opportunity not only to reduce air pollution concentrations but also to improve public health and align with climate goals in the short run by reducing regional warming and disruptions to monsoon patterns. Moreover, South Asia already has policies in place to curb black carbon emissions, such as electrification of transport or promoting household access to LPG for cooking, which, if fully implemented, could reduce emissions by 23%.

Looking ahead, effective policy action to curb black carbon emissions and protect Himalayan glaciers should be based on three key themes:

1. Starting from the sub-national level, Himalayan states must recognise the adverse impact of polluting activities conducted near glaciers. Unbridled development in ecologically sensitive areas, while profitable in the short run, can prove to be highly detrimental in the long run by contributing to glacier deterioration. Development decisions that promote growth while safeguarding fragile ecosystems can be a far wiser economic choice for these developing states. Himachal Pradesh’s recent efforts to move toward electric mobility in both urban and rural areas reflect this kind of thinking.

2. At the regional level, increased cooperation between Himalayan states can foster the efficacy of air pollution management actions. Studies of black carbon deposits on Himalayan glaciers have identified sources ranging from diesel vehicles on highways near the glaciers to brick kilns far away in the plains. Fumes from the kilns rise through convection currents and the constituent solid pollutants get deposited on the ice. Sandwiched between the two largest black-carbon-emitting countries, India and China, Himalayan glaciers face an imminent threat from polluting sources both near and afar. Actions to control air pollution in one region within an airshed will have limited impact if the region remains exposed to pollutants from neighbouring areas within the airshed. Coordinated monitoring and tracking of transboundary air pollution and its impacts, such as those outlined in the 1998 Malé Declaration for control of air pollution in South Asia, should be considered.

3. At the global level, low- and middle-income countries (LMICs) such as those surrounding the Himalayas must prioritise air pollution action. The co-benefits that accrue from these actions will also have far-reaching knock-on effects for health and climate change mitigation. For example, a recent study argues that the ideal strategy for sharing the burden of climate mitigation responsibility should entail LMICs prioritising air pollution mitigation strategies, while high-income countries (HICs) bear most of the climate mitigation cost. This approach would enable just climate action while maximising health gains from avoided pollution.

Himalayan glaciers find themselves at the confluence of two major environmental threats – air pollution and climate change, both fuelled by harmful emissions. Despite their overlaps, the narrative around air pollution and climate change mitigation has recently taken a dangerous turn. Evidence is emerging that air pollution management actions, such as reducing sulphur in shipping fuel, have led to increased atmospheric warming. In the face of a warming planet, this narrative presents air pollution reduction and climate impacts as being at odds with each other. This framing is misleading and counterproductive. 

Air pollution and climate change interact in complex ways across different environments. Still, the main message is always the same: reducing emissions will address both the air pollution and climate change crises. The nuance lies in the kinds of emissions we must reduce to maximise gains. Ultimately, it is a matter of recognising that development decisions play out in many forms on the ground – be it air pollution or climate change. We can use this confluence strategically to secure our natural resources, livelihoods and, effectively, our future.

(The author would like to thank Bhargav Krishna, Kartikeya Jain, Upamanyu Das, and Sonali Verma for their feedback and suggestions.)

Delhi’s Air Push Needs Delivery to Line up with Intent

Delhi has started treating its air as a year-round problem, not just a winter emergency, and transport emissions, the one source that pollutes just as much in June as in December, are rightly at the centre of that shift. A cluster of new measures, from an ambitious Electric Vehicle Policy to a consolidated Winter Action Plan and a large World Bank-supported clean-air programme, marks a shift from episodic response towards sustained, source-focused action. The direction of travel is right; what it needs now are adjustments that would allow the government to deliver on its goals.

It is winter when Delhi’s air is at its worst, when cold, still air and a low mixing layer trap primary particulate matter emissions near the ground and drive the chemistry that forms secondary particulate matter – the toxic fine particles that condense from gases like nitrogen oxides emitted by vehicles. But summer no longer offers relief. The city has seen high levels of ground-level ozone, a byproduct of heat and sunlight reacting with nitrogen dioxide and volatile organic compounds emissions. Transport feeds both, which is why the only durable cure is cutting its emissions year-round. The sector accounts for 20-25% of Delhi’s fine particles (PM2.5) year-round, unlike dust and crop-residue smoke that are seasonal and transient, and it is also a leading source of nitrogen oxides that drive secondary particle formation12.

The recent measures each aim for a different part of this persistent problem. The Electric Vehicle Policy phases out new petrol- and diesel-powered two- and three-wheelers and backs its mandates with incentives3. The Centre’s Naya Safar scheme replaces ageing trucks and buses that pollute disproportionately relative to their numbers across Delhi, Haryana, Rajasthan and Uttar Pradesh4. The World Bank-supported Clean Air, Healthy Delhi programme funds a seven-year, source-by-source effort.5 At the same time, the Winter Action Plan folds once-scattered and often unpredictable seasonal orders into a single instrument6. Together, these signal genuine intent. Delivering on this intent requires three tweaks and a fourth to track whether these new interventions have directly contributed to improvements in air quality.

First, the deferred mandate to support four-wheelers under the EV policy has presented an opportunity to make the fleet not just cleaner but leaner. Incentives graduated by vehicle weight, footprint, and energy efficiency (kilometres per kilowatt-hour) would steer buyers away from the heavier electric SUVs that shed the most particulates from tyre and road wear7 and take up the most road and parking space in a city short of both. This is worth considering before the mandate is formally declared and electric SUV production is locked in.

Electric car charging station in Begumpet, Hyderabad. Wikimedia

Second, restrictions are more likely to succeed once alternatives are in place. Delhi saw this last July, when denying fuel to end-of-life vehicles was withdrawn within days, undone by public anger and an enforcement system that could not yet read number plates across state lines8; the same unreadiness has just forced Hanoi, Vietnam, to water down a far more ambitious petrol-vehicle ban9. Charging, like the CNG switch two decades ago, is at heart an energy-supply problem, and the fix is to build the supply first — reliable public chargers and a real right and ability to charge at home.

Third, none of these fundamentally change why Delhi runs on so many private vehicles. An electric car occupies the same lane and space as a petrol or diesel car and does nothing for congestion, urban sprawl, asphalt-driven heat islands, or the daily danger to pedestrians. The larger prize remains a network built around buses and the metro, with routes rationalised to feed the metro and cover both under-served peripheries and the short trips it misses. Alongside, the footpaths, shade, lighting, and safe crossings that make walking and waiting bearable must also be built and maintained. The Chief Minister’s Metro Monday is a welcome signal10 but requires the supporting infrastructure designed to aid daily commuters.

A CNG AC Bus at Anand Vihar ISBT. Wikimedia.

Finally, none of this can be focused on Delhi alone, or judged only by how much money is allocated or spent. Roughly two-thirds of the city’s fine particles come from beyond its borders11, according to CAQM’s own analysis. Hence, the World Bank programme and Naya Safar matter most for what they do to bring Haryana, Uttar Pradesh, and Rajasthan onto the same path12, and the real test is whether the region acts as a single system. Monitoring, too, must track what these transitions add, not only what they remove — the non-exhaust particles from a heavier electric fleet and the toxic aldehydes from ethanol-blended petrol. It must reward verified results alongside disbursement metrics.

Cleaner air and a more liveable city have never been separate projects: fewer, cleaner and lighter vehicles, improved public transport, and streets built to serve people rather than vehicles result in better air quality while making the city both safer and more desirable to live in. The cause to do both has always existed; what is new is the intent and the instruments, and the work now is to sustain the momentum while improving effectiveness.

Endnotes

  1. S. Guttikunda et al., What Is Polluting Delhi’s Air? A Review from 1990 to 2022, Sustainability 15(5): 4209 (2023). https://www.mdpi.com/2071-1050/15/5/4209 ↩︎
  2. Commission for Air Quality Management, Identification of the Causes for Worsening AQI in Delhi-NCR (January 2026). https://caqm.nic.in/WriteReadData/LINKS/AQI%20Report%20V5%20Final637d7a8a-8dad-44fb-9c8c-8be0dfe42839.pdf ↩︎
  3. Transport Department, Government of NCT of Delhi, Delhi Electric Vehicle Policy, 2026 (30 June 2026). https://transport.delhi.gov.in/sites/default/files/Transport/circulars-orders/delhi_ev_policy_2026-30_0.pdf ↩︎
  4. Press Information Bureau, Cabinet approves Scheme for support to NCRPB for replacement of old trucks and buses in Delhi-NCR (3 June 2026). https://www.pib.gov.in/PressReleasePage.aspx?PRID=2268342&reg=3&lang=1 ↩︎
  5. Delhi govt to launch Rs 8,300-crore ‘Clean Air, Healthy Delhi’ project with help of World Bank, ThePrint (3 July 2026). https://theprint.in/environment/delhi-govt-rs-8300-crore-clean-air-healthy-delhi-project-world-bank/2976914/ ↩︎
  6. Department of Environment and Forests, Government of NCT of Delhi, Directions for Air Pollution Control in Delhi (Notification F. No. 10(39)/ENV/2021) (23 June 2026). Gazette ID: SG-DL-E-01072026-273956. https://egazette.gov.in/(S(kk0xjv3gequbeq0g0yipkr2f))/ViewPDF.aspx ↩︎
  7. A. Karkun, Can EVs Solve India’s Air Pollution Crisis?, Environmentality (9 December 2021). https://web.archive.org/web/20211214105528/https://environmentality.cprindia.org/blog/can-evs-solve-the-air-pollution-crisis ↩︎
  8. Fuel Ban on EOL Vehicles in Delhi and Five NCR Districts Pushed to November 1, The Wire (8 July 2025). https://m.thewire.in/article/environment/fuel-ban-end-of-life-vehicle-pushed-to-november-1 ↩︎
  9. Hanoi Delays Gas-Powered Motorcycle Ban in City Centre, Vietcetera (16 May 2026). https://vietcetera.com/en/hanoi-delays-gas-powered-motorcycle-ban-in-city-centre ↩︎
  10. Rekha Gupta takes Delhi Metro ride under ‘Metro Monday’ campaign, The Pioneer (18 May 2026). https://dailypioneer.com/news/slug-lite/rekha-gupta-takes-delhi-metro-ride-under-metro-monday-campaign?year=2026 ↩︎
  11. Commission for Air Quality Management, Identification of the Causes for Worsening AQI in Delhi-NCR (January 2026), on the share from outside Delhi. https://caqm.nic.in/WriteReadData/LINKS/AQI%20Report%20V5%20Final637d7a8a-8dad-44fb-9c8c-8be0dfe42839.pdf ↩︎
  12. World Bank, India: World Bank Approves Financing for Programs to Promote Clean Air in Haryana and Uttar Pradesh States (10 December 2025). https://www.worldbank.org/en/news/press-release/2025/12/10/india-world-bank-approves-financing-for-programs-to-promote-clean-air-in-haryana-and-uttar-pradesh-states ↩︎

Strengthening the Scientific Foundations of NCAP: Building a Standardised Framework for Source Apportionment and Emission Inventories

Introduction

India’s first comprehensive action plan for air quality management in cities, the National Clean Air Programme (NCAP), was launched by the Ministry of Environment, Forests, and Climate Change (MoEF&CC) in 2019. The programme initially aimed to achieve a 20–30% reduction in PM10 and PM2.5 concentrations by 2024 across 102 identified cities with an emphasis on PM2.5 due to its significant health impacts. In 2022, the Non-Attainment Cities (NACs) list was revised to include 130 cities. In parallel, PM10 was designated as the pollutant of interest, with its reduction as the metric of progress, due to limitations in PM2.5 baseline data. The programme goal was revised to achieve a 40% reduction in PM10 levels, or attainment of national ambient air quality standards
(NAAQS), by 2025–26 in the NACs.

The 130 NACs were chosen based on an analysis of 2017 manual monitoring data from the National Ambient Air Quality Monitoring Programme (NAMP). Among these, more than 40 cities with over a million residents received air quality performance grants through the 15th Finance Commission’s Million-Plus City Challenge Fund. The remaining cities are supported under the ‘Control of Pollution’ budgetary head of the MoEF&CC. Consequently, cities lacking functional monitoring stations or those that did not fulfil the requirement (cities that exceeded NAAQS for five consecutive years from three monitoring stations) were excluded from the NAC classification. This has resulted in the omission of several other polluted cities (such as Ranchi and Howrah) from the NCAP non-attainment list.

The NCAP vision document also outlined a vision for “comprehensive, multi-scale, and cross-sectoral” action to address not only sources within the remit of the MoEF&CC but also those outside it. It also sought to mainstream air pollution action through existing programmes such as the Smart Cities Mission. Additionally, it aimed to convene sector-specific working groups (such as with the Ministry of Power (MoP) to focus on emissions from thermal power plants and the Ministry of Road Transport and Highways (MoRTH) on vehicular emissions) to promote broader action on pollution mitigation. However, there has been little documented progress on the constitution of these working groups, the development of sectoral action plans, or the integration with other programmes.

Based on NCAP goals, the 130 non-attainment cities prepared city action plans detailing source-specific interventions categorised as short-, medium-, and long-term measures, which the CPCB subsequently approved. These city action plans, meant to be backed by analyses that determine source-specific emissions, form the basis for how cities are supposed to approach air quality action under the NCAP. However, five years into the programme, most cities have yet to complete their source apportionment (SA) or emissions inventory (EI) studies, and their role in determining city-level actions remains unclear. In this brief, we highlight the significance of SA and EI studies as the backbone of effective air quality management, and explain why India needs to strengthen its approach to conducting these studies to integrate them into policy actions.

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Different Paths to Clean Air: Global Insights for India’s Reform Agenda

Summary

India’s air pollution crisis cannot be solved without addressing key structural and institutional constraints, such as reforming our environmental regulatory regime – one that remains under-capacitated, poorly equipped, and under-funded. Previous works have examined their capacities, constraints, and performance in isolation to understand why frontline environmental regulators in India struggle to meet their mandate. Our new issue brief presents a comparative analysis of learnings from diverse air quality regimes and charts a roadmap for building a capable and forward-looking environmental regulatory regime in India.

We study how countries across the Global South and North, such as Brazil, China, Germany, Mexico, Poland, South Korea, and the USA, have built and reformed their air quality regimes, and what India can learn from them to address the challenges ahead. These countries were chosen to be comparable and relevant to India, and the group is therefore a mix of countries with large economies, a history of dealing with high air pollution, and rapid industrialisation coupled with high GDP growth. The varied source profiles, regulatory institutions, history of air pollution policymaking, and differing governance regimes (unitary vs. federal) in these countries also present differing approaches that could inform Indian policymaking on air quality.

Table 1: Sampling parameters for the 7 countries

We highlight trends and examples relevant to India – how countries set health-based standards, strengthen accountability for action, scale air quality monitoring, and manage airsheds.

Key Learnings

1. Science plays a fundamental role in establishing strict, health-based air quality standards
2. Strong focus on PM2.5 reductions through top-down or bottom-up approaches, depending on country contexts
3. Large increases in monitoring capacity alone may not necessarily yield spatial and temporal representativeness
4. Indian regulators are comparatively resource-poor
5. Airshed-level governance is gaining importance and requires nested governance
6. Accountability is a catalyst for sustained improvements in air quality

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