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South Asia bears the highest current economic burden from air pollution among world regions, equivalent to 10 per cent of regional gross domestic product (GDP), while implementing 25 integrated climate and clean air solutions could generate $21 in economic benefits for every $1 invested, according to a new UN assessment.
The assessment Hidden Assets: The Economic and Health Case for Climate and Clean Air Action by the United Nations Environment Programme (UNEP) and the Climate and Clean Air Coalition found that the 25 solutions could avoid damages equivalent to around 4 per cent of South Asia's GDP in 2035, rising to 14.5 per cent by 2100, the highest of the 15 regions assessed. The 21 clean air and near-term climate solutions alone would deliver benefits exceeding 3 per cent of regional GDP in 2035.
In South Asia, clean cooking and heating is the leading solution in 2035, followed by energy transformation for power generation and industrial process emissions standards.
The assessment cites India's Pradhan Mantri Ujjwala Yojana (PMUY) as an example of a clean cooking programme addressing distributional impacts and equity. Citing research by Mani et al (2020), it said PMUY expanded liquefied petroleum gas (LPG) access to approximately 80 million low income households. The report's India case study further showed that much of the recent progress in reducing emissions from the residential sector is attributable to PMUY, which expanded LPG connections and facilitated the spread of cleaner cooking fuels.
The report's findings placed this progress in the context of a continuing global clean cooking challenge. In 2025, 24 per cent of the world's population relied on solid fuels for cooking, while the assessment's integrated action scenario assumes that efficient access to clean cooking can eliminate traditional solid fuel cooking by 2035.
By 2050, clean cooking and heating falls to fourth, overtaken by industrial process emissions standards, vehicle emission standards and energy transformation for power generation. The assessment showed that the relative importance of individual measures changes according to a region's energy system, pollution profile and stage of development.
The authors of the report also said clean cooking and heating remains highly significant in developing regions even as energy transformation becomes more prominent with rising energy demand. In South Asia, its importance reflects the region's starting point, energy system and pollution profile rather than a different policy framework.
The assessment projected that fine particulate matter or PM2.5, concentrations will rise in South Asia and Southeast Asia without further action, contrasting with Centrally Planned Asia, where concentrations are projected to decline under existing legislation. By 2050, avoided heat related labour productivity losses alone are estimated to be worth approximately 2 per cent of South Asia's GDP.
The 25 solutions are intended to operate as a package. The report says their full benefits materialise only when they are implemented together, although their economic returns and priority differ across regions and over time.
The assessment cautioned that no single measure can fully address the PM2.5 burden in any region. Any one measure delivers at most 50 per cent of the total reduction potential in a region or year, reinforcing the need to combine clean cooking with measures across energy, transport, industry, agriculture and waste.
Globally, implementing the 25 solutions could generate around $15 in economic benefits for every $1 invested. The benefits will be equivalent to 2.8 per cent of global GDP in 2035, 4.5 per cent in 2050 and 11.4 per cent in 2100.
The economic returns include market benefits such as lower healthcare expenditure, higher labour productivity and avoided physical damage, as well as the monetary value of fewer premature deaths and healthier lives. Even excluding non market welfare benefits, the measures return around $4 for every $1 invested. Market returns exceed implementation costs within 10 years.
“For too long, we have treated climate action as a cost to be managed and air pollution as the unfortunate outcome of development. This report shows the opposite: clean air is a key driver of development, health, food and energy security, and climate stability,” said Inger Andersen, executive director of UNEP.
“Proven solutions already exist. What we lack is the decisive leadership from governments, financial institutions, and businesses to deliver them with the speed and coordination this crisis demands,” she said.
The annual economic benefits of implementing the 25 measures are estimated at 2.8 per cent of global GDP in 2035, 4.5 per cent in 2050 and 11.4 per cent in 2100. This compares with government spending equivalent to 2.18 per cent of global GDP on explicit fossil fuel subsidies in 2022 and healthcare spending equivalent to 9.3 per cent of GDP in 2023.
Every year of delayed action would forgo more than $1.5 trillion in annual combined market and non market benefits, equivalent to 0.5 per cent of global GDP.
The authors of the report estimated that implementation delays could average 7.5 to eight years globally. Institutional barriers are the single largest contributor, accounting for approximately 2.4 years over a notional 15 year implementation window. A delay of this scale roughly halves the emissions reductions achievable by 2035.
In Delhi, achieving current national air quality standards on schedule from 2026 would reduce the cumulative PM2.5 exposure burden by 20 per cent by 2040. With an eight year delay, the reduction would be only 10 per cent, meaning half the benefit would be lost.
“A benefit cost ratio of 15 to 1 would attract capital instantly in almost any other sector. The only reason it hasn't integrated climate and clean air action yet is that the returns are split across health systems, productivity and avoided climate damage rather than landing on a single balance sheet,” said Elliott Harris, independent co-chair of the assessment.
“Every year of delay costs the world more than $1.5 trillion in benefits we will not get back. Finance ministries and investors who keep climate and air quality in separate budget lines are leaving trillions on the table,” Harris said.
The package covers six broad sectors: Energy and fossil fuel systems, industry, transport, agriculture and food systems, residential cooking and heating, and waste management.
The measures combine long term decarbonisation with action on super pollutants, including methane, black carbon and hydrofluorocarbons (HFCs). They include renewable power and energy efficiency, clean cooking and heating, tighter vehicle emission and efficiency standards, vehicle inspection and maintenance, electric vehicles, low sulphur shipping fuels, recovery of associated gas to end routine venting and flaring, measures to reduce oil and gas leaks, livestock and manure management, efficient fertiliser use, improved rice cultivation, alternatives to crop residue burning, better solid waste and wastewater management, and phasing down HFCs.
The experts identified four long term climate solutions and 21 clean air and near term climate solutions. No single measure can address the entire PM2.5 burden in any region. Any one measure achieves at most 50 per cent of the total reduction potential in a region or year.
In 2025, exposure to human caused outdoor air pollution, including PM2.5 and ozone, was linked to an estimated 6.4 million premature deaths worldwide. Household air pollution was linked to a further 2 million premature deaths, including around 300,000 children.
Outdoor air pollution also contributed to 5.5 million new cases of childhood asthma and 2 million new cases of dementia in 2025. The dementia cases represented 20 per cent of all new dementia cases globally.
The analysts estimated that avoiding healthcare costs and productivity losses could save 0.7 per cent of global GDP by 2050.
By 2050, full implementation of the 25 measures could cumulatively prevent 277 million air pollution related premature deaths, including 192 million from ambient air pollution alone, alongside hundreds of millions of cases of chronic disease.
Compared with the baseline scenario, immediate implementation of the 25 measures would halve global carbon dioxide emissions by 2050, reduce methane emissions by 60 per cent and cut major air pollutants, including black carbon, sulphur dioxide and nitrogen oxides, by around 70 per cent.
The measures would avoid approximately 0.34°C of global warming by 2050 and 1.4°C by 2100. Because land temperatures rise faster than the global average, avoided warming in most regions could reach an estimated 1.5°C to 2°C by 2100. Major air pollutants could fall by up to 85 per cent by the end of the century.
“This report provides the most rigorous evidence yet that treating climate change and air pollution as separate problems causes us to underestimate the benefits of tackling either,” said Simon Dietz, Co Chair of the Assessment and Professor of Environmental Policy at the London School of Economics.
“When we modelled them together, the returns were larger than each could show alone, because the same sources, sectors and policies so often drive both,” Dietz said.
Fragmented decision making, limited enforcement capacity and weak government coordination are identified as the most significant implementation barriers. Together, these could delay full implementation by almost eight years globally.
The authors of the report calls for integrated climate, air quality, health and economic planning, stronger institutions and enforcement, and better alignment of public and private finance.
Fiscal policy incentives and regulations that enable the private sector to deploy technologies that are both profitable and reduce emissions could accelerate implementation and unlock up to $10 trillion in additional health and economic benefits by 2040.
Faster implementation also requires investment in sustained capacity building, air quality monitoring systems, interagency coordination mechanisms and other enabling reforms. The experts said such investments are an economic priority in their own right.
The assessment showed that financial resources needed to implement integrated climate and clean air solutions already exist. Current government spending on fossil fuel subsidies, equivalent to 2.18 per cent of global GDP annually, could finance implementation of all 25 solutions more than three times over.
The cost of implementing the 25 solutions is equivalent to 0.7 per cent of global GDP annually today and is projected to decline to 0.5 per cent by the end of the century.
The authors recommended prioritising affordable finance for countries and regions with the greatest needs and highest potential returns, alongside technology transfer, capacity building and improved access to evidence and data.
Africa records the highest regional returns. Southern Africa has a benefit to cost ratio of 26 to 1, while Sub Saharan Africa and North Africa each record 11 to 1. The 25 solutions could avoid damages equivalent to 3.5 to 4 per cent of GDP by 2035 in Sub Saharan and Southern Africa, rising to 8.5 per cent and 13.5 per cent respectively by 2100. North Africa reaches approximately 11.5 per cent by 2100.
In sub-Saharan Africa, clean cooking and heating is the leading measure in both 2035 and 2050. In Southern Africa, clean cooking and heating leads in 2035, followed by reduced burning of agricultural crop residues and vehicle emission standards. By 2050, household energy transformation will become the leading measure.
West Asia has an overall return of 11 to 1, with the 25 solutions capable of avoiding damages equivalent to approximately 1.5 per cent of regional GDP in 2035, 4 per cent in 2050 and 12.5 per cent in 2100. Oil and gas upstream emissions rank first in both 2035 and 2050, with controls on methane leakage, venting and flaring identified among the most cost effective measures available.
Latin America and the Caribbean recorded a 9 to 1 return. The 25 solutions could avoid damages equivalent to approximately 1.5 per cent of regional GDP in 2035, 2.5 per cent in 2050 and 8.5 per cent in 2100. Industrial process emissions standards, vehicle emission standards, dietary changes and vehicle inspection and maintenance lead in 2035, while vehicle emission standards move to first place by 2050.
In Europe, returns are lower because decades of air pollution controls have already captured many available gains, climate damages are smaller at higher latitudes and fewer low cost measures remain. Benefit cost ratios range from 3 to 1 in the European Union, European Free Trade Association and United Kingdom grouping to 8 to 1 in the Western Balkans and Western Asia.
North America has the lowest air pollution burden among the regions assessed, at 1.7 per cent of regional GDP, but the 25 solutions would still generate a return of 5 to 1. Dietary changes rank first in both 2035 and 2050, followed by international shipping, livestock manure management and post combustion controls in 2035.
The report authors said the regional variation does not imply different approaches. The same package of 25 solutions is required globally, but the measures need to be prioritised according to each region's energy system, pollution profile, development stage and costs.