Key findings

Air pollution is the world’s largest environmental health threat, causing 7.9 million premature deaths every year.¹ Nine in ten of these deaths occur in low- and middle-income countries. Despite this urgent challenge, international development funding for clean air – from bilateral and multilateral development finance institutions and governments – remains chronically low. 

This findings of the eighth edition of our annual report present a mixed picture. There are promising signals that some development funders are raising air quality up their list of priorities, but funding remains too low, highly concentrated, and fails to reach the countries facing the great pollution burden.

Year-on-year funding shows some progress

The 2024 data contains some positive signals:

• Outdoor air quality funding increased by $1.7 billion between 2023 and 2024, almost returning to its 2022 peak. Yet despite this rebound, it still represents less than 1% of international development funding.
• Air quality funding that was not related to climate also saw an uptick, suggesting that some funders are beginning to prioritise air quality as an issue in its own right.
• Fossil fuel-prolonging funding fell by 48% between 2023 and 2024, to $4.7 billion, bringing the ratio of air quality spend to fossil fuel-prolonging spend down to 1:1.

However, for both of these shifts, it is too early to determine whether this represents a longer-term structural change. There were also encouraging regional developments:

• Sub-Saharan Africa was the only region to sustain year-on-year growth in total air quality funding between 2020 and 2024.
• In Latin America and the Caribbean, regional development institutions played an increasingly important role in financing projects with air quality benefits.

Long-term trajectory remains concerning

Recent gains remain fragile. The real challenge will be whether they can be sustained as aid budgets shrink. The data does not yet reflect the sharp contraction in official development assistance (ODA) seen in 2025.² In this constrained funding environment, funders should embed air quality objectives across their climate and development portfolios so that limited resources deliver benefits for health, climate, and economies.

Across the two most recent five-year periods, total air quality funding increased by 9%, from $113.8 billion in 2019-2023 to $124.6 billion in 2020-2024. However, this medium-term growth masks a recent reversal: total air quality funding fell by 6% in 2024, its first annual decline in five years.

Two significant areas of air quality funding saw a longer-term decline:

• The share of outdoor air quality funding that was climate-related fell from 86% to 83% between the two most recent five-year periods.
• Funding for projects that do not explicitly target air quality but nevertheless deliver air quality improvements also fell by around 13% in 2024, after three consecutive years of growth.

As these projects account for the majority of total air quality funding, a continued decline could have a significant impact.

Funding is heavily concentrated

Funding is still concentrated among a small number of funders and projects. Just ten projects accounted for 53% of all outdoor air quality funding between 2020 and 2024, and four funders, provided almost three quarters of all outdoor air quality funding across the same period.

Funding is also regionally concentrated, with South Asia receiving almost a third of all air quality funding.

Funding is not reaching the places where need is greatest

Air quality funding remains poorly aligned with need. In 2024, half of the world’s ten most polluted countries received less than $2 per person in total air quality funding.

This mismatch may reflect differences in countries’ ability to access development finance, as well as a lower priority given to air quality in funding decisions. Countries with weaker financial systems or limited capacity to prepare investable projects may face greater barriers to accessing finance, even when pollution exposure is high.

The dominance of loan finance likely creates an additional barrier. Loans accounted for 89% of total air quality funding between 2020 and 2024, potentially limiting the ability of countries already saddled with high debt levels to borrow more.

Super pollutants remain a missed opportunity

Super pollutants like black carbon and tropospheric ozone have serious climate and health impacts, yet projects explicitly targeting their reduction receive tiny amounts of funding.

While total black carbon-related funding increased to $7.5 billion in 2024, almost all of this finance was delivered as a co-benefit rather than through projects explicitly targeting black carbon reduction. Less than 0.1% of black carbon funding between 2020 and 2024 was primary funding.

Tropospheric ozone received even less attention. In 2024, only $111 million went to projects addressing pollutants that contribute to tropospheric ozone formation, without explicitly identifying ozone reduction as an objective. This represented just 0.4% of total air quality funding. Finance explicitly targeting tropospheric ozone remained negligible throughout 2020-2024.

Why funders must prioritise clean air

The findings show that progress is possible, but current investment remains too low, too concentrated and too poorly aligned with the need to address the global air pollution crisis. To deliver significant benefits for public health, climate change and economic growth, international development funders should:

• Make air quality an explicit objective in project design and embed it across climate and development portfolios.
• Adjust funding methods to overcome barriers to accessing funds, including through concessional and blended finance, technical assistance, predictable multi-year funding, and regional financing approaches where appropriate.
• Explicitly prioritise super pollutants to maximise health, climate and air quality benefits.
• Direct support towards the countries and communities facing the greatest pollution burden.

See our full recommendations.

References

¹Health Effects Institute. 2025. State of Global Air Report 2025

²OECD. 2026. Preliminary official development assistance levels in 2025