Investing in climate and clean air action can deliver 15-fold returns

Released on the International Day of Clean Air for blue skies, Hidden assets: The economic and health case for climate and clean air action is the first comprehensive global economic assessment of integrated climate and clean-air action. Several researchers from the IIASA Energy, Climate, and Environment (ECE) Program are report coauthors, contributing to key elements of the analysis.

The economic value of action

The annual economic benefits of implementing the report’s 25 measures would be equivalent to:

• 2.8% of global GDP in 2035
• 4.5% of global GDP in 2050
• 11.4% of global GDP in 2100

Every year of delayed action would forgo more than US$1.5 trillion annually – 0.5% of GDP – in combined market and non-market benefits.

The human cost of air pollution

The US$15 return includes measurable market benefits – such as lower healthcare expenditure, greater labor productivity, and avoided physical damage – and the monetary value of fewer premature deaths and healthier lives.

In 2025, exposure to human-caused outdoor air pollution (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.

Unlike previous assessments, the report factors in the economic effects of air pollution-related illness, including healthcare costs, productivity losses, and impacts on wellbeing. In 2025, outdoor air pollution contributed to 5.5 million new cases of childhood asthma, 2 million new cases of dementia, and millions of cases of heart attack, pulmonary disease, diabetes, stroke, and lung cancer.

A package of 25 proven measures

The report examines 25 proven measures spanning six sectors – energy and fossil fuel systems, industry, transport, agriculture and food systems, residential cooking and heating, and waste management – combining long-term decarbonization with measures targeting super pollutants such as methane, black carbon, and hydrofluorocarbons (HFCs).

IIASA contributed to the development of long-term scenarios and the assessment of mitigation opportunities using the MESSAGEix-GLOBIOM-GAINS modeling framework. Using the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model, IIASA researchers assessed the measures’ mitigation potential, health impacts, implementation costs, and air pollution reduction benefits globally and across 15 world regions.

This work builds on IIASA’s longstanding research using integrated modeling to identify cost-effective clean air and climate solutions and support science-based policymaking in Europe, Asia, and globally, including through collaborations with the World Bank and UNEP.

By 2050, full implementation of the 25 measures could cumulatively prevent 144 million air pollution-related premature deaths, including 96 million from ambient air pollution alone, and hundreds of millions of cases of chronic disease.

“Our analysis shows the value of looking at climate and air pollution together. By combining long-term scenarios with detailed analysis of mitigation options, we can identify measures that deliver benefits for climate, health, and economies, and show how their potential differs across regions,” explains IIASA Pollution Management Research Group Leader and report coauthor Zbigniew Klimont.

Air quality and climate gains

Compared with the report’s baseline scenario, immediate implementation of the measures would halve global carbon dioxide emissions by 2050, reduce methane emissions by 60% and cut major air pollutants – including black carbon, sulphur dioxide, and nitrogen oxides – by around 70%.

The measures would avoid approximately 0.34°C of global warming by 2050 and 1.4°C by 2100. By the end of the century, carbon dioxide emissions under the scenario would be net negative, while major air pollutants would fall by up to 85%.

The economic value of cleaner air would outweigh implementation costs within a decade and would continue to account for almost half of total economic benefits in 2100.

Closing the implementation gap

Institutional barriers – including fragmented decision-making, limited enforcement capacity, and weak government coordination – are the most significant implementation barriers identified in the report.

Cumulatively, they risk delaying full implementation by almost eight years globally. Addressing them through fiscal incentives, regulation, and other measures could accelerate deployment and unlock up to US$10 trillion in additional health benefits by 2040.

The report calls for integrated climate, air-quality, health, and economic planning, stronger institutions and enforcement, and better alignment of public and private finance.

Read the full report

Adapted from a press release prepared by UNEP and CCAC. Read the original article.