Climate change and air pollution are closely interconnected phenomena, yet they are almost always analysed separately. On the International Day of Clean Air for blue skies, on 7 September 2026, the United Nations Environment Programme (UNEP) and the Climate and Clean Air Coalition (CCAC) challenged this approach to the two problems. They have published a new report that, for the first time, provides a comprehensive global economic assessment of all measures that benefit both the climate and air quality.

The report, titled Hidden assets. The economic and health case for climate and clean air action, notes that tackling these two challenges together would generate significant economic returns. The report estimates that every US dollar invested in tackling climate change and air pollution could generate around 15 dollars in economic benefits. Some of these benefits can be measured in market terms, including lower healthcare spending, increased labour productivity and more effective prevention of physical damage. Others, meanwhile, reflect the monetary value of reducing premature deaths caused by living in an unhealthy environment.

The negative impacts of climate change and air pollution

The climate crisis has negative consequences that affect not only the environment, but also the economy and public health. The same is true of air pollution, including in Italy. Around the world, the UN report recalls, exposure to outdoor air pollution caused by human activity (PM2.5 and ozone) was associated with around 6.4 million premature deaths in 2025. It also contributed to 5.5 million new cases of childhood asthma, 2 million new cases of dementia and millions of cases of heart attacks, lung disease, diabetes, stroke and lung cancer. Household air pollution was linked to a further 2 million premature deaths, including around 300,000 children.

“For too long, we have treated climate action as a cost to be managed and air pollution as the unfortunate outcome of development,” said Inger Andersen, Executive Director of UNEP. “This report shows the opposite: clean air is a key driver of development, health, food and energy security, and climate stability – an asset we must invest in. 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.”

Two linked problems, 25 possible solutions

Unlike previous assessments, this report considers the economic effects of diseases linked to air pollution, including pressure on healthcare services and losses in productivity and wellbeing. It then proposes 25 possible measures covering both decarbonisation and reductions in air pollutants such as methane, black carbon (an especially harmful fine particulate matter), and hydrofluorocarbons (HFCs).

The package of measures spans six sectors. First is energy, where it proposes renewable energy and energy-efficiency solutions, as well as the recovery of associated gas – the gas that is often lost into the atmosphere during oil extraction – to end routine venting and flaring and reduce leaks. In transport, it calls for stricter emissions and vehicle-efficiency standards, together with stronger enforcement through inspections and maintenance. The measures also include expanding the use of electric vehicles and low-sulphur fuels in shipping.

In agriculture, the proposed solutions include better management of livestock and manure, more efficient use of fertilisers, improved rice-growing techniques and the wider adoption of alternatives to the burning of crop residues. Regarding domestic heating, the proposed measures focus primarily on expanding the use of green solutions for food cooking and heating. The proposals also cover the industry, waste and wastewater management sectors.

The economic benefits

Implementing the 25 measures identified in the report as soon as possible would bring significant benefits, UNEP says. They could prevent 144 million premature deaths linked to atmospheric pollution, including 96 million caused exclusively by air pollution, as well as hundreds of millions of cases of chronic disease. The benefits would also extend to the economy: putting these solutions into practice would prove more cost-effective than current investment in fossil fuels.

Annual economic benefits would correspond to 2.8% of global GDP as early as 2035, rising to 4.5% in 2050 and further to 11.4% by 2100. By comparison, 2.18% of global GDP was spent on explicit fossil-fuel subsidies in 2022, while 9.3% of global GDP was devoted to healthcare in 2023.

“A benefit-cost ratio of 15 to 1 would attract capital instantly in almost any other sector,” said Elliott Harris, independent, co-chair of the Assessment. “The only reason it hasn’t on 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. Every year of delay costs the world more than USD1.5 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.”

The benefits for air quality and the climate

Immediate implementation of the measures would also halve global carbon dioxide emissions by 2050, cut methane emissions by 60% and reduce major air pollutants, including black carbon, sulphur dioxide and nitrogen oxides, by around 70%. The measures would avoid around 0.34°C of global warming by 2050 and 1.4°C by 2100, making action even more urgent given that, according to another recent UNEP report, global temperatures will exceed the 1.5°C threshold above pre-industrial levels in the coming years. If these 25 measures were implemented, carbon dioxide emissions would be net negative by the end of the century, while major air pollutants would fall by as much as 85%.

“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, 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.”

Among the barriers to implementation identified by the report, the most significant are institutional, including fragmented decision-making processes, limited capacity to enforce regulations and poor coordination between public institutions. These barriers can only be overcome by creating the conditions that enable institutions, businesses and other actors to work together towards the same goal.

Cover: the Po Valley, Europe’s most polluted area in terms of nitrogen dioxide, photo by Luca Ponti, IPA Agency