Every USD 1 invested in addressing climate change and air pollution together can generate around USD 15, says a report published on September 7 by the UN Environment Programme (UNEP) and the Climate and Clean Air Coalition (CCAC). The economic benefits ate higher when climate and clean air are addressed together than separately. The benefits both market and non-market economic gains.
The report, ‘Hidden assets: The economic and health case for climate and clean air action’, claims to be “the first comprehensive global economic assessment of integrated climate and clean-air action”. It was released on the International Day of Clean Air and Blue Skies, September 7.
Need to invest in clean air climate benefit
“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 — an asset we must invest in,” 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,” added Andersen.
The report states that the annual economic benefits of implementing 25 measures that would amount to 2.8% of global GDP in 2035; 4.5% of global GDP in 2050 and 11.4% of global GDP in 2100.
These projections are compared with the current spends on fossil fuel in terms of global GDP.
“In comparison, 2.18% of global GDP was spent on explicit fossil fuel subsidies in 2022 and 9.3% of global GDP was spent on healthcare in 2023,” says the report.
Delayed action cost
Every year of delay in investing on climate and clean air action would mean a loss of more than USD 1.5 trillion annually, which is 0.5% of the global GDP, in terms of combined market and non-market benefits. If non-market welfare benefits are excluded, the investment returns would still amount to USD 4 for every USD 1.
“A benefit-cost ratio of 15 to 1 would attract capital instantly in almost any other sector. 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,” said Elliott Harris, independent co-chair of the report.
“Every year of delay costs the world more than USD 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 added.
Air pollution killed 6.4 million in 2025
The 15 times return includes measurable benefits, such as less healthcare expenditure, more labour productivity and avoided physical damage — and the monetary value of fewer premature deaths and healthier lives, says the report.
In 2025, exposure to human-created outdoor air pollution sources PM2.5 and ozone was linked to an estimated 6.4 million premature deaths globally. “Household air pollution was linked to a further 2 million premature deaths, including around 300,000 children,” the report points out.
The report mentions the economic effects of air pollution-related illness, including pressure on health services, losses to productivity and well-being. “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,” it says.
Twenty-five “proven measures”
The assessment examines measured related to six sectors: energy and fossil fuel systems, industry, transport, agriculture and food systems, residential cooking and heating and waste management. These measures are both long-term, such as decarbonisation, and target super pollutants such as methane, black carbon, and hydrofluorocarbons (HFCs).
The measures are renewable power and energy efficiency, increasing clean cooking and heating solutions, tighter vehicle emission and efficiency standards, inspection and maintenance, electric vehicles and low-sulfur shipping fuels, recovery of associated gas to end routine venting and flaring and reduce oil and gas leaks, livestock and manure management, more efficient fertiliser use, improved rice cultivation and alternatives to crop residue burning, better solid waste and wastewater management and phasing down HFCs.
Death prevention
“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,” says the report.
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 report projects. The measures would avoid approximately 0.34°C of global warming by 2050 and 1.4°C by 2100. “The 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,” Dietz observed.
The report identified institutional barriers, including “fragmented decision-making, limited enforcement capacity, and weak government coordination” as the most significant of the implementation barriers.