Superpollutants are extremely potent climate pollutants that have an excessive ability to trap heat. While climate attention has long focused on carbon dioxide (CO₂), these potent pollutants are responsible for approximately 45 % of global warming we've experienced so far. Many of them also pollute the air, leading to millions of premature deaths and crop damage. Unlike CO₂, which lingers in the atmosphere for centuries, many super pollutants are short-termThis means that reducing them can lead to immediate improvements in air quality and a slowdown in global warming.

Short-lived climate pollutants, a subset of super pollutants, include gases and aerosols that remain in the atmosphere for only days, weeks, or years. Key super pollutants include:

• Methane: The second most important greenhouse gas after CO₂, with 86 times more warming power than CO₂ during its first 20 years in the atmosphere. It comes from both natural and human sources, with most human emissions coming from agriculture, fossil fuel extraction, and waste. It remains in the atmosphere for about 12 years.
• Black carbon (soot): An aerosol component of air pollution (PM2.5) that stays in the atmosphere for only 12 days. It is produced, for example, by car engines, wood stoves and forest fires. It pollutes the air and raises the temperature of the planet by absorbing sunlight, with a warming effect up to 1,500 times greater than carbon dioxide per tonne.
• Tropospheric ozone (ground-level ozone): A major pollutant gas and the main component of smog. It persists in the atmosphere for days to weeks and is formed by chemical reactions between precursors such as methane, volatile organic compounds, and nitrogen oxides in the presence of sunlight.
• Hydrofluorocarbons (HFCs): Artificially created gases used in refrigeration and air conditioning.
• Nitrous oxide: Released from synthetic fertilizers and industrial processes, HFCs and nitrous oxide have less direct health impacts, but are also key super pollutants.

The impact of super pollutants on our health and food security is significant. Ozone-contributing methane emissions are estimated to cause up to 12 % annual yield losses of staple crops. Food shortages associated with crop failure can exacerbate malnutrition, which is linked to nearly half of all deaths of children under 5. Ground-level ozone also damages plants, crops, grasslands and forests. Black carbon reduces the amount of sunlight reaching the Earth, alters precipitation patterns and accelerates the melting of snow and ice, contributing to crop failure.

Reducing superpollutants is one of the fastest ways to slow global warming, improve public health by reducing air pollution-related diseases, protect food supplies, and boost economies by reducing healthcare costs and increasing productivity. The tools are already there to help us act. Key steps include:

• Support strong policies, which limit greenhouse gas emissions and air pollution.
• Investments in clean solutions, such as renewable energy sources, electric vehicles and heat pumps.
• Improving local air quality through cleaner energy and industry, promoting walking and cycling, low-emission zones and better waste management.
• Raising awareness on the link between air pollution and climate change.
• Support global efforts and international agreements such as the Global Methane Pledge and the Kigali Amendment.
• Local leadership, as shown by the example of Mexico, which reduced ozone and increased life expectancy through air quality regulations.

The Wellcome Trust is actively supporting evidence-based action to reduce super pollutants, identifying the most effective solutions for health and climate, and supporting research. The solutions are within reach. It is time to act locally, nationally and globally to create a healthier and more resilient future for all. Spring