Short-lived Climate Pollutants: A Critical Threat to Our Planet

Short-lived climate pollutants (SLCPs) include black carbon, methane, hydrofluorocarbons (HFCs), and tropospheric ozone. They are air pollutants with a global warming potential many times higher than carbon dioxide. They significantly impact food, water, and economic security for large populations worldwide. The direct impact is through their harmful effects on public health, agriculture, and ecosystems. On the other hand, indirect impact occurs through the climate.

Despite their relatively short atmospheric lifetimes, the strong warming potential of SLCPs means that strategies to reduce their emissions can deliver climate and development benefits within decades.

Potential for Emission Reductions

• Black carbon emissions can be reduced by 70% globally by 2030.
• Methane emissions can be reduced by 40% globally by 2030.
• HFC emissions can be reduced by 99.5% by 2050.

Methane

Methane is the world’s second-largest contributor to global warming after carbon dioxide and a key ingredient in ground-level ozone pollution.

• Warming Impact: Methane has a warming impact 86 times more potent than CO2 per unit of mass over 20 years.
• Lifespan: Methane has an atmospheric lifespan of around 12 years.
• Source: Over 60% of methane emissions come from human activity.
• Agriculture: It is the largest human source of methane emissions, accounting for 40% of total emissions.

Black Carbon

Black carbon is an air pollutant that damages human health, crops, ecosystems, and the climate.

• Warming Impact: Black carbon has a warming impact up to 1,500 times stronger than CO2 per unit of mass.
• Lifespan: The average atmospheric lifetime of black carbon particles is 4-12 days.
• Emissions: About 5.8 million tons of black carbon were emitted in 2019.
• Sources: Household energy accounts for nearly half of global black carbon emissions.

Hydrofluorocarbons (HFCs)

HFCs are potent greenhouse gases with a global warming potential many times that of carbon dioxide.

• Warming Impact: The most abundant HFC warms the planet 3,790 times as much as CO2 over 20 years.
• Lifespan: HFCs have an atmospheric lifespan of about 15 years.
• Source: All HFCs are human-made for use in refrigeration and cooling equipment.
• Growth: HFC usage is growing at over 10% per year.

Tropospheric Ozone

Tropospheric ozone is a potent greenhouse gas – an air pollutant that harms human health, crops, and ecosystems.

• Lifespan: Tropospheric ozone has an atmospheric lifetime ranging from a few hours to a few weeks in polluted urban regions.
• Impact: Ozone absorbs radiation, acting as a potent greenhouse gas and altering evaporation, cloud formation, and atmospheric circulation.
• Agriculture: Estimated global crop production losses owing to ozone total 79–121 million tons, worth US$ 11–18 billion annually.
• Health: Long-term exposure to ozone air pollution is linked to 1 million premature deaths annually from respiratory diseases.

Addressing the emissions of short-lived climate pollutants is crucial for mitigating climate change and protecting public health. Reducing SLCPs can provide rapid and significant benefits, given their short atmospheric lifetimes. We can substantially reduce these harmful pollutants through international cooperation, technological innovation, and practical policy implementation, paving the way for a healthier and more sustainable future.

For more information on this topic, visit the Climate & Clean Air Coalition.

This article is part of the Marquis Intelligence series “Air Quality, Environment and Sustainability”, which addresses sources of pollution, as well as technical and technological solutions and their impact on air quality.
Document: MI-AES-001.24 – Short-lived Climate Pollutants: A Critical Threat to Our Planet