Short-lived climate pollutants - including black carbon, methane, hydrofluorocarbons, and tropospheric ozone - are powerful climate forcers with global warming potentials many times that of carbon dioxide.
These pollutants also significantly impact air quality, food, water and economic security for much of the world, both directly through their negative effects on public health, agriculture and ecosystems, and indirectly through their impact on the climate.
The measures and technologies to reduce short-lived climate pollutants are available today and are practical, technically feasible, and cost-effective. Putting them in place can bring immediate climate benefits, help achieve many global sustainable development goals (SDGs), and improve the health and livelihoods of millions.
Many air pollutants also cause global warming... tackling air pollution therefore presents a double opportunity.
United Nations Secretary-General
It is not enough to act. We must act now.
Delayed efforts to mitigate either carbon dioxide or short-lived climate pollutant emissions will have negative, and potentially irreversible, consequences for global warming, rising sea levels, food security, and public health.
Due to their relatively short lifetime in the atmosphere, ranging from a few days to a few decades, reducing short-lived climate pollutants can rapidly slow the rate of global temperature rise, complement efforts to mitigate carbon dioxide emissions and keep warming below 2°C.
The Climate and Clean Air Coalition’s measures can cut methane emissions by at least 40% and black carbon by up to 70% by 2030, and virtually eliminate (99.5%) high-global warming potential hydrofluorocarbons altogether by 2050 (all compared to 2010 levels).
Reducing short-lived climate pollutants provides other significant benefits. These include preventing millions of premature deaths annually, improving food security by avoiding tens-of-millions of tonnes of annual staple crop losses, protecting vital ecosystems and ecosystem services, reducing the risk of dangerous and irreversible climate tipping points, and making significant contributions to achieving the 2030 Agenda for Sustainable Development.
Widespread actions to reduce short-lived climate pollutants can prevent 0.6°C of warming by 2050. Cutting emissions of carbon dioxide and short-lived climate pollutants is critical to slow the rate of global warming and achieve the 2°C target set by the Paris Agreement. The Intergovernmental Panel on Climate Change’s (IPCC) found that pathways that limit global warming to 1.5°C must include deep reductions in all climate forcing emissions, including short-lived climate pollutants.
What we all now agree, and the IPCC Special Report on 1.5°C Global Warming confirms, is that it is imperative that we reduce both carbon dioxide as well as the short-lived pollutants. We're not talking about one or the other.
Dr. Mario Molina
Nobel Laureate in Chemistry and Distinguished Professor of Chemistry and Biochemistry
A warmer climate increases public health challenges like heat aggravated illnesses, increases in vector borne diseases, and decreased access to safe water and food. Cutting short-lived climate pollutants can slow the rate of warming and lower public health risks.
Short-lived climate pollutants like tropospheric ozone (O3) and black carbon (a component of fine particulate matter or PM2.5) are also dangerous air pollutants. Reducing them will prevent millions of premature deaths each year from air pollution. The biggest benefits will be felt locally, with the greatest health benefits expected in Asia.
Rising temperatures threaten food security. Increases in pests and diseases and more frequent and intense droughts and floods, reduce the availability of food. Heat-stress causes poor yields, or worse, crop failures. Reducing short-lived climate pollutants gives us our best chance to rapidly limit global temperature rise and reduce the risks to food security.
Tropospheric ozone causes around 110 million tonnes in annual losses of the major staple crops: wheat, rice, maize and soybeans. This represents around 4% of the total annual global crop production, and up to 15% in some regions. Reducing methane, an ingredient in the formation of tropospheric ozone, can halve these losses by 2050 and save between $4 to $33 billion annually.
The impacts of short-lived climate pollutants on public health, ecosystems, and agricultural productivity have economic consequences. Reducing short-lived climate pollutants can have immediate economic benefits from job creation and increased household income – as well as lasting ancillary benefits from improved public health, reduced poverty and inequality, and lessened climate change impacts.
Actions to reduce short-lived climate pollutants will produce important near-term benefits that will support the success of the Sustainable Development Goals (SDGs) by improving human health and reducing vulnerability, driving economic growth and innovation such as catalyzing improvements in energy efficiency and combatting near-term climate change.
Brief document providing an overview of the main short-lived climate pollutant sources and impacts and the multiple benefits from mitigation actions. Available in French, ...
Time to Act, released in abbreviated form in 2013, has already proved valuable to governments, organizations, businesses and others interested in new ways to reduce global warming, improve health...
This assessment report looks into all aspects of anthropogenic emissions of black carbon and tropospheric ozone precursors, such as methane. It analyses the trends in emissions of these substances...
This report addresses the mitigation of short-lived climate forcers (SLCFs) and its key role in air pollution reduction, climate protection and sustainable development. SLCFs are substances in the...
This is a background paper prepared by the Climate and Clean Air Coalition (CCAC) Scientific Advisory Panel (SAP) for the Science Policy Dialogue, March 31, 2016, Washington DC, USA. This...