Short-lived climate pollutants (SLCPs) are potent emissions that pack a lot of punch in a short time. Their life span is typically less than 15 years, unlike CO2 which stays in the atmosphere for about 100 years. SLCPs refer primarily to black carbon, methane, tropospheric ozone and hydrofluorocarbons (HFCs). Although they have a much shorter lifespan than CO2, SLCPs are responsible for at least 40% of the radiative forcing that is heating the planet, globally. Therefore, aggressively reducing SLCPs is one of the most effective ways of keeping global temperatures from rising to the all-important 1.5 degrees Celsius in the next 30 to 40 years.
Black carbon is the fine particulate or soot that results from the incomplete combustion of fossil fuels (diesel fuel, in particular) and biomass - primarily in the form of forests and crop residues. It warms the atmosphere by absorbing solar radiation and emitting it as heat, changes cloud formation and rain patterns, and darkens the surface of snow and ice, which accelerates heat absorption and melting. Black carbon is also responsible for premature deaths and crop damage each year. Despite the fact that black carbon only remains in the atmosphere for a few weeks at most, it is estimated to the second or third largest cause of climate change behind CO2 and methane.
Methane accounts for about 11%of global greenhouse gas emissions and is at least 25 times more potent then CO2 in spite of its relatively short life span of roughly 12 years. One of the main climate change culprits in the food supply chain, methane is produced primarily from the enteric fermentation of ruminant livestock such as cattle and sheep and is released when the animals burp as well as from their manure. Methane is also released by rice cultivation - the warm, waterlogged soil of rice paddies provides ideal conditions for methanogenisis- the formation of methane by microorganisms. It is also released by landfills, the burning of biomass, coal mining and a few other sources.
New technologies and practices can curb methane from rice growing such as through periodic field drying (see the Lotus Foods video below for more information). Using anaerobic digestion to capture methane from livestock manure is an effective approach to convert waste into energy while reducing methane emissions. In addition, simple changes such as avoiding adding straw to manure, applying manure to fields as quickly as possible, and avoiding wet conditions when applying manure can reduce the emission of methane. There are promising solutions to enteric emissions with feed additives and modifying feed to decrease methanogenisis such as adding seaweed and high omega-3 feeds to the diet of livestock.
Check out how Lotus Foods achieves 30%-60% reductions in methane emissions from rice production.
HFCs from refrigerants in air conditioning, cold chain transportation and storage are thousands of times more potent than CO2. Used as replacements for ozone-depleting substances (chlorofluorocarbons), HFCs are one of the fastest growing climate pollutants. Solutions for HFCs in refrigerants include managing leakage and recovery, enhancing energy efficiency within the cold chain, and using low-GWP (global warming potential) refrigerants and other alternative technologies such as transcritical CO2 .
Businesses that commit to reducing SLCPs – such as potent HFCs, black carbon and methane - join a global initiative to slow climate change impacts in the near term, improve air quality, and enhance future food security. Business has the power to provide this much-needed rapid response.
What is expected of companies who commit to reducing short-lived climate pollutant emissions?
Companies will want to establish targets and a timeline and commit to taking action at scale to make a significant impact on the climate in a relatively short time span. Following the lead of global industry initiatives for example, companies could commit to reducing HFCs by 30-50% within 10 years.
To get started, companies may choose to engage with suppliers to provide training, conduct pollutant inventories, and establish systems for tracking, measuring and monitoring SLCP emissions.
A critical component of reducing SLCPs will be supporting the development of new technologies through advocacy and investment strategies. A number of local and global initiatives are seeking partners and financing to develop and launch new technologies such as no or low-emitting alternatives to HFCs or biogas projects at many scales from small to large. Companies might also consider investment in offsets to reduce methane such as investing in offsite projects that capture methane such as methane digesters on dairy farms.
Companies committing to reducing SLCPs will be expected to complete a short annual questionnaire updating the Climate Collaborative on progress made toward the commitment.
How can the Climate Collaborative Help?
Our goal is to support businesses and stakeholders in the rapid reduction of SLCPs throughout the food production supply chain. We will facilitate networking, connect partners to initiatives and identify resources to help companies engage suppliers and support training efforts for tracking and measuring SLCPs.
We are planning webinars with partners and topic experts to help companies navigate the SLCP commitment while highlighting industry best practices, initiatives and financing options. Please let us know your needs and interests for reducing SLCPs in your supply chain to enable us to better focus our efforts.
Initiatives and Tools:
- Climate & Clean Air Coalition (CCAC)
- CCAC - HFC Initiative & factsheet
- CCAC - Methane from Agriculture
- EPA - AgStar Program
- CalCan – Diversified Strategy for Reducing Methane Emissions from Dairy Operations
More information on SLCPs:
- CCAC - SNAP SLCP National Planning Guide
- IGSD - Primer on Short-lived Climate Pollutants
- EESI - Short-Lived Climate Pollutants: Why are They Important?
- UNEP - HFCs: A Critical Link in Protecting Climate and the Ozone Layer
- Montreal Protocol HFC Amendment - Kigali Agreement to phase out HFCs