California Air Resources Board

Short-lived climate pollutants (SLCP) are warming compounds that stay in the atmosphere for a shorter period of time than carbon dioxide, including black carbon particles, methane, and some hydrofluorocarbon gases (HFC).

This page contains data and documentation for the short lived climate pollutant inventories and projections for methane, short-lived HFCs, and black carbon used in the SLCP Strategy. These inventories represent a snapshot of the best available data used at the time of SLCP Strategy development in 2015.

Methane Inventory

The methane inventory and projection is based on the 2015 edition of the CARB greenhouse emission inventory.

Methane Emissions Data & Documentation

Methane Inventory 100-yr GWP
Methane Inventory 20-yr GWP
2000 & 2013 Emission Documentation
2020 & 2030 Projection Documentation

Hydrofluorocarbon Inventory

Hydrofluorocarbons (HFC) constitute a class of fluorinated compounds with a wide range of lifetimes and global warming potentials (GWPs). Many HFCs have short lifetimes thus are considered SLCPs. The HFC SLCP inventory includes nine short-lived HFCs from the 2015 Edition of California's official greenhouse gas emission inventory. These are: HFC-125, HFC-134a, HFC-143a, HFC-152a, HFC-227ea, HFC-245fa, HFC-32, HFC-365mfc, and HFC-43-10mee.

Short-Lived HFC Emissions Data and Documentation

Short-Lived HFC Summary 100-yr GWP
Short-Lived HFC Summary 20-yr GWP
HFC Technical Support Document

Black Carbon Inventory

The California Air Resources Board has developed a statewide emission inventory for black carbon in support of the Short-Lived Climate Pollutant Strategy. The black carbon inventory uses elemental carbon (EC) speciation profiles developed by CARB as a proxy for black carbon. Speciation profiles are applied to PM_2.5 mass emissions to estimate black carbon emissions.

Black Carbon Emissions Data and Documentation

Black Carbon Summary 100-yr GWP
Black Carbon Summary 20-yr GWP
2015 Edition Black Carbon Technical Support Document

Pie Chart of Non-Forestry Black Carbon Data (included in SLCP black carbon targets)

Forestry Black Carbon Data

The forestry category includes non-agricultural prescribed burning and wildfire emissions. Emissions from these activities exhibit high year-to-year variability and large uncertainty in current and future emissions, and are not included in the SLCP black carbon reduction target. To provide a more representative view of emissions without large year-to-year variability driven by natural forces, forestry emissions are calculated as a ten year average.

Ten Year Average California Forestry Black Carbon Emissions

Sulfuryl Fluoride

Sulfuryl fluoride (SO₂F₂) is a fluorinated gas with a lifetime of 36 years. It is used as a pesticide for building fumigation and post-harvest storage of commodities, but is not licensed for use in agricultural fields. Sulfuryl fluoride was believed to have a negligible GWP until 2009, when new research assigned a 100-year GWP of 4090 and a 20-year GWP of 6840. Because sulfuryl fluoride was not identified as a high-GWP gas at the time, it was not included as an AB 32 gas, and is not annually inventoried as a part of CARB's statewide GHG inventory.

The Department of Pesticide Regulation (DPR) tracks usage of sulfuryl fluoride. A summary of 2013 emissions based on DPR data is shown below. Usage for other years can be obtained from DPR.

2013 California Sulfuryl Fluoride Emissions

* Totals may not add due to rounding

Short-Lived Climate Pollutants CARB Home Page

SLCP Publications

Proposed Strategy - April 11, 2016
Draft Strategy Report - September 30, 2015
Concept Paper - May 7, 2015

Current Statewide Greenhouse Gas Emission Inventory