The California Air
Resources Board (ARB) released a draft Short-Lived Climate
Pollutant Reduction Strategy. The draft strategy describes proposed actions the State will take to move forward aggressively to reduce emissions of short-lived
climate pollutants (SLCPs).
SLCPs include methane, black carbon and fluorinated gases
(F-gases) such as refrigerants, insulating foam and aerosol
propellants. They are harmful air pollutants and powerful
contributors to climate change, trapping heat at many times the
level of carbon dioxide, and are responsible for about 40%
of current global warming, ARB said.
The draft strategy follows Governor Brown’s announcement last
Thursday that California would
reduce emissions of methane and hydrofluorocarbons (HFCs) by 40% below current levels by 2030, and black carbon by 50% below current levels by 2030. It also comes a week after
bi-partisan legislation was re-introduced in the US Senate to
address SLCPs nationally.
Black Carbon. Black carbon is not one of the climate pollutants originally included in international climate frameworks, and is not included in California’s AB 32 inventory. However, the draft notes, recent studies have shown that black carbon plays a far greater role in global warming than previously believed.
Black carbon is a component of fine particulate matter, which the
State has addressed for decades through its efforts to improve
air quality and reduce toxic air pollution from diesel vehicles.
California has cut emissions of black carbon by well over 90% since the 1960s. These efforts avoid an estimated 5,000
premature deaths in the State each year, have cut cancer risk
from exposure to air toxics by nearly 70% since 1990, and
have been linked to improved lung function and capacity in
These reductions have come from strong efforts to reduce on-road vehicle emissions, especially diesel particulate matter. Car and truck engines used to be the largest sources of black carbon emissions in California, but California’s existing air quality policies will virtually eliminate black carbon emissions from on-road diesel engines within 10 years.
… With the large reduction in emissions of black carbon from vehicles, other sources of black carbon emissions will become more significant contributors to the State’s black carbon inventory over time. In particular, without additional actions, off-road mobile, fuel combustion in the industrial and power sectors, and residential fireplaces will account for more than three-quarters of black carbon emissions in California in 2030. However, black carbon emissions from these sources have declined significantly, as well—by almost 30 percent since 2000.
… The largest source of black carbon emissions in California, by far, is wildfire. An average wildfire season contributes two-thirds of current black carbon emissions in California. …many of California’s forests are already in a perilous condition and require accelerated management and investment to protect them. Several Federal, State, and local agencies are currently coordinating on forest planning, which will lead to the development of a comprehensive Forest Carbon Plan in 2016. As part of this and related efforts, black carbon mitigation will be considered along with forest health, carbon sequestration, habitat and watershed production, and other drivers associated with protecting our forests.
Methane. California already has measures in place to reduce methane from
many of its sources, and is developing a comprehensive framework
to minimize methane emissions from oil and gas systems.
The draft strategy proposes achieving additional reductions
through investments, incentives, regulations and other actions to
capture value from organic waste streams in California that are
responsible for about half of the state’s methane emissions.
Renewable energy, compost and other products from organic waste
streams could represent a billion dollar market for California,
with much of the economic activity centralized in the Central
Valley and rural parts of the state.
To put these resources to good use, the strategy proposes a
regulation that would effectively eliminate the disposal of organics in
landfills by 2025, and actions to cut methane emissions from
dairy manure by 75% below current levels by 2030.
Fluorinated gases. Under AB 32, the State already has a program in place to address
leaks from commercial refrigeration systems that will cut F-gas
emissions by an estimated 25% in 2020 below otherwise
expected levels. Additional steps are proposed in the strategy to
accelerate the transition away from hydrofluorocarbons (HFCs) in
new refrigeration, air conditioning equipment and by taking early
actions to significantly reduce these gases from commercial
International support is growing for an agreement in November to
phase down the production and use of HFCs under the Montreal
Protocol. Doing so would significantly curtail greenhouse gas
emissions from the fastest growing source globally. If an
agreement is not reached in November, California may develop its
own phase down, as Europe and other countries already are doing, ARB said.