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Why Is This Important?
Carbon dioxide (CO2) is a greenhouse gas linked to climate change.  CO2
enters the atmosphere through nature’s carbon cycle and human activities
such as the burning of fossil fuels and deforestation.  Human activities
are the main driver of increased CO2 in the earth’s atmosphere.  They
have led to global atmospheric concentrations of CO2 that are 35 percent higher
than they were before the industrial revolution.  Potential impacts from
climate change include extreme weather events, changes in amounts and forms
of precipitation, and species migration.   Climate change may also
exacerbate air pollution and expand the range of certain infectious diseases
into San Mateo County.

What Is a Sustainable State?
A sustainable state is one where CO2 emissions are reduced to a level that
is in balance with nature’s ability to absorb those emissions.

How Are We Doing?
In 2006, CO2 emissions in San Mateo County totaled 5.91 million metric tons,
a 1 percent decrease from 2005 and a 5 percent decrease from 2000.  On
a per capita basis, emissions are 7 percent lower than in 2000.  A decrease
in gasoline consumption is the primary reason for the decline in emissions
from 2000.

Data sources: California Department of Transportation, California Energy
Commission, and California Integrated Waste Management Board

 

Data sources: California Department of Transportation, California Energy
Commission, California Integrated Waste Management Board, and California
Department of Finance

 

Data sources: California Department of Transportation, California Energy
Commission, and California Integrated Waste Management Board

Transportation

• Although gasoline consumption has declined by 9 percent since 2000, in
  2006 transportation-related emissions still accounted for 58 percent of the
  county’s total CO2 emissions. 
• In each year this decade, transportation has accounted for over 55 percent
  of total annual CO2 emissions.

Electricity
Emissions from electricity are driven by both total electricity use and the
carbon content of the generation source of that electricity.  Pacific
Gas and Electric Company (PG&E), delivers most of the electricity in
San Mateo County and has a mix of generation sources that is less carbon
intensive than the electricity for the state as a whole (see Energy Use indicator
for more information).

• In 2006, electricity use accounted for 20 percent of total CO2 emissions.
• Between 2000 and 2006, electricity use has accounted for 19 to 23 percent
  of annual CO2 emissions.  This is because of both varying levels of
  electricity use and a changing mix of energy sources generating PG&E’s
  electricity.

Natural gas

• In 2006, natural gas accounted for 20 percent of total CO2 emissions. 
• Between 2000 and 2006, natural gas has accounted for 18 to 20 percent of
  annual CO2 emissions.

Solid waste

• The decomposition of solid waste disposed of in landfills accounts for
  a small but still significant portion of the county’s total CO2 emissions
  (130,000 metric tons or 2 percent of all CO2 emissions). 
• In 2006, CO2 emissions from solid waste were nearly 19 percent below 2000
  levels.

Residential and nonresidential energy use

• In 2006, residential consumption of electricity and natural gas accounted
  for 19 percent of total CO2 emissions.  Nonresidential electricity and
  natural gas consumption accounted for 21 percent.
• In 2006, CO2 emissions from nonresidential consumption of electricity and
  natural gas were 3 percent higher than in 2000, whereas emissions from the
  residential sector were down slightly.

Other sources of CO2 emissions

Our calculation of total CO2 emissions does not include airplane travel.  We
do not have an estimate for the number of airplane trips county residents made
nor for the amount of jet fuel used.  We also did not calculate emissions
from off-road vehicles or boats.

Carbon Dioxide Emissions (Thousand Metric Tons) in San Mateo County, 2006
	Electricity	Natural Gas	Solid Waste	Transp.	Total
Atherton	13	25	2	54	94
Belmont	23	37	3	87	150
Brisbane	15	9	2	35	61
Burlingame	55	65	6	172	297
Colma	7	4	1	16	27
Daly City	64	92	11	231	398
East Palo Alto	16	25	3	60	104
Foster City	45	45	3	129	223
Half Moon Bay	16	23	5	60	104
Hillsborough	14	29	2	61	106
Menlo Park	83	103	2	258	446
Millbrae	21	35	2	80	139
Pacifica	25	42	4	98	169
Portola Valley	6	12	0	25	43
Redwood City	140	118	30	397	685
San Bruno	42	46	5	129	223
San Carlos	44	50	6	139	239
San Mateo	121	141	16	383	661
S. San Francisco	135	159	15	426	735
Woodside	10	15	1	35	61

* Note, transportation-related emissions were assumed to be the same percentage
as for the county as a whole. 
Data sources: California Department of Transportation, California Integrated
Waste Management Board, and Pacific Gas and Electric Company

California AB32
In 2006, Governor Schwarzenegger signed AB32, the California Global Warming
Solutions Act, requiring the California Air Resources Board (CARB) to establish
a statewide greenhouse gas emissions cap for 2020, based on 1990 levels.  CARB
is required to adopt a plan by January 1, 2009 indicating how emissions reductions
will be achieved from significant greenhouse gas sources via regulations,
market mechanisms, or other actions.

 

See appendix page 71, CLICK HERE. Researcher: Danielle Lee