Why is this Important?


Increased levels of greenhouse gases (GHG) are the primary cause of man-made climate change. While some GHGs enter the atmosphere through nature’s carbon cycle, an increasing share now comes from human activities such as the burning of fossil fuels and deforestation.

Earth’s average temperature has increased 1.4 º Fahrenheit over the last century and is projected to rise another 2-11 º over the next 100 years if we do not curb emissions. The impacts of climate change”altered rainfall patterns, rising sea levels, and more extreme weather events”can already be observed, and Bay lands and coastal areas in San Mateo County are vulnerable to these threats.

California’s Global Warming Solutions Act, AB32, requires the state to reduce GHG emissions to 1990 levels by 2020 and then reach an 80% reduction from 1990 levels by 2050. Recent passage of SB32 added an interim goal requiring reducing carbon emissions to 40 percent below 1990 levels by 2030. Local governments and businesses will play a key role in meeting these goals.


What is a Sustainable State?


In a sustainable state, GHG emissions are reduced to a level that is in balance with nature’s ability to absorb them. Mileage standards for automobiles continue to rise, and multi-modal transportation options reduce total vehicle miles of travel. Energy is produced from renewable and greenhouse gas-neutral sources and is used efficiently.

New buildings are constructed to the highest green standards, and older buildings are retrofitted to ensure efficient energy use. While working to mitigate GHG emissions, communities simultaneously implement adaptation measures, such as building levees or restricting development in floodplain areas.


Key Findings

  • Total county GHG emissions in 2013 were 5.4 million metric tons of carbon dioxide equivalents.
  • In 2013, the three main sources of GHG emissions in the state were: transportation (37%), industrial (23%), and electricity generation (11%).
  • Total energy use in the county in 2015 was 34.6 trillion British thermal units (Btu), 15% lower than peak levels in 2008.
  • In 2015, almost all of the power in San Mateo County was purchased from Pacific Gas & Electric (PG&E). In 2015, 30% of the PG&E energy mix came from renewable sources; to meet California’s Renewable Portfolio Standard, the share of renewables must increase to 33% by 2020.
  • As of January 2013, 17 of the 20 cities and the county itself have approved Green Building ordinances, requiring new construction as well as major renovations to meet certain minimum green rating levels.
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Greenhouse Gas Emissions


Greenhouse Gas Emissions, San Mateo County, 2013


California Greenhouse Gas Emissions, 2013

  • Emissions in most sectors have gone down since 2000. Sectors that have seen an increase in GHG emissions are Commercial, Residential, and Agriculture.
  • In 2013, total GHG emissions decreased by 1.5 million metric tons of CO2 equivalents (MMTCO2e) compared to 2012.
  • Annual per capita GHG emissions in California have continued to drop from a peak in 2001 of 14.0 metric tons per person to 12.0 metric tons per person in 2013; a 14% decrease.
  • The transportation sector is the largest source of GHG emissions in California, responsible for over three times the emissions of electricity generation.
  • Note: the above chart measures include emissions only and does not include “Excluded” or “Biogenic emissions”. To see the complete inventory of CA emissions, click here.

Climate Action Plans

Local governments have a key role in helping the state meet its greenhouse gas (GHG) emissions reductions targets for AB32. Adopting a Climate Action Plan (CAP) is the first step. Cities are encouraged to start by creating a baseline inventory of municipal and community GHG emissions and then to identify target reductions. Emissions reductions strategies unique to the community are then evaluated, and after public meetings and an environmental review process, the most promising strategies are put into the CAP and/or General Plan. As of May 2016, 71% of cities/unincorporated county had a completed CAP (Brisbrane, Burlingame, Colma, Daly City, East Palo Alto, Foster City, Hillsborough, Menlo Park, Pacifica, Redwood City, San Carlos, City of San Mateo, County of San Mateo, South San Francisco, and Woodside), and 29% were in the process of completing one (Atherton, Belmont, Millbrae, Portola Valley, and San Bruno).

[smc-box]The National Climate Assessment, released in May 2014, paints a sobering picture of the impacts of climate change in the U.S. According to the Report, climate change is not distant issue but is something being felt now, with varying effects throughout the country. In California and the Southwestern United States the main threats are:

  • Reduced snowpack and stream flows which will lead to decreased water supply for cities, agriculture, and ecosystems.
  • Declining agriculture yields resulting from increased temperatures and droughts.
  • Increased and more severe wildfires due to rising temperatures, droughts, and insect outbreaks.
  • Sea level rise for coastal communities.

Climate change, once considered an issue for a distant future, has moved firmly into the present.” -2014 National Climate Change Assessment Report

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Vehicle Miles Traveled

Vehicle Miles Traveled (VMT) is the total number of miles driven by all vehicles in a given time period and geographical area. Factors influencing VMT include population, the state of the economy, personal income, number of registered vehicles per person, and fuel costs. Vehicle Fuel Consumption (VFC) is the total gasoline and diesel fuel usage on all public roads in a given time period, and it is influenced by VMT and fuel efficiency of vehicles.


  • Though both vehicle miles traveled and vehicle fuel consumption have increased since the economic downturn of 2008, fuel consumption has leveled in recent years.



  • Between 2014 and 2005, gas prices increased by 48%.

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Energy Use

  • Total energy use in the county in 2015 was 34.6 trillion British thermal units (Btu), 15% lower than peak levels in 2008.
  • Annual per capita usage dropped to 20 million Btu, a decline of 1.3% from the previous year.

  • In 2013, there was an even split between residential and non-residential energy use. This changed in 2014 when San Mateo showed a higher share of non-residential usage, similar to neighboring counties.

Energy Watch

San Mateo County Energy Watch has partnered with the San Mateo County Office of Education to benchmark all 173 public k-12 schools in the county and provide assistance with Prop 39 energy upgrades. Their Climate Corps Bay Area Fellow is benchmarking water usage of the public schools and performing domestic water audits to identify opportunities for water conservation. SMC Energy Watch is providing engineering services to cities in the county to enable them to move forward with energy efficiency retrofits.

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Energy Supply


  • In 2015, almost all of the power in San Mateo County was purchased from PG&E, making its supply mix an important measure of the impact of electricity use.

  • The portion of solar power has greatly increased from 8% in 2012 to 38% in 2015, while all other renewable sources decreased.


Progress Towards California's Renewable Portfolio Standards 2014

  • Under California’s Renewable Portfolio Standard (RPS), the state’s utility providers must procure 33% of their electricity from renewable sources by 2020.




PACE (Property Assessed Clean Energy) is an innovative energy financing mechanism that began in California in 2008. Through a PACE program, property owners can finance energy efficiency, water efficiency or clean energy projects with no up-front costs. Property owners first have their upgrades assessed by an experienced contractor to weigh the cost of the upgrade against the projected energy savings. Qualifying property owners receive 100% funding for their projects from their local PACE program and then pay it back over the long term (usually 20 years) as a property tax assessment. PACE enabling legislation is in place in 31 states, including California, and nearly 500 municipalities.

While municipalities have to set aside resources to launch programs such as PACE, there is evidence that investing in this type of upgrade has significant economic benefits. A 2011 study showed that $4 million invested in PACE generated $10 million in economic output, $1 million in net tax revenue, and 60 jobs.

All of the cities plus the County of San Mateo are eligible for California First, a program that provides financing for commercial & residential PACE programs. California First requires cities to market the program and pay fees to bring down the interest rates. HERO, a residential PACE, and Fig Tree, a commercial PACE, have no costs to the cities. To operate either program, the cities need to opt into a statewide Joint Power Authority (JPA). To date, approximately 150 cities/counties in California have adopted the HERO and Fig Tree programs. On April 29th, Menlo Park adopted the HERO PACE Program and has indicated it is conducting due diligence on the Fig Tree Program. The City of South San Francisco adopted the Fig Tree program.


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Green Buildings


  • Green building square footage continues to climb. 99% of green building square footage has been built since 2008.

Approved Green Bldng Ordinances Table-1.eps

  • As of May 2014, 18 of the 21 jurisdictions in the county have approved Green Building ordinances, which require new construction as well as major renovations to meet certain minimum green rating levels.
  • Greenpoint is used for residential construction, LEED is primarily used for commercial, while CalGreen is a statewide green building code that applies to both residential and commercial buildings.

Living Building Challenge

The Living Building Challenge is an international sustainable building certification program created in 2006 by the non-profit International Living Future Institute. It is described by the Institute as a philosophy, advocacy tool and certification program that promotes the most advanced measurement of sustainability in the built environment. It can be applied to development at all scales, from buildings – both new construction and renovation – to infrastructure, landscapes and neighborhoods, and is more rigorous than green certification schemes such as LEED.
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