Climate Disruption & Adaptation

Climate Disruption & Adaptation

Greenhouse Gas Emissions  Sea Level Rise and Flooding Projections ♦ Temperature

Sustainability Goals

In a sustainable state, greenhouse gas (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.

Indicator Overview

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 1.4º Fahrenheit over the last century and is projected to rise another 2–11º 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.

Greenhouse Gas Emissions

ssmc_2016_juneupdate_LOW Greenhouse Gas Emissions, San Mateo County, 2013 ssmc_2016_marchupdate-01 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).

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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Sea Level Rise and Flooding Projections

Sea level rise is the result of thermal expansion (water temperature increase) and the melting of vast bodies of ice. These phenomena, as well as high intensity storms are a result of climate change. The combination of sea level rise, high tide, and wind caused by storms pose a major threat of flooding in low lying areas along the coast and the bay side of the county.

According to the National Ocean and Atmospheric Administration (NOAA), sea level remained stagnant until the 20th Century. Since 1900, sea level has risen 0.04 to 0.1 inches per year, and an alarming 0.12 inches annually since 1992. Though these numbers may not seem immediately threatening, many analysts believe San Mateo County will experience up to 55 inches of sea level rise by 2100. An estimated 10% of San Mateo County’s population will be directly affected by a sea level rise of 36 inches. According to SPUR, 40 percent of the state’s land drains its water into the San Francisco Bay.

The Bay Institute reports that flooding from storm surges is the greatest threat to developed areas along the bay’s shoreline. Intense waves and sea level rise will result in erosion of the county’s coastal bluffs and beaches. The 2013-2014 San Mateo County Civil Grand Jury report on sea level rise estimates the cost to repair buildings and other infrastructure in San Mateo County will exceed $23 billion along the bay and $910 million on the coast.

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Evaluation and Preparation Projects

  • The San Mateo County Office of Sustainability in collaboration with the Coastal Conservancy is conducting a Sea Level Rise Vulnerability Assessment set for completion in March 2016. The project utilizes sea level rise projections combined with storm scenarios to evaluate the risk to assets including infrastructure, wetlands, and wild life habitat. Learn more at the Sea Change San Mateo County website.
  • In 2013, SFO began its Airport Shoreline Protection Feasibility Study to determine areas of improvement in preparation for sea level rise and a 100-year flood. This resulted in the establishment of the Shoreline Protection Program (SPP) in 2015.
  • The San Francisquito Creek Joint Powers Authority is conducting a feasibility study to restore marshlands, create recreation trails, and protect against flooding and three feet of sea level rise. The project has secured funding from three city governments, a local business, and the US Fish and Wildlife Service. Learn more about the SFJPA’s projects on their website.
  • In 2014, FEMA revised its flood and wave data for the San Mateo County Flood Insurance Study report and Flood Insurance Rate Map, which are used to determine flood insurance rates.

Flood Risks from Sea Level Rise in San Mateo County

Flood Risks from Storms in San Mateo County

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Global weather measurements indicate that 2015 was the hottest year on record. As shown in the chart below, the warming trend was present in the Central Coast region (which includes San Mateo County).

Climate is a major factor in agricultural crop production. Plant growth is determined by atmospheric temperature, humidity, moisture, and nutrients (carbon, nitrogen, etc.). Crops are selected for compatibility with the local climate and fluctuations may require a shift in production. Shown below are examples of how climate affects agriculture, drought, and other resources.

  • Though a slight temperature increase will result in higher crop output, a change beyond 3 degrees Celsius will decrease production (TIMM, 2015).
  • Rising temperatures shift snow and rain patterns, causing precipitation to fall as rain. In California, this means less snow in the Sierra snow pack, the state’s largest water storage system.
  • Higher temperatures extend growing seasons, which increases the demand for water to maintain crops. Competition for water resources will heighten demand for energy, while hydropower generation will become less reliable (CalCAN, 2015).
  • Heat may damage crops, but its greatest threat is to the well-being of farmworkers.
  • Chill time is another climate factor affected by temperature. Minimum hours of chill are needed for apples, cherries, grapes, pears, nuts, avocados, stone fruit, tomatoes, rice, corn, sunflower, and wheat.
  • Higher concentrations of atmospheric carbon dioxide stimulate crop growth, as well as weeds, and pests. Warmer weather may cause weeds and pest to migrate north. To combat these threats, growers may increase their use of herbicides and pesticides resulting in air and water pollution.
  • Heavy rainfall is another potential side effect of climate change that may damage crops and cause soil erosion.
  • Climate change poses threats to pollinators as flowers may bloom at different times of the season out of sync with pollinator’s migration patterns.

8% of California’s greenhouse gas emissions come from agriculture. 

Many of the state’s farmers and the organizations that support them are developing techniques to reduce the carbon footprint of farming and enhance resilience to climate change. The California Climate and Agriculture Network and the Natural Resource Conservation Service circulate information about best practices in farming, from water efficiency to soil integrity.

  • Irrigation water management plans that improve water efficiency also reduce the amount of energy needed to supply that water, which leads to a reduction in greenhouse gas emissions.
  • Healthy soil has an abundance and diversity of microbial life, which not only emits less greenhouse gases, but also stores carbon, preventing absorption into the atmosphere.
  • Academic institutions and conservation organizations conduct regional research on soil and guidance for farmers to know exactly which cover crops and nutrients are most beneficial for their soil and climate.
  • Crop rotation and diversification, composting, and covers crops are healthy alternatives to excessive tilling and synthetic chemical inputs such as fertilizers, pesticides, and fungicides (Kane, 2015).
  • Biochar is an example of transforming excess organic matter to soil amendment with potential benefits for carbon sequestration.

In 2016, the USDA allocated $72.3 million in funding, nationwide, for its new climate smart agriculture strategy. The program will support soil health, nitrogen stewardship, sustainable grazing practices, forest retention, and renewable energy generation on agricultural land.

Cattle and Methane

Over half of California’s methane emissions are from cattle and dairy farms (CalCAN, 2015). To decrease the carbon footprint of cattle products, ranchers and dairy producers are developing a suite of best practices.

Co-digestion of manure and other waste streams is a method to reduce methane emissions, extract reusable water, and create fertilizer. This method is practiced at Straus Family Creamery in Petaluma, CA. Research has shown that dry manure management has the potential to reduce methane emissions and reduce contamination of food and soil compared to wet management practices; however, dry manure management requires more labor.

Local ranches, such as LeftCoast Grass-fed at TomKat Ranch and Markegard Family Grass-fed, implement Holistic Management systems that preserve grassland and contribute to carbon storage. In this system, cattle eat grass and trim the top to stimulate new growth, while fertilizing the land with manure. The cows are then moved to a new swath of grass or pasture to begin the process again. This practice is also beneficial for habitat conservation where riparian areas are maintained; and carbon sequestration is enhanced where perennial grasses exist.

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Gasoline and Diesel Consumption.California Air Resources Board EMFAC Database. Retrieved from:

Climate Action Plans comes from the San Mateo County Climate Energy Watch, retrieved from

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From the 2014 Indicators Report

22 percent of adults in the county are considered obese

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Quotable Quote

‟The future will be green, or not at all. This truth lies at the heart of humankind's most pressing challenge: to learn to live in harmony with the Earth on a genuinely sustainable basis.”—Sir Jonathon Porritt