This page provides primary key terms that help to understand the Climate Acton Plan, including the regulatory framework and issues that the Climate Action Plan will address.

AB 32 (Assembly Bill 32)

Establishes a comprehensive program of regulatory and market mechanisms to achieve real, quantifiable, cost-effective reductions of greenhouse gases (GHG) for the State of California. Makes the California Air Resource Board (CARB) responsible for monitoring and reducing statewide GHG emissions, with a target to reduce emissions to 1990 levels by 2020. The AB 32 Scoping Plan, adopted in December 2008, recommends that local governments adopt a GHG reduction target of 15% below current (2005 to 2008) levels by 2020. Find more information from the California Air Resources Board.

Bay Area Air Quality Management District (BAAQMD) CEQA Guidelines

The Bay Area Air Quality Management District (BAAQMD) adopted an update to their CEQA Guidelines in December 2010. The update includes numeric GHG thresholds of significance to ensure that the Bay Area meets AB 32 targets. The Guidelines also establish a definition for a Qualified GHG Reduction Strategy, which can be developed and adopted locally to create an operational threshold of significance. Find more information from the Bay Area Air Quality Management District.

California Environmental Quality Act (CEQA)

A state law requiring state and local agencies to assess the environmental impacts of a proposed private or public project they undertake or permit. If a proposed activity has the potential for a significant adverse environmental impact, an environmental impact report (EIR) must be prepared and certified as to its adequacy before action can be taken on the proposed project. General plans require the preparation of a "program EIR."

Carbon Dioxide Equivalent (CO2e)

A metric measure used to compare the emissions from various greenhouse gases based upon their global warming potential (GWP), or potency. Carbon dioxide equivalents are commonly expressed as "million metric tons of carbon dioxide equivalents (MMTCO2E)." The carbon dioxide equivalent for a gas is derived by multiplying the tons of the gas by the associated GWP. For example, the GWP for methane is 24.5. This means that one million metric tons of methane is equivalent to 24.5 million metric tons of carbon dioxide. (Source: U.S. Environmental Protection Agency,

Climate Change

(also referred to as global climate change)

The term "climate change" is sometimes used to refer to all forms of climatic inconsistency, but because the Earth's climate is never static, the term is more properly used to imply a significant change from one climatic condition to another. In some cases, climate change has been used synonymously with the term "global warming"; scientists however, tend to use the term in the wider sense to also include natural changes in climate.

Energy Conservation

Means reducing energy waste, such as turning off lights, heating, and motors when not needed

Energy Efficiency

Doing the same or more work with less energy, such as replacing incandescent light bulbs with compact fluorescent light bulbs or buying an Energy Star appliance to use less energy for the same or greater output.

Green Building

Sustainable or "green" building is a holistic approach to design, construction, and demolition that minimizes the building's impact on the environment, the occupants, and the community.

Greenhouse Gases

Gases that trap heat in the atmosphere are often called greenhouse gases. Some greenhouse gases such as carbon dioxide occur naturally and are emitted to the atmosphere through natural processes and human activities. Other greenhouse gases (e.g., fluorinated gases) are created and emitted solely through human activities. The principal greenhouse gases that enter the atmosphere because of human activities are:

  • Carbon Dioxide (CO2): Carbon dioxide enters the atmosphere through the burning of fossil fuels (oil, natural gas, and coal), solid waste, trees and wood products, and also as a result of other chemical reactions (e.g., manufacture of cement). Carbon dioxide is also removed from the atmosphere (or "sequestered") when it is absorbed by plants as part of the biological carbon cycle.
  • Methane (CH4): Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from livestock and other agricultural practices and by the decay of organic waste in municipal solid waste landfills.
  • Nitrous Oxide (N2O): Nitrous oxide is emitted during agricultural and industrial activities, as well as during combustion of fossil fuels and solid waste.
  • Fluorinated Gases: Hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride are synthetic, powerful greenhouse gases that are emitted from a variety of industrial processes. Fluorinated gases are sometimes used as substitutes for ozone-depleting substances (i.e., CFCs, HCFCs, and halons). These gases are typically emitted in smaller quantities, but because they are potent greenhouse gases, they are sometimes referred to as High Global Warming Potential gases ("High GWP gases").

Greenhouse Gas Inventory

A greenhouse gas (GHG) inventory provides estimates of the amount of GHG emitted to and removed from the atmosphere by human activities. A city or county that conducts an inventory looks at both community emission sources as well as emissions from government operations. A base year is chosen and used to gather all data from that year. Inventories include data collection from such things as vehicle miles traveled (VMT), energy usage from electricity and gas, and waste. Inventories include estimates for carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), hydrofluorocarbons (HFC), and perfluorocarbons (PFC), which are referred to as the "six Kyoto gases."

Reduction Measure

A reduction measure is the City's action to reduce GHG emissions from municipal operations and in the community.

SB 375

Requires the California Air Resources Board (CARB) to develop regional greenhouse gas emission reduction targets to be achieved from the automobile and light truck sectors for 2020 and 2035. (Source: Air Resources Board of California)

Vehicle Miles Traveled (VMT)

A key measure of overall street and highway use. Reducing VMT is often a major objective in efforts to reduce vehicular congestion and achieve regional air quality goals.

Water Conservation

Reducing water use, such as turning off taps, shortening shower times, and cutting back on outdoor irrigation.

Water Efficiency

Replacing older technologies and practices in order to accomplish the same results with less water, for example, by replacing toilets with new low-water-using models and by installing "smart controllers" in irrigated areas.