skip to main content


A growing number of stakeholders, including investors, are asking companies to reduce their greenhouse gas emissions.
At Sempra Energy, we agree that this is important and work to minimize our emissions.

In 2015, Sempra Energy’s reported scope 1 and scope 2 emissions (see below for definitions) were approximately 8.5 million* metric tons of carbon-dioxide equivalent, also known as CO2e. This figure includes the 2.1 million* metric tons of CO2e from the Aliso Canyon leak. Although the leak took place from October 2015 to February 2016, we are reporting the total emissions figure in our 2015 report. Excluding the emissions related to this leak, Sempra Energy’s emissions decreased 9 percent, year-to-year, primarily due to a decrease in stationary combustion emissions related to the sale of the Mesquite natural gas-fired power plant.

*SoCalGas has pledged to mitigate the actual natural gas lost in the Aliso Canyon leak.

In addition to the greenhouse gas emissions described above, the operations of each of Sempra Energy’s businesses also result in greenhouse gas emissions by others. In 2015, Sempra Energy’s reported scope 3 emissions (see below for definition) were approximately 54.5 metric tons of carbon-dioxide equivalent or CO2e. This figure includes emissions from the generation of electricity that SDG&E purchased and delivered to its customers; and emissions from our customers’ combustion of natural gas delivered to them by our utilities SoCalGas, SDG&E, Ecogas, Mobile Gas* and Willmut Gas*. Our reported scope 3 emissions exclude upstream emissions from natural gas production wells.

*On April 24, 2016, Sempra U.S. Gas & Power agreed to sell Mobile Gas and Willmut Gas, subject to customary regulatory approvals.

For more information on Sempra Energy’s emissions, please visit

Categorizing greenhouse gas emissions

Greenhouse gas emissions are categorized as follows: scope 1 or direct emissions are emitted by the reporting company; scope 2 and scope 3 emissions are emitted by other companies or customers as a result of the reporting company’s activity.

  • Scope 1 emissions – Emissions from sources that are owned or controlled by the reporting company. For Sempra Energy, these include emissions from natural gas-fired power plants, natural gas pipelines and fleet vehicles.
  • Scope 2 emissions – Emissions emitted by another company to generate electricity, heating/cooling or steam that the reporting company purchases and then uses in its own operations. For Sempra Energy, these include emissions from electricity purchased and used in our own facilities, as well as emissions from the electricity purchased for our customers but lost during transmission and distribution.
  • Scope 3 emissions – Emissions (excluding those already reported in scope 2) that are a result of the reporting company’s activity, but occur at sources owned or controlled by another company. For Sempra Energy, these include emissions from customer use of our services (such as customers burning natural gas we have delivered); emissions from the generation of electricity purchased for and delivered to our customers; emissions from the production of natural gas purchased for and delivered to our customers; and emissions from the production and delivery of the raw materials we need for our business (pipes, wires, meters, office supplies). Note that due to the complexity involved in tracking or estimating emissions from some sources, Sempra Energy does not report on all of types of scope 3 emissions.

These descriptions are based on definitions provided in the World Resources Institute’s Greenhouse Gas Protocol.

As a responsible energy company, we take an interest in how the energy we procure is produced — and in how the energy we deliver is used. More information on this topic can be found in the Supply chain impacts subsection of this report.

Natural gas-fired power plants operated by Sempra Energy subsidiaries are our most significant source of direct (scope 1) greenhouse gas emissions. Yet these power generation operations are very efficient: In 2015, we emitted just 649 pounds of carbon dioxide per megawatt-hour of electricity generated, achieving our target to decrease this emissions rate by 10 percent from our 2010 baseline of 731 pounds per megawatt-hour. As we continue to develop and operate additional renewable energy resources, we expect our total energy mix will become even cleaner and our emissions rate will continue to decline.

New Sempra Energy headquarters uses less electricity and water

Improving energy and water efficiency can help reduce an organization’s greenhouse gas emissions.

Sempra Energy’s new headquarters building opened in July 2015. The 16-story tower has a 52-kilowatt solar panel system; drought-tolerant landscaping; and a bio filtration system to process storm water. It uses 63 percent less electricity and 32 percent less water than the old building, according to the most recent data (March 2016 compared with March 2015).

Although the new building uses significantly more natural gas, this is due to the fact that the old building used an outdated electric heating system instead of more efficient natural gas for heating.

Water filling stations, located throughout the new building, have prevented nearly 100,000 water bottles from entering the waste stream.

The headquarters was recently certified LEED Gold by the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) program. Company-owned or -operated buildings have received 19 LEED certifications.