NGA ISSUE BRIEF: Natural Gas & Climate Change

SUMMARY
  • Natural gas is the cleanest of the fossil fuels, with far lower emissions of carbon dioxide.
  • With its positive environmental profile, gas has been the "fuel of choice" for power generation in the Northeast.
  • Natural gas can also play a positive role in reducing transportation sector emissions.
  • The natural gas industry is striving to reduce its environmental impacts, through such cooperative efforts as the U.S. EPA's "Natural Gas STAR" program, and efforts to reduce methane emissions.

Natural gas is a low carbon fuel, and is seen as a key element in U.S. efforts to transform its energy system to be more efficient and environmentally positive.

Natural gas has been the "fuel of choice" for power generation in the Northeast for over the last decade in large part because of its positive impacts on air quality and the environment; and it is also seen as a positive environmental fuel for transportation and other sectors. Natural gas is a critically important component of the U.S. energy mix today, providing over one-quarter of all energy supplies. In the future, it can play an even larger role and thereby help achieve a balanced lower-carbon energy future for the U.S. Supplies of natural gas in the U.S. are abundant, and these resources hold great promise for the nation's energy supply availability, security and cost competitiveness.

A review of natural gas's potential to address the nation's climate change challenge is provided in this summary.

Natural Gas: Less Carbon Intensive than other Fossil Fuels

Natural gas is composed primarily of methane. As described by U.S. EPA: "Natural gas is a fossil fuel formed when layers of buried plants and animals are exposed to intense heat and pressure over thousands of years. The energy that the plants and animals originally obtained from the sun is stored in the form of carbon in natural gas."

Natural gas has lower emissions of carbon dioxide than other fossil fuels such as coal and oil. Compared to coal, natural gas produces half as much carbon dioxide, and about 30% less than oil.

Advantages for Transportation Sector

Natural gas represents an efficient alternative transportation fuel for the U.S. and the Northeast region. Natural gas vehicles employ a technology that is available now and applicable to taxis, passenger vehicles, heavy-duty trucks and buses. Natural gas vehicles provide lower emissions of carbon dioxide, carbon monoxide and nitrogen oxide compared to gasoline and diesel vehicles. (For more information, click here.)

Advantages for Power Generation

For power generation, natural gas has been the leading fuel option in the U.S. and the Northeast over recent years, reflecting the technological advances of natural gas combined cycle power plants, with higher efficiency, lower heat rates, and lower emissions than other fuel options. Natural gas is the least carbon-intensive fossil fuel, and is helping to drive down overall CO2 emissions in the electric power sector.
Natural gas is positioned to remain a reliable fuel for electric generation in the coming decades. Gas also can readily and reliably provide the back-up power generation for intermittent renewable resources like wind and solar power.
In May 2010, the National Research Council (NRC), part of the National Academy of Sciences, released a series of reports on climate change. In the paper entitled "Limiting the Magnitude of Future Climate Change" the NRC recommended the following as one of the opportunities for reducing emissions:
    "Expand the use of low- and zero-carbon energy sources (e.g., switch from coal and oil to natural gas), expand the use of nuclear power and renewable energy sources such as solar, wind, geothermal, and biomass; capture and sequester CO2 from power plants and factories."


In New York State, from 2000 to 2016, NY ISO reports that emissions rates from the power sector dropped by 43% for CO2, 87% for NOx, and 98% for SO2. ISO-NE reports that from 2001 to 2017, total emissions from power plants in New England dropped by 98% for sulfur dioxide (SO2), 74% for nitrogen oxides (NOx), and 34% for CO2. PJM emissions data indicates a significant drop in SO2, NOx and CO2 for its entire region, which includes declining trends for all three pollutants in both New Jersey and Pennsylvania.

Natural gas has been a key factor in all three power systems in helping achieve these environmental gains.



Advantages for Residential and Business Customers


For homes and businesses, natural gas also offers opportunities for increased efficiency and reduced emissions. As the Natural Gas Council pointed out in its 2009 paper, "Solving the Climate Change Puzzle": "America's 70 million natural gas customers have collectively succeeded at doing what no other energy users have done - holding consumption steady. Despite the fact that the number of natural gas customers has doubled since 1970, consumption has remained about the same. By using natural gas in their homes and businesses, insulating their windows and doors, and using energy-efficient appliances, natural gas customers are using about 1 percent less energy than they did in 1980-and this rate of decline has accelerated to about 2 percent annually since 2000."

Efficiency remains a supply resource of immense opportunity to the nation and climate change legislation should encourage cost-effective programs that yield positive results. The Northeast states already are national leaders in per capita energy efficiency, and the natural gas and electric utilities in the region have been active for years in efficiency programs. These natural gas efficiency program investments will be expanded even further in coming years. (For more information, click here.)

Reducing Methane Emissions within Gas System Operations


Natural gas companies are committed to reducing their own carbon footprint and are actively involved in such initiatives as the U.S. EPA's "Natural Gas STAR" Program to reduce methane emissions from natural gas system operations. Progress continues on this front, and new technologies are helping in that regard.

NGA encourages increased funding for innovative research and development programs that support improved technologies in all stages of the natural gas supply and delivery chain to achieve environmental improvements.

More information on Natural Gas STAR can be found here: https://www.epa.gov/natural-gas-star-program/natural-gas-star-program#tab-4

Natural gas systems are a leading contributor to CH4 or methane emissions in the U.S., along with agriculture, landfills and coal mining. But methane emissions from natural gas have come down compared to prior decades. CH4 emissions from natural gas systems declined by 14.3% from 1990 to 2017, according to the U.S. EPA's draft 2017 Greenhouse Gas Inventoryreleased in February 2019. (This decline occurred in a timeframe when total U.S. natural gas consumption grew from 19 Tcf in 1990 to 27 Tcf in 2017 - a growth of 42%.)

EPA notes: "The decrease in transmission and storage emissions is largely due to reduced compressor station emissions (including emissions from compressors and equipment leaks)...Distribution system emissions, which account for 7 percent of CH4 emissions from natural gas systems and less than 1 percent of non-combustion CO2 emissions, result mainly from leak emissions from pipelines and stations. An increased use of plastic piping, which has lower emissions than other pipe materials, has reduced both CH4 and CO2 emissions from this stage, as have station upgrades at metering and regulating (M&R) stations. Distribution system CH4 emissions in 2017 were 73 percent lower than 1990 levels." [EPA, draft Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2017, pages ES-16 and 3-82]

Massachusetts has seen a considerable decline in methane emissions over the last 25 years. The MA DEP's greenhouse gas emissions inventory shows that methane (CH4) emissions from natural gas systems declined by 67% from 1990 to 2017 (the most recent data year; note - 2017 data is still preliminary). New York State reports that emissions related to "natural gas leakage" in-state declined by 52% from 1990 to 2015. Also, "natural gas leakage" overall represents 1% of total statewide GHG emissions. The leading sources of methane emissions in New York State are landfills and agricultural animals, followed by natural gas, according to NYSERDA's March 2018 GHG state inventory. Connecticut reported in June 2017 that the "contribution of methane emissions from natural gas distribution systems within Connecticut is less than one percent (0.03%) of all GHG emissions.".

Accelerated pipeline replacement of "leak-prone" system components, such as cast iron and bare steel, is an industry and U.S. DOT priority - see the separate issue brief at: https://www.northeastgas.org/accelerated_infrastructure.html

Natural gas is contributing to positive environmental achievements in the Northeast and the nation in terms of carbon reductions. In November 2017, in its annual World Energy Outlook, the International Energy Agency (IEA) stated that "As oil and coal fall back and renewables ramp up strongly, natural gas becomes the largest single fuel in the global mix in the Sustainable Development Scenario. Securing clear climate benefits from gas use depends on credible action to minimise leaks of methane - a potent greenhouse gas - to the atmosphere. Consumption of natural gas rises by nearly 20% to 2030 in the Sustainable Development Scenario and remains broadly at this level to 2040."

For Further Information:

U.S. EPA's Greenhouse Gas Emissions Inventory