Reducing Greenhouse Gas Emissions
Various federal programs and international agreements are in place to reduce greenhouse gas emissions. These federal programs are generally designed to promote emissions reductions technologies in the energy and transportation sectors. In addition, Congress may consider taking action to reduce greenhouse gas emissions in the future.
According to the Environmental Protection Agency, the primary sources of U.S. greenhouse gas emissions by economic sector in 2013 were electricity production (31 percent), transportation (27 percent), and industry (21 percent). The remaining 21 percent of 2013 U.S. greenhouse gas emissions were contributed by the agriculture, commercial, and residential sectors. A number of programs aimed at reducing greenhouse gas emissions have been proposed or enacted in the United States and other developed countries, including:
- carbon taxes,
- cap-and-trade programs,
- carbon offsets,
- energy efficiency standards,
- financial incentives (e.g., subsidies or tax credits),
- voluntary agreements,
- education campaigns, and
- research, development and deployment of advanced technologies.
Table 1 shows options for addressing climate change.
Table 1: Selected Policies, Measures, and Instruments Used by Various Nations to Reduce Emissions and Address Climate Change, as of 2008
In addition, technologies such as carbon capture and storage and biofuels production have the potential to supplement policies designed to reduce emissions. Carbon capture and storage involves separating and storing carbon dioxide from an industrial or energy-related source, and preventing the release of carbon dioxide emissions into the atmosphere. The figure below illustrates potential technologies for capturing and storing carbon dioxide emissions.
Figure 1: CO2 Capture, Transport, and Storage in Geologic Formations
GAO-16-669: Published: Jul 5, 2016. Publicly Released: Jul 5, 2016.
In fiscal years 2008–2015, U.S. agencies obligated a total of about $97 million for clean energy cooperation with China. Two-thirds of this money was obligated for three key programs (projects of which are depicted from left to right below):Department of Energy (DOE) program, the U.S.-China Clean Energy Research Center (CERC), that has focused on research and development in clean coal, clean veh...
GAO-11-345: Published: Feb 15, 2011. Publicly Released: Mar 17, 2011.
Carbon offsets are reductions in greenhouse gas emissions in one place to compensate for emissions elsewhere. Examples of offset projects include planting trees, developing renewable energy sources, or capturing emissions from landfills. Recent congressional proposals would have limited emissions from utilities, industries, or other "regulated entities," and allowed these entities to buy offsets....
GAO-10-675: Published: Jun 16, 2010. Publicly Released: Jul 16, 2010.
Coal power plants generate about half of the United States' electricity and are expected to remain a key energy source. Coal power plants also account for about one-third of the nation's emissions of carbon dioxide (CO2 ), the primary greenhouse gas that experts believe contributes to climate change. Current regulatory efforts and proposed legislation that seek to reduce CO2 emissions could affect...
GAO-09-554: Published: Jun 8, 2009. Publicly Released: Jun 8, 2009.
Aircraft emit greenhouse gases and other emissions, contributing to increasing concentrations of such gases in the atmosphere. Many scientists and the Intergovernmental Panel on Climate Change (IPCC)--a United Nations organization that assesses scientific, technical, and economic information on climate change--believe these gases may negatively affect the earth's climate. Given forecasts of growth...
GAO-09-151: Published: Nov 18, 2008. Publicly Released: Dec 2, 2008.
International policies to address climate change have largely relied on market-based programs; for example, under the European Union's Emissions Trading Scheme (ETS) phase I (2005 to 2007) carbon dioxide emissions reductions were sought by setting a cap on each member state's allowable emissions and distributing tradable allowances to covered entities, such as power plants. Beginning operation in...
GAO-08-1080: Published: Sep 30, 2008. Publicly Released: Sep 30, 2008.
Key scientific assessments have underscored the urgency of reducing emissions of carbon dioxide (CO2) to address climate change. Many have cited carbon capture and storage (CCS) as an essential technology because it has the potential to greatly reduce CO2 emissions from power plants while allowing for projected increases in electricity demand. CCS involves capturing CO2 from a power plant's emissi...
GAO-12-545R: Published: Apr 18, 2012. Publicly Released: May 18, 2012.
Older electricity generating unitsthose that began operating in or before 1978provided 45 percent of electricity from fossil fuel units in 2010 but produced a disproportionate share of emissions, both in aggregate and per unit of electricity generated. Overall, in 2010 older units contributed 75 percent of sulfur dioxide emissions, 64 percent of nitrogen oxides emissions, and 54 percen...
GAO-10-818: Published: Jul 30, 2010. Publicly Released: Aug 5, 2010.
Nations that are Parties to the United Nations Framework Convention on Climate Change periodically submit inventories estimating their greenhouse gas emissions. The Convention Secretariat runs a review process to evaluate inventories from 41 "Annex I" nations, which are mostly economically developed nations. The 153 "non-Annex I" nations are generally less economically developed and have less stri...
GAO-10-377: Published: Feb 24, 2010. Publicly Released: Mar 26, 2010.
Congress is considering proposals for market-based programs to limit greenhouse gas emissions. Many proposals involve creating a cap-and-trade program, in which an overall emissions cap is set and entities covered by the program must hold tradable permits--or "allowances"-- to cover their emissions. According to the Congressional Budget Office (CBO), the value of these allowances could total $300...
GAO-09-950T: Published: Aug 4, 2009. Publicly Released: Aug 4, 2009.
Congress is considering proposals to establish a price on greenhouse gas emissions through a cap-and-trade program that would limit overall emissions and require covered entities to hold tradable emissions permits, or allowances, for their emissions. The purpose of such a program is to raise the cost of activities that produce emissions and thereby provide an economic incentive to decrease emissio...