Climate Change: Action by States to Address Greenhouse Gas Emissions

In the absence of a federal climate change program, a number of states have taken actions that directly address greenhouse gas (GHG) emissions. States’ efforts cover a wide range of policies. Although much of the early activity was largely symbolic, the more recent state actions have been more aggressive.

Twenty-three states have joined one of the three regional partnerships that would require GHG (or just carbon dioxide) emission reductions. Set to take effect in 2009, the Regional Greenhouse Gas Initiative (RGGI) is a partnership of 10 Northeast and Mid-Atlantic states that creates a cap-and-trade system aimed at limiting carbon dioxide emissions from power plants. Seven western states (and four Canadian provinces) have formed the Western Climate Initiative, which set an economy-wide GHG emissions target of 15% below 2005 levels by 2020. In addition, six states (and one Canadian province) signed the Midwestern Greenhouse Gas Reduction Accord, which aims to establish a multi-sector, GHG cap-and-trade program in the Midwest. The latter two programs are still in the early development stages; RGGI is on schedule for 2009, and participating states have already held one emission allowance auction.

California has addressed GHG emissions on several fronts. To complement its statewide emissions reduction regime, California established GHG performance standards that would effectively limit the use of coal-generated electricity in California. In 2004, California issued regulations to reduce greenhouse gases from motor vehicles. At least 16 other states have indicated they intend to follow California’s new vehicle requirements. In addition, the state has also taken action to reduce the carbon intensity in its transportation fuels.

Predicting the precise consequences of the state-led climate change actions is difficult. Some actions, particularly the mandatory emission reductions, may create economic effects, especially in the automotive manufacturing and electricity-generating sectors. Industry stakeholders are especially concerned that the states will create a patchwork of climate change regulations across the nation. This prospect is causing some industry leaders to call for a federal climate change program. If Congress seeks to establish a federal program, the experiences and lessons learned in the states may be instructive.

Although some states are taking aggressive action, their possible emission reductions may be offset by increased emissions in states without mandatory reduction requirements. This is perhaps the central limitation of state climate change programs in actually affecting total greenhouse gas emissions. Legal challenges represent another obstacle for state programs, particularly for the more aggressive, mandatory programs.

Climate Change: Action by States to Address Greenhouse Gas Emissions

December 4, 2008 (RL33812)



In the absence of a federal climate change program, a number of states have taken actions that directly address greenhouse gas (GHG) emissions. States' efforts cover a wide range of policies. Although much of the early activity was largely symbolic, the more recent state actions have been more aggressive.

Twenty-three states have joined one of the three regional partnerships that would require GHG (or just carbon dioxide) emission reductions. Set to take effect in 2009, the Regional Greenhouse Gas Initiative (RGGI) is a partnership of 10 Northeast and Mid-Atlantic states that creates a cap-and-trade system aimed at limiting carbon dioxide emissions from power plants. Seven western states (and four Canadian provinces) have formed the Western Climate Initiative, which set an economy-wide GHG emissions target of 15% below 2005 levels by 2020. In addition, six states (and one Canadian province) signed the Midwestern Greenhouse Gas Reduction Accord, which aims to establish a multi-sector, GHG cap-and-trade program in the Midwest. The latter two programs are still in the early development stages; RGGI is on schedule for 2009, and participating states have already held one emission allowance auction.

California has addressed GHG emissions on several fronts. To complement its statewide emissions reduction regime, California established GHG performance standards that would effectively limit the use of coal-generated electricity in California. In 2004, California issued regulations to reduce greenhouse gases from motor vehicles. At least 16 other states have indicated they intend to follow California's new vehicle requirements. In addition, the state has also taken action to reduce the carbon intensity in its transportation fuels.

Predicting the precise consequences of the state-led climate change actions is difficult. Some actions, particularly the mandatory emission reductions, may create economic effects, especially in the automotive manufacturing and electricity-generating sectors. Industry stakeholders are especially concerned that the states will create a patchwork of climate change regulations across the nation. This prospect is causing some industry leaders to call for a federal climate change program. If Congress seeks to establish a federal program, the experiences and lessons learned in the states may be instructive.

Although some states are taking aggressive action, their possible emission reductions may be offset by increased emissions in states without mandatory reduction requirements. This is perhaps the central limitation of state climate change programs in actually affecting total greenhouse gas emissions. Legal challenges represent another obstacle for state programs, particularly for the more aggressive, mandatory programs.

Climate Change: Action by States to Address Greenhouse Gas Emissions


Over the past century, particularly in recent decades, scientists have documented increases in global temperature and sea levels, decreases of sea ice in the Arctic, and melting of continental ice sheets and mountain glaciers. There is increasing evidence that human activities are at least partially responsible for some of these effects.1 This is based upon the combination of two conclusions. First, global temperature increases are linked in some manner to the measurable increases of greenhouse gas (GHG) concentrations in the atmosphere.2 Second, human activities (e.g., fossil fuel combustion, industrial processes, and deforestation) have contributed to the increased concentration of GHG emissions in the earth's atmosphere.

The link between GHG emissions and climate change has motivated efforts to achieve reductions of emissions. In 1992, the United States ratified the United Nations' Framework Convention on Climate Change (UNFCCC), which called on industrialized countries to initiate GHG reduction.3 However, in early 2001, President George W. Bush rejected the UNFCCC 1997 Kyoto Protocol, which called for legally binding commitments by developed countries to reduce their GHG emissions.

Over the past decade, the federal government has promulgated or proposed a variety of voluntary and regulatory actions that, while not specifically seeking to reduce GHG emissions, may have yielded emission reductions as a byproduct.4 In the 110th Congress, Members introduced multiple bills to address climate change issues in some fashion and enacted several pieces of legislation that contained climate change provisions.5

In recent years, there has been some congressional support for a mandatory reduction program. For example, the Senate version of the Energy Policy Act of 2005 included a "sense of the Senate" Resolution6 stating:

It is the sense of the Senate that Congress should enact a comprehensive and effective national program of mandatory, market-based limits and incentives on emissions of greenhouse gases that slow, stop, and reverse the growth of such emissions at a rate and in a manner that, No. 1, will not significantly harm the U.S. economy and, No. 2, will encourage other action and key contributors to global emissions.

Members in the 110th Congress introduced multiple bills that would have established some type of a mandatory emissions reductions program. One of these proposals—the Lieberman-Warner Climate Security Act of 2008 (S. 2191/S. 3036)—was reported by the Senate Environment and Public Works Committee (December 2007) and debated in the Senate in June 2008.7

In the absence of action by the federal government to establish a national program that directly addresses GHG emissions, a number of states (and local governments, whose activities are not covered in this report8) have taken action in this arena.

States' efforts cover a wide spectrum, from developing climate action plans to setting mandatory GHG emission standards. Arguably, early state actions were largely symbolic. In the late 1980s, Vermont9 and Oregon10 were the first states to set GHG reductions goals, but during the subsequent decade (1990-2001), both states increased their GHG emissions: Vermont by 18% and Oregon by 30%.11 However, a majority of states have more recently begun to develop their own climate change strategies or policies, with an increasing number of states adopting or proposing more significant provisions, including mandatory GHG reductions.

The motivating factors for the various states' actions may be as diverse as the actions themselves. Some actions are motivated by projections of climatic changes, such as sea level rise or agricultural impacts. Some states view their GHG policies as economic opportunities. States want to position themselves for a "less-carbonized" future,12 by promoting, for example, alternative energy supplies, particularly sources available in-state. Other states champion GHG reduction policies because of the possible co-benefits: improved air quality, reduced traffic congestion, and less reliance on foreign energy supplies. Another motivating factor for state action is the possibility of catalyzing federal legislation.

This report covers state actions that directly and explicitly address GHG emissions (see the text box below). First, the report describes the different types of state actions, both individual and cooperative efforts, that are either proposed or under way, and highlights several of the more significant developments. Second, the report examines state actions from a federal policymaking perspective, including both the potential effects of state-led actions and their limitations.

Direct Action Versus Indirect Action

Direct state actions that address GHG emissions include laws, regulations, or policies that are established explicitly to reduce GHG emissions. In some cases, it is difficult to draw a line between direct and indirect actions, because a specific policy may be undertaken for multiple purposes, including GHG reduction. One of the best examples of this ambiguity is a Renewable Portfolio Standard (RPS). An RPS requires that a certain amount or percentage of electricity is generated from renewable energy resources (e.g., solar, biomass). Twenty-nine states have a mandatory RPS. Although GHG reduction is not the primary driver for an RPS in most states, some states list their RPS as part of a comprehensive strategy to reduce GHG emissions.

Indirect actions are often characterized as "no regrets" approaches, providing net benefits regardless of the magnitude of their impacts on climate change. For the purposes of this report, indirect actions are those developed primarily to address other concerns, such as improvements in energy efficiency, energy security, or air quality. Examples of indirect actions include:

  • Building codes: A majority of states have building codes that promote energy efficiency in commercial and residential structures; many of these states' standards are more stringent than federal policy.
  • Appliance Standards: Twelve states have set energy efficiency standards for appliances that are not covered under the federal program.

For the above statistics and more information, see Pew Center on Global Climate Change, States and Regions, at []; and EPA, at [].

Mandatory Programs to Reduce Greenhouse Gases

Mandatory programs to require GHG reductions represent the most aggressive end of the state action spectrum. As with state actions overall, these programs can vary significantly in scope, stringency, and design. Mandatory programs are generating considerable interest and some controversy. This section discusses the different types of mandatory programs and highlights the regional initiatives and individual state actions that are currently in effect or under development.

Regional Activities

Arguably, the most significant action on the state level in recent years has involved the development of regional agreements to address GHG emissions. As of the date of this report, 23 states have joined—more states are acting as observers—one of the 3 regional partnerships that would require GHG (or only CO2) emission reductions (Figure 1). Except for the partnership between 10 northeastern states, the regional activities are still in their developmental phases. Moreover, the western and midwestern regional partnerships were initiated by state governors and may not be approved and/or implemented by the relevant state legislatures.

In addition, the regional agreements may raise legal issues, particularly constitutional concerns. Article I, Section 10, Clause 3 of the U.S. Constitution states that "[n]o State shall, without the Consent of Congress ... enter into any Agreement or Compact with another State, or with a foreign Power.... " In particular, two of the regional agreements include Canadian provinces. However, it is uncertain whether this clause (the "compact clause") will create legal hurdles for any of the agreements.

Figure 1. Regional Activities to Control Greenhouse Gas Emissions

Source: Prepared by CRS.

Note: Figure 1 only includes states that are participants in the regional agreements. Several states are acting as observers in the initiatives in their regions.

Regional Greenhouse Gas Initiative

One of the more significant climate change developments at the state level is the Regional Greenhouse Gas Initiative (RGGI, pronounced "Reggie"). RGGI has been under development since 2003, when states from the Northeast and Mid-Atlantic regions began to discuss setting up a cooperative effort to reduce carbon dioxide emissions. Subsequent meetings and workshops culminated in a Memorandum of Understanding (MOU) that was signed in December 2005. RGGI is a market-based effort by 10 states—Connecticut, Delaware, Maine, Maryland,13 Massachusetts,14 New Hampshire, New Jersey, New York, Rhode Island, and Vermont—to reduce carbon dioxide emissions from power plants. RGGI would set up the nation's first mandatory cap-and-trade program for carbon dioxide.15

The initial objective of RGGI is to stabilize current carbon dioxide emissions from power plants in RGGI states, starting in January 2009, followed by a 10% reduction by 2019. A primary strategy of RGGI is to create a program with flexibility, so that in the future other emission sources/sectors, GHGs, or states could be included.

Some observers consider RGGI to be a possible test-case for a federal cap-and-trade program, and thus several of RGGI's design elements are generating interest and debate. For example, one specific feature—the emission allocation scheme—is drawing both praise and criticism. In both RGGI's Memorandum of Understanding and its Model Rule, states agreed that at least 25% of emission allowances will be allocated for a "consumer benefit or strategic energy purpose."16 Since then, all of the states have indicated—either through legislation or rulemakings—that they intend to allocate more than 25% of their state's emissions allowances for various purposes related to those two overarching objectives.17

This allocation strategy requires power plants to purchase the allowances through an auction, instead of receiving them at no charge.18 On September 25, 2008, RGGI participants held the first emission allowance auction related to climate change mitigation. Six RGGI states—Connecticut, Maine, Maryland, Massachusetts, Rhode Island, and Vermont—sold allowances for the first RGGI compliance period (2009-2011).19 By many accounts, the auction was successful: the clearing price as $3.07/ton (60% higher than the reserve price); compliance entities received about 80% of the allowances; and states received nearly $40 million in revenues.20

Although RGGI is one of the more aggressive state programs addressing climate change, the program has received some criticism and may face upcoming challenges. For example, recent emissions data indicate that the RGGI cap—188 million short tons of carbon dioxide—will most likely be higher than actual emissions, when RGGI goes into effect in 2009. The cap was set slightly above (about 4%) the average emission levels observed between 2000 and 2002. RGGI designers anticipated that emissions would gradually increase, so that actual levels would approximately match the cap in 2009. Although emissions increased in 2007 from their relatively dramatic decline of 2006, emissions data from the first half of 2008 are similar to 2006 figures, suggesting that 2008 emission are unlikely to increase further;21 another estimate projects that 2008 emissions may go as low as 150 mtCO2, approximately 20% below the 2009 cap.22

Figure 2. Comparison of Observed Emissions from RGGI Facilities (2000-2007) to RGGI Cap (effective in 2009)

Source: Prepared by CRS with data from the following: observed state emission data (2000-2006) provided by RGGI; 2007 data provided by Environment Northeast. Note that Environment Northeast generated its data from EPA's Clean Air Markets data, at

If actual emissions are below the cap when it goes into effect, the effectiveness of the RGGI program may be impacted. The allowance price might drop to such a low level that facilities would have no financial incentive to make reductions beyond their required allocation.23 This potential problem may be alleviated by the opportunity for affected sources to bank emission reductions for future use, when the cap will likely be lower than expected emissions. The RGGI program allows unlimited banking. The ability to bank reductions effectively spreads the costs of emission reduction over time. Banking emissions would reduce compliance costs in the future, but also increase the value of current allowances (because they can be sold later). The incentive to make additional reductions would remain. The recent auction sales data support this notion, as the clearing price was above the reserve price.

In addition to allocation concerns, a critical design detail—electricity imports from non-RGGI states—is arguably unresolved. This is often described as the "leakage" problem. Leakage can occur when an emissions reduction program does not include all sources contributing to the environmental problem. For example, if a RGGI state lowers its emissions by importing more power from a non-RGGI state, the emissions reductions in the RGGI state may be offset by an emission increase in the exporting state. A RGGI working group issued a final report on leakage March 2008. Among the four recommendations, the working group concluded that states should monitor for emissions leakage and evaluate whether more aggressive measures—e.g., carbon adders, procurement emissions rates, or load-based caps—should be considered at a later date.24

Western Climate Initiative

Seven U.S. states and four Canadian provinces are participating in the Western Climate Initiative (WCI). WCI got off the ground in February 2007, when the governors of six western states25—Arizona, California, Oregon, New Mexico, Utah, and Washington—agreed to reduce GHG emissions in their region.26 Montana and the four Canadian provinces—British Columbia, Manitoba, Quebec, and Ontario—joined at later dates.27 The states and provinces set a regional, economy-wide target to reduce GHG emissions to15% below 2005 levels by 2020. In order to implement this target, the participants agreed to develop a market-based program, such as a "load-based cap and trade program."

In September 2008, the WCI developers issued design recommendations for meeting the emission reduction goals. The recommendations include a cap-and-trade system that would cover emissions from electricity generation and large industrial and commercial sources in 2012. In 2015, the program would cover emissions from the transportation sector and fuel consumption from residential, commercial, and industrial uses not otherwise covered.28 The recommendations also include flexible design elements, such as unlimited emission banking, three-year compliance periods, and offsets, which may satisfy up to 49% of the emission reductions. Although this number may appear relatively high compared to federal cap-and-trade proposals, limiting offsets by percentage of reductions is different from limiting offsets as a percentage of allowance submissions (as many federal proposals would do). As a comparison that may provide additional context, RGGI participants agreed to a similar principle: at least half of the reductions should come from covered sources, thus allowing offsets to cover up to 50% of reductions. To apply this principle, RGGI designers allow offsets to satisfy up to 3.3% of a compliance submission.29 In contrast, most federal proposals would allow domestic offsets to satisfy at least 15% (international offsets often add a further percentage) of a covered sources allowance submission.

Although the WCI is still in early development, there are several issues that may hinder its implementation. As noted, the WCI is an agreement between the states' governors. To implement the program, the states' legislatures would need to enact laws to carry out the initiative's objectives. This may present an obstacle if a state's legislative branch finds fault with the reduction program developed by states' executive branch officials.

Midwestern Regional Greenhouse Gas Reduction Accord

On November 15, 2007, the governors of six states—Illinois, Iowa, Kansas, Michigan, Minnesota, and Wisconsin—signed the Midwestern Regional Greenhouse Gas Reduction Accord.30 The Premier of the Canadian Province of Manitoba also signed the Accord, potentially raising the same legal issues discussed above.

The Accord does not establish discrete GHG emissions targets, but directs the participating states (and their relevant state agencies) to set their own GHG emission reduction targets. In order to meet these GHG emission targets, the Accord calls for the participants to develop a cap-and-trade program and a model rule by November 2008. Although draft recommendations were made available November 2008, the time line was amended by the participants: a draft model rule is now scheduled for September 2009.31

The participants agreed that full implementation of the Accord will be completed by May 2010. Although not full participants in the Accord, the Governors of Indiana, Ohio, and South Dakota signed on as observers, agreeing to participate in the formation of the regional cap-and-trade system.

Individual State Efforts Requiring GHG Reductions

Individual state efforts that seek to reduce GHG emissions cover a range of activities. Outside of regional agreements, several states currently require power plants to make GHG emission reductions or submit offsets. Other states are developing "economy-wide"32 GHG emission reduction programs. Multiple states are planning to adopt California's motor vehicle standards for GHG emissions. In addition, states are working on other mechanisms that would require GHG emission reductions. These state efforts are discussed below.

Economy-Wide Reduction Initiatives

Three states—California, Hawaii, and New Jersey—have passed legislation that lays the groundwork for "economy-wide" reduction programs. In general, the state statutes lack critical details regarding the design of the reduction programs. Instead, the statutes direct state agencies to develop the logistical elements that would implement the reduction requirements. However, these programs vary substantially in their progress of development, the California program being well ahead of the other programs. These programs are described below.


In September 2006, California enacted landmark legislation—AB 32 or the Global Warming Solutions Act33—that would establish a comprehensive GHG reduction regime. The legislation is far-reaching in principle, but does not include many crucial details. Instead, the act directs the California Air Resources Board (CARB) to develop and implement a statewide program that would reduce the state's GHG emissions to 1990 levels by 2020.

The statute grants considerable authority to CARB, which is charged with determining critical details concerning the framework and applicability of the program. For example, the law does not specifically require the use of a market-based system, such as a cap-and-trade program, to reduce GHG emissions. Instead, AB 32 authorizes CARB to develop regulations to "achieve the maximum technologically feasible and cost-effective GHG emission reductions.... " Moreover, the statute does not include a list of regulated emission sources or categories,34 but instructs CARB to determine which sources are necessary to meet the statewide target.35

The statute does dictate a schedule for various agency deadlines. The following dates highlight significant milestones of the mandatory schedule:

  • June 30, 2007: Identify the early reduction options, which can be implemented prior to the mandatory program, and for which a facility will receive emissions credit. In October 2007, CARB submitted its final report of early actions, which are to be implemented via regulation and enforceable by January 1, 2010.36
  • January 1, 2008: Establish the 1990 baseline, which becomes the 2020 emissions cap. A baseline estimate is a critical determination for a cap-and-trade program.37 On December 7, 2007, CARB approved a baseline of 427 million metric tons of carbon dioxide equivalent (mmtCO2e).
  • January 1, 2008: Develop a mandatory reporting scheme for sources that will covered by the cap. Sources report emissions for four years in order to establish accurate facility baselines. CARB submitted regulations for approval to the Office of Administrative Law in October 2008.38 The regulations would require the first emissions reports to be submitted in 2009 based on 2008 emission levels.39
  • January 1, 2011: Finalize regulations, including possible market-based programs, that will implement the statewide emissions cap. Related to these efforts, the Scoping Plan was prepared in October 2008 and awaits approval from CARB.40
  • January 1, 2012: Implement and enforce the mandatory emission reduction program created in 2011.

In June 2007, Hawaii enacted the Global Warming Solutions Act of 2007, mandating statewide GHG emissions reduction to 1990 levels by 2020. The statute establishes a GHG emissions reduction task force, which is directed to offer policy recommendations by January 1, 2009. Before December 31, 2011, the Department of Health is instructed to adopt implementing regulations that would take effect January 1, 2012. Similar to California's statute, Hawaii's act does not specify details, but gives considerable responsibility to the Department of Health. The act does require the Department of Health "to endeavor to make the requirements consistent with the requirements of international, federal, and other states' greenhouse gas emission reporting programs, as necessary."41

New Jersey

In July 2007, New Jersey enacted the Global Warming Response Act, which states that GHG emissions shall be reduced to 1990 levels by 2020 and to 80% below 2006 levels by 2050. The statute instructs the Department of Environmental Protection (DEP) to develop a GHG emissions inventory for the baseline years—1990 and 2006—and a system for monitoring and reporting GHG emissions from specific sources (e.g., electricity generators), as well as entities deemed to be significant emitters by the DEP. The law does not specify how the reductions will be met, but directs the DEP, in coordination with other agencies, to submit recommendations to the governor and state legislature. In response to this provision, the DEP prepared a report November 2008.42 However, unlike the California and Hawaii statutes, the New Jersey act does not grant specific authority to DEP to implement the reduction program through regulation. Although not specifically stated, further legislative action would likely be required to implement the reduction program.43

Emission Reduction from Power Plants

A sector-specific approach that focuses on carbon dioxide is relatively easier to implement than an economy-wide program that includes multiple GHGs. The electricity-generating sector is often considered a primary candidate for emission reduction, because in most states electric power plants account for the highest percentage of carbon dioxide emissions.44 Many of these facilities are already tracking their carbon dioxide emissions as required by the 1990 Clean Air Act.

Oregon and Washington

Both Oregon and Washington have programs that require new power plants to reduce carbon dioxide emissions or purchase offsets. In 1997, Oregon became the first state to regulate carbon dioxide emissions by passing legislation45 requiring new power plants to equal or exceed carbon dioxide levels that are 17% below the best natural gas-fired plant in the nation. Plants can either reduce emissions directly or purchase offsets from a nonprofit organization (the Oregon Climate Trust) that was established with the 1997 law. This organization helps develop various projects that will reduce or sequester GHG emissions. These projects generate the pool of offsets available (by purchase) to the power plants. So far, all of the new facilities have chosen to purchase offsets instead of reducing onsite emissions.46 Washington passed similar legislation in 2004, requiring new power plants to offset 20% of their carbon dioxide emissions.47

Massachusetts and New Hampshire

These states have established emission reduction requirements at existing power plants:

  • Massachusetts: In 2001, Massachusetts became the first state to take formal action on carbon dioxide emissions at operational power plants. As part of a multi-pollutant strategy, which went into effect in 2006, the state's six largest power plants must reduce carbon dioxide to levels consistent with those produced in the late 1990s. In 2008, this cap was lowered further.48 The program allows the plants to either make the reductions, demonstrate offsite reductions, or purchase emissions credits from other verifiable sources. Note that the carbon dioxide components of this program will be superceded when RGGI goes online in 2009. RGGI will require reductions from 32 power plants in the state.
  • New Hampshire: In 2002, the state enacted multi-pollutant legislation49 requiring its three fossil fuel power plants to reduce carbon dioxide to 1990 levels by the end of 2006. In order the meet the cap, the law allowed sources to bank early reductions or buy credits through other programs deemed acceptable by state officials. The carbon dioxide elements of this program also will be superceded by RGGI.

In June 2008, Florida enacted legislation that authorizes the Florida Department of Environmental Protection to craft a cap-and-trade system that would cover the electric utility sector.50 Pending subsequent approval by the state legislature, the cap-and-trade program would go into effect in 2010.

Emission Reduction from Motor Vehicles

The U.S. transportation sector accounts for a substantial percentage—26% in 200651—of the nation's GHG emissions. Automobiles and light-duty trucks (fueled by gasoline or diesel) generate the majority—62% in 2006—of the nation's transportation-related GHG emissions.52 The transportation sector is the single largest source of the primary GHG, carbon dioxide, in 17 states.53

California's transportation sector, in particular, generates almost 41% of the state's annual greenhouse emissions.54 California is in a unique position regarding the regulation of air emissions from motor vehicles. It is the only state with conditional authority (i.e., the state needs a waiver from EPA) to develop motor vehicle pollution standards that are more stringent than federal requirements.55 The federal Clean Air Act permits other states to choose to follow California's more stringent provisions,56 and states have adopted California standards in the past.

In 2002, California enacted the first state law (AB 1493) requiring GHG limits from motor vehicles.57 As directed by the statute, the California Air Resources Board (CARB) issued regulations in September 2004, limiting the "fleet average GHG exhaust mass emission values from passenger cars, light-duty trucks, and medium-duty passenger vehicles."58 The fleet average caps first apply to model year 2009 vehicles. The caps become more stringent annually, so that by 2016, the fleet average would be 30% below the 2009 level.

At least 16 states have formally adopted or announced plans to follow the California regulation.59 In order for the states to implement this standard, California must receive a waiver from the EPA. California requested a waiver (as required by Section 209 of the Clean Air Act) in December 2005. In December 2007, EPA decided to deny the waiver request. EPA's decision is being challenged in court—by California and other states, and environmental groups. For more discussion regarding this issue, see CRS Report RL34099, California's Waiver Request to Control Greenhouse Gases Under the Clean Air Act, by [author name scrubbed] and [author name scrubbed].

Other Mandatory Programs

Although they do not require emission reductions or offsets from specific facilities or sources, other mandatory programs may have an impact on GHG emissions. A few states, California in particular, have recently developed requirements that aim to influence investment in long-term power generation. These state actions may impact GHG levels by influencing which energy sources—coal, oil, natural gas, etc.—are used to generate electricity for consumers.

Greenhouse Gas Emissions Performance Standard

Two states—California and Washington—have enacted laws requiring a GHG emissions performance standard for applicable power plants. In September 2006, California passed legislation (SB 1368)60 forbidding "load-serving entities"61 from entering into new "long-term financial commitments"62 with power plants unless a plant's GHG emissions are as low or lower than those of a new, combined-cycle natural gas facility. This emissions performance standard apply to both in-state power plants and out-of-state facilities that seek to export electricity to California. As directed by the statute, the California Public Utilities Commission (PUC) issued interim performance standards for investor-owned facilities63 January 25, 2007.64 The California Energy Commission's (CEC) comparable regulations for publicly owned utilities65 were approved (by the Office of Administrative Law) in October 2007.

Washington passed similar legislation (SB 6001) in May 2007. Regulations implementing this statute were adopted in June 2008, and went into effect the following month.66

The new performance standards complement the emissions reductions programs being developed in California and Washington. As discussed above, California is developing a mandatory reduction program, and Washington has a statewide emissions reduction target; both states are participants in a regional emissions reduction program (WCI). The implementation of California's emissions reduction program and the WCI is several years away (irrespective of legal challenges). The performance standards act as a stop-gap measure, preventing further utility investment in carbon-intensive fuels while the states develop broader reduction regimes.

Once the new performance standards are applicable (and previous commitments expire), they will effectively prohibit California and Washington consumers from using electricity generated by conventional coal-fired power plants. Compared with a combined-cycle natural gas plant, a conventional coal-fired power plant emits more than twice the amount of carbon dioxide. Using current technologies, coal-fired generators would fail to meet the new emissions standards.67

From 2002 through 2005, approximately 20% of California's electricity was generated from coal;68 approximately 10% of Washington's electricity came from coal generation facilities over the same period.69 As the laws take effect, California and Washington will likely need to reduce/conserve a comparable amount of energy or replace the coal-generated electricity with alternative sources of power.

The new emissions standards will impact not only California and Washington, but also other states in the West. For example, California's electricity imports generally comprise between 22% and 32% of the state's total electricity consumption, but its imports are responsible for 39% to 57% of the total GHG emissions linked with electricity.70 This is due to the fact that most of California's in-state electricity is produced from sources other than coal, while most of the state's imported electricity is generated through coal combustion. Once the standard takes effect, the coal-fired plants in neighboring states, which previously provided electricity to California, will need to look elsewhere for customers. The same goes for coal-fired power plants still in development in western states, which may have been designed, at least in part, to serve California consumers.71

Arguably, the GHG performance standards disproportionately affect the neighboring states that have historically exported coal-generated electricity to California and Washington consumers. This possible consequence may raise legal issues, such as a state's general inability to regulate interstate commerce.

Montana's Carbon Capture and Sequestration Standard

Montana enacted the Electric Utility Industry Generation Reintegration Act (HB 25) in May 2007. Among other things, the act prohibits the state's Public Service Commission (PSC) from providing advance approval of coal-fired electric generating units unless a minimum of 50% of the CO2 generated by the facility would be captured and sequestered. The PSC promulgated regulations to implement this standard in March 2008. At first glance, this statute may appear to be significant landmark in state climate change activity. However, the statute's applicability is relatively narrow, effectively applying to only one public utility—Northwestern Energy—in the state.72 Moreover, this utility does not own generating units in Montana73 and is unlikely to construct conventional coal-fired plants in the near future.74 Other power companies in the state are not subject to this standard.

Low Carbon Fuel Standard

To complement California's statewide GHG reduction program, the governor issued an executive order (signed January 18, 2007) establishing a low carbon fuel standard (LCFS). The LCFS aims to reduce the carbon intensity of California's transportation fuels by 10% by 2020. California currently relies on petroleum-based fuels for 96% of its transportation needs.75 Achieving the carbon intensity reduction is expected to replace 20% of the state's gasoline consumption with less carbon-intensive fuels.76 The LCFS would apply to all refiners, blenders, producers, and importers of transport fuels.

The order states that transportation fuels shall be measured on a full fuel cycle basis. Thus, regulators must factor in all of the energy used and potential GHGs emitted during the fuel's development (extraction or production), delivery (via vehicle or pipeline), and final use (combustion). Corn-based ethanol, for example, is expected to play a role in meeting California's LCFS. To comply with the full fuel cycle assessment, regulators must consider the energy needed to produce fertilizers, operate farm equipment, transport corn, convert corn to ethanol, and distribute the final product. For more information on these issues, see CRS Report RL33290, Fuel Ethanol: Background and Public Policy Issues, by [author name scrubbed].

The LCFS executive order enhances alternative fuel legislation (AB 1007) that California passed in 2005.77 AB 1007 requires the California Energy Commission (CEC), in partnership with other agencies, including CARB, to develop and adopt a State Alternative Fuels Plan. CEC adopted such a plan October 31, 2007. The executive order directs CEC to supplement this plan with a compliance schedule for meeting the 2020 LCFS target. The State Alternative Fuels Plan states that CEC will work with CARB "over the next year" to develop a compliance schedule.78 As of the date of this report, the compliance schedule remains under development.

Greenhouse Gas "Adders"

Another state action that may affect a state's sources of electricity generation is the adoption of a GHG (or carbon) adder. In general, adders require utilities to weigh the future costs of GHG emissions when considering different energy investment options (e.g., fossil fuels, renewable energy supplies). For example, California's Public Utilities Commission requires investor-owned utilities to include a value of $8/ton of carbon dioxide emissions when conducting long-term planning or procurement activities.79 The agency stated that this requirement "will serve to internalize the significant and under-recognized cost of [GHG] emissions, [and] help protect customers from the financial risk of future climate regulation.... "80 Only a few other states81 require some type of GHG adder, and California's adder may be rendered less relevant due to its new emission performance standard (discussed above). At this stage, the adders have not been credited with changing any procurement decisions.82

Greenhouse Gas Emissions Targets

State emissions targets are goals by which a state can measure its progress in achieving GHG emissions reduction. By themselves, state emissions targets do not directly reduce GHG emissions. The targets are often established by the executive branch of state government (e.g., through an executive order) and may not have the support of the state's legislative branch. However, a target signals that state officials, at least from one branch of the government, consider climate change an important issue.

Twenty states have established statewide targets for GHG emissions (see Table 1).83 Three of the state targets—California, Hawaii, and New Jersey—are mandatory (discussed above). Compared to the GHG limits and targets set on the international stage in past years, the state targets are less stringent.84 The New England states' targets are similar, if not identical, because they are part of a cooperative plan developed in 2001.85 Of the 20 states in Table 1, Colorado, Illinois, New Mexico, and Utah stand out because they have substantial coal production.86

Table 1 compares the states' GHG emissions in 1990 with emissions from the most recent years of available data.87 The emissions data show the reductions states would need to make to meet their established targets. Although some of the states appear within reach of their 2010 targets, the most recent data from many of these states suggest that emissions are not decreasing, but at best are leveling off. In some states—e.g., Arizona and Florida—emissions have increased substantially in recent years. More years of data are needed to evaluate progress, primarily because many of the states issued their GHG targets after 2003. Moreover, the emissions targets were typically created in conjunction with GHG reduction policies—some of them mandatory limits on specific industries or segments of state activities—whose implementation may not be reflected in the available emissions data.

Table 1. Statewide Greenhouse Gas Targets Compared with Emissions Data from 1990 and Recent Years of Available Data


Greenhouse Gases Target(s)

Greenhouse Gas Emissions
(million metric tons of CO2 equivalent)









2000 levels by 2020; 50% below 2000 levels by 2050









2000 levels by 2010; 1990 levels by 2020; 80% below 1990 levels by 2050









20% below 2005 levels by 2020 and 80% below 2005 levels by 2050









1990 levels by 2010; 10% below 1990 levels by 2020









2000 levels by 2017; 1990 levels by 2025; 80% below 1990 levels by 2050









1990 levels by 2020









1990 levels by 2020; 60% below 1990 levels by 2050









1990 levels by 2010; 10% below 1990 levels by 2020









1990 levels by 2010; 10% below 1990 levels by 2020









15% below 2005 levels by 2015; 30% below 2005 levels by 2025; 80% below 2005 levels by 2050









1990 levels by 2010; 10% below 1990 levels by 2020









1990 levels by 2020; 80% below 2006 levels by 2050









2000 levels by 2012; 10% below 2000 levels by 2020; 75% below 2000 levels by 2050









5% below 1990 by 2010; 10% below 1990 levels by 2020









Stabilize by 2010; 10% below 1990 levels by 2020; 75% below 1990 levels by 2050









1990 levels by 2010; 10% below 1990 levels by 2020









2005 levels by 2020.









2000 levels by 2025









1990 levels by 2010; 10% below 1990 levels by 2020









1990 levels by 2020; 25% below 1990 levels by 2035; 50% below 1990 levels by 2050








Source: Prepared by the CRS with data from the following: state targets compiled by Pew Center on Global Climate Change, at; GHG emissions data from World Resources Institute, Climate Analysis Indicators Tool, at (GHG data excludes land use changes).

a. Arizona Executive Order 2006-13 (September 7, 2006).

b. California Executive Order S-3-05 (June 1, 2005) set the 2010 and 2020 targets; AB 32 (discussed below) made the 2020 target mandatory.

c. Colorado Executive Order D-004-08 (April 22, 2008).

d. Connecticut Public Act No. 04-252 (June 14, 2004).

e. Florida Executive Order 07-127 (July 13, 2007).

f. Hawaii Governor Lingle signed the Global Warming Solutions Act of 2007 (Act 234) into law June 30, 2007. The act mandates statewide GHG emission reductions.

g. Announcement from Illinois Governor Blagojevich (February 13, 2007), related to Executive Order 2006-11 (October 5, 2006).

h. Massachusetts Climate Protection Plan of 2004 (Spring 2004).

i. Maine LD 845 (HP 622) (effective September 13, 2003).

j. Minnesota Governor Pawlenty , signed into law the Next Generation Energy Act May 25, 2007.

k. The Climate Change Challenge (December 2001).

l. New Jersey Governor Corzine signed into law the Global Warming Response Act (A3301) July 6, 2007, which requires mandatory emission reductions.

m. New Mexico Executive Order 05-033 (June 9, 2005).

n. New York State Energy Plan (June 2002).

o. Oregon Governor Kulongoski signed HB 3543 into law August 6, 2007.

p. Rhode Island Greenhouse Gas Action Plan (July 2002).

q. Announced by Utah's Department of Environmental Quality (DEQ) on June 20, 2008.

r. Virginia Governor Kaine signed Executive Order 59 (2007) December 21, 2007.

s. This target is discussed in Vermont's state plan, Fueling Vermont's Future: Vermont Comprehensive Energy Plan and Vermont Greenhouse Gas Action Plan (July 1998).

t. Washington Governor Gregoire signed SB 6001 into law May 3, 2007.

Greenhouse Gas Emissions Tracking

Reliable GHG emissions data are a keystone component of any climate change program. To implement effective solutions to climate change, policymakers need up-to-date and accurate information detailing the volume and sources of GHG emissions in their states. Precise monitoring is particularly vital for market-oriented approaches to GHG control. Whether a market-oriented program is based on tradeable emissions credits or a carbon tax, reliable and transparent emissions data would be the foundation for developing the allocation systems, reduction targets, and enforcement provisions.

Federal Tracking Programs

The federal government has several programs in place that either track or estimate GHG emissions:

  • Power plants subject to the 1990 Clean Air Act acid rain program must monitor and report to EPA various air pollutants, including carbon dioxide.88
  • The Department of Energy administers a voluntary GHG reduction registry. This program started in 1994, pursuant to Section 1605(b) of the Energy Policy Act of 1992 (P.L. 102-486).89
  • The EPA prepares an annual inventory of the nation's GHG emissions and sinks, which is submitted to the United Nations in accordance with the Framework Convention on Climate Change.

State Emission Tracking Programs

Many states have developed, or begun to develop, their own GHG tracking programs. Although tracking programs may overlap in purpose and terminology, for this report, tracking programs are divided into three categories: mandatory reporting, registries, inventories.

Mandatory Greenhouse Gas Reporting

Mandatory reporting programs allow states to monitor GHG emissions from precise sources. Although the primary purpose of mandatory reporting is typically to support an emission reduction program, a reporting program can potentially provide benefits without an accompanying reduction requirement. For example, if companies' GHG emissions were made publicly-available and thus comparable, the companies might have an incentive to reduce emissions voluntarily.90 However, there is some concern that emissions may increase under a mandatory reporting program, especially if companies suspect that the state will establish a mandatory reduction regime in later years. For instance, facilities may attempt to "game" the system by deliberately increasing emissions (or over-reporting them) in order to gain additional allowances once a reduction program is established.91

A few states already require, and others are in the process of developing, GHG emissions reporting to complement an emissions reduction program. Some states require reporting of GHG emissions that are not included in reduction programs. For example, some of the RGGI states mandate reporting of non-CO2 GHG emissions. In addition, other states currently have a mandatory reporting program that is not linked with an emissions reduction requirement. Both of these types of reporting activities are listed below, in the order of when the program started or is scheduled to start:

  • Wisconsin: In 1993, the state established a mandatory reporting program that includes carbon dioxide reporting for facilities generating over 100,000 tons annually.92
  • New Jersey: Certain facilities in New Jersey that report air pollutant emissions must also submit emission data for carbon dioxide and methane. This requirement went into effect in 2003.93 New Jersey is developing a mandatory reduction program (discussed above) that will entail a more comprehensive reporting regime.
  • Maine: Facilities in Maine that emit any criteria pollutant over a specific reporting threshold must also report GHG emissions. This provision went into effect July 2004.94
  • Connecticut: Starting in 2006, facilities subject to federal reporting under Title V of the Clean Air Act must submit GHG emissions data on an annual basis.95
  • California: See the above discussion regarding the implementation of AB 32, which includes mandatory GHG emission reporting.
  • North Carolina: Facilities with Title V permits (under the Clean Air Act)96 that submit annual air pollutant emission inventories to the state will be required to include GHG emissions in their 2009 submission (due June 30, 2009).97
  • New Mexico: Beginning in 2009, all electrical generating units of 25 megawatts capacity or higher, petroleum refineries, and cement manufacturing plants will be required to report GHG emissions. The initial report will only include CO2 emissions; reporting of other GHGs will be required in later years.98
  • Oregon: In October 2008, the Oregon Environmental Quality Commission established a GHG emission reporting requirement for entities that emit more than 2,500 metric tons of CO2 annually. Title V sources will report 2009 emissions in 2010; all other sources will report 2010 emissions in 2011.99
  • Washington: In March 2008, the state enacted H.B. 2815, directing the Department of Ecology (DEC) to develop a GHG emission reporting system. Starting in 2010, the statute requires emission reporting from entities that emit more than 10,000 t CO2 annually and vehicle fleets emitting more than 2,500 tCO2e annually.

Greenhouse Gas Registries

In general, state GHG registries are voluntary programs that allow facilities to submit and officially record emissions data. The states' voluntary registry programs encourage participation through incentives. Perhaps the primary incentive is the opportunity for participants to create an official record of emissions reductions, which the parties hope will count as emissions credits in future mandatory reduction programs. At a minimum, participants typically receive some public recognition for their efforts, which may help promote a company's environmental stewardship profile. Five states have passed legislation to establish GHG registries, of which three are now under way:100

  • New Hampshire: The New Hampshire GHG Registry went into effect in 2001. The registry is intended to record emissions reductions in a state database that can be used in addressing possible future requirements.
  • California: The California Climate Action Registry began operations in 2002. This state registry is arguably the most comprehensive, as participants register all of their GHG emissions for operations in California; other state (and federal) registries cover only emission reductions. The registry has over 100 participants.
  • Wisconsin: The Wisconsin Voluntary Emission Reduction Registry, a registry of voluntary reductions of GHG emissions, went online in 2003.

Numerous states are joining forces to establish a national registry, which may link with regional registries that were previously created.101 In May 2007, 30 states formed the Climate Registry, which aims to establish a standard system for GHG emissions reporting. As of August 2008, 39 states have joined the registry to support both voluntary and mandatory reporting schemes in the participating states.102

Greenhouse Gas Inventories

At least 42 states have developed GHG inventories. Inventories typically provide estimates of emissions for various categories: economic sector (e.g., energy, agriculture), emissions source (e.g., automobiles, power plants), GHGs (e.g., carbon dioxide, methane). In general, states create their inventories by following guidelines developed by the Environmental Protection Agency (EPA) that are based on internationally recognized standards. Inventories are often used to obtain an overall assessment of a state's emissions levels and sources, and are perhaps best suited for monitoring trends and/or developing comprehensive strategies. Although some states have performed inventory updates, most of the states' inventories only cover 1990 emission levels.

State Action Plans

At least 38 states have either completed or are in the process of preparing climate change action plans (see Figure 3). Typically, state action plans are drafted by a climate change task force, composed of members with diverse backgrounds and expertise. In general, task force members examine their state's sources of GHG emissions, and identify and rank the policy options that are most appropriate (i.e., cost-effective, politically feasible, etc.) for controlling emissions in their state. Often the state action plan is made available for public comment, revised if necessary, and then submitted for approval to state officials.

Figure 3. States with Completed (Orange) and
Under-Development (Blue Lines) Climate Change Action Plans

Source: Prepared by the Congressional Research Service with data from U.S. EPA Climate Change Division and Pew Center on Global Climate. Online links to individual state action plans are available through EPA's website, at

Reflecting the fact that states have different economic sectors, natural resources, and political structures, state climate change action plans can vary substantially. Some state action plans focus more on indirect, "no regrets" strategies, such as improved energy efficiency, which will likely yield benefits irrespective of climate change effects. Other state action plans are more comprehensive and recommend a portfolio of direct efforts that address GHG emissions. Although the state climate change action plans may recommend an array of policy options, the plans do not necessarily result in direct actions to reduce GHG emissions. However, the number of completed state plans indicates the interest that a majority of states have in addressing climate change mitigation on some level.

Issues for Congress

The climate change activity in the states raises several issues that may be of interest to Congress. This section discusses some of the potential effects of state action in lieu of federal legislation. This section also examines the limitations of state actions, both from a climate change policy perspective and in the context of legal challenges.

Potential Effects of State Actions

Many states generate significant emissions of GHGs. If individual U.S. states were classified as sovereign nations, 18 U.S. states would rank in the top 50 for nations that annually emit the primary GHG: carbon dioxide.103 Compared with other nations, Texas, the combined Midwest Accord states, the WCI states, the RGGI states, and California rank as top carbon dioxide emitters (Table 2).

Table 2. Top-Ranked Carbon Dioxide Emissions by Nation,
U.S. States, and U.S. Regional Partnerships (2005 data)

Country, State, or Group

CO2 Emissions
(million metric tons)

Country, State, or Group

CO2 Emissions
(million metric tons)

United States






RGGI states


European Union




Russian Federation


United Kingdom








South Korea






Midwest Accord states




WCI states




Source: Prepared by CRS with data from World Resources Institute, Climate Analysis Indicators Tool, at Note that the carbon dioxide data excludes land use changes.

Note: Midwest Accord states include Illinois, Iowa, Kansas, Michigan, Minnesota, and Wisconsin. WCI states include Arizona, California, New Mexico, Montana, Oregon, Utah, and Washington. RGGI states include Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island and Vermont. In addition, the emissions data for China entails some uncertainty. More recent estimates (from other sources) indicate that China has surpassed the United States in GHG emissions. For more information, see CRS Report RL34659, China's Greenhouse Gas Emissions and Mitigation Policies, by [author name scrubbed], [author name scrubbed], and Anna Mackey.

Almost half (23) of the states have joined one of the three regional emission (all GHGs or just carbon dioxide) reduction programs: the Midwest Accord, WCI, and RGGI. The states in these regional programs account for a substantive percentage of U.S. carbon dioxide emissions (about 38%). However, the remaining 27 states are pursuing considerably less aggressive climate change policies. With this range of state activity, it is difficult to predict the precise consequences of state-led climate change actions. This section highlights possible effects from state actions.

States as Policy Laboratories

A central argument in support of state climate change action is that states can serve as laboratories for policymaking. States can test different ideas and policies on a smaller scale, and help determine which climate change solutions are most effective. For example, there has been some debate regarding how a cap-and-trade program might work on a national level. Although the federal acid rain program, which involves sulfur dioxide emissions trading, is generally considered a success, emissions trading programs for other purposes have encountered problems during implementation.104State and regional programs offer the opportunity to iron out logistical details that are crucial in a cap-and-trade system:

  • How high to set the emissions cap.
  • Which sources to regulate.
  • How to allocate emissions allowances.
  • Whether to allow the use of offsets as compliance alternatives.
  • Whether to include a safety valve and, if so, how high to set it.

State programs can inform federal policymakers in other ways. The political process by which states create climate change policy can be enlightening and perhaps adaptable on the federal level. For instance, by examining the development and passage of state legislation, federal policymakers may better understand the motivations of different stakeholders and learn how best to frame the issues.

Possible Economic Effects

Emission reduction programs will likely have economic effects on consumers, businesses and manufacturers, and possibly interstate commerce.105The most immediate effects of the emissions programs (at least the ones furthest along in development) will be on the automotive manufacturing and electricity generation sectors.

For automotive manufacturers, the California motor vehicle regulations—which at least 16 states have indicated they plan to implement if EPA approves the waiver (discussed above)—will likely have the effect of dividing the market, potentially requiring the manufacture of a different class of cars to meet the new standards (scheduled to apply in 2009). For automotive companies, this raises the issues of the technical means of meeting the standard, marketing, ensuring compliance, and pricing. Depending on how the emission limits are to be met, they may also influence fueling infrastructure. State governments will need resources to enforce the standards. Consumers in regulated states may face higher prices for vehicles.

Regarding the electric power industry, the mandatory reduction requirements will likely promote generation from low carbon-intensive fuels, while curtailing generation from high carbon-intensive fuels, such as coal. The GHG performance standards in California and Washington will reach into neighboring states as well, effectively barring electricity imports generated by conventional coal-fired power plants. Because coal-fired plants tend to produce lower-cost electricity, the result of these requirements may be to increase electricity prices within the states that limit emissions, and possibly lower prices in states without such emission standards.

If the GHG limitations lead to energy price increases in the regulated states, businesses and manufacturers may factor this cost into location decisions. There is some concern that regulated industries will have a financial incentive to move (and thus transfer jobs) to states (or nations) that do not limit GHG emissions.106 Others fear that emission limits will raise the cost of living and doing business within those states, although in theory such effects can be at least partially addressed through the design of the emissions reduction program.107

Patchwork of Regulations

One concern shared by many observers, particularly industry stakeholders, is that state climate change programs (in lieu of a federal program) will create a patchwork of regulations across the nation. A patchwork system of standards may hinder a company's efficiency and possibly create economic burdens for firms that operate in multiple states. The prospect of regulations that vary from state to state is driving some companies to support a federal climate change program with comparable requirements across the entire United States.

Limitations of State Actions

Climate change has been described as the "ultimate global commons problem."108 The global warming and climate impacts associated with increased GHG emissions in the atmosphere cannot be linked with specific emission sources. Unlike localized reductions in other air pollutants (e.g., sulfur dioxide, particulate matter), when an emissions source reduces its carbon dioxide emissions, it does not generate a corresponding local climate change benefit unless there are similar widespread reductions globally or at least in wide areas.

From a practical standpoint, the actions of one or a group of states or nations cannot by themselves reduce the global accumulation of GHG emissions in the atmosphere. However, as discussed above, actions now under way by many states in the United States may create examples and/or models that will prove instructive in more widespread applications. Moreover, when business and industry have confronted a growing patchwork of state requirements, these sectors have historically begun to favor a national policy—as has begun to happen in the case of state-level actions on climate change. However, the lack of a national program or a truly global approach to GHG emissions reductions does limit what individual states can accomplish in actually reducing GHG emissions and accumulations.

Legal challenges may further limit the effectiveness of state action. The possibility of legal challenges creates considerable uncertainty regarding the future of state climate change actions, particularly the more aggressive programs. There are already several lawsuits against state actions that seek to regulate GHG emissions from motor vehicles.109 As discussed above, the April 2007 Supreme Court decision (Massachusetts v. EPA) did not specifically address all of the plaintiffs' arguments, so uncertainty remains as to the resolution of these cases.

Further litigation confronting other types of state action is anticipated. However, many expected RGGI to face a legal challenge when the first state's rule was officially issued, but that did not occur. Regardless, there is some question as to whether California's recently enacted GHG performance standards are constitutional.110 Arguably, the standards disproportionately impact the neighboring states that have historically exported coal-generated electricity to California consumers. The legal arguments in these cases are beyond the scope of this report, but many observers conclude that it is difficult to predict how the courts will interpret and decide upon these issues. For a more in-depth analysis of various legal issues regarding climate change, see CRS Report RL32764, Climate Change Litigation: A Growing Phenomenon, by [author name scrubbed].



This report does not address the debates associated with the climate change science nor the role of human activity. For more information, see CRS Report RL34266, Climate Change: Science Update 2007, by [author name scrubbed].


For example, carbon dioxide, the primary GHG, has risen worldwide from 280 parts per million (ppm) to over 380 ppm over the past 150 years.


The United Nations Framework Convention on Climate Change (UNFCCC) defines GHGs to include carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.


For example, federal programs that promote energy efficiency or the use of renewable energy sources have the potential to reduce GHG emissions.


For more details regarding this legislation, see CRS Report RL34067, Climate Change Legislation in the 110th Congress, by [author name scrubbed] and [author name scrubbed].


Senate Amendment No. 866 to H.R. 6, passed by voice vote June 22, 2005. A motion to table the amendment was rejected by a roll call vote (44 - 53).


For more information on the progress and details regarding this legislation, see CRS Report RL33846, Greenhouse Gas Reduction: Cap-and-Trade Bills in the 110th Congress, by [author name scrubbed], [author name scrubbed], and [author name scrubbed].


A number of local governments are pursuing activities that may directly or indirectly reduce GHG emissions. For example, numerous local governments (cities, counties) in at least 35 states have joined the Cities for Climate Protection (CCP). Participating entities commit to reduce local emissions that contribute to global warming. For more information on this program, see


Vermont Executive Order 79 (October 23, 1989) called for a 15% reduction below 1989 levels by 2000. See U.S. Congress, Office of Technology Assessment, 1991, Changing by Degrees: Steps to Reduce Greenhouse Gases, p. 327.


Oregon Senate Bill 576 (1989) set a goal of 20% reduction of 1988 levels by 2005. See U.S. Congress, Office of Technology Assessment, 1991, Changing by Degrees: Steps to Reduce Greenhouse Gases, p. 327.


See World Resources Institute, Climate Analysis Indicators Tool, at


See Rabe, Barry, 2006, "Second Generation Climate Policies in American States: Proliferation, Diffusion, and Regionalization," Issues in Governance Studies, The Brookings Institution, August 2006.


Maryland Governor O'Malley signed RGGI's Memorandum of Understanding on April 20, 2007, making Maryland the first state that was not an original RGGI participant to join the regional initiative.


Massachusetts and Rhode Island were involved in RGGI's development from the beginning. However, both states' governors declined to sign the Memorandum of Understanding in 2005, citing costs as their primary rationale for not participating. Massachusetts and Rhode Island joined RGGI as participants in January 2007.


In a cap-and-trade system, regulators set a cap (or limit) on the overall emissions of a given gas from a specified group of sources, such as power plants. The emissions allowed under the new cap are then allocated in the form of credits (or permits) to individual sources. Sources that emit more than their allowance must buy credits from those who emit less than their allowance, thus creating a financial incentive for sources to reduce their own emissions. For more information on cap-and-trade systems, see EPA's website at


See RGGI Model Rule, issued August 15, 2006, p. 42; and RGGI Memorandum of Understanding, Section G(1), signed by participating state governors December 20, 2005, both available at


Environment Northeast compiled a summary of the states' plans regarding emission allocation, at


For more discussion regarding these issues, see CRS Report RL34502, Emission Allowance Allocation in a Cap-and-Trade Program: Options and Considerations, by [author name scrubbed].


All 10 states intend to sell a portion of their allowances in a subsequent auction December 17, 2008.


For more details, see the "Post-Auction Reports," at


Environment Northeast, Emissions Trends and the Inaugural Allowance Auction (September 2008), at


Point Carbon, RGGI's First Auction: Will Short-term Expectations Prevail? (September 2008).


This problem occurred during the first phase of the European Union's Emission Trading System. For more discussion see CRS Report RL34150, Climate Change and the EU Emissions Trading Scheme (ETS): Kyoto and Beyond, by [author name scrubbed].


See RGGI Emissions Leakage Multi-State Staff Working Group to the RGGI Agency Heads, Potential Emissions Leakage and the Regional Greenhouse Gas Initiative (RGGI), (March 2008), at


For the text of the agreement, see


Utah joined the initiative May 21, 2007; the five other states were charter members, signing the agreement February 26, 2007.


Montana joined January 2008; British Columbia signed April 2007; Manitoba signed June 2007; Quebec joined April 2008; Ontario joined July 2008.


See Western Climate Initiative, Design Recommendations for the WCI Regional Cap-and-Trade Program (September 2008), at


The 3.3% figure is based on an estimate of reductions needed to meet the emissions cap. RGGI developers estimated that, compared to a business-as-usual estimate of emissions, covered sources would need to reduce emissions by approximately 6.6% (on average) through 2012, at which time the program would undergo a comprehensive review. Thus, the percentage my change based on updated estimates. For a further explanation of RGGI's offset rationale, see


The text of the Accord is available at


For more details, see the Accord's website at


Also described as statewide or multi-sector, "economy-wide" GHG emission reductions programs seek to control and reduce emissions from several economic sectors. In general, these programs cover the sectors—e.g., electricity generation, industry, and transportation—that account for the vast majority of a state's emissions. Depending on the design of the program, some sectors (e.g., agricultural or residential) may be excluded.


California Governor Schwarzenegger signed the legislation September 27, 2006.


Earlier drafts of the legislation specifically cited the electric power, oil/gas, and cement industries, and landfills as significant emitters.


The statute instructs CARB to regulate mobile sources if the 2004 mobile sources regulatory program (described above) does not remain in effect (presumably due to legal challenges).


CARB, Expanded List of Early Action Measures to Reduce Greenhouse Gas Emissions in California Recommended for Board Consideration (October 2007), at


Past estimates of 1990 levels ranged from a low of 425 mmtCO2e to a high of 468 mmtCO2e. This is a 10% variance between low and high estimates. See California Energy Commission, Inventory of California Greenhouse Gas Emissions and Sinks: 1990 to 2004—Final Staff Report, December 22, 2006, p. 4.


This office has until December 2, 2008, to make a determination. For updated information, see


According to CARB, the reporting regulations will account for approximately 94% of the total CO2 produced in California from industrial and commercial stationary sources of emissions. See




Section 8 of the act, revising Hawaii Revised Statute § 342B.


New Jersey DEP, New Jersey Greenhouse Gas Inventory and Reference Case Projections 1990-2020 (November 2008), at


According to an official with the NJ DEP, existing statutory authorities may allow some regulations to move forward without additional legislative action. However, subsequent legislative action is most likely necessary to implement the reduction regime in full (per telephone conversation, August 28, 2007).


Based on 2001 data. Energy Information Administration, Emissions of Greenhouse Gases in the United States 2004 (Table C2).


HB 3283, codified in Oregon Administrative Rules, Chapter 345, Division 24.


Point Carbon, 2006, "Carbon Trading in the US: The Hibernating Giant," Carbon Market Analyst, September 13, 2006.


HB 3141 (signed into law on March 31, 2004).


310 Massachusetts Code of Regulations 7.29.


New Hampshire Clean Power Act (May 9, 2002), codified in New Hampshire Statute, Title X, Chapter 125-O (Multiple Pollutant Reduction Program).


HB 7135, signed into law June 25, 2008.


EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2006, Executive Summary (2008), at


The transportation sector also includes emissions (in descending order) from heavy-duty trucks, aircraft, boats, and trains. EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2004 (2008).


Based on data from Energy Information Administration (EIA), State CO2 Emissions by Energy Sectors, at


California Energy Commission, 2006, Inventory of California Greenhouse Gas Emissions and Sinks: 1990 to 2004, p. 8.


See Clean Air Act Section § 209, codified at 42 U.S.C. § 7543.


Clean Air Act § 177, codified at 42 U.S.C. § 7507.


AB 1493 (or the California Vehicle Global Warming Law) was signed into law by Governor Gray Davis on July 22, 2002.


Title 13, California Code of Regulations § 1961.1.


The 16 states are Arizona, Colorado, Connecticut, Florida, Maine, Maryland, Massachusetts, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Utah, Vermont, and Washington.


SB 1368 was signed by the governor on September 29, 2006.


Defined as "every electrical corporation, electric service provider, or community choice aggregator serving end-use customers in the state." SB 1368 (codified in Public Utilities Code, Section 8340(h)).


Defined as a "new ownership investment in baseload generation or a new or renewed contract with a term of five or more years, which includes procurement of baseload generation." SB 1368 (codified in Public Utilities Code, Section 8340(j)).


In 2003, these facilities accounted for 68% of the electricity consumed in California. See California Energy Commission, Electricity Consumption by Utility Type, at


More information is available at


Publicly owned utilities accounted for 27% of California's electricity consumption in 2003. Self-generation units made up the remaining percentage (about 5%). See California Energy Commission, Electricity Consumption by Utility Type.


More information is available at the Washington Department of Ecology website, at


As technology advances, coal-fired plants might be able to reduce GHG emissions through carbon capture and sequestration (CCS). However, "there is relatively little experience in combining CO2 capture, transport and storage into a fully integrated CCS system. The utilization of CCS for large-scale power plants (the application of major interest) still remains to be implemented." Intergovernmental Panel on Climate Change (IPCC), 2005, IPCC Special Report Carbon Dioxide Capture and Storage, Summary for Policymakers.


The percentage of California's electricity generated from coal should decrease, because a large coal-fired plant (Mohave facility) was shut down at the end of 2005. California Energy Commission, Gross System Electricity Production, at


Washington State Department of Community, Trade and Economic Development, 2007, 2007 Biennial Energy Report: Issues and Analysis for the Washington State Legislature and Governor, p. 7, at


California Energy Commission, 2006, Inventory of California Greenhouse Gas Emissions and Sinks: 1990 to 2004, Draft Staff Report, p. 12.


See Holly, Chris, "California PUC Issues IOU Greenhouse Rules; Muni Nixes Coal Deal," The Energy Daily, December 15, 2006.


Per conversation (December 1, 2008) with staff from Montana Public Service Commission.


See Northwestern Energy website, "About Us," at


Per conversations (December 1, 2008) with personnel from the Montana Public Service Commission and the Montana Environmental Information Center; and a conversation with personnel from Northwestern Energy (December 3, 2008).


Executive Order S-01-07, signed January 18, 2007.


California Office of the Governor, The Role of a Low Carbon Fuel Standard in Reducing Greenhouse Gas Emissions and Protecting Our Economy, January 18, 2007.


The governor signed AB 1007 September 29, 2005.


CEC, State Alternative Fuels Plan, (December 2007), p. 18, at


California Public Utilities Commission, Decision 05-04-024, April 7, 2005.


California Public Utilities Commission, Decision 04-12-048, December 16, 2004.


Oregon and Colorado. See Pew Center on Global Climate Change website, at


Pew Center on Global Climate Change, "California PUC Carbon Adder" (case-study).


Several states have also developed more narrow targets, either for industry or electricity generation or only for carbon dioxide emissions.


The U.S. Kyoto target was 7% below 1990 levels, averaged over the commitment period 2008 to 2012. For more on international climate agreements and U.S. involvement, see CRS Report RL33826, Climate Change: The Kyoto Protocol, Bali "Action Plan," and International Actions, by [author name scrubbed] and [author name scrubbed].


New England Governors/Eastern Canadian Premiers, Climate Change Action Plan 2001, August 2001, at


In 2007, Colorado, Illinois, New Mexico, and Utah ranked 6th, 9th, 11th, and 12th, respectively, in coal production. See U.S. Department of Energy, Energy Information Administration Statistics, at


The emissions data in Table 1, particularly the 1990 levels, may differ from the official estimates provided by individual states. The objective of the table is to compare emission levels over time, and assess the challenge of meeting emissions targets. Because some states only have estimates for 1990 levels, this report uses data from the World Resources Institute for a consistent comparison.


Section 821, 1990 Clean Air Act Amendments (P.L. 101-549, 42 USC 7651k). For more information regarding federal programs see CRS Report RL31931, Climate Change: Federal Laws and Policies Related to Greenhouse Gas Reductions, by [author name scrubbed] and [author name scrubbed].


For more information on this program, see


This notion is analogous to the arguments in support of EPA's Toxic Release Inventory (TRI) Program, which requires facilities to submit annual data concerning their releases of chemicals to the environment. The TRI program is generally considered a success, as releases have decreased since the program's inception. Rabe, Barry, 2002, Greenhouse & Statehouse: The Evolving State Government Role in Climate Change, Prepared for the Pew Center on Global Climate Change.


This notion assumes that allowances would be allocated based upon past performance, instead of sold through an auction process.


Wisconsin Chapter NR 438.03.


New Jersey Administrative Code 7:27-21.3.


Maine Department of Environmental Protection Rules, Chapter 137 (per 38 MRSA, Section 575).


Connecticut Public Act No. 04-252 (June 14, 2004).


Sources subject to the Title V permit requirements generally include major sources that emit or have the potential to emit 100 tons per year of any regulated pollutant, plus stationary and area sources that emit or have potential to emit lesser specified amounts of hazardous air pollutants. See CRS Report RL30853, Clean Air Act: A Summary of the Act and Its Major Requirements, by [author name scrubbed] et al.


More information regarding this program is available at


Rulemaking (Title 20, Chapter 2, Parts 73 and 87) from the New Mexico Environment Department, at


The Oregon rulemaking is available at


The other two states are Maine and Georgia. Maine's registry is not yet operational, but the state does have a mandatory reporting requirement (discussed below). Georgia, instead of tracking GHG emissions, established a registry for counting the offsetting reductions in GHG emissions obtained by carbon sequestration. Not counted as one of the five states, New Jersey repealed a previously enacted registry program in 2004.


New England and Mid-Atlantic states are developing the Eastern Climate Registry. In addition, the Lake Michigan Air Directors Consortium (LADCO) is working on a registry for several states in the Midwest.


For more information see


This is based on 2005 data from the World Resources Institute, Climate Analysis Indicators Tool, at


For example, the Southern California's Regional Clean Air Incentives Market (RECLAIM), which was implemented in 1994 to reduce emissions of nitrogen oxides (NOx) and sulfur dioxide (SO2), saw a 50-fold increase in NOx allowance prices during the 2000-2001 California energy crisis. The European Union's GHG trading system has also experienced drastic swings in allowance prices during its start-up years, making planning and decision-making difficult for participating entities. For additional information on the EU trading system, see CRS Report RL33581, Climate Change: The European Union's Emissions Trading System (EU-ETS), by [author name scrubbed].


The question of whether and in what circumstances states can regulate interstate commerce may raise legal questions, which are briefly discussed below.


This is also a central argument against having federal emission limits without cooperation with other large economies (e.g., China and India).


A cap-and-trade program with an auction system (as discussed above), for instance, would generate revenues that could be funneled to parties who bear an unfair percentage of the program's costs. See, for example, National Commission on Energy Policy, 2007, Allocating Allowances in a Greenhouse Gas Trading System.


Stavins, Robert, 2006, "A Utility Safety Valve for Cutting CO2," The Environmental Forum, Volume 23, Number 2, March/April, 2006, p. 14.


For more details, see CRS Report RL34099, California's Waiver Request to Control Greenhouse Gases Under the Clean Air Act, by [author name scrubbed] and [author name scrubbed].


See Potts, Brian, 2006, "Regulating Greenhouse Gas Leakage: How California Can Evade the Impending Constitutional Attacks," Electricity Journal, Vol. 19, Issue 5, June 2006.