Introduction

Millions of discrete sources throughout the U.S. economy produce carbon dioxide (CO₂) and other greenhouse gas (GHG) emissions.¹ These sources include motor vehicles, electric power plants, industrial facilities, commercial buildings, and households, among others. Human-related GHG emissions have increased since the beginning of the industrial era, unequivocally increasing atmospheric concentrations of GHGs.² For example, atmospheric concentrations of CO₂ have increased by over 45% compared to preindustrial levels.³ Methane has increased by 156% over the same time frame.⁴

The GHGs in the atmosphere trap infrared radiation as heat, warming earth's atmosphere, land, and ocean. The Intergovernmental Panel on Climate Change (IPCC) concluded in 2021 that "[i]t is very likely that well-mixed GHGs were the main driver of tropospheric warming since 1979"⁵ and that "[g]lobal warming of 1.5°C and 2°C [compared with preindustrial temperatures] will be exceeded during the 21^st century unless deep reductions in CO₂ and other GHG emissions occur in the coming decades."⁶ 

The increasing atmospheric concentrations of GHGs have led to various changes to the climate: increases in average global temperature and related rising sea levels, changes in precipitation, and increases in frequency and intensity of some extreme weather events. The latest major U.S. scientific assessment, known as the Fourth National Climate Assessment (NCA4), concluded that the increase in GHGs is driving global land and ocean warming and other climate changes that are now unprecedented in the history of modern civilization. The second volume of the NCA4, published in 2018, concluded, inter alia, that human-induced climate change is affecting U.S. communities across the country through extreme weather events and generally warmer temperatures, more variable precipitation, and other observed trends.⁷ The NCA4 describes continued and increasing disruption to infrastructure, economic, and social systems, including economic disparities. According to its assessment, projected climate change impacts are affecting, and are virtually certain to increasingly affect, the U.S. economy, trade, and other essential U.S. interests. Some stakeholders, as well as some Members of Congress, consider that the resulting impacts of climate change in the United States and abroad are and would be modest and manageable.

A range of actions that seek to reduce GHG emissions are currently under way or being developed by international and subnational entities (e.g., financing by multilateral development banks, or U.S. state actions or regional partnerships), as well as by the U.S. federal government (e.g., support for carbon capture technologies). Nonetheless, Members of Congress and stakeholders have different viewpoints concerning what, if anything, to do about future climate change and related impacts. President Joseph Biden's Administration has increased the ambition⁸ of U.S. GHG reduction targets and announced a whole-of-government approach to addressing climate change. In the legislative branch, numerous Members of Congress have expressed a range of perspectives regarding climate change issues. Some Members seeking to take action on climate change have proposed a variety of legislative approaches.

This report provides an overview of U.S. climate change policy as of September 2021. It begins with background on U.S. emission trends and a brief history of U.S. climate change policy, and discusses emissions mitigation activities at the subnational level, including state and regional programs. Next, the report discusses legislative developments, including recently enacted legislation related to climate change and legislative proposals in the 117^th Congress. The report also considers executive branch actions and presents information about the Biden Administration's GHG targets, announced policies, proposals for legislative action, and examples of other policy actions. The report concludes with issues for Congress.

This report does not provide a comprehensive summary of these actions, given their breadth and continuously evolving nature. Rather, it aims to provide a snapshot of the current climate change policy landscape. Upcoming international discussions, strongly held public opinions, expected forthcoming scientific and economic reports, and other factors make it likely that climate change may continue to be a topic of deliberation and proposed actions in Congress. Moreover, developments may occur rapidly.

U.S. Emission Trends

The most recent U.S. GHG Inventory prepared by the U.S. Environmental Protection Agency (EPA) reports annual emissions and emission sinks from 1990 through 2019.⁹ EPA's inventory includes gross and net emission levels.¹⁰ As illustrated in Figure 1, the highest level of gross U.S. GHG emissions—15.6% above 1990 levels—occurred in 2007. Gross U.S. GHG emissions in 2019 were 6,558 million metric tons of carbon dioxide-equivalent emissions (MMTCO₂e),¹¹ which is 1.8% higher than 1990 GHG emission levels and 11.6% below 2005 levels—the year the United States uses as a benchmark for its international GHG pledges.¹²

Figure 1 also shows the gross emissions contributions and trends by sector. The electricity sector historically accounted for the largest percentage of U.S. GHG emissions from fossil fuel combustion. As the figure indicates, emissions in the electricity sector decreased by 33% between 2005 and 2019. As the side-by-side comparison in Figure 1 illustrates, the decrease in total U.S. GHG emissions over the past 15 years was largely related to decreases in the electricity sector. The evolving electricity generation portfolio played a key role in the emissions decrease in the electricity sector. Different fossil fuels, like coal and natural gas, generate different amounts of GHGs per unit of generated electricity. For example, a natural-gas unit typically yields about 40% of the GHG emissions of a coal-fired unit per megawatt-hour of electricity. Some sources of electricity generation, such as nuclear power, wind, and solar, emit no GHG emissions at the point of power generation. Over the past decade, coal's contribution to electricity generation decreased, while natural gas and renewable generation both increased. Several factors likely played a role in this change, including technological advances, particularly hydraulic fracturing, as well as federal tax incentives for renewable energy and renewable portfolio standards in the states. These and other factors have affected the relative price differences between sources of electricity, influencing their deployment in the electricity sector.¹³

Due to declines in the electricity sector emissions over the past decade, emissions from the transportation sector surpassed those from electricity in 2016.¹⁴ In 2019, the transportation sector accounted for 29% of total U.S. GHG emissions, and the electricity and industrial sectors accounted for 25% and 23%, respectively.

Figure 1. U.S. GHG Emissions: 1990-2019 Total U.S. Emissions and Emissions by Sector

Source: Prepared by CRS; data from EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2019, April 14, 2021, https://www.epa.gov/ghgemissions/draft-inventory-us-greenhouse-gas-emissions-and-sinks-1990-2019. Notes: The scales of the y-axes in the above figures are different. The figure presents gross emissions (i.e., the total emissions from all sources), and it does not account for net removals of CO2 emissions from the atmosphere by vegetation and other sinks. U.S. GHG emissions can be categorized in a variety of ways. This figure uses the economic sectors from EPA's Inventory. EPA's Inventory (Table 2-12) also presents emissions by economic sector, with the emissions from the electricity sector distributed to each sector based on the sector's electricity use.

History of U.S. Federal Climate Policy

The United States has historically demonstrated varying approaches and intent with regard to addressing climate change generally and to participating in GHG abatement under the 1992 United Nations Framework Convention on Climate Change (UNFCCC).¹⁵ While the United States was instrumental in establishing the negotiations toward that treaty, it did not support binding GHG "targets and timetables" and financial assistance to lower-income countries to reduce their emissions and adapt to climate change. The UNFCCC did not contain binding targets.

The 1997 Kyoto Protocol to the UNFCCC included binding GHG targets for the industrialized countries, including the United States, listed in its Annex I ("Annex I Parties"), but no new commitments for developing countries.¹⁶ The United States signed but did not ratify this treaty. Following a stalemate in 2009 toward negotiation of a legal instrument that would include the United States, China, and other major emitting countries, the Barack Obama Administration led development of a more collaborative and bilateral relationship with China and others.¹⁷ This more collaborative process resulted in adoption of the Paris Agreement (PA) in 2015.¹⁸ President Obama accepted the agreement without submitting it to the Senate for advice and consent, and the United States became a Party to the agreement when the PA entered into force in 2016.¹⁹ President Donald Trump announced U.S. withdrawal from the PA in June 2017, which, following the procedures of the treaty, became effective in November 2020. On President Biden's first day in office, he accepted the PA, and the United States again became a Party on February 19, 2021.

To date, U.S. climate change policy has involved actions—such as standards, investments, tax incentives, programs, and support for technology innovation—implemented under various legal authorities. Congress has previously deliberated comprehensive authority to address climate change, but votes on such legislation have been relatively rare. One example is H.R. 2454 in the 111^th Congress, the American Clean Energy and Security Act of 2009 ("Waxman-Markey"), which would have established an economy-wide cap-and-trade system to reduce GHG emissions. The House passed H.R. 2454 in 2009. Although companion legislation in the Senate, S. 1733, was ordered reported from the Committee on Environment and Public Works, the bill was not brought to the Senate floor for consideration. In the absence of new comprehensive legislative authority to reduce GHGs, the Obama Administration pursued GHG emissions abatement under existing authorities.²⁰ State and local governments have also historically implemented a variety of climate change actions (see "Climate Mitigation Activities in U.S. States").

Mostly Voluntary or Indirect Federal Approaches Until 2010

From negotiation of the UNFCCC through the mid-2000s, the federal government primarily relied on "no regrets" programs to address climate change, along with some efficiency regulation that also limited GHGs.²¹ The programs assisted agencies and nonfederal partners in achieving voluntary GHG reductions using technical assistance and reputational incentives offered by the EPA, the U.S. Department of Energy (DOE), and the U.S. Department of Agriculture (USDA). Examples include Energy Star, AgStar, and EPA's Center for Corporate Climate Leadership programs.²² A number of studies, however, concluded that voluntary action alone could not substantially reduce GHG emissions.²³

Several regulatory programs indirectly limited GHG emission increases from vehicles, appliances and equipment, and buildings. These continue, and largely have had increasing influence on reducing GHG emissions as standards tightened over time. For example, the Corporate Average Fuel Economy (CAFE) standards promulgated by the National Highway Traffic Safety Administration (NHTSA) set fuel economy targets, in miles per gallon, for newly manufactured passenger cars and light trucks sold in the United States. These standards have the co-benefit of reducing GHG emissions from these vehicles.

DOE's conservation and energy efficiency programs provide another example of standards that indirectly limit GHGs. Congress has enacted several broad energy policy laws—including support for energy conservation and energy efficiency—since the 1970s, most recently the Energy Act of 2020 (Division Z of P.L. 116-260). The Energy Policy and Conservation Act (EPCA; P.L. 94-163) authorized a federal program to establish minimum energy conservation standards for consumer products and industrial equipment, among other provisions. EPCA, as amended, authorizes DOE's Appliance and Equipment Standards Program, which sets efficiency standards for approximately 60 product categories.²⁴ The Energy Conservation and Production Act (ECPA; P.L. 94-385) established federal voluntary performance standards for new residential and commercial buildings and encouraged state and local governments to adopt and enforce standards through building codes, among other provisions. ECPA, as amended, also established federal building energy efficiency standards.²⁵

Congress established requirements for the federal government related to GHGs. The Energy Policy Act of 2005 (EPACT 2005; P.L. 109-58) established a renewable electricity goal for the federal government. The Energy Independence and Security Act of 2007 (EISA; P.L. 110-140) required agencies to report GHG emissions, although it did not specify what types of emissions. EPACT 2005 also established the Renewable Fuel Standard (RFS), which mandates that U.S. transportation fuels contain a minimum volume of renewable fuel; EISA subsequently expanded the RFS mandate.²⁶ The RFS mandate requires that transportation fuels sold or introduced into commerce in the United States contain an increasing volume of a predetermined suite of renewable fuels.²⁷ In order to be eligible for the RFS, a renewable fuel has to meet a GHG emission reduction threshold, among other criteria. The statute required 4.0 billion gallons of renewable fuel in 2006, ascending to 36.0 billion gallons required in 2022, with EPA determining the volume amounts after 2022 in future rulemakings.²⁸

After the mid-2000s, tax incentives and federal grants, including for research and development, increasingly supported renewable energy generation, biomass fuels, and lower-emission vehicles.²⁹ Administrations, over decades, have supported research to develop technologies, such as renewable energy systems, that could achieve deeper GHG reductions and reduce the cost of doing so. Increases in tax incentives for technology deployment, along with growing competition among manufacturers, led to increased efficiencies and reduced costs of many technologies, including wind and solar electricity generation.³⁰

In late 2007, Congress directed EPA to establish a GHG reporting program. Specifically, the Consolidated Appropriations Act, 2008 (P.L. 110-161), provided $3.5 million for EPA to develop and publish a rule that would "require mandatory reporting of greenhouse gas emissions above appropriate thresholds in all sectors of the economy of the United States." In response to the congressional directive, EPA established the Greenhouse Gas Reporting Program (GHGRP). It requires reporting from facilities in nearly all categories of direct emitters and from suppliers of certain fuels and manufactured GHGs (e.g., fluorinated GHGs) in the United States. The broad scope of emissions data collected from these sources allows the agency to assess trends in emissions over time and within industry sectors for use in agency policy and programs. The GHGRP does not impose emissions limits, but reporting programs may create transparency incentives for sources to limit their emissions due to public or reputational pressures.³¹

Federal Regulation of GHGs Under Existing Authorities, 2010 to 2021

A shift toward direct federal regulation of GHG emissions occurred following the 2007 decision in Massachusetts v. EPA, in which the Supreme Court found that EPA has authority to regulate GHG emissions from motor vehicles as air pollutants under the Clean Air Act (CAA).³² In the 5-4 decision, the Court's majority concluded that EPA must decide whether GHG emissions from new motor vehicles contribute to air pollution that may reasonably be anticipated to endanger public health or welfare—or provide a reasonable explanation why it cannot or will not make that decision. On December 15, 2009, EPA promulgated findings that six GHGs³³ endanger both public health and welfare and that GHG emissions from new motor vehicles contribute to that endangerment. These findings are collectively referred to as the "endangerment finding."

Of the six GHGs discussed in EPA's endangerment finding, CO₂ is the most prevalent, accounting for about 80% of U.S. GHG emissions, on a CO₂-equivalent basis, from human activities in 2019.³⁴ The second-most-prevalent gas in the United States in terms of emissions is methane (10% of U.S. GHG emissions in 2019), followed by nitrous oxide (7% in 2019).³⁵ In 2019, about two-thirds of domestic CO₂ emissions were produced by the combustion of fossil fuels for energy and transportation.³⁶ The primary sources of U.S. methane emissions include oil and natural gas systems, agriculture, and landfills,³⁷ and the primary source of nitrous oxide emissions is agricultural soil management.³⁸

The endangerment finding triggered EPA's duty under CAA Section 202(a) to promulgate emission standards for new motor vehicles, which are discussed below.³⁹ EPA has also since issued rules to limit GHGs under other CAA authorities. For example, the agency promulgated regulations under CAA Section 111 to limit GHGs from the electricity sector, the oil and gas industry, and municipal solid waste landfills. EPA also finalized, in consultation with the Federal Aviation Administration, CO₂ emission standards for civilian aircraft under CAA Section 231 in January 2021.⁴⁰ EPA developed the aircraft standards in line with the internationally negotiated standards agreed to by parties to the International Civil Aviation Organization.

The remainder of this section discusses GHG rules for vehicles, power plants, oil and natural gas systems, and municipal solid waste landfills that were promulgated prior to the Biden Administration.

Vehicle Fuel Economy and GHG Standards

As noted previously, transportation emissions are currently the largest source of GHG emissions in the United States.⁴¹ In 2010, the Obama Administration brokered an agreement among 13 auto manufacturers, the State of California,⁴² the United Auto Workers union, and other interested parties for GHG emission standards for automobiles and light trucks. EPA promulgated these GHG standards, which aligned with NHTSA's CAFE program, as well as with those developed by California to facilitate a "single national standard" for manufacturers.⁴³ EPA and NHTSA also promulgated two phases of fuel efficiency and GHG standards for newly manufactured heavy-duty vehicles and engines (e.g., long-haul tractor-trailers, buses, and construction and utility vehicles).⁴⁴

In 2020, EPA and NHTSA promulgated the SAFE Vehicles Rule, which relaxed the GHG and fuel economy standards for light-duty vehicles.⁴⁵ EPA also withdrew the waiver that had allowed California to set GHG emission standards stronger than the national standards to meet "compelling and extraordinary conditions," as authorized under the CAA.⁴⁶ Various states, local governments, and environmental and consumer organizations filed petitions for review in the U.S. Court of Appeals for the D.C. Circuit challenging the SAFE Vehicles Rule.

Power Plants and GHG Standards

To limit CO₂ from the electricity sector, currently the second-largest emitting source category in the United States,⁴⁷ EPA in 2015 promulgated New Source Performance Standards (NSPS) for new and modified fossil-fuel-fired power plants⁴⁸ and—for existing plants—the Clean Power Plan (CPP).⁴⁹ The CPP was the subject of ongoing litigation and was never implemented. While the NSPS remain in place, the Trump Administration repealed the CPP and finalized a new rule, the Affordable Clean Energy (ACE) rule, to limit CO₂ from existing power plants. The ACE rule applied a narrower interpretation than the CPP of the "best system of emission reduction," defining it as on-site "heat rate improvement" measures, also known as efficiency improvements, for existing coal-fired units.⁵⁰ In January 2021, a federal appellate court vacated and remanded the ACE rule to EPA, and it remains unclear how EPA may act on the rule.⁵¹ The CPP and ACE rules, issued under separate Administrations, relied on different interpretations of EPA's CAA authority, which may raise questions about EPA's potential approach to regulating GHG emissions under the CAA.

Although federal requirements to limit GHG emissions in the electricity sector have not been implemented,⁵² GHG emissions in the sector declined by 33% between 2005 and 2019, as discussed earlier in this report. See "U.S. Emission Trends" and Figure 1.

Oil and Natural Gas Systems, Solid Waste Landfills, and GHG Standards

Under the Obama Administration, federal activities in support of GHG emissions reductions in various industrial sectors became a cornerstone of President Obama's "Climate Action Plan." The Administration promulgated several regulations to address these emissions, including

• EPA standards to reduce methane emissions from new and modified activities and equipment in the oil and natural gas sector (finalized on June 3, 2016);⁵³
• EPA standards to reduce methane emissions from new and existing municipal solid waste landfills (finalized on August 29, 2016);⁵⁴ and
• Bureau of Land Management (BLM) standards to prevent the waste of gas (i.e., methane) through venting and flaring during oil and natural gas production on public lands (finalized on November 18, 2016).⁵⁵

President Trump subsequently signed Executive Order 13783 on March 28, 2017, requiring agencies to review existing regulations and "appropriately suspend, revise, or rescind those that unduly burden" domestic energy production and use. Further, the federal courts reviewed provisions in the Obama-era standards and the Trump Administration's revisions. As a result, the status of federal methane regulation was as follows by the end of the Trump Administration:

• EPA rescinded the 2016 methane standards for the oil and gas sector (September 14, 2020).⁵⁶ (See also "Recently Enacted Legislation Related to GHGs" for related legislative action undertaken in 2021, in particular, S.J.Res. 14 and P.L. 117-23, which disapproved the 2020 policy revisions of EPA's 2016 methane standards for the oil and natural gas sector. Although most of the requirements under EPA's 2016 rule are back in force, their fate remains unclear because of pending legislative, executive, and judicial actions.⁵⁷)
• The 2016 methane standards for new and existing municipal solid waste landfills remain in effect.⁵⁸ Stakeholders have challenged the 2016 methane standards for existing landfills in court, but the litigation is on hold.⁵⁹
• BLM rescinded the 2016 waste prevention standards for the oil and gas sector (September 28, 2018). A California federal district court vacated the rescission (July 15, 2020);⁶⁰ however, a Wyoming federal district court subsequently vacated all provisions in the 2016 rule related to the loss of gas (October 8, 2020).⁶¹ Appellate litigation is ongoing.⁶²

Climate Mitigation Activities in U.S. States

In the absence of comprehensive federal controls on GHG emissions, state and local governments have taken a variety of actions―both legal mandates and voluntary efforts―for nearly 20 years. Generally, these efforts include emission controls on power plants and vehicles; building codes; and other actions. In particular, a number of U.S. states have mandatory GHG reduction programs, including the following:

• California has a GHG emissions cap-and-trade program that went into effect in 2013 that applies to electric power, selected industries, and fossil fuel distributors.⁶³ The program is linked with a cap-and-trade program in the Canadian province of Quebec. The program is a key component of the state's plan to meet its legislated target of reducing GHG emissions 40% below 1990 levels by 2030.⁶⁴
• Eleven U.S. states participate in the Regional Greenhouse Gas Initiative (RGGI),⁶⁵ a cap-and-trade program on CO₂ emissions from electric power that went into effect in 2009. The RGGI states have revised their program over time. The most recent revision aims to reduce power-sector emissions in the 11 states to 30% below 2020 levels by 2030.⁶⁶
• Thirty states, three U.S. territories, and the District of Columbia have mandatory electricity portfolio standards (clean energy standards or renewable portfolio standards), which require a minimum amount of electricity be generated by eligible sources such as renewables. Of these, 11 jurisdictions are to ultimately require 100% of electricity to come from eligible clean sources.⁶⁷
• Regarding vehicle emissions, California set standards in 2009, jointly with the federal government, to increase fuel efficiency and reduce GHG emissions from many types of on-road vehicles.⁶⁸ California also set standards to require auto manufacturers to increase the number of zero emission vehicles (ZEVs) sold in the state.⁶⁹ Fourteen other states and the District of Columbia adopted California's vehicle standards.⁷⁰ California's authority to set these standards under the CAA was preempted by the Trump Administration, but related litigation paused in February 2021 so the incoming Biden Administration could review and potentially revise the rule. Additionally, 45 states and the District of Columbia provide incentives for electric vehicles and/or hybrids. The incentives range from tax credits or rebates to fleet acquisition goals, exemptions from emissions testing, or favorable electricity rate treatment.⁷¹ Further, seven states have some version of a low carbon fuel standard or alternative fuel standard.⁷² Additionally, 13 Northeast and Mid-Atlantic states plus the District of Columbia have sought policies to reduce carbon emissions from the transportation sector, and are seeking to use a policy modeled on RGGI and coordinated through the Transportation and Climate Initiative.⁷³

When President Trump announced in June 2017 his intention to withdraw the United States from the PA, some U.S. mayors, county executives, governors, tribal leaders, college and university leaders, businesses, faith groups, and investors formed the We Are Still In organization to pledge and demonstrate nonfederal climate change actions to the international community.⁷⁴ In addition, the U.S. Climate Alliance, which includes governors from 24 states and Puerto Rico, announced a commitment to reduce net GHG emissions from their states at least 50%-52% below 2005 levels by 2030 and to achieve net-zero GHG emissions no later than 2050.⁷⁵ The degree to which state and local governments can achieve these targets without federal action is uncertain, as the legal authorities and jurisdictions over GHG emissions sources may be limited in some cases.

U.S. Legislative Action

Members of Congress have historically expressed a range of perspectives regarding climate change issues and have proposed a variety of legislative approaches. Legislative proposals have included

• carbon pricing frameworks (e.g., carbon taxes or cap-and-trade programs)⁷⁶ that would address a majority of U.S. GHG emissions;
• sectoral approaches, such as a clean energy standard;
• funding or tax policies that support GHG-abating technology development and deployment;
• efforts to increase adaptation to climate change; and
• international cooperation.

On the other hand, some Members have introduced resolutions expressing that the multisector carbon pricing approaches are not in the economic interests of the United States.⁷⁷

Votes on comprehensive climate change proposals have been relatively rare in either chamber of Congress, although votes on proposals that may indirectly address climate change have been more common. For example, Congress has repeatedly enacted legislation with tax incentives for renewable energy and carbon capture and sequestration efforts.⁷⁸

Recently Enacted Legislation Related to GHGs

The Consolidated Appropriations Act, 2021 (P.L. 116-260), contained measures relevant to reducing GHG emissions, including the Energy Act of 2020 (Division Z) and the American Innovation and Manufacturing (AIM) Act of 2020 (Division S, §103). The Energy Act of 2020 promotes increased energy efficiency in homes, schools, and federal buildings; expands research and development in nuclear energy, energy storage, electric vehicles, renewable energy, and carbon capture utilization and storage (CCUS); and promotes energy storage development, among other provisions.⁷⁹

The AIM Act of 2020 establishes a 15-year timeline to reduce domestic hydrofluorocarbons (HFCs), a potent class of GHGs used in air conditioning and refrigeration equipment, and directs the EPA to implement the requirements, including through regulations. AIM's phasedown schedule appears to align with international commitments to phase down HFCs under the Kigali Amendment to the Montreal Protocol to the 1985 Vienna Convention for the Protection of the Ozone Layer.⁸⁰ EPA has begun developing a program to phase down HFCs under AIM Act authorities.⁸¹

The 117^th Congress passed, and President Biden signed into law, S.J.Res. 14 (P.L. 117-23), on June 30, 2021, disapproving of the Trump Administration's 2020 policy revisions of EPA's 2016 methane standards for the oil and natural gas sector. Although most of the requirements under EPA's rule are back in force, their fate remains unclear because of pending legislative, executive, and judicial actions.⁸² 

Legislative Proposals in the 117^th Congress

Majority leadership in both the House and the Senate in the 117^th Congress have called for whole-of-chamber approaches to addressing climate change.⁸³ Members have introduced many proposals that address climate change in some capacity, and climate change legislation has been referred to more than 35 committees.

Among these proposals is legislation intended to modernize U.S. infrastructure and fund initiatives that may also increase climate resilience or reduce GHGs. In June 2021, a group of Senators reached agreement with President Biden on the "Bipartisan Infrastructure Framework" (BIF), a $1.2 trillion plan that would authorize $579 billion in new spending on transportation infrastructure, power infrastructure, climate resiliency, and other initiatives.⁸⁴ The BIF served as the basis for the Infrastructure Investment and Jobs Act (IIJA), a substitute amendment (S.Amdt. 2137) to H.R. 3684, which the Senate passed on August 10, 2021. IIJA is both an authorizing bill and an appropriations bill,⁸⁵ and it would authorize funds for federal-aid highways, highway safety programs, water and electricity infrastructure, broadband, and other initiatives. IIJA would also provide funds intended to promote, among other things, clean energy and increased resilience of U.S. infrastructure, such as schools and ports. For example, IIJA would authorize funds for a Port Infrastructure Development Program, which would include projects "that improve the resiliency of ports to address sea-level rise, flooding, extreme weather events, earthquakes, and tsunami inundation, as well as projects that reduce or eliminate port-related criteria pollutant or greenhouse gas emission."⁸⁶ As of September 2021, the House had not considered IIJA.

Congress has also considered climate change spending through its work on FY2022 budget reconciliation. Both chambers agreed to a $3.5 trillion budget resolution, S.Con.Res. 14, which established the congressional budget for FY2022, set budgetary levels for FY2023-FY2031, and provided reconciliation instructions to committees in the House and Senate.⁸⁷ Among other things, S.Con.Res. 14 sought to authorize spending that would support the President's goals of "80 percent clean electricity and 50 percent economy-wide carbon emissions reductions by 2030."⁸⁸ It set a September 15, 2021, deadline for House and Senate committees to submit legislative language to their respective Budget Committees for the reconciliation package. The House Budget Committee combined the House committee markups into one bill, H.R. 5376, which is also referred to as "The Build Back Better Act." H.R. 5376 would provide funding, establish programs, and modify various "provisions relating to a broad array of areas, including education, labor, child care, health care, taxes, immigration, and the environment." Among other things, the bill would provide funding for energy efficiency and weatherization projects; electric vehicles and zero-emission, heavy-duty vehicles; and transit services and "clean energy projects" in low-income communities. It also includes provisions for a methane fee for certain oil and natural gas facilities. As of September 27, 2021, the House Budget Committee approved H.R. 5376 and reported it to the House of Representatives.

Members of Congress have also introduced many other proposals addressing climate change in the 117^th Congress. CRS identified over 750 bills in Congress.gov that address climate change in some capacity in the 117^th Congress, as of September 27, 2021.⁸⁹ CRS searched for bills by identifying climate-related key words in five broad categories: equity; land use; energy (including electricity, transportation, and energy efficiency); adaptation; and finance. These categories are summarized below.⁹⁰ The categories are not mutually exclusive, given that many bills contain provisions that fall under more than one category. In particular, CRS identified seven bills, listed below, that appeared in all of the five broad categories, indicating that these bills span a potentially wide range of climate change topics. (See Appendix A for details about the search methodology.)

• S. 283, "National Climate Bank Act," sponsored by Senator Markey, and referred to the Senate Committee on Environment and Public Works. Latest action: Hearings held by Senate Committee on Environment and Public Works, Subcommittee on Clean Air, Climate, and Nuclear Safety (April 27, 2021).
• S. 685, "America's Clean Future Fund Act," sponsored by Senator Durbin. Latest action: Read twice and referred to the Committee on Finance (March 10, 2021).
• S. 1201, "United States Climate Leadership in International Mitigation, Adaptation, and Technology Enhancement Act of 2021," sponsored by Senator Menendez. Latest action: Read twice and referred to the Committee on Foreign Relations (April 19, 2021).
• H.R. 1512, "Climate Leadership and Environmental Action for our Nation's Future Act," or CLEAN Future Act, sponsored by Representative Pallone. Latest action: Referred to multiple House committees and subcommittees (March 3, 2021).⁹¹
• H.R. 1848, "Leading Infrastructure For Tomorrow's America Act," or "LIFT America Act," sponsored by Representative Pallone. Latest action: Referred to five subcommittees of the House Transportation and Infrastructure Committee (March 12, 2021).⁹²
• H.R. 4309, "Clean Energy Innovation and Deployment Act of 2021," sponsored by Representative DeGette. Latest action: Referred to the Subcommittee on Railroads, Pipelines, and Hazardous Materials of the House Committee on Transportation and Infrastructure (July 2, 2021).
• H.R. 4350, "National Defense Authorization Act for Fiscal Year 2022," sponsored by Representative Smith. Latest action as of the end of September: The Clerk was authorized to correct section numbers, punctuation, and cross references, and to make other necessary technical and conforming corrections in the engrossment of H.R. 4350 (September 23, 2021).

Thirty-four of the more than 750 legislative proposals that CRS identified received floor consideration, as of September 27, 2021.⁹³ Many of these bills fit into multiple broad topic categories. Also, some bills may contain only small provisions addressing climate change, while others are solely focused on a particular climate change topic in one or more of the five categories. Two of these bills (H.R. 3684 and H.R. 4350) fell into all five categories. Twenty-seven of the 34 fell into the energy category, and 18 of the 34 fell into the adaptation category. The remainder of this section briefly describes each category and presents the status of proposals that have at least received floor consideration as of September 27, 2021. Table A-1 in Appendix A also provides a complete list of the bills that have at least received floor consideration.

Additional CRS reports examine certain legislative approaches under consideration by some in the 117^th Congress and prior Congresses:

• CRS Report R45472, Market-Based Greenhouse Gas Emission Reduction Legislation: 108th Through 117th Congresses, by Jonathan L. Ramseur.
• CRS Report R46691, Clean Energy Standards: Selected Issues for the 117th Congress, by Ashley J. Lawson.

Adaptation

As of September 27, 2021, CRS identified 197 bills introduced in the 117^th Congress that seek to address adaptation in some capacity.⁹⁴ This category includes proposals to address natural disasters, extreme weather events, coastal resilience, sea level rise, and more. Eighteen of these 197 bills received at least floor consideration.

Energy

As of September 27, 2021, CRS identified 682 bills introduced in the 117^th Congress that seek to address energy issues related to climate change. These bills represent the majority of the bills identified in all of the searches. For the purposes of this research, CRS defined energy broadly to include GHG emissions mitigation efforts in the electricity generation, residential and commercial, and transportation sectors. Examples of mitigation efforts include renewable energy incentives, energy efficiency incentives, methane emission reduction efforts, and proposals to alter fossil fuel production practices, among others. Bills in this category propose a wide range of policy options, including carbon pricing, tax incentives, grants, R&D, and others. Twenty-seven of these 682 bills received at least floor consideration. Of these, H.R. 1319 became law (The American Rescue Plan Act of 2021, P.L. 117-2).⁹⁵

Equity

As of September 27, 2021, CRS identified 104 bills introduced in the 117^th Congress that seek to address equity issues related to climate change.⁹⁶ Bills identified in this search may include either an international or a domestic focus, or both. These bills include provisions to address issues such as community resilience, "just transitions" for the energy workforce, infrastructure, environmental justice, and other topics. Seven of these 104 bills received at least floor consideration and one, H.R. 1319, became law (The American Rescue Plan Act of 2021, P.L. 117-2).⁹⁷

Finance

As of September 27, 2021, CRS identified 48 bills introduced in the 117^th Congress concerning climate change and the financial industry. These bills include provisions regarding climate change risk disclosure and proposals to create climate or green banks, among others. Seven of these 48 bills received floor consideration.

Land Use

As of September 27, 2021, CRS identified 117 bills introduced in the 117^th Congress that seek to address land use issues related to climate change. These bills address deforestation, propose carbon sequestration efforts through forestry and agricultural practices, and include provisions regarding coastal resilience and adaptation, among others. Ten of these 117 bills received at least floor consideration.

Executive Branch Approach to Climate Change Mitigation

GHG Targets

Executive branch policies and actions influencing future U.S. GHG emissions are dependent on the policy objectives of each administration. After the United States rejoined the PA, the Biden Administration communicated a new Nationally Determined Contribution (NDC) to the Paris Agreement,⁹⁸ which contains a new GHG target for the United States: to reduce net GHG emissions by 50%-52% below 2005 levels by 2030.⁹⁹ According to the Biden Administration, the NDC "exceeds a straight-line path to achieve net-zero emissions, economy-wide, by no later than 2050."¹⁰⁰ For comparison, the previous U.S. NDC, released in 2015, set a target of 26%-28% below 2005 levels by 2025, which President Obama had indicated was on a straight-line trajectory to a reduction of 80% below 2005 levels by 2050. The content of NDCs is nationally determined and nonbinding, but it should reflect what a Party to the PA intends to achieve.

Figure 2 shows historical net GHG emissions with the 2015 and 2021 NDCs and the Biden Administration's net-zero emissions goal for 2050. In 2019, U.S. GHG emissions, after accounting for removals by carbon sinks, were 5,769 MMTCO₂e.¹⁰¹ The 2019 net GHG emissions are about 13% below net 2005 levels and about 4% above net 1990 levels.

Figure 2. U.S. Net GHG Emissions (1990-2019) and Selected Emissions Targets

Source: Prepared by CRS; historical emissions from EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2019, 2021, https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks. Notes: Net GHG emissions include net carbon sequestration from land use, land use change, and forestry. This involves carbon removals from the atmosphere by photosynthesis and storage in vegetation. Million metric tons of CO2 equivalent (MMTCO2e) is used because GHGs vary by global warming potential (GWP). GWP is an index that allows comparisons of the heat-trapping ability of different gases over a period of time. Consistent with international GHG reporting requirements, EPA's most recent GHG inventory (April 2021) uses the GWP values presented in the Intergovernmental Panel on Climate Change (IPCC) 2007 Fourth Assessment Report for warming potential over 100 years.

The 2021 NDC also sets a goal to eliminate carbon emissions from the electricity sector by 2035. The Biden Administration reports that it will seek to decarbonize the energy sector in various ways, "including by cutting energy waste; shifting to carbon pollution-free electricity; electrifying and driving efficiency in vehicles, buildings, and parts of industry; and scaling up new energy sources and carriers."¹⁰²

Announced Policies and Rulemakings

In many respects, early executive orders and actions directed by the Biden Administration may be viewed as reinstatement and expansion of policies of the Obama Administration on climate change, with some important differences. In his first three months in office, President Biden rejoined the PA, announced U.S. GHG reduction targets, and centralized executive branch organizations to identify and coordinate climate-related actions. The remainder of this section describes the Biden Administration executive orders addressing climate change, as of September 2021. Appendix B provides examples of additional climate-related policy actions, as summarized by White House statements, as of September 2021.

Executive Order 13990, Protecting Public Health and the Environment and Restoring Science To Tackle the Climate Crisis

Executive Order (E.O.) 13990 of January 20, 2021, outlined a federal policy

to improve public health and protect our environment; to ensure access to clean air and water; to limit exposure to dangerous chemicals and pesticides; to hold polluters accountable, including those who disproportionately harm communities of color and low-income communities; to reduce greenhouse gas emissions; to bolster resilience to the impacts of climate change; to restore and expand our national treasures and monuments; and to prioritize both environmental justice and the creation of the well-paying union jobs necessary to deliver on these goals.¹⁰³

To this end, the order directed all executive departments and agencies to immediately review and, as appropriate and consistent with applicable law, consider suspending, revising, or rescinding actions promulgated, issued, or adopted between January 20, 2017, and January 20, 2021. The order specifically listed a number of climate-related actions by agencies to be reviewed by a given date, including EPA's methane standards for the oil and natural gas sector, EPA's and NHTSA's GHG and fuel economy standards for passenger cars and light trucks, and several of DOE's efficiency improvements and appliance standards, among others.¹⁰⁴ Further, the order directed heads of agencies, as appropriate and consistent with applicable law, to reinstate, or move forward with, several other climate-related actions, including proposing new methane guidelines on existing oil- and gas-sector sources, placing a temporary moratorium on the implementation of the Coastal Plain Oil and Gas Leasing Program in the Arctic National Wildlife Refuge, establishing an interagency working group on the social cost of GHGs, and rescinding a number of executive actions, including the March 2019 permit for the Keystone XL pipeline and the Council on Environmental Quality's 2019 draft GHG guidance on the National Environmental Policy Act, among others. It also stated that it is the Administration's policy "to bolster resilience to the impacts of climate change," and effectively reinstated several Obama Administration presidential documents related to climate change adaptation.¹⁰⁵

Executive Order 14008, Tackling the Climate Crisis at Home and Abroad

E.O. 14008 of January 27, 2021, ordered a whole-of-government approach to addressing climate change and set forth a number of directives with a view toward decisions that support meeting the Administration's GHG reduction targets.¹⁰⁶ The order created a new position of the Special Presidential Envoy for Climate. To coordinate across agencies, E.O. 14008 established a White House Office of Domestic Climate Policy (Climate Policy Office) within the Executive Office of the President led by an Assistant to the President and National Climate Advisor.

E.O. 14008 also established a National Climate Task Force, which is chaired by the National Climate Advisor and composed of departments and major agencies. The order instructed the National Climate Task Force to organize the whole-of-government approach to addressing climate change and to facilitate planning and implementation of federal actions. In particular, E.O. 14008 instructed task force members to "prioritize action on climate change in their policy-making and budget processes, in their contracting and procurement, and in their engagement with State, local, Tribal, and territorial governments; workers and communities; and leaders across all sectors of our economy."¹⁰⁷

E.O. 14008 called for additional actions, including the following:

• Adaptation. Federal agencies must develop Climate Action Plans to improve adaptation and resilience to climate changes. After review by the Federal Chief Sustainability Officer,¹⁰⁸ agencies must report annually on their implementation of the plans.
• Conservation, Agriculture, and Forestry. E.O. 14008 called for development of certain strategies and reports related to conservation, agriculture, and forestry. It called for a strategy to create a Civilian Climate Corps to provide jobs and training for conservation, restoration, resilience, carbon sequestration, and other objectives.¹⁰⁹ The E.O. called for a report recommending steps to achieve conservation of at least 30% of U.S. lands and waters by 2030, and included mechanisms to measure progress toward that goal. A preliminary report was released on May 6, 2021.¹¹⁰ E.O. 14008 also addressed the potential role of farming in addressing climate change and reducing GHG emissions, highlighting opportunities to promote carbon sequestration in soils and to source sustainable bioproducts and biofuels. It required USDA to solicit stakeholder input and issue a report—within 90 days—making recommendations for a climate strategy for agriculture and forestry. USDA released this report on May 20, 2021.¹¹¹
• Energy and Public Lands. E.O. 14008 directed the Secretary of the Interior to identify actions that would increase renewable energy production on public lands and in offshore waters, with a goal to double offshore wind production by 2030.¹¹² It also directed the Secretary to pause new oil and gas leases on public lands or offshore waters pending review and reconsideration of federal oil and gas leasing and permitting practices. It directed the Secretary to consider, among other things, potential climate and other impacts associated with oil and gas activities on federal lands and to consider adjusting royalty rates for coal, oil, and gas extracted from public lands or to take other actions to account for climate costs.¹¹³
• Foreign Policy and National Security. E.O. 14008 increased the prioritization of international actions on climate change, as compared to actions under President Obama and President Trump, establishing the policy that "climate considerations shall be an essential element of United States foreign policy and national security."¹¹⁴ The Special Presidential Envoy for Climate sits on the National Security Council (NSC), representing the first time the NSC includes a principal fully dedicated to climate change.¹¹⁵ E.O. 14008 also called for relevant federal agencies to coordinate with the Special Presidential Envoy for Climate to develop strategies and implementation plans for integrating climate considerations into their international work.¹¹⁶
• Infrastructure. E.O. 14008 directed the Chair of the Council on Environmental Quality (CEQ) and the Director of the Office of Management and Budget (OMB) to (1) ensure that investments in federal infrastructure reduce GHGs; (2) require that permitting decisions consider GHG emission impacts; and (3) identify steps to accelerate clean energy and transmission projects.¹¹⁷
• Procurement. E.O. 14008 established a policy to align management of federal procurement and real property to "support robust climate action."¹¹⁸ In particular, it called for the National Climate Advisor and National Climate Task Force, assisted by the heads of relevant federal agencies, to develop a plan that uses available procurement authorities to achieve or facilitate a decarbonized electricity sector by 2035 and the use of clean and zero-emission vehicles for federal, state, local, and tribal government fleets.¹¹⁹
• Transition and Equity (Energy Communities). E.O. 14008 established an Interagency Working Group on Coal and Power Plant Communities and Economic Revitalization (IWG). The order directed the IWG, which is housed within DOE, to coordinate the delivery of federal resources "to revitalize the economies of coal, oil and gas, and power plant communities," develop strategies for economic and social recovery, and evaluate "opportunities to ensure benefits and protections for coal and power plant workers."¹²⁰
• Transition and Equity (Justice40 Initiative). E.O. 14008 established the Justice40 Initiative to recommend, in consultation with disadvantaged communities, how to direct certain federal investments such that 40% would flow to "disadvantaged communities."¹²¹ The Administration published "initial recommendations" on July 20, 2021.¹²² According to the order, the scope of those federal investments includes clean energy and energy efficiency; clean transit; affordable and sustainable housing; training and workforce development; remediation and reduction of legacy pollution; and critical clean water infrastructure. The initiative must publish an annual Environmental Justice Scorecard.

Executive Order 14027, Establishment of the Climate Change Support Office

E.O. 14027 of May 7, 2021, established, within the Department of State, a temporary organization called the Climate Change Support Office (CCSO).¹²³ The purpose of the CCSO is to support "bilateral and multilateral engagement to advance the United States' initiative to address" climate change.¹²⁴ The CCSO is also intended to "support efforts that go beyond the climate work currently carried out by the Department of State across a wide range of international fora that address clean energy, aviation, shipping, the Artic [sic], the ocean, sustainable development, and migration."¹²⁵

Executive Order 14030, Climate-Related Financial Risk

E.O. 14030 of May 20, 2021, directed federal agencies, including financial regulators, to analyze and mitigate the risks that climate change poses to financial stability.¹²⁶ It called for the development of a comprehensive, government-wide strategy that identifies climate-related financial risk to government programs, assets, and liabilities. It also required the strategy to identify financing needs associated with climate change goals, including achieving net-zero greenhouse gas emissions for the U.S. economy by no later than 2050. The order directed financial regulators to assess climate-related financial risks and issue a report that discusses current federal efforts to incorporate climate-related risks into policies and programs. The order also directed agencies to consider taking actions to protect life savings and pensions from climate-related financial risk, and to consider updating procurement and budgetary processes to account for climate-related risk analyses.

Executive Order 14037, Strengthening American Leadership in Clean Cars and Trucks

E.O. 14037 of August 5, 2021, set a nonbinding goal for electrification in the transportation section, namely that 50% of all new passenger cars and light trucks sold in 2030 be zero-emission vehicles, including battery electric, plug-in hybrid electric, or fuel cell electric vehicles.¹²⁷ The order also directed EPA and NHTSA to begin work on future rulemakings for multipollutant emissions, including for greenhouse gas emissions, and fuel economy standards for light- and medium-duty vehicles beginning with model year (MY) 2027 and extending at least through MY 2030. Further, the agencies are to begin work on new nitrogen oxides standards beginning in MY 2027, updated GHG emission standards for MYs 2027-2029, and new GHG emission and fuel efficiency standards beginning in MY 2030, for heavy-duty engines and vehicles.

In conjunction with the release of E.O. 14037, the Biden Administration proposed amendments to the existing CAFE and light-duty vehicle GHG emission standards through MY 2026.¹²⁸ The proposal was not a joint rulemaking. EPA and NHTSA released their proposals separately, with different MY requirements, target stringencies, and compliance flexibilities. However, both proposals would increase in stringency by approximately 25% between MYs 2023 and 2026, achieving a projected fleet-wide, sales-weighted fuel economy of roughly 48 miles per gallon in 2026. In addition to the amended standards, NHTSA has proposed to fully repeal the SAFE Vehicles Rule, Part One: One National Program,¹²⁹ and EPA has announced that it is reconsidering the 2019 withdrawal of California's CAA preemption waiver.¹³⁰

FY2022 Budget Request

E.O. 14008 identifies the budget process as another task through which agencies shall, to the extent permitted by law, prioritize action on climate change.¹³¹ The President's FY2022 budget request, released May 28, 2021, included specific proposals aimed at reducing GHG emissions. For example, the FY2022 budget request included an Administration initiative on infrastructure, the American Jobs Plan, which would invest in climate and clean infrastructure projects, among other things.¹³² For more information, see Appendix B.

The President's FY2022 budget request stated that in addition to the American Jobs Plan, the Administration proposed an increase of over $14 billion of federal funding, compared to FY2021, to support GHG reductions and increasing adaptation or resilience to climate-related impacts.¹³³

The President's FY2022 budget request included, among other proposals, the following:¹³⁴

• Clean Energy Projects and Workforce Development. The President's FY2022 budget states that it would provide $2 billion for "welders, electricians, and other skilled laborers" to build clean energy projects.¹³⁵
• Clean Energy, Energy Storage, and Transmission Projects in Rural Communities. The President's FY2022 budget states that it would provide $6.5 billion for lending.¹³⁶
• Agriculture and Conservation. The President's FY2022 budget states that it would provide more than $300 million in "new investments in the next generation of agriculture and conservation," which would include support for voluntary private lands conservation, renewable energy grants and loans, and creation of the Civilian Climate Corps.¹³⁷
• Efficiency Grants. The President's FY2022 budget states that it would provide $1.7 billion for retrofits to homes, schools, and federal buildings.¹³⁸
• Environmental Justice. The President's FY2022 budget states that it would provide more than $1.4 billion to support "marginalized and overburdened communities," including $936 million toward a new initiative, Accelerating Environmental and Economic Justice.¹³⁹ The FY2022 budget also proposes an increase of more than $450 million to support climate mitigation, resilience, adaptation, and environmental justice projects in Indian Country.¹⁴⁰
• Federal Procurement and Electric Vehicles. The President's FY2022 budget states that it would provide $600 million for federal zero-emission vehicles and charging infrastructure.¹⁴¹
• GHG Reductions Under Existing Authorities. The President's FY2022 budget requests $1.8 billion for EPA programs to address climate change, a $100 million increase for air quality grants to states and tribes to implement programs and reduce GHGs under the Clean Air Act, and an additional $60 million to research climate change impacts on health and the environment.¹⁴²
• International Climate Change Financing. The President's FY2022 budget requests $2.5 billion for international climate change programs.¹⁴³ It includes a $1.2 billion contribution to the Green Climate Fund (GCF) and $485 million to support other multilateral climate initiatives, including $100 million for international climate adaptation programs.¹⁴⁴ Also the President's budget requests about $700 million for the Department of State and U.S. Agency for International Development to assist developing countries in adapting to climate disruptions, to invest in clean energy, and to reduce GHG "landscape emissions."¹⁴⁵
• Methane Reductions from Oil and Gas Systems. The President's FY2022 budget requests over $580 million to "remediate thousands of abandoned oil and gas wells and reclaim abandoned mines" in order to reduce methane leakage.¹⁴⁶
• Technology Research, Development, and Demonstration. The President's FY2022 budget requests more than $10 billion in "clean energy innovation across nondefense agencies."¹⁴⁷ For example, DOE requested more than $8 billion in clean energy and climate innovation to develop "advanced" nuclear energy technologies,¹⁴⁸ electric vehicles, "green hydrogen,"¹⁴⁹ and innovative approaches to air conditioning and refrigeration.¹⁵⁰ The President's budget request includes a total of $1 billion to establish a new Advanced Research Projects Agency for Climate (ARPA-C), and invest in the existing Advanced Research Projects Agency-Energy, which would both support high-risk funding of climate change adaptation/resilience and GHG mitigation technology development.¹⁵¹ The Administration expects to house ARPA-C at DOE.¹⁵² Additional agencies contributing to ARPA-C include the departments of Agriculture, Commerce, Homeland Security, Housing and Urban Development, the Interior, and Transportation, and EPA.¹⁵³ Secretary of Energy Jennifer Granholm indicated that the current proposal would initiate "a path to quadruple clean energy research government-wide in four years."¹⁵⁴
• Transportation Incentives. The President's FY2022 budget requests a $174 billion investment in the electric vehicle market, including support for domestic manufacturing of batteries and electric vehicles, consumer point-of-sale rebates and tax incentives to purchase electric vehicles manufactured in the United States, and establishment of grants and incentive programs to build a network of electric vehicle chargers.¹⁵⁵ The President's FY2022 budget also proposes to invest $80 billion for rail improvements, including the development and adoption of clean energy rail propulsion systems, such as near-zero emission diesel locomotives, battery technology, and electrification.¹⁵⁶

As of September 2021, congressional debate has continued on annual appropriations for FY2022. Appropriators in each chamber have supported some of the Biden Administration's proposals to varying degrees. For more information, see the CRS collection of reports on FY2022 appropriations.¹⁵⁷

Congress has also considered climate change spending through its work on FY2022 budget reconciliation. Both chambers agreed to a $3.5 trillion budget resolution, S.Con.Res. 14, which established the congressional budget for FY2022, set budgetary levels for FY2023-FY2031, and provided reconciliation instructions to committees in the House and Senate.¹⁵⁸ For more information, see "Legislative Proposals in the 117th Congress."

Issues for Congress

The Biden Administration has increased the ambition of domestic GHG reduction goals compared to previous Administrations, aiming to achieve "net zero" emissions in the next three decades. It has signaled it will pursue its GHG reduction goals through a variety of climate change actions, including both regulatory and nonregulatory measures. Some observers have expressed skepticism that the Administration's GHG reduction goals can be reached absent new or enhanced authorities and appropriations from Congress. As the Biden Administration begins to implement a whole-of-government approach to climate change, Congress may consider issues concerning U.S. GHG targets, policy approaches, and funding.

GHG Targets and International Commitments

The Biden Administration rejoined the PA, which seeks to hold the GHG-induced "increase in global average temperature to well below 2^o Celsius (C)" and to try to limit it to 1.5^oC.¹⁵⁹ In particular, the PA includes a collective commitment to achieve approximately net-zero GHG emissions in the second half of this century.¹⁶⁰ The United States established a new pledge to reduce its economy-wide net GHG emissions by 50%-52% below the 2005 level by 2030, in a required communication, the U.S. Nationally Determined Contribution (NDC) to the PA. See Figure 2 for historical net GHG emissions compared with these goals.¹⁶¹ The target itself is not binding. The U.S. NDC also stated that the target "exceeds a straight-line path to achieve net-zero emissions, economy-wide, by no later than 2050."¹⁶² The pledges made in the U.S. NDC and other parties' NDCs to 2030 are intended to support near-term steps in a multidecadal process to avoid adverse impacts on people, economies, and the environmental systems on which societies depend.

U.S. participation in the PA raises issues that Congress may consider, such as the ambition of the U.S. NDC and assessment of other parties' NDCs. Members may be interested in the actions required to fulfill the U.S. NDC, the efficacy of such actions, and the economic and equity implications of such actions. Congress may consider assessing the ambition, relative level of effort, and performance of other parties' GHG mitigation, adaptation, technology, and financing associated with the PA. It could request the executive branch to provide such analysis, conduct its own assessment, or rely on third parties.

Differences in the scope, stringency, and timing of parties' GHG policies may raise concerns for policymakers. One concern many have is that U.S. policies could raise U.S. prices more than the prices of goods manufactured in countries with relatively less stringent climate policies, potentially creating a competitive disadvantage for some domestic businesses. Certain businesses could potentially become less profitable, lose market share, and reduce jobs. In addition, climate policy differences between countries could potentially lead to emissions leakage, which "occurs when economic activity is shifted as a result of the emission control regulation and, as a result, emission abatement achieved in one location [e.g., the United States] that is subject to emission control regulation is [diminished] by increased emissions in unregulated locations."¹⁶³

Policymakers might consider approaches to address these potential outcomes in several ways. One approach that has received interest in recent years is a border carbon adjustment (BCA) mechanism. Several national governments and the EU have discussed imposing BCAs on imported goods from countries that do not make similarly ambitious efforts to reduce GHG emissions. A BCA would likely apply a tariff to emission-intensive imported goods such as steel, aluminum, cement, and certain chemicals. Also, China, South Korea, European countries, and others are pursuing investment in low-GHG-emitting technologies in advanced energy, materials, electronics, vehicles, and other sectors that they expect to provide future competitiveness advantages.¹⁶⁴

Transparency and verification of GHG reductions is another issue potentially of interest to Congress. Some Members may be concerned about whether parties to the PA are taking actions and will achieve their GHG targets. Scientific advances in remote sensing systems, ground-based measurements, and modeling can help the United States and other countries independently verify where entities may be meeting their GHG targets, and where they may be falling behind. Congress may be interested in the federal and international programs that support, or could enhance support for, greater transparency of reporting, verification, and review of GHG emissions and related actions.

U.S. Federal Policy Approaches

If Congress seeks to limit or remove GHG emissions from the atmosphere, then there are a range of policy options it may consider.¹⁶⁵ For example, options include carbon pricing, regulatory approaches, investment in research and development, tax incentives, and federal procurement requirements. A number of these policy tools are currently being implemented in the United States—as discussed earlier in this report—and in other countries, to varying degrees and to support a range of policy objectives.

If there is interest in legislating a national climate mitigation strategy, Congress may assess a range of potential concerns and how particular policies could be designed to address them. Members frequently raise questions about the potential costs of policies and alternative policy designs. Congress may also consider options that help alleviate some of the expected negative consequences from certain emissions mitigation policies. These consequences may include economy-wide impacts, disproportionate costs to lower-income households, and job losses in certain industries, among others. When examining these concerns, policymakers may wish to evaluate the tradeoff between the estimated consequences from mitigation policies and the benefits of reducing emissions and avoiding climate change, among other considerations.

Many actions to reduce GHG emissions may bring co-benefits—positive effects beyond the intended GHG reduction benefits. An example is reduced health care costs and mortality associated with improvements in air quality (e.g., from reductions in non-GHG emissions). Factors relevant to the extent of co-benefits include policy design and depth of GHG reductions.

Congress, in its oversight role, may also consider the feasibility, challenges, and economic impacts associated with the Biden Administration's GHG targets. Some recent studies have examined pathways that rely partly on federal policies to reduce domestic GHG or CO₂ emissions in the next decade.¹⁶⁶ While a synthesis of these studies is beyond the scope of this report, such studies highlight issues for congressional consideration, including options and incentives to accelerate development and deployment of decarbonization technologies and regulations for sector-specific or economy-wide emissions targets, should that be a goal. In particular, studies indicate that achieving these emission reduction targets would generally rely on, among other things, increasing use of renewable energy and decreasing use of unabated coal for power generation (i.e., coal-fired generation that does not use carbon capture and sequestration), electrification of end-uses (i.e., replacing technologies that rely on fossil fuel combustion with electrical ones), energy efficiency improvements, reductions in methane leaks in the oil and gas sector, and maintenance of the carbon sink in natural and working lands.¹⁶⁷

A question policymakers may consider is whether economy-wide or sectoral targets—such as decarbonization of the electricity sector—could be achieved under existing federal authorities as well as through state and local climate change actions. Examples of existing authorities include Clean Air Act regulations, energy efficiency standards, and renewable portfolio standards. Among other considerations, it is unclear whether one of these existing authorities—the Clean Air Act—is well-suited to the Administration's climate change goals or whether it could achieve the more ambitious targets supported by some Members and stakeholders. Members supporting decarbonization might consider legislative options, should existing authorities appear inadequate to achieve emission reduction objectives. As discussed in "Legislative Proposals in the 117th Congress," Congress continues to deliberate new authorities and spending to set and achieve specific GHG reductions, provide tax and other financial incentives to businesses and consumers, and set regulatory performance standards (including clean energy standards), among other policy options.

Climate Change Funding

Congress may consider how federal funding, including appropriations, might influence the Administration's climate change actions. Congress is currently deliberating FY2022 appropriations and budget reconciliation options. As discussed in this report, President Biden directed agencies to prioritize action on climate change through the budget process, among other things, and his Administration's FY2022 budget request included specific proposals aimed at reducing GHG emissions. The Administration's American Jobs Plan appeared to anticipate that hundreds of billions of dollars in new federal funding and tax incentives would stimulate technological advancements and enhance competitiveness of low- or no-GHG emitting technologies, and hence facilitate a long-term transition to a substantially modified and net-zero-emissions economy. Senate Majority Leader Schumer released a letter to colleagues with preliminary estimates of reductions from proposed provisions in the Infrastructure Investment and Jobs Act and budget reconciliation.¹⁶⁸ While the bills have not been enacted as of September 2021, he reported that, with

the combined impact of both the Infrastructure Investment and Jobs Act and the Budget Resolution's instructions, we are on track to reduce U.S. emissions to approximately 45 percent beneath 2005 levels by 2030. When you add Administrative actions being planned by the Biden Administration and many states - like New York, California, and Hawaii - we will hit our 50 percent target by 2030.

The federal government has long supported research and development efforts beyond those the private sector pursues, with investments in, among other areas, science, technology development, and economic research. Federal research funding could help shape the direction and pace of technological developments that many expect could achieve significant reductions in emissions, or could lower costs, compared with current commercial technologies. Some advocate that further innovation would be useful, and in some instances required, to abate emissions from the industrial sector.¹⁶⁹ Congress may look to provide funding for alternative technologies, whether through research and development, or infrastructure planning. Congress may also consider options to incentivize consumer purchases, either through tax incentives, mandates, or government procurement policies.

Members of Congress have expressed differing viewpoints concerning the scope of IIJA and the Build Back Better Act and each proposal's spending priorities.¹⁷⁰ Some Members of Congress have called for greater spending on climate change and social programs, such as education and health care. Other Members of Congress have raised concerns that total proposed spending levels are too high and that these legislative proposals invest in climate change and social programs at the expense of programs, such as roads and bridges, they regard as higher priorities.

Finally, Congress appropriates funds for the State Department's and Department of the Treasury's contributions to foreign assistance. Further, Congress has sole authority to lay tariffs and regulate foreign commerce—the most direct way being through Trade Promotion Authority. That is, it is the authority that Congress uses to establish trade-negotiating objectives. The most recent authority (P.L. 114-26) expired on July 1, 2021. Congress may consider whether any new authority should be written to include objectives on climate.

Appendix A. Climate Change Legislation in the 117^th Congress: Search Methodology

The "Legislative Proposals in the 117th Congress" section of this report identified bills by running a number of searches in Congress.gov, an authoritative and up-to-date resource for legislation, which is updated daily when Congress is in session. Initial searches were run in May 2021 and subsequent searches were run to update legislation until September 27, 2021. CRS compiled a list of search terms related to adaptation, greenhouse gas emissions (including sources of emissions by economic sector), climate change mitigation (including technologies), climate change impacts, climate change economics, climate change finance, and research and development. CRS also sought to include terms relevant to climate change policy at an international scale (such as potential U.S. participation in international agreements or bilateral or multilateral funding assistance). CRS grouped these terms within five broad categories: adaptation, energy, equity, finance, and land use. Each of the five searches was run in the full text of all legislation introduced in the 117^th Congress, and results were downloaded into Excel for analysis.¹⁷¹ Individual search results were tagged with the broad topic tag associated with the search from which they resulted (i.e., "adaptation" or "finance"). Duplicate bills (i.e., bills that were identified in more than one search) were assigned a broad topic tag for each search in which they were identified, and then all but one listing was removed from analysis. Amendments and resolutions were also removed from the spreadsheet. CRS identified a number of bills as not relevant—meaning these bills contained search terms but did not translate to relevant provisions—by reviewing titles, summaries (where available), and full text. CRS removed these bills from consideration. CRS also included all relevant related and companion bills (as identified in Congress.gov) in analysis. Additional searches were run using the "introducedDate:" function in Congress.gov to identify both newly introduced legislation as well as updated bill status and other metadata that may have changed since the prior search.

Bill Status Table

Table A-1 was created by using Congress.gov's "Status of Legislation" filter in each set of search results. Each set of results was limited to the following statuses: Became Public Law, Passed Both Chambers, Passed One Chamber, or Floor Consideration. Thirty-four of the more than 750 legislative proposals that CRS identified progressed beyond introduction in the legislative process, as of September 27, 2021, and are identified in Table A-1. Many of these bills fit into multiple broad topic categories. Also, some bills may contain relatively small provisions addressing climate change, while others are solely focused on that topic in one or more sectors. Twenty-seven of the 34 bills fell within the energy category, and 18 of the 34 fell within the adaptation category. Table A-1 reflects the September 27, 2021, search, the most recent search conducted for this report.

Search Limitations

These searches reflect the best available information from Congress.gov within the specified time frame, but there are some limitations. First, there are many ways to define, consider, and address climate change. Legislative proposals may specify climate change as an objective. Other proposals that may be considered directly or indirectly relevant to climate change may not expressly state climate change as an objective. Some bills may contain only small provisions that met search criteria, while others are solely focused on addressing climate change in one or more sectors. Stakeholders may also disagree about the extent to which proposals may be relevant to climate change. CRS designed broad searches in an effort to capture the many ways that Members of Congress and stakeholders have considered climate change. Given the broad scope and variability of the subject matter, these and any other searches for "climate change legislation" should be viewed as illustrative rather than a definitive record.

Second, the search results should be viewed as a snapshot in time. Bills typically change as they move through the legislative process, both in content and for procedural reasons. In some instances, the searches may not have captured all such revisions. As previously noted, the Congress.gov database is updated daily when Congress is in session, but the full text of different bill versions and additional metadata may be added over time, affecting search results.

Appendix B. Selected Additional Actions in the Executive Branch

The Biden Administration has begun implementing its whole-of-government approach to addressing climate change. This appendix identifies examples of climate-related policy actions as summarized by the following White House statements, in alphabetical order, as of September 2021. The actions and proposals summarized in this section do not constitute a comprehensive list of efforts by the Biden Administration.

• American Jobs Plan. The Administration's American Jobs Plan proposed a total of $2 trillion in federal funding and outlined many incentives and investments in U.S. jobs, infrastructure, and market competitiveness. The plan targeted 40% of the benefits of climate and clean infrastructure investments to disadvantaged communities. The plan also proposed to invest in rural communities and communities affected by the market-based transition to clean energy, among other climate change initiatives.¹⁷² It called on Congress to fund $35 billion "to achieve technology breakthroughs that address the climate crisis and position America as the global leader in clean energy technology and clean energy jobs."¹⁷³ Congressional deliberations subsequently focused on a different but related infrastructure plan, known as the "Bipartisan Infrastructure Framework" (BIF), a $1.2 trillion plan that would authorize $579 billion in new spending on transportation infrastructure, power infrastructure, climate resiliency, and other initiatives.¹⁷⁴ A group of Senators reached agreement with President Biden on the BIF and drafted legislation. See "Legislative Proposals in the 117th Congress" for more information.
• Building Modernization Proposals. There are a number of proposals to fund building modernization. For example, CEQ, DOE, the General Services Administration (GSA), and EPA announced $30 million in new federal investments to modernize and upgrade the nation's residential and commercial buildings to be affordable, resilient, accessible, energy efficient, and electrified.¹⁷⁵ As another example, DOE requested an increase of $387 million for the Federal Energy Efficiency Fund to improve the climate resilience of federal buildings.¹⁷⁶
• Climate Innovation Working Group Formation. The Administration announced a Climate Innovation Working Group and discussed funding to support "transformational low-carbon energy technologies."¹⁷⁷
• Coal and Power Plant Community Economic Revitalization Plan. The Administration released a report that identifies communities affected by coal mine and power plant closures ("energy communities") that should be prioritized for federal investment, details existing resources for these communities, and provides recommendations for further actions.¹⁷⁸
• Electric Vehicle Charging Infrastructure Plan. The departments of Transportation and Energy, and the GSA, announced a suite of actions intended to accelerate the deployment of electric vehicles and charging stations.¹⁷⁹
• Financial Sector Oversight (Assessing Climate Risks and Disclosures). U.S. financial regulators and the Biden Administration have taken public steps toward focusing financial regulatory attention on assessing climate risks to the financial system, including whether, and how, current standards for disclosure of climate risks are being followed and how they might be updated. The Biden Administration is reportedly working on a government-wide strategy, under an upcoming executive order, to better assess climate-related risks for public and private financial assets.¹⁸⁰ Several key financial agencies have announced they are looking at updating existing climate-related risk guidance. Treasury Secretary Janet Yellen flagged climate change as "an existential threat" and the biggest emerging risk to the health of the U.S. financial system, at the first meeting of the Financial Stability Oversight Council (FSOC), established after the 2008 financial crisis so the heads of financial agencies could coordinate regarding emerging risks.¹⁸¹ She reiterated in a July 11, 2021, speech that the FSOC would assess the potential risk climate change may pose to the financial stability of the United States, and would complement the SEC's work on improved financial disclosures of climate-related risks.¹⁸²
• Financial Sector Oversight (Federal Reserve). On January 25, 2021, the Federal Reserve announced the creation of an internal Supervision Climate Committee (SCC) to "strengthen the Federal Reserve's capacity to identify and assess financial risks from climate change" and to "develop an appropriate program to ensure the resilience of supervised firms to climate-related financial risks."¹⁸³ In March 2021, the Federal Reserve announced the creation of a Financial Stability Climate Committee (FSCC) to identify, assess, and address climate-related risks to financial stability from a macro-prudential perspective.¹⁸⁴ On July 11, 2021, Fed Vice Chair for Supervision Randall Quarles flagged the Financial Stability Board's (FSB's) publication of a roadmap for addressing climate-related financial risks.¹⁸⁵ The FSB roadmap is aimed at supporting international coordination of climate disclosures for standard-setting bodies internationally,¹⁸⁶ although Quarles did not specifically address any additional steps by the United States or the Federal Reserve. On December 15, 2020, the Federal Reserve Board joined the Network of Central Banks and Supervisors for Greening the Financial System (NGFS), a group of central banks and supervisory authorities from around the world developing best practices on climate risk management for the financial sector.¹⁸⁷
• Financial Sector Oversight (Securities Disclosures). On July 28, 2021, Securities and Exchange Commission (SEC) Chair Gary Gensler said he had requested that the SEC's staff develop a mandatory climate risk disclosure rule proposal for the commission's consideration by the end of 2021.¹⁸⁸ He noted that such mandatory disclosures should be "consistent and comparable," enabling investors to compare both qualitative and quantitative metrics across companies.¹⁸⁹ He suggested quantitative disclosures could include metrics related to greenhouse gas emissions, financial impacts of climate change, and progress toward climate-related goals.¹⁹⁰ In February 2021, the former Acting Chair of the SEC, Allison Herren Lee, directed the SEC's Division of Corporation Finance to enhance its focus on climate-related disclosure in public company filings.¹⁹¹ She noted that the SEC would assess compliance related to disclosure of climate change risks under the SEC's existing 2010 guidance, and would start updating that 2010 SEC guidance.¹⁹² The SEC also announced in March 2021 the creation of a "Climate and ESG [Environmental, Social and Governance] Task Force" within the SEC's Division of Enforcement to identify ways to proactively identify ESG-related misconduct.¹⁹³
• International Climate Finance Plan. U.S. agencies that work with development partners (e.g., the departments of State and the Treasury, U.S. Agency for International Development, the Millennium Challenge Corporation) announced a plan containing directives to (1) mobilize financial resources, both public and private, to assist developing countries to reduce and/or avoid greenhouse gas emissions and build resilience and adapt to the impacts of climate change; (2) scale back public investments in carbon-intensive fossil-fuel-based energy; (3) make international capital flows consistent with low-emissions, climate-resilient pathways; and (4) better define, measure, and report U.S. international climate finance. The plan states an intention to double, by 2024, the U.S. annual public climate finance to developing countries, including tripling its annual adaptation finance, "relative to the average level during the second half of the Obama Administration."¹⁹⁴ According to the U.S. Government Accountability Office, the average annual funding for climate change international assistance over the period 2013-2016 was $1.177 billion.¹⁹⁵
• Offshore Wind Energy Plan. The U.S. departments of the Interior, Energy, Commerce, and Transportation announced new leasing, funding, and development goals to accelerate and deploy offshore wind energy.¹⁹⁶
• Paris Agreement Accession. The Administration accepted on behalf of the United States the Paris Agreement, the second major subsidiary agreement for international cooperation under the United Nations Framework Convention on Climate Change.¹⁹⁷
• President Biden's Leaders Summit on Climate. The Administration convened a summit with "heads of state and government, as well as leaders and representatives from international organizations, businesses, subnational governments, and indigenous communities" to discuss international climate ambition, among other things.¹⁹⁸
• Resilience Funding. The Federal Emergency Management Agency (FEMA) announced three pre-disaster funding opportunities intended to help states and communities increase their preparedness in advance of climate-related extreme weather events and other disasters, and improve their ability to recover after these events. The FEMA initiatives include (1) $1 billion in funding for its Building Resilient Infrastructure and Communities (BRIC) program for FY2021; (2) $3.46 billion in funding for its Hazard Mitigation Grant Program (HMGP); and (3) $160 million in funding for its Flood Mitigation Assistance (FMA) grant program for FY2021.¹⁹⁹
• U.S.-Germany Climate and Energy Partnership. President Biden and German Chancellor Angela Merkel jointly launched the U.S.-Germany Climate and Energy Partnership.²⁰⁰