Congress has debated climate change for nearly 30 years with varying results. Laws and congressionally approved funding have led to new programs to reduce emissions and incentives to speed the deployment of clean energy. Other efforts to address climate change more holistically, including by using market-based approaches, have not advanced.

Some major milestones on climate in Congress include:

1992: Senate approves U.N. Framework Convention on Climate Change. The process of designing a global agreement to tackle climate change began in the early 1990s. In 1992, President George H.W. Bush signed the United Nations Framework Convention on Climate Change (UNFCCC), which committed all nations to take action and laid the foundation for future agreements. At the time, President Bush declared, “The United States fully intends to be the world’s pre-eminent leader in protecting the global environment.” The U.S. Senate ratified the treaty in October 1992.

1992: Renewable energy gets a boost. To help support the fledgling wind industry, Sen. Chuck Grassley (R-IA) added the renewable energy production tax credit to the 1992 Energy Policy Act, which has been critical in the rapid expansion of the wind energy industry. The tax credit has been extended in short stints – with occasional lapses – since then. An investment tax credit for solar energy installations was later added to the tax code through the Energy Policy Act of 2005.

1997: Senate pre-empts Kyoto Protocol. In June 1997, six months ahead of a U.N. climate conference in Kyoto, Japan, the Senate adopted a nonbinding resolution introduced by Sen. Robert C. Byrd (D-W.Va.), with Sen. Chuck Hagel (R-Neb.) and 44 other cosponsors, stating that the United States should not enter into any international climate agreement that did not include comparable emissions commitments by developing countries or that “would result in serious harm to the economy of the United States…” The Clinton Administration proceeded to negotiate and sign the Kyoto Protocol, which set emission targets for developed countries only. But the agreement was never submitted to the Senate for advice and consent, and in 2001, President George W. Bush declared that the United States would not join it.

2003-2007: Bipartisan bills in the Senate. By the 108th Congress (2003–2004) significant bipartisan efforts to reduce U.S. greenhouse gas emissions started to gain traction. Among other bills in 2003, Sen. John McCain (R-Ariz.) and Sen. Joe Lieberman (D-Conn.) offered The Climate Stewardship Act of 2003 to institute a cap-and-trade program to reduce emissions from electricity, manufacturing, commercial, and transportation sectors of the economy (representing 85 percent of U.S. emissions). The bill had a House companion and was reintroduced in the 109th and 110th Congresses.

2007: Congress mandates emissions reporting. As part of the Fiscal Year 2008 Consolidated Appropriations Act, signed into law in 2007, the U.S. Environmental Protection Agency (EPA) was ordered to publish a rule requiring public reporting of greenhouse gas emissions from large sources. The Greenhouse Gas Reporting Program database provides comprehensive nationwide greenhouse gas emissions data (electric power companies were already reporting their carbon dioxide emissions under the Clean Air Act Amendments of 1990). Over 40 source categories are now covered by the reporting program.

2008–2010: Cap-and-trade legislation passes the House. Shortly after being elected, President-elect Barack Obama declared a comprehensive climate and energy bill among his top legislative priorities. The U.S. House of Representatives passed the American Clean Energy and Security Act of 2009 by a vote of 219 to 212 in June 2009. The legislation, written by Reps. Henry Waxman (D-Calif.) and Edward Markey (D-Mass.), would have established an economy-wide greenhouse gas cap-and-trade system and critical complementary measures.

Other major climate legislation was proposed during this period:

• The American Clean Energy Leadership Act of 2009 would have established a renewable energy standard and addressed several other energy-related issues.
• John Kerry (D-Mass.), Joseph Lieberman (I-Conn.), and Lindsey Graham (R-S.C.) worked outside of the committee process in an attempt to broaden the base of support for climate legislation within the Senate. Kerry and Lieberman released a draft discussion of their American Power Act in May 2010 that would have established a cap-and-trade system for utilities and industry, and a fee for transportation fuels.
• Maria Cantwell (D-Wash.) and Susan Collins (R-Maine) introduced a Carbon Limits and Energy for America’s Renewal Act, which would have capped carbon dioxide emissions while allowing very limited emissions trading, and rebating the revenue from this system directly back to the public on a per-capita basis.
• Richard Lugar (R-Ind.) and Lisa Murkowski (R-AK) introduced the Practical Energy and Climate Plan, intended to reduce oil imports, improve and create new efficiency standards, and establish a clean energy standard.

Senate Majority Leader Harry Reid (D-Nev.) was expected to combine elements of the climate and energy legislative proposals into a comprehensive climate bill. Citing a lack of bipartisan support in the Senate, however, Reid announced in July 2010 that upcoming energy legislation would not include a cap on greenhouse emissions. This effectively ended action on climate legislation for the 111th Congress.

2012: Shoring up flood protection. Funding the National Flood Insurance Program, established in 1968, is important for the many communities likely to face increased flooding from sea level-rise and more frequent and extreme downpours. In May 2012, Congress passed the National Flood Insurance Program Extension Act reauthorizing the program for five years, ending a series of short-term extensions. The bill was a major step toward actuarial pricing and full accounting of climate risk, ensuring that climate impact projections are factored into future calculations of flood risk. Although the word “climate” does not appear in the text, the bill directed the Federal Emergency Management Agency to use “the best available science regarding future changes in sea levels, precipitation, and intensity of hurricanes” — likely projected impacts of climate change — as it updates flood maps and sets insurance premiums.

2012: Clean Energy Standard. Following the failure of Congress to act on climate, Sen. Jeff Bingaman (D-N.M.) introduced the Clean Energy Standard Act to enact a tradeable energy standard to reduce emissions in the power sector.

2015: Extension/phasedown of renewable energy tax credits. After more than 20 years of regular extensions of the production tax credit for wind power and investment tax credit for solar power, Congress agreed in late 2015 on a multi-year extension and ultimate phase-out of the incentives. The tax credits have been critical in making renewable energy cost-competitive and continue to help reduce carbon emissions from power sector in the absence of federal regulations.

2016: Formation of the Climate Solutions Caucus. In February 2016, Reps. Carlos Curbelo (R-Fla.) and Ted Deutch (D-Fla.) launched the bipartisan Climate Solutions Caucus in the House of Representatives. The caucus describes its mission as educating members on “economically-viable options to reduce climate risk and protect our nation’s economy, security, infrastructure, agriculture, water supply and public safety.” The caucus has been adding dozens of members in Republican-Democratic pairs.

2018: Tax credits and carbon pricing. In February 2018, Congress enacted a two-year budget deal that extended and expanded key financial incentives for investments in several advanced low-carbon technologies. The budget deal included a bipartisan proposal to reform and extend the Section 45Q tax credit to boost carbon capture. In addition, the first Republican-led carbon pricing proposal and bipartisan carbon pricing proposals in nearly eight years were introduced.

2019: Renewed interest in climate change. Climate change has become a priority since Democrats regained control of the House of Representatives. While most activities have been led by democrats, republicans have become more responsive to climate issues and some bipartisan efforts have emerged. Some significant developments include:

• The introduction of a Green New Deal resolution in the House and the Senate.
• The formation of a Select Committee on the Climate Crisis in the House, which released a majority staff report containing policy recommendations to address climate change.
• The formation of a bipartisan Climate Solutions Caucus in the Senate.
• The continued introduction of market-based climate measures (e.g., carbon taxes and clean energy standards).

2020: Major energy legislation. In December 2020, Congress passed an omnibus package which includes the first major energy policy since 2007. The bipartisan bill includes research and development and deployment for clean energy technologies, clean energy tax incentives, and directs EPA to phase down the production and consumption of hydrofluorocarbons (HFCs) over a 15-year period.