Since the mid-2000s, states have worked to fill the void of federal leadership on climate. Most states, though, are responsible for only a tiny share of global emissions. To expand their environmental influence, and to increase the size of the markets for clean energy they seek to create, states have worked together. This has spawned a variety of multi-state initiatives on climate. This is a brief overview of the main initiatives—their objectives, their members, and their status to date.

Regional Greenhouse Gas Initiative (RGGI)

The Regional Greenhouse Gas Initiative (RGGI) is the first U.S. cap-and-trade program to reduce carbon dioxide (CO2) emissions from the power sector. Currently, the program includes Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, and Vermont. Since 2009, RGGI has set a cap on CO₂ emissions from power plants throughout the region. To comply, regulated entities trade emission allowances. The program is administered through the non-profit RGGI, Inc., but individual state governments have enforcement authority. Following a comprehensive program review in 2012 and 2013, RGGI adjusted the program cap to achieve an annual 2.5 percent emissions reduction each year between 2014 and 2020 from estimated 2012 levels. After another program review, members agreed in August 2017 to reduce the cap an additional 30 percent between 2020 and 2030.

Western Climate Initiative (WCI)

The Western Climate Initiative (WCI) was initially formed as a collaboration of jurisdictions working together to identify, evaluate, and implement emissions-trading programs at a sub-national level. In November 2011, WCI transitioned into WCI, Inc., a nonprofit corporation that provides administrative and technical assistance to support the implementation of state and provincial greenhouse gas emission trading programs. Each participating jurisdiction sets its own individual program rules and maintains enforcement authority.

The State of California and the Province of Quebec are current participating jurisdictions. Both of them have implemented a cap-and-trade program with compatible (though not identical) program design elements and have committed to forming a single carbon market for all covered sources in their jurisdictions.

U.S. Climate Alliance

The U.S. Climate Alliance was formed by the governors of California, New York, and Washington in 2017, shortly after President Trump announced his intention to withdraw the United States from the Paris Agreement. Membership now includes 25 states and Puerto Rico. Member states have committed to reducing greenhouse gases consistent with the goals of the Paris Agreement.

Governors Accord for a New Energy Future

This accord was signed in February 2016 by a group of 17 governors representing all regions of the country. Signatories are California, Connecticut, Delaware, Hawaii, Iowa, Massachusetts, Michigan, Minnesota, Nevada, New Hampshire, New York, Oregon, Pennsylvania, Rhode Island, Vermont, Virginia, and Washington. The group is committed to promoting and deploying clean energy, including energy efficiency, renewable energy and alternative-fuel vehicles.

Pacific Coast Collaborative

Established in 2008, the Pacific Coast Collaborative (PCC) is a cooperative agreement among the leaders of Alaska, British Columbia, California, Oregon, and Washington to leverage clean energy innovation and low-carbon development to reduce the effects of climate change on the regional economy. Participating jurisdictions coordinate, propose, and adopt policy aimed at generating investments in renewable energy, climate resilience, low-carbon transportation infrastructure, and environmental conservation. The PCC promotes coordination of state-level climate policies to achieve the broader goals reflected in PCC agreements.

The PCC has announced a series of joint efforts on infrastructure, energy and climate policy, transportation, and environmental protection. All these joint efforts allow the jurisdictions to coordinate planning and expand their purchasing power in the market for clean energy solutions.

Transportation and Climate Initiative

Transportation currently accounts for roughly 40 percent of greenhouse gas emissions in the U.S. Mid-Atlantic and Northeast. To promote investment in solutions to reduce transportation emissions, 12 jurisdictions came together in 2010 to launch the Transportation Climate Initiative (TCI). The TCI aims to expand safe and reliable transportation options, attract federal investment, lower transportation costs, improve overall air quality and public health, and mitigate the transportation sector’s impact on climate change. The TCI consists of Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and the District of Columbia. In December 2019, TCI states released a draft memorandum of understanding (MOU). The states are now finalizing the MOU during 2020 with the goal of starting implementation in 2022.