​​​​Maryland is committed to finding real bipartisan, common sense solutions to protect our environment, combat climate change, and improve our air quality. By working together, we are showing that it is possible to find consensus to protect our natural resources, promote clean energy, and grow our economy for current and future generations.
Governor Larry Hogan

Regional Greenhouse Gas Initiative (RGGI) in Maryland

RGGI Updates

  • The RGGI states congratulate Virginia on finalizing its regulation to establish a market-based program to reduce greenhouse gas emissions. Maryland and the other RGGI states worked collaboratively with Virginia during its initial program design and have continued to follow developments in Virginia as it renewed its work towards participation in RGGI.  Accordingly, the RGGI states are pleased to welcome Virginia as a participant in our successful regional initiative starting January 1, 2021. Read the news release​.

  • The RGGI states find that New Jersey’s final rule is consistent with the RGGI Model Rule and with existing state regulations and that New Jersey’s starting CO2 allowance budget and emissions reduction trajectory demonstrates comparable stringency with the existing RGGI program. Accordingly, the RGGI states welcomed New Jersey as a participant in our successful regional initiative as of January 1, 2020.​

RGGI in Maryland


Science has demonstrated with a high degree of certainty that Earth's climate is being altered by human activities, principally by the emission of heat-trapping greenhouse gases (GHGs), such as carbon dioxide (CO2), into the atmosphere.1 According to the 2014 Report of the Intergovernmental Panel on Climate Change (IPCC), "effective adaptation and mitigation responses will depend on policies and measures across multiple scales: international, regional, national and sub-national".2

The actions Maryland takes to mitigate climate change at the state level are integral to protecting the future and prosperity of not only the state of Maryland but also the United States of America and the global community to which it belongs.

The RGGI Program is a central component of Maryland's GHG reduction strategy. As the first program of its kind in the United States, RGGI serves as a model and inspiration to other states and regions to either participate in RGGI or implement their own regional CO2 trading initiatives.

Program Overview

RGGI is a cooperative effort by ten northeast and mid-Atlantic states to reduce CO2 emissions generated by fossil fuel-fired power plants while benefiting the regional economy. Guiding the program are the shared commitments to reducing CO2 and allowing flexibility and autonomy among the states. Maryland has participated in RGGI since 2007. Other states currently participating are Connecticut, Delaware, Maine, Massachusetts, New Hampshire, New York, New Jersey, Rhode Island, and Vermont.

RGGI is structured as a "cap and invest" program, with a regional cap or limit on CO2 emissions that declines by a certain amount annually. The states establish individual emission budgets, which they distribute as "allowances" permitting the holder to emit one short ton (2,000 lbs.) of CO2 per allowance. The regional cap consists of the sum of the states' emission budgets. Each state participating in the regional initiative has developed its own program and regulations based on the blueprint provided by the RGGI Model Rule. States sell a majority of emission allowances at regional quarterly auctions, and auction proceeds fund various state and local programs which promote energy efficiency, renewable energy, bill assistance, or other consumer benefits.

Last year, the participating states reached consensus on a series of improvements to the program. The Model Rule contains four major improvements:

  1. Reduce the emissions cap by an additional 30% from 2020 to 2030;
  2. Add the innovative new Emissions Containment Reserve, which will reduce emissions, even more, when it is inexpensive to do so;
  3. Adjust for the allowance bank remaining at the end of 2020; and
  4. Improve and maintain the Cost Containment Reserve, which is an important element to manage compliance costs.

Upcoming stakeholder meetings dates are posted to the RGGI website.



1Maryland Commission on Climate Change Scientific and Technical Working Group, 2015. Appendix 1 of 2015 Maryland Commission on Climate Change Report. "Reducing Emissions of Greenhouse Gases Beyond 2020".
2Intergovernmental Panel on Climate Change, 2014. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.