Greenhouse Gas Emissions Inventory

A greenhouse gas (GHG) emissions inventory is a historical accounting of the quantity of greenhouse gases emitted to, or removed from, the atmosphere over a specific period (e.g., one year) from all sectors of the economy.

The 2021 Act on Climate was signed into law by Governor Dan McKee, which requires mandatory, enforceable, GHG emission reduction mandates in 2020, 2030, 2040, and 2050. The Rhode Island GHG emissions inventory is the primary scientific tool for assessing progress towards the reduction mandates.

Rhode Island’s GHG emissions inventory is updated annually based on available data from federal, state, and local partners. Data limitations from the federal government cause a three-year delay between the current calendar year and the inventory year. DEM is working to shorten this delay to provide the most up-to-date information for policymakers, stakeholders, and the public.

Rhode Island’s GHG emissions inventory details economy-wide emissions and sinks back to 1990, which is considered the “baseline” year for measuring progress towards the 2021 Act on Climate's emission reduction mandates.

The primary GHGs carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) are included. Fluorinated gases, including hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF₆), and nitrogen trifluoride (NF₃) are also covered. GHG emissions and sinks are reported in million metric tons carbon dioxide equivalent (MMTCO₂e) based on their global warming potential.

DEM uses the Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report (AR5) 100-year global warming potentials (GWPs) to report emissions of different GHGs on the same scale. Learn more about GWPs.

Rhode Island’s GHG emissions inventory generally follows the economic sector reporting guidelines used by the U.S. Environmental Protection Agency (EPA). Many other states also follow this approach, which allows for an apples-to-apples comparison across state lines.

• Transportation (aviation, highway vehicles, and non-road sources)
• Electricity Consumption
• Residential Heating
• Industry (industrial heating and industrial processes)
• Commercial Heating
• Natural Gas Distribution
• Waste (municipal solid waste and wastewater) 
• Agriculture
• Land Use, Land Use Change, and Forestry (forest land, croplands, grasslands, wetlands, and settlements)

DEM obtains robust, state-level data for use in the GHG emissions inventory from a range of sources. The EPA’s State Inventory Tool (SIT) contains the latest state-level fuel consumption data from the Energy Information Administration’s State Energy Data System (SEDS). Data from the New England Power Pool Generation Information System (NEPOOL-GIS) and ISO New England (ISO-NE) are used to estimate emissions from electricity consumption. DEM also obtains local data from intra-departmental sources including the Division of Agriculture & Forest Environment and the Office of Water Resources.

Gross emissions are the sum of all GHG emitting sectors (those sectors with positive emissions). Net emissions include the gross emissions plus Rhode Island's carbon sink, the Land Use, Land Use Change, and Forestry (LULUCF) sector. Learn more about how net-zero emissions are defined in the 2022 Rhode Island Climate Update.

The electricity consumption sector is the only sector to include imported emissions from outside of Rhode Island. To assess progress towards Rhode Island's 100% renewable energy standard (R.I. General Laws § 39-26-4), renewable energy certificates (RECs) are counted against Rhode Island’s share of the ISO-New England system residual mix. Click here to learn more about electricity generation vs. consumption accounting.

• Proposed Methodology Improvements for the 1990 Baseline
  • Public Listening Session Presentation
  • Public Listening Session Recording
• Updates to Electricity Sector GHG Accounting
• Accounting Carbon Sequestration from LULUCF
• Electricity Generation vs. Consumption Accounting
  • EC4 Endorsement of Electricity Consumption Accounting

• 2021 Act on Climate
• EPA Inventory of U.S. Greenhouse Gas Emissions and Sinks
• EPA Facility Level GHG Emissions Data (FLIGHT)
• Energy Information Administration (EIA) State Profile
• U.S. Climate Alliance