Air Quality

Air Days               Air Pollutants

Climate Changers

 

 

 

Using the electric consumption model, it is estimated that total GHG emissions in 2022 (most recent data available) for all economic sectors increased by approximately seven percent from 2020 levels to 35 million metric tons of carbon dioxide equivalents (MMTCO2e*). However, this total was approximately 12 percent less than the previous ten-year average. The transportation sector is estimated to have accounted for the most GHG emissions in 2022 at approximately 43 percent, while the residential, commercial, and industrial sectors accounted for approximately 21 percent, 13 percent, and 11 percent, respectively. From 2020 to 2022, the largest increases in GHG emissions were seen in the industrial (24.6 percent), commercial (15 percent), and transportation (14 percent) sectors.

Using the electric generation model, it is estimated that total GHG emissions in 2022 (most recent data available) for all economic sectors increased by approximately nine percent from 2020 levels to 43.26 MMTCO2e. The transportation sector still accounted for the highest percentage of GHG emissions at 34 percent, but the percentage of emissions from the electric power sector ranked second at 25 percent.³ 

 

 

Per capita GHG emissions in 2022 (most recent data available) were estimated at 9.65 metric tons, using the electric consumption model. The goals on the chart have been adjusted to account for actual (2020) and projected (2030) population in Connecticut.

Goal: Prior to 2022, state law (Public Acts 08-98 and 18-82) set three goals for greenhouse gas emissions: reduce statewide emissions to 10 percent below 1990 levels by 2020, 45 percent below 2001 levels by 2030, and 80 percent below 2001 levels by 2050.  Public Act 22-5 established a new goal for the state to reduce GHG emissions to a level of zero percent from electricity supplied to electric customers in the state by 2040.

GHG emissions from Large Facilities:

In general, facilities that directly emit 25,000 metric tons of carbon dioxide equivalent (CO2e) or more per year are required to submit annual reports to EPA (“large facilities”). Facility-specific data from the EPA indicates that in 2023 (most recent data available), GHG emissions from 40 large reporting facilities in the state decreased by 1.4 percent from the previous year but was approximately 10.6 percent higher than the previous ten-year average. GHG emissions from 15 reporting facilities in the “power plant” sector decreased by approximately 0.3 percent from 2022 levels; however, emissions from these facilities were 17.2 percent higher than the previous ten-year average.⁴**

_{Technical Note: *Connecticut’s GHG emissions are now calculated by the Department of Energy and Environmental Protection (DEEP) using the consumption of electricity, not the generation of electricity in the state. Emissions are reported in terms of carbon dioxide equivalents (CO2e, i.e., CO2 and other gases with equivalent climate warming impact). While carbon dioxide is the primary GHG, emissions of other GHGs are expressed on the basis of their potential to contribute to global warming, relative to carbon dioxide’s potential. **The “power plant” sector made up approximately 83 percent of GHG emissions from large “reporting” facilities in Connecticut in 2023.} 

 

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³ _{DEEP, Bureau of Energy and Technology Policy, personal communication from M. Malmrose, March 28, 2024. 1990-2021 with a preliminary look at 2022 Connecticut Greenhouse Gas Emissions Inventory, April 2024; portal.ct.gov/-/media/deep/climatechange/1990-2021-ghg-inventory/deep_ghg_report_90-21_pre-22.pdf.}

⁴ _{EPA, Facility Level Information on Greenhouse Gases Tool, accessed October 30, 2024; ghgdata.epa.gov/ghgp/main.do. Includes power plants, petroleum and natural gas systems, chemicals, waste, metals, pulp and paper, and other emissions.}