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Connecticut's Greenhouse Gas Inventory: Lower Emissions or Magical Accounting?

Samantha Dynowski

May 2023

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Photo: Millstone Nuclear Power Plant

Photo credit: JJBers

The short answer: magical accounting.

On April 20, the Connecticut Department of Energy and Environmental Protection (DEEP) released its latest greenhouse gas inventory report, an accounting of greenhouse gas emissions in our state. The report asserts that Connecticut met the 2020 emission reduction target of 10% below 1990 levels, with a calculated reduction of 13.9%. 

Sounds good, until you look closer. Questions surround the new methodology and DEEP’s failure to hold itself accountable for dirty electricity generation that harms the climate, the air we breathe, and the health of communities in the shadow of these damaging power plants.

The first issue with DEEP’s rosy picture of our progress towards meeting Connecticut’s emission reduction targets is the omission of electricity generated in our state for export, and reporting “biogenic” electricity, i.e. wood and other biomass burning, as carbon neutral. Sierra Club opposed both of these changes to the methodology when they were proposed by the agency in 2021. 

By removing electricity generated in our state, but consumed elsewhere, the inventory does not count these emissions towards our greenhouse gas calculations. Yet, they are producing greenhouse gas emissions, as well as other pollutants. DEEP must not absolve itself from the harm that these dirty power plants do to our health and our climate. We have become the hub of dirty energy in the region. We consume only 73% of the energy produced here, the rest is exported to other states. There are 54 large fossil fuel power plants in Connecticut—more than 40 have been constructed here since 1998. DEEP and legislators must enact policies that reduce emissions from electricity generation in our state in addition to electricity consumed in our state. We cannot depend on other states that are consuming this energy to do it for us.

DEEP has decided to treat emissions from electricity generated by all biogenic energy, biomass and fuel cells as carbon neutral.  Fuel cells burn fossil gas and biomass is not carbon neutral on any relevant time scale and has very high combustion emissions of carbon dioxide. Other pollutants such as SOx, N2O, PM are also emitted. According to the IPCC, it is inaccurate to “automatically consider or assume biomass used for energy [is] ‘carbon neutral,’ even in cases where the biomass is thought to be produced sustainably. DEEP must not pretend that these emissions don’t exist just because they changed their methodology.














Second, how DEEP calculates environmental attributes from the Millstone nuclear power plant may be artificially inflating the reduction in greenhouse gas emissions. Other states can purchase Millstone environmental attributes. If the agency applies more credit that Connecticut should be taking for this plant, the numbers will not be accurate. 


Finally, DEEP’s comparison of the 2021 numbers with unamended reports from previous years is apples to oranges. Comparing the numbers calculated using this brand new methodology with emission figures calculated using the previous methodology does not provide an accurate picture of how we are doing.


In sum, DEEP’s greenhouse gas inventory is concerning, both the new methodology and the reality that our state is not on track to meet the challenge of climate change. Connecticut doesn’t want magical accounting to make us believe we have reached our greenhouse gas reduction targets, we want honest numbers and real greenhouse gas emission reductions.

Samantha Dynowski is State Director of Sierra Club Connecticut.

Photo: Wood biomass

Photo credit: ybernardi

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