Decreased fossil fuel use helped Maine meet its 2020 greenhouse gas reduction target, according to a state Department of Environmental Protection report released Thursday.

The department’s analysis of the most up-to-date federal GHG emissions data through 2019 showed that Maine’s GHG emissions were 25% below 1990 levels, surpassing a reduction target of 10% below 1990 levels by Jan. 1, 2020.

Total estimated annual GHG emissions in Maine peaked in 2002 compared to 1990 levels and declined to below 1990 levels by 2009, according to the department’s Ninth Biennial Report on Progress Toward GHG Reduction Goals. Emissions increased slightly from 2013 to 2015, then continued to drop through 2019.

“A reduction in residual fuel oil consumption, 97% since 1990, is a large driver of the overall decline in GHG emissions,” the report said.

Included in the report are the state’s first CO₂ budget data, including details on sequestration by forests, fields and wetlands.

“It is essential for the creation and evaluation of emission reduction programs to take into account this more comprehensive view of carbon released and captured within Maines borders,” DEP Commissioner Melanie Loyzim said in a statement.

The department’s analysis of total GHG emission sources and sinks showed the state is 75% of the way to achieving its 2045 carbon neutrality target.

“Maine’s significant forest cover — approximately 89% — results in the state having a large capacity to store carbon, and in recent past, a high accumulation rate of forest carbon via tree growth, offsetting a high percentage of anthropogenic emissions,” the report said.

Forest biomass and soils in the state are sequestering -26.2 million metric tons of CO₂ (MMTCO₂) per year, while wetlands and urban biomass are sequestering carbon at -0.2 and -0.4 MMTCO₂ per year, respectively.

Although the department said there are “many uncertainties” associated with the CO₂ accounting methodologies used for the budget, it expects to continue to improve the budget, update data through 2021 for the next report and further research opportunities.

Sector Insights

While Maine’s industrial sector emissions were higher than transportation emissions from 1990 to 2009, they have steadily decreased, leaving transportation as the highest emitting sector. In 2019, the report said, the transportation sector produced 49% of all CO₂ emissions from fossil fuel combustion in the state, up from 42% in 1990. The sector also was responsible for 31% of Maine’s gross GHG emissions.

By comparison, the state’s electric power sector generated 9% of Maine’s gross GHG emissions in 2019, down 41% from 1990 levels.

For 2019, the report said, natural gas was the top contributor, at 72%, to fossil fuel-based CO₂ emissions in the electric power sector. And renewable resources, including hydropower, wood, wind, waste, solar and geothermal, provided 84% of the energy consumed by electricity generating facilities in 2019, up from 37% in 1990.

Maine’s industrial sector is the biggest contributor to emissions from the combustion of wood, and it was followed by the electric sector until the residential sector surpassed it in 2019, according to the report. In 2019, electric sector wood emissions were 13% lower than in 1990, while residential wood emissions increased 50% for the same period.