Per capita emissions have trended down from 2015 - 2020 due to emissions reductions gradually trending downward in several of the major sectors, including the Transportaiton/Mobile Sources sector, and the Residential/Commercial/Industrial Fuel Use (RCI) sector, but have been mainly driven by reductions in the electricity sector.  Year to year variability is common due to the multitude of factors that influence the calculations.  The 2020 value per capita value is significantly lower due to a reduction in Transportation/Mobile Sources sector emissions associated with the COVID-19 pandemic as well as a higher population estimate from the 2020 Census.  It is expected that emissions estimates in 2021 will increase in the transportation sector, but the extend to which that rebound will occur in the longer term is unclear.

With the establishment of the Global Warming Solutions Act (GWSA) and the subsequent deveopment and adoption of the Climate Action Plan (CAP) by the Vermont Climate Council, a number of greenhouse gas mitigation strategies are in the process of being prioritized and implemented.  Those strategies are intended to reduce overall greenhouse gas emissions in the coming years. 

The Global Warming Solutions Act established mandatory statewide greenhouse gas emissions levels as opposed to aspirational targets for 2025, 2030, and 2050.  The 2025 requirement is based on the Paris goals and is 26% below 2005 levels.  The 2030 and 2050 goals are 40% and 80% below the 1990 baseline respectively.

Population values for 2018 and 2019 are from the U.S. Census Bureau, Table 1. Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2019 (NST-EST2019-01) released in December 2019.  Population values for 2020 are from the U.S. Census Bureu, Annual Estimates of the Resident Population for the United States, Regions, States, District of Columbia, and Puerto Rico: April 1, 2020 to July 1, 2022 (NST-EST2022-POP) released in December 2022.  The greenhouse gas emissions values that inform the per capita values are taken from the latest VT GHG Emissions Update issued in April 2023.  The data are reported as annual values that were calculated as a part of the Vermont Greenhouse Gas Emissions Inventory and Forecast (1990 - 2020) report.  Greenhouse gas emissions calculations are generally based on some measure of activity data (e.g. fuel sales) coupled with process specific emissions factors, however the methodologies vary by inventory sector.  The several year lag in emissions estimates is due to several factors, the main one being the inherent lag time in large federal datasets utilized in a portion of the calculations.