Greenhouse Gas Emissions Inventory
A state-wide inventory of the greenhouse gas emissions occurring from all sectors in New Hampshire.
NHDES conducts an annual greenhouse gas (GHG) emissions inventory that tracks the six main GHGs listed below. The inventory relies on data provided by the U.S. Department of Energy and the U.S. Environmental Protection Agency. Throughout the inventory, the individual gases are quantified using their Global Warming Potential (GWP), a measure of their relative warming potential compared to carbon dioxide (CO2). By tracking and reporting each gas in CO2-equivalents, the GHG inventory can provide a uniform measure of New Hampshire’s contribution to the global warming and climate change each year.
The six GHGs in state-wide inventory are listed below with their relative contribution to the state’s total GHG emissions in 2017.
- Carbon dioxide (CO2) (92%)
- Methane (CH4) (1%)
- Nitrous oxide (N2O) (4%)
- Industrial Process Gases (3%):
- Hydrofluorocarbons (HFCs)
- Perfluorocarbons (PFCs)
- Sulfur hexafluoride (SF6)
These gases are generated from a variety of activities that are commonly categorized into sectors. The sectors include, in order of their percent contribution to the state's total emissions in 2017:
- Transportation (47.4%)
- Residential (18.3%)
- Electric Generation (11.7%)
- Industry (9.8%)
- Commercial (8.7%)
- Agriculture (3.1%)
- Waste and Wastewater (1.1%)
CO2 emissions make up the vast majority of New Hampshire's greenhouse gas emissions (92%), most of which is generated by burning fossil fuels (such as oil, coal, gas) to produce heat and electricity, and to power motor vehicles. CO2 is emitted by all sectors of the state's economy. The remaining greenhouse gases are generated by the industrial, agriculture, forestry and waste sectors. The synthetic gases (such as HFCs, PFCs and SF6) are generated during industrial processes. Methane (CH4) is generated by the decomposition of organic wastes in landfills, during the wastewater treatment process, and from livestock. Nitrous oxide (N2O) is generated from the production and use of fertilizers and from transportation sources.
Overall, New Hampshire’s GHG emissions have fallen 5% below 1990 levels, the established baseline year in the inventory. This has been driven primarily by reductions in emissions from the electric sector.