The US Environmental Protection Agency (EPA) released its 28^th annual Inventory of US Greenhouse Gas Emissions and Sinks (GHG Inventory), which presents a national-level overview of annual greenhouse gas emissions from 1990 to 2019. Key findings from the 1990-2019 US Inventory include:

1. In 2019, US greenhouse gas emissions totaled 6,558 million metric tons of carbon dioxide equivalents, or 5,769 million metric tons of carbon dioxide equivalents after accounting for sequestration from the land sector.

2. Total GHG emissions decreased from 2018 to 2019 by 1.7% (after accounting for sequestration from the land sector). This decrease was driven largely by a decrease in emissions from fossil fuel combustion resulting from a decrease in total energy use in 2019 compared to 2018 and a continued shift from coal to natural gas and renewables in the electric power sector.

3. CO₂ emissions decreased 2.2% from 2018 to 2019, and CO₂ emissions just from fossil fuel combustion decreased 2.7% from 2018 to 2019.

4. Greenhouse gas emissions in 2019 (after accounting for sequestration from the land sector) were 13% below 2005 levels. Total GHG emissions in 2019 were up 1.8% from 1990 levels, with CO₂ emissions up 2.8% and CO₂ emissions from fossil fuel combustion up 2.6% over the same period.

Source: EPA

Transportation. Transportation activities are the largest source of emissions, accounting for 29% of total US greenhouse gas emissions in 2019. From 1990 to 2019, transportation CO₂ emissions from fossil fuel combustion rose by 24% due in large part to increased demand for travel.

The number of vehicle miles traveled (VMT) by light-duty vehicles (i.e., passenger cars and light-duty trucks) increased by 48% from 1990 to 2019; VMT by medium- and heavy-duty trucks increased 109% over the same period. While an increased demand for travel has led to increasing CO₂ emissions since 1990, improvements in average new vehicle fuel economy since 2005 has slowed the rate of increase of CO₂ emissions.

In 2019, light-duty vehicles represented 58% of CO₂ emissions from transportation fossil fuel combustion and medium- and heavy-duty trucks and buses represented 25%.

Petroleum-based products supplied 95% of the energy used for transportation, with 60% from gasoline consumption in automobiles and other highway vehicles. Diesel fuel for freight trucks and jet fuel for aircraft accounted for 25% and 10% of fuel consumption, respectively. The remaining 5% of petroleum-based energy used for transportation was supplied by natural gas, residual fuel, aviation gasoline, and liquefied petroleum gases.

Source; EPA

Preliminary outlook for 2020. Prior to the COVID-19 pandemic, 2020 fossil fuel combustion emissions were projected to decrease by about 2% compared to 2019 (EIA 2020). However, the pandemic reduced economic activity and caused changes in energy demand and supply across all energy end-use sectors.

Preliminary 2020 data suggests that from 2019 to 2020, total energy use decreased by nearly 8% and fossil fuel combustion CO₂ emissions decreased by roughly 11%. The transportation sector saw some of the biggest reductions where gasoline use decreased by 13% and jet fuel use decreased by 38%.

Overall US electricity use decreased by 4% and the trend of decreased coal use and increased use of natural gas and renewables continued. Reduced economic and manufacturing activity resulted in lower energy use in the commercial and industrial sectors and there was a mixed impact on energy use in the residential sector due to stay-at-home orders increasing energy use combined with warmer temperatures leading to lower energy demand.

The GHG Inventory covers seven key greenhouse gases: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride. In addition to tracking US greenhouse gas emissions, the inventory also calculates carbon dioxide that is removed from the atmosphere through the uptake of carbon in forests and other vegetation.

This impartial, policy-neutral report, has been compiled annually since 1993 and submitted to the United Nations Framework Convention on Climate Change. The report is prepared by EPA in collaboration with numerous experts from other federal agencies, state government authorities, research and academic institutions, and industry associations. Under the United Nations Framework Convention on Climate Change (UNFCCC), national inventories for UNFCCC Annex I parties should be provided to the UNFCCC Secretariat each year by April 15.