Overview

The United States ranks as the world’s second-highest greenhouse gas emitter, with 38.45 billion tonnes CO2e since 2015, representing 12.64% of total global emissions. With 331 million people and the highest rate of vehicle ownership in the world, the country continues to have high per capita emissions — 18.7 tonnes in 2020, compared to the global average of 6.4 tonnes.

Although China has overtaken the United States as the top emitter in recent years, the U.S. is responsible for the largest share of historical emissions (around 25% of all GHGs emitted since 1751). John Kerry, the Special Presidential Envoy for Climate (then Secretary of State) has acknowledged this historical responsibility of the country.

President Joe Biden also announced an enhanced GHG reduction target of 50–52% across all sectors by 2030 from 2005 levels. Both the official and Climate TRACE data show that this would require a significant ramping up of decarbonization efforts.

President Biden has proposed to achieve the goal by reaching 100% carbon pollution-free electricity by 2035, and reducing tailpipe emissions by boosting the transition to electric vehicles (EVs). Other areas of focus will be using agriculture and other lands as carbon sinks. Climate Action Tracker rates the country’s overall mitigation approach as ‘insufficient’.

By the Numbers

United States GHG emissions decreased by 5.4% during the period 2015–2020, excluding the land use sectors. However, a significant drop in emissions in 2020 is likely due to the COVID-19 pandemic-related lockdowns that reduced activities in multiple sectors. Emissions reductions from 2015 to 2019 were negligible. Fossil fuel-based sectors (energy, manufacturing, buildings, and transport) accounted for over 90% of emissions in 2020, excluding land use change.

How It Compares

The latest available official inventory for the United States from 2019 as submitted to the UNFCCC estimates total emissions to be 6.56 billion tonnes CO2e, excluding land use change. Climate TRACE’s estimates are in broad agreement with this estimate. However, there are some significant differences in the details:

• In some sectors, the UNFCCC inventory and the Climate TRACE inventories are measuring different things, as the U.S. also reports GHGs other than carbon dioxide, methane, and nitrous oxide.
• Transport data from Climate TRACE also includes international aviation and transport.
• There are differences at the sectoral level, which is particularly stark for manufacturing, where UNFCCC inventory estimates are approximately 40% higher. This may be due to how the sub-sectors are categorized.
• For some of the agriculture sub-sectors, Climate TRACE currently uses FAOSTAT and EDGAR data.

Data Highlights

ENERGY & POWER

Power sector emissions have decreased by 18% during the period 2015–2020. This is an ongoing trend — not related to COVID impacts alone — due to the dual influence of coal-fired power plant retirements and a rapid increase in renewable energy.

By contrast, Climate TRACE data for the oil and gas industry in the U.S. shows that the sector’s GHG emissions are both rising and higher than previously reported. Comparing 2015 through 2020 shows a 14% emissions increase; comparing through pre-pandemic 2019 numbers shows a 30% increase.

FOREST FIRES

Climate TRACE data found a 130% increase in gross forest fire emissions. By contrast, #1 emitter from land use change — Brazil — saw forest fire emissions only increase by just shy of 40% (though it should be noted that Brazil also saw a significant increase in emissions from forest clearing). In recent years due to the impacts of climate change, wildfires now pose a devastating risk to forests and the country’s GHG bottomline. In fact, they may be trapping the country into a feed-forward loop, as climate change increases the risk of wildfires, which then emit more GHGs.

OTHER SECTOR HIGHLIGHTS

• The United States remains the #1 emitter of GHGs from aviation, accounting for 22% of global emissions from the sector. Even though the sector was affected by COVID-19 related lockdowns and caused a 44% reduction in emissions compared to the previous year, the country’s share in the sector remains the same.
• Global shipping emissions are difficult to attribute to specific countries due to the registration of individual vessels to flag states. Due to regulatory advantages, a significant percentage of vessels are registered with the countries of Panama, Liberia, and the Marshall Islands and this can mask the actual emitter. When attributing emissions by which country the shipping company is registered in, the United States emerges as one of the top 5 emitters globally for recent years (2018–2020).

Explore the data for yourself by visiting the Climate TRACE emissions inventory.