Greenhouse Gas Emissions by Country 2025

A greenhouse gas (GHG) is a gas that traps heat in the atmosphere. Greenhouse gases are so named because they function similarly to the glass in a greenhouse. They pose no hindrance to sunlight which passes straight through and generates heat when it reaches the ground. However, when that heat attempts to rise and dissipate, it cannot penetrate the gases/glass and instead builds up, raising the ambient temperature. This phenomenon is known as the greenhouse effect.

Greenhouse gases are essential to keeping the Earth warm; without them, the global temperature would average about 0°F. However, human activity—particularly certain agricultural practices and the burning of fossil fuels—has created an overabundance of greenhouse gases in the atmosphere. This is widely understood to be the primary cause of unnatural global warming. The world’s countries produce and release varying amounts of greenhouse gases into the atmosphere. The overall emissions level in a country can be explained by the size of its population, its GDP, its energy sector, and more.

Top 10 Countries with the Highest CO₂ Emissions Per Capita (metric tons, 2022)

According to the International Energy Agency, global carbon dioxide emissions from fuel combustion reached a new record of 36.3 billion tons (36.3 Gt) in 2021. Overall, greenhouse gas emissions fell 9% from 2019 to 2020, largely as a result of COVID-19-related lockdowns which limited the use of motor vehicles (and in effect greatly reduced the emission of GHGs in vehicle exhaust). However, early data indicate that GHG emissions not only rose in 2021, but reached the highest global level yet recorded. Both coal and renewable power (wind, hydro, solar, etc.) rose to their highest recorded levels of consumption in 2021.

Top Greenhouse Gases and Their Sources

The primary greenhouse gases generated by humans are carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and the “fluorinated gases” such as hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride. Water vapor and ozone (O₃) could also be classified as greenhouse gases, but both offer substantial benefits that far outweigh their influence upon global warming.

According to the Environmental Protection Agency (EPA), the economic sectors that produced the largest amounts of greenhouse gas emissions in 2022 were Transportation (gasoline, diesel, etc) - 35%, Electricity generation (coal, natural gas) - 30%, Industry (manufacture of metals, cement, chemicals) - 16%, Residential and Commercial (heating, cooking) - 12%, and Other - 7%.

Sources of Greenhouse Gas Emissions in the United States in 2022 (EPA)

Carbon dioxide (CO₂)

Carbon dioxide (CO₂) is the most abundant greenhouse gas, and by a massive margin. CO₂ makes up approximately 4/5 of all human-generated greenhouse gas emissions. It is emitted primarily through the burning of fossil fuels (coal, natural gas, oil) either in motor vehicles as fuel or in power plants to generate electricity. Additional sources include solid waste, biological materials, and certain chemical reactions.

Since 1970, global carbon dioxide emissions have increased by 90%, with emissions from fossil fuel combustion and industrial processes contributing to about 78% of the total greenhouse gas emissions increase.

Sources of Carbon Dioxide Emissions in the United States in 2022 (EPA):

Methane (CH₄)

Although it is emitted in much smaller volumes than carbon dioxide, methane has a much greater impact in the atmosphere and is roughly 25 times as damaging as an equal volume of CO₂ over 100 years. Methane is released into the atmosphere by both natural sources (35-50%), such as wetlands, and by human activities (50-65%).

Human-generated sources of methane include natural gas production, coal mining, wastewater treatment, and landfills. Arguably the best-known source of atmospheric methane is the rearing of livestock. The size of the global meat industry is such that the animals’ collective flatulence and biological waste releases a considerable amount of methane into the atmosphere.

Sources of Methane Emissions in the United States in 2022 (EPA):

Nitrous oxide (N₂O)

With an atmospheric impact 300 times that of carbon dioxide, nitrous oxide is a major greenhouse gas. It is primarily released through agricultural soil management practices (75%) such as the application of fertilizers. Chemical production, the combustion of fossil fuels, and the treatment of wastewater also contribute to N₂O emissions. It is also part of the natural nitrogen cycle.

Fluorinated gases

The fluorinated gases, including hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride, are almost entirely man-made gases generated by various chemical and industrial processes. 93% of the fluorinated gases released into the atmosphere come from their use in various industrial roles including that of refrigerants, aerosol propellants, solvents, fire retardants, foam blowing agents, gaseous insulators. Although they appear in only trace amounts in the atmosphere, fluorinated gases are tremendously impactful, with an effect roughly 10,000 to 22,800 times that of an equivalent volume of carbon dioxide.

Greenhouse gas contributions around the world

China

China has the highest greenhouse gas emissions of any country in the world, with an estimated 10.6 gigatons of CO₂ equivalent released in 2022. The country’s economic growth has primarily been powered by coal, which produces up to twice the amount of carbon dioxide as other fossil fuels. China’s industrial sector is the primary coal consumer. Manufacturing, agriculture, mining, and construction make up about 62.5% of China’s energy use and 49% of its coal use. What’s more, China’s coal use rose in 2021, as a 10% spike in demand for electricity (fueled by the post-pandemic economic recovery) coincided with a spike in natural gas prices, leading to an increased reliance on coal-powered electrical plants.

United States

The United States is the second-largest contributor of CO₂ emissions, responsible for 4,620 megatons of CO₂ in 2022. U.S. net emissions decreased by 12% between 2005 and 2017, with the electric power sector emissions falling 27% as a result of increased use of renewable energy, shifting from coal to natural gas, and a leveling of electricity demand. The transportation sector was the largest contributor to emissions in 2022, responsible for 35% of emissions, followed by electricity (30%), and industry (16%).

India

India, with an estimated 1.41 billion people in 2022, is the third-largest contributor of carbon dioxide emissions, releasing approximately 2,800 megatons of CO₂ that year. Cattle, coal power plants, and rice paddies are the country’s major sources of emissions which continue to rise rapidly. The country has pledged a 33-35% reduction in its emissions by 2030 compared to 2005 levels.

Russia and Japan

Russia is the fourth-largest contributor of CO₂ emissions, having emitted 1,720 megatons of carbon dioxide in 2022. Russia’s per capita emissions (11.7 tons in 2022) are among the highest in the world, much higher than that of Germany (7.3), the U.K. (4.6), or France (43.3)—though still lower than the United States (13.5). Most greenhouse gas emissions in Russia come from the energy industry (around 78%), nearly half of which comes from the production of electricity and heat for the general population.

Japan is the fifth-largest contributor of greenhouse gases, having contributed almost a thousand (998) megatons in 2022. Japan is the only G7 country still building new coal-fired power plants. Japan’s climate targets (carbon neutrality by 2050, but weaker near-term reductions) have faced both criticism and pressure from the international community for the lack of ambition.

Germany and South Korea

Germany emitted approximately 613 million tons of carbon dioxide equivalent in 2022, representing a roughly 40% reduction compared to 1990 levels—achieved largely by phasing out coal-fired power plants, expanding wind and solar energy, and reforming the European emissions trading system. Germany’s climate goals include a 65% reduction in emissions by 2030, 80% renewable energy by 2030, and net-zero emissions by 2045.

After emitting a record 605.9 megatons of CO₂ in 2018, South Korea lowered its emissions to 586 million tons in 2019. The country lowered its emissions further to 553 megatons in 2022. While emissions from electricity, coal, and steel production have increased, South Korea has committed to greening its energy platform by decommissioning old and inefficient coal and nuclear power plants and transitioning to more efficient systems, including a blossoming hydrogen industry.

Iran, Canada, and Saudi Arabia

Iran is the eighth-largest emitter of greenhouse gases in the world, emitting 635 million tons of CO₂ in 2022. Between 1990 and 2018, Iran’s CO₂ emissions rose by roughly 5% annually. The burning of natural gas and oil are the two leading contributors to Iran’s carbon emissions. Iran is rich in resources with enormous oil and gas reserves; however, it still has considerable potential to produce renewable energy, such as solar power. Iran has pledged to reduce carbon emissions by 4% by 2030, but increased sanctions and a lack of trade have negatively impacted the country’s economy, hindering the use of resources for climate initiatives.

Canada emitted 519 million tons of carbon dioxide in 2022. Canada is warming up twice as quickly as the rest of the world, despite the country’s many hydroelectric dams and nuclear power plants, which do not require fossil fuels to produce electricity. Oil and gas production is Canada’s largest emitting sector, accounting for about 45% of emissions, followed by transportation, which accounts for about 28% of emissions. Since 1990, Canada’s gross domestic product (GDP) has more than tripled and its population has grown by 6 million people, yet overall total greenhouse gas emissions have risen less than 30%, and per-capita emissions have declined.

Saudi Arabia emitted approximately 608 million tons of CO₂ in 2022. Saudi Arabia’s economy is highly oil-dependent, and Saudi Aramco, the official Saudi Arabian Oil Company, has contributed the most to global carbon dioxide emissions since the 1960s. However, the 2020 COVID-19 pandemic lockdowns triggered a massive drop in global demand for oil and made clear that Saudi Arabia needs to diversify away from oil for both environmental and economic reasons. Like most Middle Eastern countries, Saudi Arabia has massive potential to generate solar power.