The 10 Biggest Carbon-dioxide Emitting Firms In The World

According to the CDP, just a hundred companies across the world are responsible for 71% of global greenhouse gas emissions.

According to the Carbon Majors Database, a report published by the Carbon Disclosure Project (CDP), just a hundred companies across the world are responsible for 71% of global greenhouse gas emissions that have led to global warming. CDP is a non-profit organization that is focussed on the disclosure of information to help investors, companies, and governments formulate better environmental policies. According to a study conducted by the organization, over half of global emissions can be traced back to 25 companies and entities. The companies responsible for the most carbon emissions are Saudi Aramco, Chevron, Gazprom, ExxonMobil, National Iranian Oil Co., BP, Royal Dutch Shell, Coal India, Pemex, and Petróleos de Venezuela.


Aramco is a Saudi Arabian Oil Company based in Dhahran. The company is the most profitable firm in the world. The company is also ranked as the largest carbon-dioxide emitting firm in the world. The company is responsible for the production of 59.26 billion tonnes of Carbon dioxide since 1965. In recent times the company launched an IPO, which effectively made it the world’s largest listing company. Aramco expects a compound annual growth rate for global crude oil demand of 0.85 from 2018 to 2030, with developing countries, especially in the Asia Pacific region driving demand. Some experts believe that the move signals that the Kingdom is eyeing a future with declining oil production and usage. 


Chevron Corp, a US-based company, is ranked as the second-largest emitter of greenhouse gases. The company is responsible for the emission of 43.35 billion tonnes of carbon-dioxide since 1965. The company has revealed plans to reduce the intensity of greenhouse gas emissions from its oil production by 5% to 10% by 2023 as part of an effort to combat climate change. The company, however, does not have plans to reduce scope 3 emissions or emissions from the use of its fuels by customers. The company is part of the Oil and Gas Climate Initiative (OGCI) along with BP Plc and Exxon Mobil Corp, an organization that was formed in 2014 to increase carbon efficiency and reduce methane emissions. The company has also stated that it has spent over US$ 1 billion on carbon capture and storage projects in Canada and Australia. The facilities are expected to cut greenhouse emissions by 5.5 million tons per year. 


Russia’s Gazprom ranks 3rd among the world’s top carbon-emitting firms. The company is responsible for the production of about 43.23 billion tonnes of carbon-dioxide since 1965. Between 2011 and 2018, the company saved about 22.5 million tons of fuel, indicating continued efforts by the company to improve energy efficiency in its operations. The company has also taken measures such as upgrading facilities, including renovation and modernization of compressor stations, deploying energy-efficient equipment, and rationalizing of heating, lighting, and ventilation schemes. Last year the company’s deputy chairman Yelena Burmistrova stated that drastic reduction in carbon emissions could have dangerous consequences, including the collapse of the world economy and the loss of millions of jobs. The statement was criticized by environmental conservationists who believe that emission should be reduced at a higher rate.


Exxon Mobil is a US-based investor-owned company responsible for about 41.9 billion tonnes of carbon-dioxide emissions since 1965. Exxon Mobil has, in the past, been accused of misleading investors on the impact of the firm’s operations on climate change. On October 22, the company was put on trial at the New York Supreme Court for failing to disclose to its investors the costs it incurred from government rules designed to cut greenhouse gas emissions. The company is part of the Oil and Gas Climate Initiative (OGCI), a group of 13 major oil companies that account for 32% of the world's oil and gas production. The membership indicates the company’s willingness to increase carbon efficiency and reduce methane emissions in line with the organization’s objectives. The company recently pledged US$100 million for emissions-reduction research.

National Iranian Oil Co

The state-owned National Iranian Oil Co is responsible for 35.66 billion tonnes of carbon dioxide emitted to the atmosphere since 1965. The company is the nation’s top greenhouse emitter. An official of Iran’s Fuel Conservation Organization (IFCO), a subsidiary of National Iranian Oil Co, recently indicated that the country had plans to set up a carbon trading market to reduce industrial emissions in a bid to help in the fight against climate change. Under the planned scheme, industrial facilities will be allocated credits to emit a specific amount of carbon and will have to buy permits on the market to cover further emissions.


BP, a UK based investor-owned company, is responsible for 34.02 billion tonnes of carbon-dioxide emissions since 1965. The company aims to keep carbon emissions flat until 2025, even as oil and gas output is set to grow. The move is a response to growing investor pressure on the need to increase efforts to tackle climate change. The company also aims to reduce CO2 emissions by 3.5 million tonnes through increased production of gas, the least polluting fossil fuel. The company also wants to invest US$500 million every year into renewable energy such as wind, solar, and power storage. BP’s reduction targets, however, do not include scope 3 emissions. 

Royal Dutch Shell

Royal Dutch Shell, a company based in the Netherlands, is responsible for 31.95 tonnes of Carbon-dioxide emissions since 1965, making it the seventh-largest emitter. The company plans to reduce carbon emissions from gas and oil and product sales by 2% to 3% during the 2016 to 2021 period. The Anglo-Dutch company has also announced its plans to reduce its carbon footprint by 50% by 2050 by increasing the production of lower-carbon products such as natural gas, hydrogen, and biofuels. 

Coal India

Coal India has produced 23.12 billion tonnes of carbon-dioxide since 1965. The company ranks as one of the polluters among state-owned companies. Thermal power companies currently provide three-quarters of India’s electricity. The country is suffering from some of the worst air pollution levels on the planet. The government has plans to ensure coal power plants are retrofitted with equipment to curb air pollution. Experts, however, believe that over half of the nation’s coal-fired power plants are set to miss emission norm deadlines that have been set by the government. 


Pemex is ranked among the leading polluting companies in Latin America. The Mexican oil company is responsible for 1.67% of the total greenhouse gas emissions in the world. The state-owned company is responsible for the production of 22.65 billion tonnes of carbon dioxide since 1965. The high levels of emission call into question of Mexico’s commitment to the Paris Agreement.

Petróleos de Venezuela

Petróleos de Venezuela is ranked as the tenth leading polluting companies in the world. The company is responsible for the production of 15.75 billion tonnes of carbon dioxide since 1965. Since the nation spiraled into economic and social chaos, the government has censored environmental and scientific data from several institutions in the country, making it difficult to accurately tell the environmental impact of various firms in the country. 

Impact Of Investor Pressure

The report revealed that 32% of the emissions came from public investor-owned companies, meaning that investors are critical in the transition to a sustainable economy. Investors could use their financial leverage to pressure companies to commit to the decarbonization of their operations. Experts believe that investment in companies based on fossil fuels will become risky in the future. The energy sector is changing rapidly, and companies that are unable to transition will face challenges remaining of going concern to investors. Fortunately, large companies are increasingly supporting the transition to a carbon-free economy.

The 10 Biggest Carbon-dioxide Emitting Firms In The World

RankFirmBillion tonnes of carbon dioxide equivalent produced (1965 to 2017)
1Saudi Aramco59.26
5National Iranian Oil Co35.66
7Royal Dutch Shell31.95
8Coal India23.12
10Petroeos de Venezuela15.75

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