An investigation by Richard Heede at the Climate Accountability Institute and covered by The Guardian
has found that 20 fossil fuel companies can be directly linked to more than a third of all greenhouse gas emissions
in the modern era. Between 1965 and 2017, those 20 companies contributed to 35 percent of all energy-related carbon dioxide and methane worldwide, totalling 480 billion tonnes of carbon dioxide equivalent.
The following infographic provides an overview of those companies which range from investor owned firms to state-owned companies. Saudi Aramco is at the top with 59.26 billion tonnes, followed by Chevron and Gazprom
with over 43 billion tonnes each. 12 of the top 20 companies are state-owned and they accounted for 20 percent of all emissions since 1965.