Study shows 20 companies account for one third of all CO2 emissions worldwide

A study by the US-based climate accountability research institute says that a group of 20 companies has been responsible for more than one-third of greenhouse gas emissions worldwide since 1965. Brazilian state-owned Petrobras appears in the list at 20th position.

According to the analysis, first published by The Guardian newspaper on Wednesday, the 20 oil, natural gas and coal companies accounted for 480.16 billion tons of carbon dioxide and methane released into the atmosphere during this period. This represents 35% of total fossil fuel and cement emissions, which were 1.35 trillion tons.

The calculation is based on the annual production of oil, natural gas and coal reported by each company, and takes into account emissions from extraction to final fuel use.

The list has 12 state-owned companies and eight private companies, and is headed by Saudi state-owned Saudi Aramco, responsible for the emission of 59.26 billion tons of carbon dioxide equivalent, equivalent to 4.38% of the world total in the period analyzed.