"Revealed: the 20 firms behind a third of all carbon emissions", 9 October 2019

...20 fossil fuel companies... can be directly linked to more than one-third of all greenhouse gas emissions in the modern era... [A]nalysis, by Richard Heede at the Climate Accountability Institute... evaluates the global corporation[s' actions]... since 1965 – the point at which experts say the environmental impact of fossil fuels was known by both industry leaders and politicians... Chevron topped the list of the eight investor-owned corporations, followed closely by Exxon, BP and Shell. Together these four global businesses are behind more than 10% of the world's carbon emissions... [In response, all companies] pointed out efforts they were making to invest in renewable or low carbon energy sources and said fossil fuel companies had an important role to play in addressing the climate crisis... Heede said: "These companies and their products are substantially responsible for the climate emergency, have collectively delayed national and global action for decades, and can no longer hide behind the smokescreen that consumers are the responsible parties"... "[the companies have a] significant moral, financial, and legal responsibility for the climate crisis, and a commensurate burden to help address the problem".