A coalition of environmental NGOs has written to seven international banks to express their alarm over the banks' decision to underwrite the planned Initial Public Offering (IPO) of Saudi Aramco. The state-owned oil giant is the world's largest emitter of carbon dioxide; a recent Guardian investigation revealed that Saudi Aramco has produced about 4.4% of the world's total carbon dioxide and methane emissions since 1965.

The letter also outlines the NGOs concerns that the banks will be facilitating the profiteering of a regime with a history of egregious human rights abuses. It cites the examples of Saudi Arabia's role in airstrikes on civilians in Yemen and in the murder of Jamal Khashoggi.

The Guardian approached the banks for comment on the letter. JP Morgan Chase, Morgan Stanley and Goldman Sachs declined to comment on the letter, whilst the other banks did not respond to requests for comment.