ExxonMobil and Chevron, the two largest US energy groups, have joined the Oil and Gas Climate Initiative, a group of companies supporting curbs on greenhouse gas emissions. The move is the latest sign of how pressure from the public and investors is forcing the industry to address the threat of global warming. Occidental Petroleum, the Texas-based oil group, is also joining the initiative, which was launched in 2015 with European companies including Royal Dutch Shell and BP making up most of its members.

The new arrivals mean OGCI members provide about 30 percent of global oil and gas production. Exxon and Chevron declined to join the initiative when it started but both companies have since changed their chief executives. Darren Woods replaced Rex Tillerson at the head of Exxon at the start of 2017 and Michael Wirth replaced John Watson at Chevron in February. The companies have come under pressure from investors to disclose more about the potential implications for their business of policies to limit global warming.

They have also faced legal action from US states and cities over their contribution to the harm caused or threatened by rising global temperatures. Mr Wirth said that Chevron was joining the OGCI “to work constructively on addressing the risks of climate change”. Mr Woods said developing affordable solutions to address the threat would “take the collective efforts of many in the energy industry and society”. He added that Exxon’s mission was to meet a dual challenge, “to supply energy for modern life and improve living standards around the world while minimizing impacts on the environment”.