The release of the report, "Tracing anthropogenic carbon dioxide and methane emissions to fossil fuel and cement producers 1854-2010" and published in the Climatic Change journal, came as a 12-day global climate summit in Warsaw nears its end on Friday. Rich and developing countries remain divided over the share of responsibility for climate change and future emissions cuts, ahead of final talks on a new treaty to be signed in Paris in late 2015. Chevron and ExxonMobil topped the list of emitters, accounting for almost 100 billion tonnes of CO2-equivalent between them, or about 7.74 per cent of the total. Saudi Arabia's Aramco, BP and Russia's Gazprom took the next three positions. BHP Billiton, the world's largest mining company with a history dating back to 1851, was ranked as 19th-largest polluter, contributing 7.24 billion tonnes, or about one-two-hundredths of total industrial emissions. Rio Tinto, which is partly Australian-owned, vented almost 6 billion tonnes, placing it 34th on the list. The study noted many of the largest producers of fossil fuels are based in developing nations, such as Saudi Arabia, Iran, China, India, Abu Dhabi and Mexico. Indeed, 31 of the 85 remaining entities are based outside the United Nations' Annex I nations, which in 1992 committed to cutting emissions.

“Considerable benefits have accrued to these carbon majors, and to their state sponsors and investors,” the paper said. “Given this, it seems reasonable to argue that they have an ethical obligation to help address climate destabilisation.” “Some of these nations are, in their role as carbon producers, as important contributors to climate change as the Annex 1 nations who until now have been the focus of attention," the paper said. BHP view BHP protested that "only about 10 per cent of the emissions attributed to BHP Billiton" come from its own operations. We've recognised for some time that climate change ... is a big strategic risk.

"Our current target is to keep (emissions) below our 2006 baseline by 2017 despite the expected growth in our business," a spokeswoman said. "The remaining 90 per cent of the emissions are produced by the general public in their day-to-day lives when they use carbon-based fuels." BHP Billiton's management were questioned on the company's exposure to carbon constraints at its annual general meeting in Perth on Thursday. Challenges included a bid by former coal industry executive and climate change campaigner, Ian Dunlop, to join the board. Chairman Jac Nasser said BHP “believed” in climate change and had done so for some 20 years. The company had sought to diversify its resources, including favouring gas over thermal coal and investing into potash. “We've recognised for some time that climate change ... is a big strategic risk,” Mr Nasser told the AGM. “We're not blindfolded to risks ahead of us.” Mr Nasser said the mining giant possessed an asset portfolio that was “robust under an extreme climate change scenario”.

Julie Macken, a Greenpeace spokeswoman, said the list of major emitters could form the basis for future legal action. People and nations have already suffered real losses, such as from rising sea levels and less predictable growing seasons. They will "want to know who to contact for redress,” she said. Loading “This report tells them that.” “Even if the community accepts the argument that these companies were unaware that their product was generating dangerous climate change until the late 1980s or 1990s, that still makes them reasonably liable for the damage done over the last 25 years,” Ms Macken said.