Only 48 of the top 100 companies trading on the UK stock exchange have published a plan to address and reduce their carbon emissions and a significant minority refuse even to reveal their carbon footprint, a Guardian survey shows...In a separate study...Forum for the Future analyses the carbon footprints of the top 10 global companies...ExxonMobil has the highest emissions in the group, equivalent to the annual discharge from Saudi Arabia. Sally Uren, director of the organisation's business programme, writes: "Five of the 10 - Exxon, DaimlerChrysler [now Daimler], Chevron, Total and ConocoPhillips - do not appear to have published targets to reduce carbon dioxide emissions." The remaining five - Wal-Mart, Shell, BP, General Motors and Toyota - have publicly disclosed varying levels of sustainable investment.