The Financial Times, 6 July 2005 reports - George W. Bush, US president, may have difficulty admitting the extent to which human activity - such as rapidly increasing air travel - is to blame for global warming but airlines are becoming acutely aware that many of their corporate clients take a different view.

As the Group of Eight leaders strive to find common ground on climate change and poverty today, the travel industry is already facing pressure to take action.

It is no longer enough for airlines and hotel groups simply to dangle discount fares and room upgrades to secure the loyalty of corporate clients. Now customers are also beginning to demand sustainability. Flights that produce the lowest possible greenhouse gas emissions, use solar energy, have efficient waste management and show sensitive handling of local employment have all entered the equation when companies negotiate deals with preferred travel suppliers.

"We would like to hear from airlines that can offer carbon-neutral travel," says Francis Sullivan, former ­conservation director of WWF and now environmental adviser at HSBC, the UK bank. "In other words, they would offset emissions by making a ­payment to organisations investing in energy ­efficiency."