Business executives should be more economical with their company's corporate travel budgets for the sake of shareholders, but also for the sake of the environment, the founder of budget airline EasyJet wrote in the Financial Times recently.

"Despite the fact that climate change dominated the agenda in Davos this year, I did not detect any abatement in the use of private jets by moguls who gathered there to save the world," wrote Stelios Haji-Ioannou.