< PrevNext > Greta Thunberg, High School Student Green Genie By Amon Cohen / December 13, 2019 Share She may be by far the youngest nominee on this list, but Greta Thunberg's influence in 2019 arguably proved the profoundest. Starting in August 2018, her weekly one-child protest outside Sweden's parliament, demanding an urgent response to the climate emergency, mushroomed this year into regular demonstrations by millions of activists in hundreds of cities worldwide. Environmental campaigner pressure has prompted serious soul-searching in the business travel industry. Corporate customers and suppliers alike now acknowledge there are questions to answer. Emissions created by aircraft are more harmful than from other polluters because of the altitude at which they are released. Unlike other polluters, there are also few ways to reduce emissions fast enough to beat global warming deadlines, especially as passenger numbers are forecast to double by 2037. By 2050, aviation will be the world's No. 1 or No. 2 source of CO2 emissions.There have been previous waves of interest in making business travel greener. Both, one in the 1990s and one in 2000s, dissipated fast when economic downturns hit. This time, the drive for sustainability feels more, well, sustainable. Consider some of the extraordinary developments witnessed in 2019: an airline (KLM) asking its own customers "Do you always have to meet face-to-face?" and "Could you take the train instead?"; flights from Swedish airports falling 4 percent in the first 10 months of 2019; a new global word: flygskam, or shame of flying; the German government pledging to increase the cost of flying and reduce the cost of rail, while other European governments also introduce air eco-taxes.Under Thunberg's unflinching gaze, travel professionals now understand they face the critical scrutiny not only of protestors but also investors, regulators and their own workforce. (One Swedish travel manager reported an employee asking if she could travel to the UK by rail.) Some are even closer to home. "I hear about [sustainability] from investors, I hear about it from customers, but my own personal barometer is my two grandsons," said United Airlines Holdings board chair Jane Garvey recently. "When I went into their rooms not too long ago, there were two posters: One was Tom Brady, and the other was Greta. Climate change is just as much a theme for them … we're going to pay a lot of attention to that."