Six countries produce nearly 60 percent of global carbon dioxide emissions. China and the United States combine for more than two-fifths. The planet's future will be shaped by what these top carbon polluters do about the heat-trapping gases blamed for global warming. How they rank, what they're doing:
River cruise companies also have their own tipping policies. A handful, such as Scenic Tours, Avalon Waterways and Tauck, include gratuities in their overall price, while Viking River Cruises recommends that guests tip at the end of the trip at a rate of between Â£5 and Â£10 a day.
Designed to cruise the worldâs great rivers, all Viking ships are built, above all, for comfort. On every Viking ship, your experience will include all onboard meals, complimentary wine, beer and soft drinks with onboard lunch and dinner service, guided tours and more.