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.
Viking Sea. Expand your horizons on comfortable, state-of-the-art ships, intimate and thoughtfully created by experienced nautical architects and designers to enrich your interaction with your destination in every way. Each sister ship carries only 930 guests and is engineered at a scale that allows direct access into most ports.