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.
Follows the list of Viking Ingvar river cruise itineraries as themes, officially announced by the Viking Cruises line:  1 WATERWAYS OF THE TSARS are 12-days luxury Volga river cruises from Saint Petersburg to Moscow, and the reverse from Moscow to Saint Petersburg.