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:
Viking River Cruises Tipping Policy. It is customary to give cruise gratuities, subject to your satisfaction of services rendered. Gratuities on board and on land are not included in your full fare.
For spa services on a crew, we recommend the typical tip of 15%-20%, unless it is a cruise line that discourages any kind of tipping, or tips are already included in the spa treatments (Norwegian Cruise Lines is an example of this)..