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.
Tips are not included in your cruise price, but are a voluntary way of showing satisfaction for good service. You may tip onboard staff in cash if you like, or you may charge your tips to your credit card at the end of the cruise (everywhere except Egypt, Southeast Asia and Portugal).