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.
Many vouch that this is the ultimate way to rack up onboard credit for that next sailing. Celebrity Cruises offers up to $500 per cabin when you book your next cruise onboard. If you make a deposit toward a future cruise on Norwegian, you earn $100 in onboard credit to spend instantly on the cruise you're already on.