Carbon offsets play a big role in this kind of green travel, with some online ticket sellers offering easy ways to purchase carbon offsets at the same time you book a flight, hotel room, or car rental. But air travel probably gets more attention than it deserves, says Arnold. While flying does have an impact, especially with regard to carbon emissions, it does not have nearly the negative effect that other carbon contributors do. For instance, he considers coal-fi red electricity-generating plants a much more serious problem. "Aviation is a minor part," Arnold says. "For certain travelers, it's an issue, but globally, it's only about 2 percent of the problem."

Green Careers

In many ways, the greening of society seems to focus on restrictions by drawing lines around what we can and can't do and by outlawing activities that we once enjoyed or profited from. But one green trend is about opening doors and expanding opportunity. That's what is behind the rising interest in green careers and green employees. Ori Sivan knows this angle inside and out, having graduated in 2005 with a college degree in environmental engineering (a field in which he briefly pursued employment) before starting his own business, Greenmaker Supply, a Chicago-based sustainable-building-materials retailer. Today, he hires people who want to work for a green company.

In contrast to the worrisome forecasts and warnings often given by environmental observers, the green-career business is booming. "Absolutely bonkers," is the way Sivan describes it.

'Working to Save the Environment:  The Top Three Jobs