I'm not wild about shopping malls at any time of the year. But I go to great lengths to avoid a trip to the mall when the holiday shopping frenzy is in full swing. 

That's the main reason that I turned to online shopping several years ago. Enjoying the season is much easier when I don't have to car-stalk pedestrians to order to score their parking spot.

But I've never been totally convinced that online shopping is truly the eco-friendliest option. I know it saves me several car trips around town. While that definitely benefit my mental health, does it actually benefit the planet?

After all, the gifts and packages I order reach their ultimate destination via planes, trains and automobiles. Each one is usually shipped individually — complete with a lot of packing material, including Styrofoam. And my guess is that a big delivery van probaby doesn't get good gas mileage.  

So, maybe its actually better if the goods go directly to a big box store in one big box. 

When I looked into the question last year, the best I could find is that online shopping is — maybe — just a bit greener than driving oneself around town. 

This year, however, we have a definitive winner: Yes, Virginia, it is online shopping.

According to a Department of Energy study I found at Grist's Ask Umbra column, last year some 30 percent of Americans shopped online. As a result, nearly half-million metric tons of CO2 emissions never floated up into the earth's atmosphere. Check out their report if you want to know how they did the math. 

Meanwhile, a few simple steps can help make online shopping even greener.

• Avoid overnight shipping.

• If you plan to re-send it, have the gift delivered directly to the recipient.

• Remember to turn off your power strip when you're done shopping.