Sales of fake trees are expected to approach 13 million this year in the United States, a record, as quality improves and they get more convenient, with features like built-in lights and easy collapsibility. All told, well over 50 million artificial Christmas trees will grace living rooms and dens this season, according to the industry's main trade group, compared to about 30 million real trees.

Kim Jones, who was shopping for a tree at a Target store in Brooklyn this week, was convinced that she was doing the planet a favor by buying a $200 fake balsam fir made in China instead of buying a carbon-sipping pine that had been cut down for one season's revelry.

But Ms. Jones and the millions of others buying fake trees might not be doing the environment any favors.

In the most definitive study of the perennial real vs. fake question, Ellipsos, an environmental consulting firm in Montréal, Canada found that an artificial tree would have to be reused for more than 20 years to be greener than buying a fresh-cut tree annually. The calculations included greenhouse gas emissions, use of resources and human health impacts.

"You're not doing any harm by cutting down a Christmas tree," said Clint Springer, a botanist and professor of biology at Saint Joseph's University in Philadelphia. "A lot of people think artificial is better because you're preserving the life of a tree. But in this case, you've got a crop that's being raised for that purpose."

While artificial trees can theoretically be recycled, most municipal recycling programs do not recycle artificial trees — and for good reason: artificial trees are largely made from polyvinyl chloride, or PVC, which is in most cases prohibitively expensive to recycle.

"Ultimately trees are likely to end up in landfills until cities offer recycling programs," said Jami Warner, executive director of the American Christmas Tree Association.

(Source: How Green Is Your Artificial Christmas Tree? You Might Be Surprised [New York Times])