How Many Trees Per Person?

Have you used up your tree allotment in your lifetime?

Thanks to the eggheads at NASA (who I guess apparently get bored staring into the abyss and sometimes point their fancy equipment back at Earth), we now know that as of 2005, there are 400,246,300,201 trees on Earth, give or take a shrub or two. But how many trees are there per person?

Like most bloggers, I got into this biz because of the explicit lack of math, so I'll leave the number crunching to ecology professor Nalini Nadkarni of The Evergreen State College in Washington. She's figured out that the planet has 61 trees per person, and she was thrilled with the initial results; like me, she initially thought there would be less than one tree per person.

But the news isn't all pretty: We use so many wood products in our daily lives, from firewood to pencils to guitars, that Nadkarni figures we must be cutting into our personal tree allotment. But there is a silver lining: Wood is renewable, of course, so as long as we keep planting trees, we can keep the tree-human ratio high and sustainable.

"I don't want people to feel guilty about their relationships with trees and say, 'Oh my God, I can never touch another tree-created product again,' " she says.

So if you blazed through a lot of paper this month and feel like your personal tree allotment is dwindling, you can always hike out to your favorite spot with a shovel and plant a few tree seeds.

(And to read an incredible story about the search for the world's tallest tree, read Tom Clynes' "Above & Beyond").

—Ted Alvarez

Going Out On A Limb With A Tree-Person Ratio (NPR)