# How many trees per person? **URL:** \ **Category:** Factual Questions\ **Created:** [June 20, 2002, 5:31pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101 "2002-06-20T17:31:20Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [June 20, 2002, 5:31pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/1 "2002-06-20T17:31:20Z")
Though the biosphere projects never quite worked out as best as possible, they must have had some idea of the oxygen/CO2 exchange process between plants and animals. _Roughly_ how many trees do _I_ need to ensure that I am looking out for my CO2 waste? I am a stunningly average American male, if that makes any difference. ---
**Author:** ![Earthling](https://avatars.discourse-cdn.com/v4/letter/e/90db22/32.png) [@Earthling](https://boards.straightdope.com/u/Earthling)\ **Post date:** [June 20, 2002, 6:30pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/2 "2002-06-20T18:30:35Z")
Well, [this](http://www.earthday.net/footprint/index.asp) calculates your entire ecological footprint in acres. Maybe someone will come along with something for just trees and O[sub]2[/sub] / CO[sub]2[/sub]. ---
**Author:** ![WV\_Woman](https://avatars.discourse-cdn.com/v4/letter/w/e95f7d/32.png) [@WV\_Woman](https://boards.straightdope.com/u/WV_Woman)\ **Post date:** [June 20, 2002, 7:02pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/3 "2002-06-20T19:02:30Z")
My score was 29. If everyone lived like me, we’d need 6 1/2 planets! WOOHOO!!! ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [June 20, 2002, 7:56pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/4 "2002-06-20T19:56:51Z")
Ouch. Somehow I have a footprint of 31. I don’t even do anything! Total hermits can’t have that much of an impact, lol. ---
**Author:** ![Beastal](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@Beastal](https://boards.straightdope.com/u/Beastal)\ **Post date:** [June 20, 2002, 8:15pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/5 "2002-06-20T20:15:31Z")
Holy sheet you guys, I’m a megre 6.3! What on earth are you doing?!? ---
**Author:** ![Achernar](https://avatars.discourse-cdn.com/v4/letter/a/e274bd/32.png) [@Achernar](https://boards.straightdope.com/u/Achernar)\ **Post date:** [June 20, 2002, 8:42pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/6 "2002-06-20T20:42:08Z")
He he. I picked the worst everything and took up 114 acres. 😃 We’d need 26 planets! You people better start packing. ---
**Author:** ![WV\_Woman](https://avatars.discourse-cdn.com/v4/letter/w/e95f7d/32.png) [@WV\_Woman](https://boards.straightdope.com/u/WV_Woman)\ **Post date:** [June 20, 2002, 8:43pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/7 "2002-06-20T20:43:27Z")
Beastal, well, first off, we put a good 400 miles on the car a week, at least. We put out a lot of trash for just the 3 of us, but then one of us is still in diapers (and no, they’re not disposable). I like my electricity as inefficient as possible and SCREW CARPOOLING! 🙂 ---
**Author:** ![WV\_Woman](https://avatars.discourse-cdn.com/v4/letter/w/e95f7d/32.png) [@WV\_Woman](https://boards.straightdope.com/u/WV_Woman)\ **Post date:** [June 20, 2002, 8:44pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/8 "2002-06-20T20:44:52Z")
Eep. Sorry. The diapers ARE disposable. ---
**Author:** ![techchick68](https://avatars.discourse-cdn.com/v4/letter/t/ea5d25/32.png) [@techchick68](https://boards.straightdope.com/u/techchick68)\ **Post date:** [June 21, 2002, 4:50am UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/9 "2002-06-21T04:50:54Z")
I have a problem with that quiz. It told me I have a score of 37 and 8.3 planets if everyone were to live as I do. Understandable that since I live alone in a 1600 sq foot house that is a free standing house. But the last two questions where really kind of dumb. Based on last August, when I had some major work done on my car I have traveled about 2,500 miles so I picked the 10-100 miles per week (when actually that’s about 57 miles per week which is a higher figure as I rounded it up to 3000 as August is still a couple of months off.) So the last two questions are: 1. How many miles per gallon does your car get? I chose the 25-35 miles per gallon 2. How often do you drive in a car with someone else, rather than alone? Almost never So that alone bumps my score up 13.6 points. But apparently it doesn’t take into consideration that I don’t drive much because in the mobility I score a 0.5. So somewhere some how, even though I do great with only driving very little my score goes up considerably because I don’t ride in the car with other people. They don’t even take into consideration that a person who have children under the driving age could count their under age children as passengers and therefore their score would drop. But the fact that I drive so little should be a consideration between the two. I think it’s a small measure of it. I wouldn’t call it gospel because they don’t ask enough questions IMHO to gauge it even close. They don’t ask detailed questions about where your power comes from. Here in Colorado Springs and in Denver you can buy blocks of power from the windmill farms. We primarily use coal here in C Springs. My central heat is F.A.G. – forced air gas for those of you that aren’t familiar with it. They don’t ask about your climate. They don’t ask if you use AC. They don’t ask how many appliances you have. They don’t ask if you “zone” your heating/cooling. They don’t ask if you conserve water. They don’t ask… Simply put, it’s not detailed enough for me to put any weight on the results. ---
**Author:** ![techchick68](https://avatars.discourse-cdn.com/v4/letter/t/ea5d25/32.png) [@techchick68](https://boards.straightdope.com/u/techchick68)\ **Post date:** [June 21, 2002, 4:57am UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/10 "2002-06-21T04:57:23Z")
I misread the results, sorry. \< shuffles the dirt with her foot \> But I still think it’s not detailed enough. ---
**Author:** ![Neptune](https://avatars.discourse-cdn.com/v4/letter/n/b5a626/32.png) [@Neptune](https://boards.straightdope.com/u/Neptune)\ **Post date:** [June 21, 2002, 5:29am UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/11 "2002-06-21T05:29:41Z")
12.3 planets ---
**Author:** ![Aro](https://avatars.discourse-cdn.com/v4/letter/a/b3f665/32.png) [@Aro](https://boards.straightdope.com/u/Aro)\ **Post date:** [June 21, 2002, 9:36am UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/12 "2002-06-21T09:36:38Z")
That quiz is so shallow it is almost meaningless. I got 5.3 hectares, needing 1.8 planets. But it asks nothing on which it can base that. Not even the type of fuel in your car. If you chose even all the best options you still need 1.1 planets to live. What is that proving? Nothing. ---
**Author:** ![ski](https://avatars.discourse-cdn.com/v4/letter/s/bbe5ce/32.png) [@ski](https://boards.straightdope.com/u/ski)\ **Post date:** [June 21, 2002, 9:52am UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/13 "2002-06-21T09:52:23Z")
Footprint 34. 7.7 planets. Yep, not detailed enough to really make a good calculation. ---
**Author:** ![Horseflesh](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/horseflesh/32/7502_2.png) [@Horseflesh](https://boards.straightdope.com/u/Horseflesh)\ **Post date:** [June 21, 2002, 10:03am UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/14 "2002-06-21T10:03:04Z")
Footprint=20. Planets needed=4.6. Guess I better get cracking on that Dyson sphere I’ve been meaning to build. 😛 ---
**Author:** ![sghoul](https://avatars.discourse-cdn.com/v4/letter/s/3ec8ea/32.png) [@sghoul](https://boards.straightdope.com/u/sghoul)\ **Post date:** [June 21, 2002, 2:15pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/15 "2002-06-21T14:15:12Z")
I just wanting to say, that I thought I remembered hearing somewhere that a good portion of our O2 comes from algea and the like…not trees. ---
**Author:** ![Paddle](https://avatars.discourse-cdn.com/v4/letter/p/f19dbf/32.png) [@Paddle](https://boards.straightdope.com/u/Paddle)\ **Post date:** [June 21, 2002, 3:33pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/16 "2002-06-21T15:33:19Z")
> [@](#): > > \*Originally posted by Aro \* > **I got 5.3 hectares, needing 1.8 planets** Are you sure? I got 3.4, needing 1.9 planets. ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [June 21, 2002, 3:41pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/17 "2002-06-21T15:41:35Z")
OK, this is all well and good, but before this gets shuffled off to some other forum, does anyone have an idea on the tree thing? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 21, 2002, 4:03pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/18 "2002-06-21T16:03:19Z")
So in order for us to all fit on the planet we have to live 4 to a 1000 sqft home, never use any mode of motor transport, never eat any anamal products, never have any fun. That seems like total BS ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [June 21, 2002, 4:29pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/19 "2002-06-21T16:29:53Z")
well, I use 45 acres, but I own 90 acres. Is that ok? Most of them are woods. ---
**Author:** ![Achernar](https://avatars.discourse-cdn.com/v4/letter/a/e274bd/32.png) [@Achernar](https://boards.straightdope.com/u/Achernar)\ **Post date:** [June 21, 2002, 5:18pm UTC](https://boards.straightdope.com/t/how-many-trees-per-person/115101/20 "2002-06-21T17:18:58Z")
Okay, erislover, I took a look around, and it seems there’s a bit of variability in the amount of O[sub]2[/sub] made by trees. Here are some sources: [Tree Benefits Page](http://www.coloradotrees.org/benefits.htm): One average acre of trees in Brooklyn gives off 2.8 ton/yr of oxygen. The amount an individual tree gives off varies from 6 to 247 lb/year, depending on its DBH class. [FAQ about America’s Forest Prodcuts Industry](http://www.virginiasfi.org/faq.html): To grow a pound of wood, a typical tree uses nearly a pound-and-a-half of carbon dioxide and gives off more than a pound of oxygen. An acre of trees might grow 4,000 pounds of wood a year, use 5,880 pounds of carbon dioxide and give off 4,280 pounds of oxygen in the process. When a forest gets old and overcrowded, the trees barely grow. They start to use oxygen rather than produce it." Also, for every pound of O[sub]2[/sub] produced, 1½ pounds of CO[sub]2[/sub] is absorbed. [How Stuff Works](http://www.howstuffworks.com/question98.htm) says that the average human 550 liter/day of oxygen. If [the density of oxygen is 1.31 kg/m[sup]3[/sup]](http://www.visionengineer.com/ref/physical_properties.shtml), that’s 0.72 kg/day, or 1.59 lb/day, or 580 lb/year. (I am slightly suspect of that How Stuff Works number, though.) So I’d say you need about one-sixth to one-ninth of an acre. **k2dave** : If five billion people live in crowded, unfun conditions, that’ll leave plenty of resources left over for the other 800 million of us. Then we can have the fun you desire. [Next page](https://boards.straightdope.com/t/how-many-trees-per-person/115101.md?page=2)