
Carbon Calculator (by Trees for the Future) - ph0rque
http://trees.org/carboncalculator/
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titojankowski
Have you paid to plant trees? I tried Terrapass a month ago and blogged about
it, it was all right: [http://titojankowski.com/blew-some-money-on-carbon-
offsets/](http://titojankowski.com/blew-some-money-on-carbon-offsets/)

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ph0rque
I have. The cost per ton of CO2 being offset is wildly different, though. At
1.5 tons/month (18 tons/year), the cost to offset that CO2 would come out to
~$11 yearly from TFTF (assuming an average tree planted would sequester CO2
for 10 years, which I think is a bit conservative).

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titojankowski
I tried their calculator with 18 tons (36,000 pounds). It said ~1050 trees @
$0.10 per tree, so $105 total per year. vs $45 or whatever on Terrapass.

Let’s shoot for an order of magnitude difference. How might we sell it for
$4.50 a year?

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ph0rque
So I should have explained my assumptions more.

If you plant 1050 trees at $105 per year (I rounded to $110), the will extract
18 tons of CO2 from the atmosphere _per year_. This assumes that you need to
just make a _one-time_ payment and as long as those 1050 trees are alive and
healthy, they'll keep extracting 18 tons of carbon from the atmosphere every
year.

Since we can't assume those trees will keep on living and being healthy as
long as you're alive, we need an average healthy lifespan for them. Instead of
trying to figure that out (googling resulted in wildly different answers), I
decided to assume their healthy lifespan is 10 years. That seems very
conservative, but it does give us round numbers to make the math convenient.

So every 10 years, you would need to pay $110 to keep offsetting your carbon.
That comes out to $11 per year.

