Sunday, October 14, 2007

Carbon Offsets

Today is Blog Action Day, so we write about the environment. Last year, we chose to sign up for the NatureWise Renewable Energy Program through our electric utility. This lets us buy 900 kWh of renewable electricity per month - close to our actual consumption. The program works by adding $1 per $100 kWh onto our monthly bill.

However, we still drive cars, and use natural gas, and have been wanting to offset those. We did some research, and found three organizations that offer carbon offsets: CoolDriver, TerraPass, and CarbonFund. Here's a mini review of each of these, and their web sites.

The offset market is really complex with lots of different non-profit and for-profit organizations involved, so it's important to do some research, and not buy offsets from the first company you come across on a Google search. So, what should you look for when buying CO2 offsets?
  • How are the offsets made? Projects vary from buying wind power, to planting trees, to capturing methane from cows. Some people question the value of tree plantings to adequately offset CO2, as it takes a long time for the trees to mature, and when the tree dies, the cO2 goes back into the atmosphere.
  • How much do you pay per ton of CO2 offset? Can vary widely - one article found a range of $4.30 to $12 per metric ton.
  • Do you get a certificate? I'd like to get a physical certificate (maybe if we display a decal on our car, others around us will be inspired to offset their CO2 consumption as well).
Our Carbon Nation is a web site that provides profiles on 34 different offset providers. The profiles are only available as PDF files, so you can't compare the different providers directly.

I will compare the three web sites' in terms of offsetting our two cars ('98 Ford Escort (avg 25 mpg) and '00 Dodge Grand Caravan (avg 20 mpg)), which each drive 12,000 miles annually.


CoolDriver is a partnership between Clean Air Cool Planet, based in Portsmouth, NH, and Native Energy.
The web site has a pleasing look with a picture of a cow with the odd speak bubble: "You don't have to stop driving to help stop global warming." It has a simple calculator where you input miles driven and mileage. They offset with wind energy projects and methane capture projects at dairy farms.
(all measures are in metric tons).
  • Caravan: 5.3 tons/yr
  • Escort: 4.3 tons/yr
  • Total: 9.6 tons/yr
  • Cost: $132/yr ($10.8/ton)

Included in the price is also a bumper sticker and a mini certificate.


This is a for-profit company based in San Francisco that funds projects in wind energy, biomass, and industrial energy efficiency. The web site is pleasing, and has an advanced calculator where you pick your specific car, and it then tells you the carbon footprint of the car.
  • Caravan: 4.6 tons/yr - $49.95 to offset 5.4 tons
  • Escort: 3.2 tons/yr - $39.95 to offset 3.6 tons
  • Total: $89.90 to offset 9 tons ($9.98/ton)
With purchase you get a bumper sticker and two different decals.


This is a 501(c)(3) non-profit organization, which means that your off-sets are considered charitable contributions and may be tax-deductible (Nice twist to get the IRS to kick in towards offsetting your climate impact). CarbonFund supports projects in renewable energy, energy efficiency, and reforestation. The calculator is a bit more advanced than the other two sites, as it allows you to calculate for several cars at a time, and then offset the actual consumption.
  • Caravan: 5.07 tons/yr - $27.88
  • Escort: 3.33 tons/yr - $18.29
  • Total: $46.17 to offset 8.39 tons ($5.50/ton)
The calculator is nice, but then when I click Offset Footprint Now, I don't get to offset these precise calculations, instead I can either just make a contribution of a certain amount, or choose to offset generic cars, bringing the cost up to $49.83 ($5.93/ton).

You can choose to only get electronic receipts or physically get a decal and certificate. When checking out, you get the option to support specific types of projects or the total basket of projects they have.


CarbonFund had the most advanced calculators and significantly lower prices. Despite the web site not always having a logical design, I was able to buy offsets for both of the cars we own!

Happy Blog Action Day!


Krissy said...

Everyone can make a difference! If you are passionate about stopping global warming and the environment you should check out this website . Changing to CFLs is a great way for individual people to really make a difference! You should also check out this site for more ideas on how to help our world!

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