There are many ways that carbon offset sites use to place a dollar value to, say, one ton of carbon dioxide.

The value of a tree:

The most direct correlation of dollars / pound of carbon dioxide, would be to consider trees. One of their major functions is absorb atmospheric carbon dioxide and release oxygen. So how does one value a tree? Well, let us say that you are the owner of one acre of forest. Depending on the type of tree in your forest, a healthy mature tree can absorb about 48 pounds of carbon dioxide per year, and up to 200 trees can fit in this acre. So, in one year, your acre of forest absorbs about 4 metric tons of carbon dioxide.

In order to save these trees from being cut down, their value is what they are worth to a timber company. Cutting down trees for their wood is a major cause of deforestation. If you were to sell your wood to a timber company, they would pay you about $5.00 per board foot (which makes the wood for building) and about $200.00 per cord of pulp (which makes firewood, paper pulp, and woodchips). Your 200 trees can produce about 10,000 board feet and 25 cords of pulp, so doing the math, your acre of forest is worth $55,000.

In other words 1 ton of carbon dioxide absorption would be worth about $12,500, but it takes 40 to 100 years for the trees to mature. Amortized over the life of the tree, each ton of carbon dioxide is worth $100 to $300 each year. This is significantly higher than what other carbon offset sites offer, but one might understand from a marketing perspective the implications.

Other cost sources:

Compared to other carbon offset sites, carbon dioxide offsets range from $10/ton to $40/ton and even as high as $100/ton (probably a more realistic rate). As a basis of comparison, the California Energy Commission suggests a rate of $30/ton.

Our plan:

At A-Day-Without-Driving, we are not offering “carbon offsets” or “carbon credits” but rather raising money to help protect the environment. As a California-based organization, we suggest the rate of $30 per ton of carbon dioxide.