Help us plant more trees!
For every $6 donated, you'll help us source one native tree seedling, plant, water, mulch, and ensure its survival in a highway interchange. Planting 12 trees may offset your annual vehicle emissions.** Choose the monthly donation option for maximum impact!
How We Calculate CO2 Offsets
The amount of carbon dioxide (CO2) absorbed per tree over the lifetime of the tree will vary based on a variety of factors including tree species, lifespan of the tree and stage of life of the tree, location planted and more. Our research indicates one tree absorbs from 16 pounds to 48 pounds of CO2 per year. Our calculations are based on an estimate of 31 pounds of CO2 absorbed per tree each year or 775 pounds per tree over a 25 year lifetime*. Using this metric 12 trees would absorb 9,300 pounds of CO2 over a 25 years period, which is 4.2 metric tons of CO2. According to the EPA, a typical passenger vehicle emits about 4.6 metric tons of carbon dioxide per year or 10,143 pounds. This means an efficient car or driver could plant 12 trees per year to offset all or most of their CO2.**
Due to tree site conditions, we expect tree mortality rates that may reach up to 30%. Because of this, for every tree offset purchased we will plant one tree at a roadway interchange tree planting event, and provide a second tree for planting by partner organizations, or through tree giveaway events. In other words if you offset your emissions with one tree per month, two trees per month will actually be planted. We will be reevaluating these calculations annually based on Green Interchange's actual trees planted, locations, conditions, mortality rates, and other factors.
* This Sierra Club article indicates one silver maple absorbs 400 pounds of C02 over a 25 year lifespan, basing their numbers on information from the U.S. Energy Information Administration. Arbor Day Foundation reports a mature tree will absorb more than 48 pounds of carbon dioxide per year which would be 1,200 pounds over a 25 year lifespan. Calculations from Urban Forestry Network put CO2 emissions per tree at about 850 pounds or 34 pounds per year.