CUFR Tree Carbon Calculator
"The CUFR Tree Carbon Calculator is the only tool approved by the Climate Action Reserve's Urban Forest Project Protocol for quantifying carbon dioxide sequestration from GHG tree planting projects. The CTCC is programmed in an Excel spreadsheet and provides carbon-related information for a single tree located in one of sixteen United States climate zones. Once the user enters information on the climate region and tree's size or age the CTCC produces information on:
- Carbon dioxide stored in the tree due to its growth over many years
- Carbon dioxide sequestered during the past year
- Dry weight of aboveground biomass that could be utilized if the tree was removed
- If trees are strategically located to shade buildings and reduce energy consumed for heating and cooling, additional inputs are required. CTCC outputs include:
- Annual energy savings in kWh of electricity and MBtu of heating per tree
- Carbon dioxide equivalents of these energy savings
The CTCC can be used to estimate GHG benefits for an existing tree or to forecast future benefits for a planting project. Tree size and growth data are developed from samples of about 650-1000 street trees representing approximately 20 predominant species in each of the sixteen regional reference cities. Biomass equations, many derived from volumetric measurements of open-grown city trees, are used to derive total CO2 stored and sequestered. To determine effects of tree shade on building energy performance, over 12,000 simulations were conducted for each reference city using different combinations of tree sizes, locations, and building vintages.
Users should recognize that conditions vary within regions, and data from the CTCC may not accurately reflect their rate of tree growth, microclimate, or building characteristics. When conditions are different it may be necessary to apply biomass equations manually using adjusted tree growth data and perform building energy simulations with modified weather and tree data to more accurately depict effects of trees on GHGs.
The CTCC is intended as "proof of concept" software that is in the testing phase. It is provided "as is" without warranty of any kind. In 2011, this version will be replaced by a Web-based version with greater functionality."