CO2 Breathing Emission vs Tree Benefits
The CO2 breathing emission calculator and the tree benefits calculator are both Ecology-category scenario estimators, and both are careful about what they will not claim. The breathing calculator converts a ventilation scenario into exhaled CO2 volume and mass and states plainly that it is not a personal footprint. The tree benefits calculator scales entered per-tree-year model outputs by tree count and supplies no generic oxygen, carbon, monetary, or energy coefficient. The genuine question is which side of an air-and-carbon conversation you are modeling: the CO2 a person’s breathing produces under entered assumptions, or the annual services a set of trees returns from a named model.
Because neither page supplies its own factors, both results inherit every boundary and uncertainty from the values you enter. Neither tool produces inventory, certification, offset, or compliance numbers, and neither includes car or tree equivalents that would let you offset one side with the other.
What each calculator does
The CO2 breathing emission calculator computes exhaled CO2 volume as breaths per minute times liters per breath times the exhaled CO2 fraction times minutes, then converts volume to mass using an entered gas density:
CO2 volume = breaths/min × L/breath × CO2 fraction × minutes
mass = volume × entered gas density
For the worked example, 12 breaths per minute, 0.5 liters per breath, 4% CO2, and 60 minutes give a volume of 14.40 liters; at a density of 1.842 g per liter, the mass is 26.52 g CO2. A zero exhaled-CO2 fraction is the lower boundary of the accepted 0–100% range and gives 0.00 g.
The tree benefits calculator scales annual benefits by tree count:
total annual benefit = tree count × entered per-tree-year model output
For the worked example, 3 trees with entered model outputs of 20 kg per tree-year and 2 cubic meters per tree-year produce 60.0 kg per year and 6.0 cubic meters per year. The page requires you to record the model, version, location, species, and calibration behind the per-tree values, and it offers no generic coefficient of its own.
Side-by-side comparison
| Feature | CO2 Breathing Emission calculator | Tree Benefits calculator |
|---|---|---|
| Scenario modeled | Breathing (ventilation assumptions) | Multiple trees (entered model outputs) |
| Core inputs | Breathing rate, tidal volume, CO2 fraction, duration, gas density | Tree count, per-tree-year model outputs |
| Formula | Volume × density (grams) | Tree count × entered output (kg, m³, or other units) |
| Worked example | 12 breaths/min, 0.5 L, 4%, 60 min → 14.40 L, 26.52 g | 3 trees × 20 kg/tree-year → 60.0 kg/year |
| Coefficient source | User-entered scenario values | User-entered values from a named i-Tree or equivalent model |
| Shared boundary | Not a personal footprint; no inventory, offset, or compliance use | No generic coefficient; no guaranteed environmental benefits |
Verdict and limitations
Use the breathing calculator for short, physiology-scale scenarios where you have ventilation assumptions and a density basis, and use the tree benefits calculator when you have per-tree-year outputs from a named, location-calibrated model and want totals across a set of trees. The two tools occupy different scales and different boundaries: the breathing example is tens of grams per hour of exhaled gas, while the tree example is tens of kilograms per year of model-based services — and only a documented model with matching units and system boundaries could relate them. Neither result is an exact footprint, a forecast, or a compliance value, and neither should be used for offsets, certifications, inventories, or claims that a specific number of trees cancels a specific amount of breathing. Record the source, version, geography, and calibration of every entered factor, and treat both outputs as scenario arithmetic for education and planning.