California Emissions Estimator Model
Description
CalEEMod (California Emissions Estimator Model) is a free, statewide land use emissions calculator used to estimate air pollutant and greenhouse gas emissions from development projects in California. It allows planners, consultants, and agencies to input project characteristics (like land use type, size, construction schedule, and operations) and then uses built?in emission factors and default assumptions to quantify construction and operational emissions (e.g., vehicle trips, energy use, area sources). The tool supports CEQA review, air district permitting, and project comparison by providing standardized, transparent emission estimates for proposed developments.
Questions this resource can help answer
What are the estimated construction?phase and operational air pollutant and GHG emissions from this proposed development?
Do project emissions exceed my air district’s CEQA screening or significance thresholds?
How much can specific mitigation measures (e.g., improved transit access, energy efficiency, EV charging) reduce emissions?
Which project components (traffic, energy, construction equipment, area sources) contribute most to total emissions?
How do emissions from alternative project designs or scenarios compare?
How do I use this resource?
To use CalEEMod, create a new project and enter basic information (location/air district, land use types, project size, and timelines). Work through the input tabs—Land Use, Construction, Mobile, Energy Use, Area Sources, Waste & Water—accepting defaults where appropriate or replacing them with project?specific data (e.g., traffic studies, building efficiency, mitigation measures). Once inputs are complete, run the model to generate emission estimates for construction and operations (criteria pollutants and GHGs) and export summary and detailed reports for agency review.
Pro tips
Always select the correct air district and climate zone first; this sets key defaults and emission factors.
Start with model defaults, then only override values when you have reliable project?specific data.
Keep a clear record of all assumptions and changes from defaults—agencies will ask.
Run a baseline scenario (no mitigation) and then separate mitigated scenarios to show reductions.
Check that trip rates, land use intensities, and schedules are realistic and consistent with your traffic and planning documents.
