Quantifying California's Anthropogenic Greenhouse Gas Budget

Marc L. Fischer


Sustainable environmental energy solutions require verifiable agreements to reduce anthropogenic greenhouse gas (GHG) emissions to the atmosphere. Supporting a vision for verified emissions reductions, LBNL is quantifying anthropogenic GHG emissions at local to regional scales in California.

We estimate California’s GHG emissions using a combination of atmospheric measurements and inverse models that balance prior knowledge and measured information, each weighted by their respective uncertainties. In collaboration with university, state, and federal partners, multi-species GHG measurements made over California are compared with high-resolution transport simulations that are carefully evaluated using the combination of radar-wind and aerosol-lidar profilers.

Fossil fuel CO2 emissions, quantified using one year of radiocarbon 14CO2 measurements at both Central (WGC) and one month at the Southern California (CIT) site, are consistent with existing emission inventories to within ~ 10%. CH4 emissions, quantified by a five-tower network over a one year period, are 1.6-2 times higher than existing inventory estimates. N2O emissions, estimated using two years of flask measurements at WGC, are ~ 2-3 times higher than existing emission inventories for Central CA. Initial comparison of selected industrial GHGs (e.g., SF6 and halo carbons) with CO show high correlations, suggesting it will also be possible to quantify HGWP GHG emissions.

We are now increasing the coverage of measurement sites across California and expect to provide comprehensive regional GHG emissions measurements for California, and eventually other regions of the world.