Home
Measuring the greenhouse gas emissions from a city, state, or country requires comprehensive tabulations of energy use, land-use changes, industrial emissions and many other factors.
The National Aeronautics and Space Administration (NASA) has recently explored new methods for managing carbon emissions inventories. Using NASA’s Terra satellite, the agency surveyed the “greenness” of California’s vegetation and then plugged the results into an ecosystem simulation model to estimate monthly variations in the accumulated biomass of wood and other plant materials. One key limitation for the method: it relied on inventory data from the California Energy Commission to model the greenhouse gas emissions from fossil fuel combustion and from agricultural lands throughout the state.
The study found that in 2004, the state’s natural ecosystems absorbed as much carbon dioxide from the atmosphere as was emitted by burning fossil fuels, with significant amounts of carbon dioxide being trapped in forests and soils during periods of above-normal rainfall. The bad news for California is that such periods of above-normal rainfall have become rare, as the state has been suffering under drought conditions since the fall of 2006.
