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NASA Employs Satellite Data to Calculate California's Carbon Budget
Calculating the greenhouse gas emissions from a city, state, or country is a tricky business, as the calculations must include comprehensive tabulations of energy use, land-use changes, industrial emissions, and other factors. However, a recent project from the National Aeronautics and Space Administration (NASA) may point the way towards a future, simpler way. NASA employed its Terra satellite to measure the "greenness" of California's vegetation, then turned to an ecosystem simulation model to estimate monthly variations in the accumulated biomass of wood and other plant materials. Unfortunately, the agency still had to draw 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. See the NASA press release and the current status of the drought from the California Department of Water Resources.