We talk a lot about reducing atmospheric carbon dioxide, but how do we know what strategies are working? Some dedicated souls with the right cutting-edge technologies will have to track and analyze carbon and other greenhouse gases, and atmospheric scientists are beginning to do just that, setting up greenhouse gas "budgets."

But the atmosphere delivers no monthly statement on greenhouse gas dynamics, so scientists have to tease out the information from disparate and often contradictory sources. The key task is measuring the sources, or emissions, of these planet-warming gases, and the “sinks” — forests, cropland and oceans that absorb carbon. This budget can then inform intelligent climate-control policy, whether it be managing one forest or shaping national emissions regulations.

Who's taking on this critical bit of accounting? Project Vulcan at Purdue University is working to quantify the North American carbon budget, "to support inverse estimation of carbon sources and sinks, and to support the demands posed by the launch of the Orbital Carbon Observatory (OCO) scheduled for 2008/2009." NOAA's Earth System Research Library has Carbon Tracker, "a system to keep track of carbon dioxide uptake and release at the Earth's surface over time." As these tools begin to appear and evolve, we still have uncertainty about "where the gases come from and where they end up," according to an article on "Carbon Detectives" in the New York Times.

“It’s a national priority to understand the carbon budget so people can make smart, good policy,” said Dr. Gurney of Purdue, adding that many scientists feel pressured to push the boundaries of knowledge in this field in their effort to slow global warming. “It’s what motivates us to wake up in the morning.”