Scientists hope to get a clearer picture of how the Earth reacts to carbon dioxide with the launch of a new spacecraft designed to collect data on the climate-changing gas.
The Orbiting Carbon Observatory is set for launch early Tuesday from California and will take about eight million measurements every 16 days for the next two years.
Researchers said that the information will give them a picture of how the carbon cycle affects climate and how net emissions vary by region.
The goal is to measure carbon dioxide (CO2) sources and so-called "sinks" that pull the gas from the atmosphere.
Scientists know that only about 40 percent of the CO2 released since the Industrial Revolution remains in the atmosphere. They can only account for the absorption of another 30 percent, leaving questions about what happened to the 30 percent.
More complete measurements from the observatory should give them a better picture of where the carbon dioxide is being stored and how it changes over time. It should also help account for the uneven absorption of the gas from year-to-year, which does not correspond consistently with how much is released each year.