Peter Henderson, PlanetArk 30 Jan 09;
SAN FRANCISCO - The United States next month will launch a satellite to study global warming by measuring carbon dioxide in the atmosphere -- and search for some the climate-changing pollutant scientists cannot find.
Carbon dioxide is the main cause of global warming. Burning fossil fuels and deforestation has shot concentrations to levels that are causing global alarm about a changing climate, but measurement of the gas outside Europe and the United States is spotty -- and sometimes limited to closing a jar of air and mailing it to a lab, NASA said on Thursday.
Scientists, meanwhile, cannot figure out where all the carbon dioxide released into the atmosphere goes, a critical detail for forecasting the speed and reach of pollution's effect on climate. After vehicles and factories release the gas into the air, the world's oceans and land absorb much of it.
"While we understand approximately how much carbon dioxide is released into the atmosphere each year due to human influences, we can only account for about half of the carbon dioxide that doesn't remain in the atmosphere," Eric Ianson, National Aeronautics and Space Administration program director for the Orbiting Carbon Observatory, told a news conference.
The $278 million program launches its satellite on February 23. Over two years the satellite will cover the earth every 16 days. Each 16-days sweep will take 8 million measurements.
Japan this month launched its own satellite to measure carbon dioxide and methane, another greenhouse gas. Both launches come as about 190 nations try to agree on a successor climate change treaty to the Kyoto Protocol, which binds wealthy nations -- not including the United States -- to emissions targets through 2012.
NASA described the Japanese and U.S. satellites as using different technology, flying in different orbits, and had slightly different missions -- the Japanese satellite is more focused on monitoring sources of carbon dioxide for treaties, while the U.S. effort focuses on where the gas goes.
The U.S. technology measures light bounced off the planet. Carbon dioxide absorbs light in some frequencies, so that the less light detected, the higher the concentration of carbon.
"What we want to understand is exactly why and how and where these sinks of carbon from the atmosphere to the oceans and plants are taking place. And the reason we want to know this is we want to be able to better predict how these sinks or these outtakes will evolve in the future," mission scientist Anna Michalak said at the news conference.
(Editing by Stacey Joyce)
