Uptick in carbon dioxide is recorded at Mauna Loa

A 50-year record of air measurements from Mauna Loa Observatory shows a steady increase in carbon dioxide, with faster growth since 2005, says station chief John Barnes.

But global warming has been slowed under an international agreement to reduce production and use of ozone-depleting chemicals, he said. "That's like the good story."

The National Oceanic and Atmospheric Administration's 11,140-foot observatory on Mauna Loa has the longest continuous measurements of atmospheric CO2 in the world.

During 800,000 years of history recorded in ice cores, including big ice ages every 100,000 years, carbon dioxide cycled from 180 to 280 parts per million molecules of air, Barnes said.

That changed around 2005, when atmospheric carbon dioxide hit 380 parts per million, he said.

"The de-seasonalized, postindustrial trend in added carbon dioxide has been increasing exponentially, with a doubling time of about 32 years," according to a NOAA report on global CO2 measurements....

The Mauna Loa Observatory is one of five base-line stations for the Earth System Research Laboratory. Scientists there are trying to get a global picture of greenhouse gases in the atmosphere for research and climate modeling, to see what will happen in 50 to 100 years, Barnes said.