Heat-Trapping Gas Passes Milestone, Raising Fears

The average carbon dioxide reading surpassed 400 parts per million at the research facility atop the Mauna Loa volcano on the island of Hawaii for the 24 hours that ended at 8 p.m. on Thursday.  Chris Stewart/Associated Press

nytimes.com - by Justin Gillis - May 10, 2013

The level of the most important heat-trapping gas in the atmosphere, carbon dioxide, has passed a long-feared milestone, scientists reported Friday, reaching a concentration not seen on the earth for millions of years.

Scientific instruments showed that the gas had reached an average daily level above 400 parts per million — just an odometer moment in one sense, but also a sobering reminder that decades of efforts to bring human-produced emissions under control are faltering.

(READ COMPLETE ARTICLE)

National Oceanic and Atmospheric Administration (NOAA) monitoring program
http://www.esrl.noaa.gov/gmd/ccgg/trends/weekly.html

Scripps Institution of Oceanography monitoring program
http://scrippsco2.ucsd.edu/