Testing, Testing...

Photographed by Will von Dauster, AP / NOAA.  Chris Carparelli adjusts a glass flask among those that line the walls of an air sample processing room at NOAA’s Earth System Research Laboratory in Boulder, Colorado.  Researchers at the lab measure levels of CO2 and other greenhouse gases in air that’s sent in weekly from sites part of an international cooperative air sampling network.
photo source: Zenfs