CIRES' Molly Crotwell processes air-filled flasks in NOAA's Earth System Research Laboratory in Boulder, Colo.

The sealed glass flasks, sent back to Boulder from dozens of remote sites around the world, contain air samples, which are analyzed for levels of greenhouse gases and much more. These and other data comprise NOAA's Annual Greenhouse Gas Index, a measure of the combined climate effects of greenhouse gases. The 2012 AGGI, released today, shows a continued steady upward trend that began with the Industrial Revolution of the 1880s.