Atmospheric Levels of Two Potent Gases on the Rise
Tuesday, March 3rd, 2009When people think of climate change, they think of carbon dioxide. But while CO2 represents 77 percent of all man-made greenhouse gas emissions, its relative contribution may be declining. According to two studies published late last year, atmospheric levels of other, more potent gases that also affect climate are on the rise. One such gas is nitrogen trifluoride (NF3), which is used to make retail items like microchips and flat-screen TVs. Atmospheric NF3 seems to be growing by 11 percent each year across the globe. NF3 lingers in the air for 550 years, on average, and is 17,000 times better at trapping heat than CO2 on a molecule-per-molecule basis. A more immediate problem for climate change is methane, which is released by landfills and melting permafrost and through farming practices. Levels of this gas are increasing today after eight years of stasis. Methane remains in the atmosphere one-tenth as long as CO2—about a decade—but traps 20 times as much heat.

