Consider sulfur hexafluoride (SF6), a man-made gas used to insulate transformers and other electrical equipment. It’s a potent greenhouse gas, 23,900 times more powerful than CO2. That means under cap and trade, the price you pay for the right to emit one ton of SF6 is also 23,900 higher than the price of CO2—which is now $18 per metric ton in Europe. Under the U.N. Framework Convention on Climate Change, industrialized countries report how much of the stuff they’re pumping into the atmosphere. They calculate emissions using information on how much SF6 manufacturers sell to customers and estimates of how much escapes to the atmosphere from devices or production facilities. If you believe the reports, emissions of SF6 are declining.
The reports are wrong. When researchers actually measure the chemical in the air, they find it in quantities more than three times greater than what the reported amounts would indicate—and levels are increasing, not declining. The findings were a surprise, says NOAA’s Tans: “It wasn’t on anyone’s radar screen.”