pollution

methane levels hold steady

levels of the greenhouse gas methane have plateaued for the first time in about 200 years, shows a report in geophysical research letters. methane is second only to carbon dioxide in contributing to our planets warming. the gas - belched out by fossil-fuel burning, rice paddies, festering farm manure and landfill sites - has been accumulating since the industrial revolution. now the tide may be turning, say ed dlugokencky of the national oceanic and atmospheric administration noaa in boulder, colorado, and his team. they found that levels steadied between 1999 and 2002, according to measurements from 43 ground-based stations around the world.
the reason for the change is unclear. dlugokencky believes that a big contributing factor was the break-up of the soviet union in 1991. oil and gas production fell, and the industry became more efficient at plugging gas leaks from pipes and wells.
experts say the platea...