Kill a camel, earn cash for cutting greenhouse gases: That offer may be coming soon in Australia, where vast numbers of the nonnative, methane-belching animals have been trampling the Outback for more than a century.

The government has proposed that killing camels be officially registered as a means of reducing greenhouse gas emissions. Australia has the world's largest population of wild camels - an estimated 1.2 million - and considers them to be a growing environmental problem.

Duke University and Duke Energy are working together to create a green machine from hog waste.

Progress Energy said this morning it signed its fourth contract to buy green energy generated by gases that seep from landfills.

The Raleigh-based electric utility signed a 12-year contract with Methane Power to buy electricity to be generated by methane from the Wayne County Landfill, about an hour southeast of Raleigh.

The methane power plant is expected to begin generating power by the end of this year and create enough electricity to serve about 1,800 typical households.