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.