While global warming is nothing to laugh at, an Australian company is providing some comic relief, selling carbon credits for flatulent pets and people. So-called carbon emissions, such as carbon dioxide and methane, are greenhouse gases that are thought to be key factors in climate change. These emissions can be offset by purchasing carbon credits, which may be used to fund environmental programs. For 35 Australian dollars (about 27 U.S. dollars), customers of Sydney-based Easy Being Green can offset a year's worth of carbon emissions linked to their dogs, from trips to the vet to, yes, breaking wind. Making your cat carbon neutral for a year costs U.S.$6, while U.S.$16 offsets two years of flatulence from that special someone. The company says it offsets the climate-warming effects of emissions from cars, planes, humans, and pets by installing energy-saving fluorescent light bulbs and water-saving shower heads in houses in New South Wales, Australia.