Another point for dogs in eternal battle of cats vs. canines: While cats are bad for the environment, dog poop could help cut carbon costs. In Phoenix, a local dog park is trying to capture methane gas from dog waste and burn it in the park’s lamps.

Dog owners scoop their pets' poop with biodegradable bags, dump it in a composter, and turn the composter's crank. Methane rises to the top of the barrel and is channeled into the lamps, where it generates light.

The project will cost $25,000, but if that seems like an expensive way to power a few lamps consider that this particular dog park has 600,000 visitors per year. That's A LOT of dog poop that would otherwise go to the landfill. Turning it into methane and compost seems worth the price tag.

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