According to two New Zealanders, owning a pet dog is worse than owning a sports utility vehicle in terms of the eco-footprint. The declaration in the book “Time to Eat the Dog: The Real Guide to Sustainable Living” by New Zealanders Robert and Brenda Vale goes over the numbers. Taking into account the land required to generate its food, a medium-sized dog has an annual footprint of 0.84 global hectares (2.07 acres). Compare that to the mere 0.41 global hectares required to drive a sports utility vehicle 10,000 kilometres (6,200 miles) a year (the number includes the energy to build the car). Some experts, however, disagree with that “dog” number.

“When I saw the study I ran some quick numbers,” Clark Williams-Derry, chief researcher at a the Sightline Institute, a Seattle-based sustainability thinktank, told the Seattle Times. “The average dog has to eat at least twice as much as the average person for this to be right. People are just heavier than dogs so, I just had to scratch my head at that.”

But, heck, forget pets. They are mere blips on the radar. By taking a quick jaunt over to Wikipedia, I was able to deduce the average eco-footprint of a human being. “In 2005, the average biologically productive area per person worldwide was approximately 2.1 global hectares (gha) per capita. The U.S. footprint per capita was 9.4 gha, and that of Switzerland was 5.0 gha per person, while China’s was 2.1 gha per person. The WWF claims that the human footprint has exceeded the biocapacity (the available supply of natural resources) of the planet by 20%. Wackernagel and Rees originally estimated that the available biological capacity for the 6 billion people on Earth at that time was about 1.3 hectares per person, which is smaller than the 2.1 global hectares published for 2005, because the initial studies neither used global hectares nor included bioproductive marine areas.” (http://en.wikipedia.org/wiki/Ecological_footprint)

Dogs have many eco-advantages to human beings. They do not drive cars, buy bottled water, burn fires in chimneys, buy plasma televisions, get new clothes every season, turn on the air conditioner, use computers, buy cosmetics, water their lawns, insist on the newest goodies for Christmas and birthdays, or commit any number of other human eco-sins. Humans are, of course, far worse for the environment than even the most anti-environmentalist of canines.

Just to see what my footprint was, I tested out this nifty footprint calculator at http://www.footprintcalculator.org/ and came up around 4 gha per year. So, for each child a U.S. resident foregoes, he or she can own approximately 62 medium-sized dogs–a fair trade, in my assessment. That number takes into account the comparative lifespans of each species, with dogs at about 14 years and humans at approximately 78 years. Dogs have other advantages to children that aren’t directly related to their environmental impact. For example, a child isn’t going to bark at a strange noise, alert me to smoke in my home, or even–in the case of my dogs–carry my laundry upstairs, get my shoes or slippers, and turn on or off the lights when needed.

So, Robert and Branda Vale, forget having any(more) kids…get a dog!

Author D. Capp holds an M.S. in medical science (biochemistry and genetics), a bachelor’s degree in biochemistry and molecular biology, and a law degree.