In their book Time to Eat the Dog:The Real Guide to Sustainable Living,Robert and Brenda
 Vale say keeping a mediumsized dog has the same ecological impact as driving 10,000 km a year
in a 4.6 liter Land Cruiser.
     "We're not actually saying it is time to eat the dog.We're just saying that we need to think about
and know the ecological impact of some of the things we do and that we take for granted."
     Constructing and driving the jeep for a year requires 0.41 hectares of land,while growing and
manufacturing a dog's food takes about 0.84 hectares-or 1.1 hectares in the case of a large dog
such as a German shepherd.
     Convincing flesheating cats and dogs to go vegetarian for the sake of the planet is a nonstarter,
the Vales say.Instead they recommend keeping "greener",smaller,and more sustainable pets,such as
goldfish,chickens or rabbits.
     The book's playful title,and serious suggestion that pet animals may be usefully"recycled",by
being eaten by their owners or turned into pet food when they die,may not appeal to animal fans.
     Annoying as the idea may be,the question is valid given the planet's growing population and limited
resources,Robert Vale said.
     "Issues about sustainability are increasingly becoming things that are going to require us to make
choices which are as difficult as eating your dog.It's not just about changing your light bulbs or taking
a cloth bag to the supermarket,"he said.
     "It's about much more challenging and difficult issues," he added.