最近，两位新西兰建筑师在他们新近出版的书中表示，猫和狗这两种全世界最普遍的家养宠物每年所消耗的能源比一辆汽车还要多。这本书名为《是时候把狗给吃了：可持续生活指南》，作者在书中指出，养一只中型犬对生态环境带来的影响跟一辆4.6升的陆地巡洋舰一年行驶1万公里的影响是一样的；而养一只猫需要耗费的生态面积平均为0.15公顷，仅次于一辆大众高尔夫轿车所需的面积。为了减少猫狗宠物对生态的影响，让宠物主人给猫狗吃素并不是什么良策。该书作者建议人们改养更加“绿色”一些的小型宠物，比如金鱼、小鸡、小兔子等。另外，他们还开玩笑地建议，在猫狗宠物死亡以后，主人可以把它们给吃了或者制作成宠物食品来喂养别的宠物，以实现宠物喂养的可循环性。

Dogs and cats, the world's most popular house pets, use up more energy resources in a year than driving a car, according to a new book.

They're faithful, friendly and furry¹（毛皮的） - but under their harmless, fluffy²（毛绒绒的，蓬松的） exteriors³, dogs and cats, the world's most popular house pets, use up more energy resources in a year than driving a car, according to a new book.

In their book Time to Eat the Dog: The Real Guide to Sustainable Living, New Zealand-based architects Robert and Brenda Vale say keeping a medium-sized dog has the same ecological⁴ impact（生态影响） as driving 10,000 km a year in a 4.6 liter Land Cruiser.

Calculating that the modern Fido chows through about 164 kg of meat and 95 kg of cereals（谷类） a year, the Vales estimated the ecological footprint of cats and dogs, based on the amount of land needed to grow common brands of pet food.

"There are no recipes（处方，食谱） in the book," Robert Vale said, laughingly, in a telephone interview.

"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（公顷） 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.

Meat-eating swells⁵（增大，膨胀） the eco-footprint of canines⁶（犬科）, and felines⁷（猫科） are not that much better, the Vales found.

The average cat's eco-footprint（生态足迹）, 0.15 hectares, weighs in at slightly less than a Volkswagen Golf.

By comparison, the ecological footprint of an average human in the developing world is 1.8 hectares, while people in the developed world take 6 hectares.

With pets' diets under the control of owners, how can their unsustainable appetites be trimmed?

Convincing carnivorous（食肉的） cats and dogs to go vegetarian⁸ for the sake of the planet is a non-starter, 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 petfood when they die, may not appeal to（对……产生吸引力） animal fans.

Offputting as the idea may be, the question is valid⁹（有效的） given the planet's growing population and finite 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 lightbulbs or taking a cloth bag to the supermarket," he said.

"It's about much more challenging and difficult issues," he added. "Once you see where (cats and dogs) fit in your overall balance of things - you might decide to have the cat but not also to have the two cars and the three bathrooms and be a meat eater yourself."