Our four-legged, furry companions are often like members of the family, and just like us, they also have a carbon footprint. A new study has now revealed the fairly sobering impact that our beloved fluffles and fido actually have on the environment.

It is thought that there are an astonishing 163 million cats and dogs living in the homes of Americans. With their mainly meat-based diets, they account for up to an incredible 30 percent of the environmental impacts of meat consumption in the US. In hard numbers, they create the equivalent of 64 million tons of carbon dioxide every single year, or roughly the same amount as 13.6 million cars.

In fact, the pets in America consume so much meat each year, the authors have found that if they were to form a breakaway nation and go it alone (a sobering thought in itself), the four-legged country would rank fifth in global meat consumption. The only countries that would beat it would be Russia, Brazil, the US itself, and China.

“I like dogs and cats, and I'm definitely not recommending that people get rid of their pets or put them on a vegetarian diet, which would be unhealthy,” said Gregory Okin, co-author of the paper published in PLOS One. “But I do think we should consider all the impacts that pets have so we can have an honest conversation about them. Pets have many benefits, but also a huge environmental impact.”

Of course, all of that food we put in one end of our pets has to go somewhere. And so the analysis then turned its attention to the other end of cats and dogs, calculating that America’s pets produced around 5.1 million tons of poop every year, the equivalent of 90 million Americans.

The important factor here is that both cats and dogs are carnivores. Their diet therefore largely consists of meat, which obviously is produced in the same way that ours is. This intensive agriculture and farming is a major source of greenhouse gases, with some estimates finding that it accounts for up to 9 percent of total emissions in the US.

Obviously, the meat that goes into many pet foods is not fit for human consumption, and so it is not necessarily extra food that then needs to be made for humans. But the authors note that the market for premium pet food does contain meat that humans could eat, and that this market is growing.

The researchers hope to highlight not that we should be making our pets vegetarian – they are still carnivores after all – but instead how using as much of an animal as possible can help to dramatically cut meat consumption, and be better for the environment too.