Tag Archives: climate change

UCLA researcher finds that feeding pets creates the equivalent of 64 million tons of carbon dioxide a year

Note from DoggyMom:  It’s important for us to understand the environmental impacts of our activities.

On a scale with the huge consumption of meat in the USA, not to mention the environmental impacts of livestock production in other countries such as New Zealand’s dairy industry, the impact of pets is minor in comparison.

I recommend home-cooking and particularly the use of toppers with commercial foods to use meat leftovers and organ meats that we often discard.  But more importantly, if you move your human family to a plant-based diet, this will hugely offset any impacts from your pets eating meat!


With many Americans choosing to eat less meat in recent years, often to help reduce the environmental effect of meat production, UCLA geography professor Gregory Okin began to wonder how much feeding pets contributes to issues like climate change.

All that meat has important consequences. Okin calculated that meat-eating by dogs and cats creates the equivalent of about 64 million tons of carbon dioxide a year, which has about the same climate impact as a year’s worth of driving from 13.6 million cars.

dog eating food out of a bowl

Photo by: Patricia Marroquin/UCLA

“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,” Okin said. “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.”

In a paper published  in the journal PLOS One, Okin says he found that cats and dogs are responsible for 25 to 30 percent of the environmental impact of meat consumption in the United States. If Americans’ 163 million Fidos and Felixes comprised a separate country, their fluffy nation would rank fifth in global meat consumption, Okin calculated, behind only Russia, Brazil, the United States and China. And it all has to go somewhere — America’s pets produce about 5.1 million tons of feces in a year, as much as 90 million Americans. If all that were thrown in the trash, it would rival the total trash production of Massachusetts — from the humans, at least.

Compared to a plant-based diet, meat requires more energy, land and water to produce, and has greater environmental consequences in terms of erosion, pesticides and waste, Okin noted. Previous studies have found that the American diet produces the equivalent of 260 million tons of carbon dioxide from livestock production. By calculating and comparing how much meat 163 million cats and dogs eat compared to 321 million Americans, Okin determined how many tons of greenhouse gases are tied to pet food.

His calculations start with publicly available information, like the number of dogs and cats in the country and the ingredients in market-leading pet foods, leading to complicated equations like the mathematical menagerie below, and producing estimates that create a starting point for conversation.

He found that the nation’s dogs and cats eat about 19 percent as many calories as the nation’s people, on par with all the calories consumed by the population of France in a year. Because dog and cat food tends to have more meat than the average human diet, this means that dogs and cats consume about 25 percent of the total calories derived from animals in the United States.

Okin, a member of UCLA’s Institute of the Environment and Sustainability, usually researches dust bowls, desert landscape dynamics and wind erosion, and how those things can impact individual ecosystems and the global climate. Pinning down the environmental impact of canine companions and feline friends was more of an — ahem — pet project that occurred to him while he was thinking about the growing trend of raising backyard chickens.

“I was thinking about how cool it is that chickens are vegetarian and make protein for us to eat, whereas many other pets eat a lot of protein from meat,” he said. “And that got me thinking — how much meat do our pets eat?”

Okin recognizes that some of the products in pet food aren’t something people should or would eat. But some of it is. In his research, he confirmed his hunch that premium pet foods usually contain more animal products than other brands, and that premium pet food purchases are increasing. As growing numbers of people consider pets less as animals and more as family members, Okin said, pampering has increased and the options for pet food with high-quality meat has kept pace. This means pets are increasingly eating cuts of meat suitable for humans.

“A dog doesn’t need to eat steak,” Okin said. “A dog can eat things a human sincerely can’t. So what if we could turn some of that pet food into people chow?”

A commitment to snout-to-tail consumption, where as much rendered product as possible is produced for human use, could significantly reduce national meat consumption. Okin estimates that if even a quarter of the meat in pet food could be consumed by humans, it would equal the amount of meat consumed by 26 million Americans, nearly the population of Texas. Okin noted that ideas about what is edible vary dramatically by culture. He also pointed to a controversy in 2012 about “pink slime,” also called lean finely textured beef.

“It’s perfectly edible and completely safe, but it’s unappetizing, so people don’t want it in their food,” Okin said. “But frankly, it’s a good, inexpensive protein source.”

As eating less meat expands from vegetarian to environmental circles as a way to reduce one’s carbon footprint, considering what to feed pets is a natural next step, Okin said. It’s not just an issue in the United States, he noted. In places like China, Brazil and other emerging countries, as the population becomes more affluent, they’re eating more meat and they’re getting more pets.

“I’m not a vegetarian, but eating meat does come at a cost,” he continued. “Those of us in favor of eating or serving meat need to be able to have an informed conversation about our choices, and that includes the choices we make for our pets.”

He doesn’t see a simple solution. Pets provide friendship and other social, health and emotional benefits that can’t be discounted, Okin said. People concerned about meat intake could consider vegetarian pets, like birds or hamsters, he suggested. The pet food industry, he noted, is also beginning to take steps toward sustainability, and could work to reduce overfeeding and consider alternative sources of protein. But it’s a complicated issue, and where pets are concerned, Okin knows it’s important to have a sense of humor about it.

“Maybe we could all have little ponies,” he said, half-jokingly. “We’d all get more exercise taking them for walks, and they would also mow the lawn.”

Source:  UCLA Newsroom

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Scat sniffer dogs help tell the story of endangered lizards

Dogs can be trained to find almost anything (people, drugs, weapons, poached ivory) but one York University researcher had them detect something a little unusual – the scat of endangered blunt-nosed leopard lizards.

The scat detection dogs helped biology PhD student Alex Filazzola discover not only scat, but the importance of shrubs in preserving lizard populations in the face of climate change.

“The loss of these lizards would likely have a cascade effect on other species,” said Filazzola, the study lead.

The research team geo-tagged 700 Ephedra californica shrubs in a 32.3-hectare area of the Panoche Hills Management Area in San Joaquin Valley, California. They then took two scat detection dogs from Working Dogs for Conservation on the hunt for lizard scat in 2013 and 2014.

In 2014, there was a drought during which time lizard scat was found more frequently under shrubs, especially those with dense canopy cover, than out in the open. The shrubs proved instrumental in providing critical micro-environments for the blunt-nosed leopard lizards, in particular, shady places to regulate their body temperature in extreme heat, as well as refuge from predators. The lizards use rodent burrows, most often found under shrubs, to escape predators.

“As the climate warms and lizards find it more difficult to regulate their body temperatures in the heat, these findings could help preserve them not only in California, but globally,” said Filazzola of York U’s Faculty of Science. “It demonstrates how much animals rely on plants for survival that goes beyond that of simply eating them. Positive plant-animal interactions could further support animal populations that are already threatened.”

The research, “Non-trophic interactions in deserts: Facilitation, interference, and an endangered lizard species,” was published in the journal Basic and Applied Ecology.

Once abundant in the San Joaquin Valley, agriculture and industrialization has reduced the lizards’ range by close to 85 per cent. Predictions of increased drought in the area put the lizards at a high risk of being wiped out. The study also pointed out that management techniques used over the past 50 years have done little to change the endangered status of the lizards.

“Planting shrubs, such as the Ephedra californica, could prove critical in managing and preserving endangered species in high-stress or arid ecosystems, such as a desert,” said Filazzola. “Continuing to remove these shrubs to install solar panels, however, further endangers this species.”

In addition, the study found that invasive grasses in the desert were not beneficial. They interfered with the lizards’ ability to move around and limited available habitat by reducing the variety of rodent species which create burrows. The invasive grasses also competed for space with shrubs and caused diminished shrub growth. Managing invasive plant species is therefore crucial in these ecosystems.

The research was funded by the Central Coast Field Office of the Bureau of Land Management, Department of the Interior, a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada and York University.

Source: York University media release

Dogs evolved with climate change

World leaders are meeting right now in Paris to discuss climate change…but did you know that dogs evolved in part because of climate change?

A study of North American dog fossils as old as 40 million years suggests that the evolutionary path of whole groups of predators  – including dogs – can be a direct consequence of climate change.  The study has been published in the journal Nature Communications.

“It’s reinforcing the idea that predators may be as directly sensitive to climate and habitat as herbivores,” said Christine Janis, professor of ecology and evolutionary biology at Brown University, who worked with lead author Borja Figueirido, a former Brown Fulbright postdoctoral researcher who is now a professor at the Universidad de Málaga in Spain. “Although this seems logical, it hadn’t been demonstrated before.”

The climate in North America’s heartland back around 40 million years ago was warm and wooded. Dogs are native to North America. The species of the time, fossils show, were small animals that would have looked more like mongooses than any dogs alive today and were well-adapted to that habitat. Their forelimbs were not specialized for running, retaining the flexibility to grapple with whatever meal unwittingly walked by.

Early Dogs

Two early dogs, Hesperocyon, left and the later Sunkahetanka, were both ambush-style predators. As climate changes transformed their habitat, dogs evolved pursuit hunting styles and forelimb anatomy to match.
Image: Mauricio Anton

But beginning just a few million years later, the global climate began cooling considerably; the forests slowly gave way to open grasslands.

Pups of the plains

Did this transition affect the evolution of carnivores? To find out, Figueirido and the research team, including Jack Tseng of the American Museum of Natural History in New York, examined the elbows and teeth of 32 species of dogs spanning the period from ca. 40 million years ago to 2 million years ago. They saw clear patterns in those bones at the museum: At the same time that climate change was opening up the vegetation, dogs were evolving from ambushers to pursuit-pounce predators like modern coyotes or foxes — and ultimately to those dogged, follow-a-caribou-for-a-whole-day pursuers like wolves in the high latitudes.

“The elbow is a really good proxy for what carnivores are doing with their forelimbs, which tells their entire locomotion repertoire,” Janis said.

The telltale change in those elbows has to do with the structure of the base where the humerus articulates with the forearm, changing from one where the front paws could swivel (palms can be inward or down) for grabbing and wrestling prey to one with an always downward-facing structure specialized for endurance running. Modern cats still rely on ambush rather than the chase (cheetahs are the exception) and have the forelimbs to match, Janis said, but canines signed up for lengthier pursuits.

In addition, the dogs’ teeth trended toward greater durability, Figueirido’s team found, consistent perhaps with the need to chow down on prey that had been rolled around in the grit of the savannah, rather than a damp, leafy forest floor.

If predators evolved with climate change over the last 40 million years, the authors argue, then they likely will have to continue in response to the human-created climate change underway now. The new results could help predict the effects we are setting in motion.

“Now we’re looking into the future at anthropogenic changes,” Janis said.

Source:  Brown University media release