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Week Five - Reduce My Carbon Pawprint

Save 625 kilograms CO2e per person per year

· Weekly experiments


- I wonder what Big Ted eats to grow so big?

My preschooler

- Fart poo and strawberries.

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Carbon Hungry Pets

There are 24 million pets in Australia, which makes for more pets than people. Nearly two in five households own a dog and one in three own a cat. We spend around $12 billion each year on our pets. Any way you look at it, that's a lot of carbon.

My household has two dogs (three, when my preschooler barks like a puppy). Our dogs are part of our family and I can't imagine life without them. What's the best way to reduce their carbon dioxide and equivalent emissions (CO2e)?

Dogs aren't usually catching planes, burning coal-fired energy or buying fast fashion (although increasing hipsterisation is changing this). Their biggest impact comes from their diet. This week, I compared the annual impact of four different feeding methods for my two medium-sized dogs.

It's a while since I've bought dog food in the supermarket. There used to be four choices - wet or dry, beef or chicken. You can now pick pork, turkey or duck, grain-free, organic or gourmet, kibble, canned, single-serve or refrigerated. There's a similarly massive range in environmental impact.

#1 Vegan kibble - 700 kilograms CO2e per year for two medium dogs

Contrary to popular belief, dogs aren't wolves and one of their major adaptations is the ability to digest grains and starch. There are strong views about whether a vegan diet is healthy for dogs, but there's limited data, although this vegan feeding trial on sled dogs looks promising. If you want to switch to vegan dog food, look for one labelled 'complete and balanced' with good feeding trials to support it and consult your vet.

#2 Mixed diet of vegan kibble + low-meat homemade food - 600 to 800 kilograms CO2e per year for two medium dogs, depending on choice of meat

My vet panicked when I suggested a vegan diet for my dogs 8 years ago, so we compromised with vegan kibble combined with a low-meat home prepared dog food. My dogs thrive on this, with the last two sadly dying at ages 15 and 16. I was surprised to see that by switching out the beef and using kangaroo or chicken instead, our emissions dropped by 200 kilograms CO2e each year. No more cow for my hounds.

#3 Kibble with grains as the first ingredient and low-carbon chicken and kangaroo meats - 1.5 tonnes CO2e per year for two medium dogs

If you don't want to cook and freeze dog food once a fortnight (fair enough, we're all busy) and if you're not keen on a vegan diet, a good choice might be a 'complete and balanced' supermarket kibble that lists grains as the primary ingredient and doesn't contain beef or lamb. This also reduces emissions in transport, as you're freighting around less than one third of the weight of fresh or canned food. It will also cost less. Unfortunately, manufacturers don't show exact amounts of each ingredient on the label and may list a range of meats without specifying which one you get. Try writing to your manufacturer and asking how much of which kind of meat they use. I assumed a 20% meat content in my scenario split across chicken and kangaroo.

#4 Canned dog food with meat as the first ingredient - 1.5 to 6.5 tonnes CO2e each year for two medium dogs

The impact of a high-meat canned diet shocked me. It could generates more CO2e than my total annual budget simply to feed my dogs. The variation between 1.5 tonnes and 6.5 tonnes largely depends on whether the meat is low impact (chicken and duck), medium (pork and kangaroo) or high (beef, lamb and turkey). I assumed a 50% meat content, which might be on the high side high but was consistent with the ingredients list and the tendency in premium canned food to contain more meat.

Manufacturer Feed Recommendations

For scenario two, I used the amounts I actually feed my dogs. For other scenarios, I used manufacturer feeding recommendations for two 15 kilogram dogs. These may not be comparable. Manufacturers want to sell you more, so their recommendations often suggest overfeeding. After years of painstaking research and field work, I have devised a simple test to empower you to ignore manufacturer guidelines and feed the correct amount.

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What were my CO2e savings?

On average, each Australian household has 1.3 dogs and 1.4 cats. I couldn't find an average for how much CO2e this generates from animal diets - it would vary widely depending on animal size and feeding components - so I'll assume my household of 2.5 people with two medium dogs is average. My household makes a massive saving of between one and six tonnes of CO2e each year with a low-carbon dog diet. This is well worth doing and should get more attention than other areas, like waste.


From an environmental perspective, cats are more contentious. They're carnivores who don't adapt well to a vegan diet (though there's debate on that). They also kill a lot of wildlife, which is why Canberra's cat containment suburbs require them to be indoors at all times. On the other hand, a small cat eating only meat has a lower impact than a large dog on a mixed diet. Fortunately, I don't like cats, so this is someone else's dilemma.

Save the planet, eat your cat

How Can I Reduce My Pets' Impact?

- Don't overfeed your pets.

- Feed pets food that would otherwise become waste, like offal or leftovers, but make sure it's not harmful (eg. don't give onion to dogs).

- Consider a low-meat, homemade and / or vegan diet. Consult your vet about dietary changes.

- Don't buy pet toys, clothes and accessories, or buy a couple of high-quality ones that last.

- Next time, get a smaller breed that eats less, a rescue animal that doesn't create a new carbon pawprint, or fewer animals.

- Save the planet. Eat your cat. I mean, keep your cat indoors and offset its carnivorous pawprint by reducing carbon in other areas.

I updated this post to include a multiplication factor of 3.8 to adjust for moisture content in fresh and canned food versus dry kibble. Other data issues include the fact that I've used bone-free human grade meat emission factors to look at petfood meat, but petfood typically uses by-products which would have a lower emission factor. For discussion of this and other data details, see 'Notes' section, Week Five.