Companion Carbon Pawprint

Billions of animals are killed every year to feed not just humans, but the dogs and cats we share our homes with. Pet food is a vast, profitable industry – and its climate impact is staggering. Yet it’s still treated as a footnote in climate policy, brushed aside with the excuse that it “just uses leftovers.” The truth is more uncomfortable: companion animal diets are fuelling environmental breakdown, and the fastest way to slash that footprint is already on the table – we’re just not using it.

The Scale of the Problem

Globally, nearly one billion dogs and cats live in over half of all households. In terms of biomass, they outweigh all remaining wild terrestrial mammals combined. In the U.S. alone, they eat 20% of all farmed animals. Globally, it’s 9%.

Pet food is a $32.2 billion industry projected to hit $44.5 billion by 2027. Demand for “premium,” human-grade flesh products is rising, often exceeding pets’ nutritional needs. Guardians also overfeed – sometimes out of misplaced affection – inflating production beyond what’s necessary. Large dogs, in particular, have an ecological footprint nine times that of small dogs.

The ingredients used in pet food drive around 70% of its total carbon impact. Processing, packaging, and transport barely compare. Wet food can generate almost eight times the emissions of dry food. Ingredient choice – especially animal protein – is where the damage is done.

The Byproduct Myth

The industry likes to claim it’s green because it “recycles” parts of slaughtered animals humans won’t eat – ears, snouts, organs, bone meal. These are called animal byproducts (ABPs). The story goes that using them keeps them out of landfill and offsets human meat consumption.

Reality check:

▫️Only 25% of ABPs in wealthy countries go to pet food.

▫️The rest are snapped up by other industries – pharmaceuticals, livestock feed, energy production – all of which would keep buying them if pet food didn’t.

▫️Byproducts bring in 11% of beef revenue and 7.5% of pork revenue. They are not waste – they’re a lucrative coproduct.

▫️ABPs are nutritionally poorer than prime cuts, so making pet food from them often requires more carcasses, not fewer. Dogs need 1.4 times the number of carcasses when fed ABP-heavy diets; for cats it’s 1.9 times.

In other words, ABPs don’t “save waste.” They keep slaughterhouses profitable, increase demand for farmed animals, and carry a bigger environmental burden per gram of protein than lean meat.

The Numbers Are Not Small

In the U.S., feeding dogs and cats accounts for 25–30% of the environmental impacts of the entire livestock sector. That’s a sector already responsible for at least a fifth of global greenhouse gas emissions – possibly more.

A medium dog in Japan has a bigger dietary footprint than the average Japanese person. Two medium dogs equal one person’s entire footprint. In high-income countries, shifting dogs to plantbased diets can deliver one quarter to one third of the climate benefit of shifting humans. Globally, the gains are smaller – one fifth to one tenth – but still enormous.

Modelled globally, a complete shift of all dogs and cats to plantbased food would:

▫️Free up land larger than Mexico and Germany combined.

▫️Cut greenhouse gas emissions greater than the total annual emissions of the UK and New Zealand combined.

▫️Save enough crops to feed an extra 520 million people – or 1.4 billion more dogs and cats.

And that’s using conservative estimates.

The Health Question

Opponents of plantbases companion diets often wave the “nutritional deficiency” flag. The evidence says otherwise. By early 2025, 11 studies in dogs and three in cats – plus a systematic review – found plantbased or vegetarian diets, when properly formulated, to be nutritionally sound and often linked to equal or better health outcomes compared to flesh-based diets.

Dogs and cats need nutrients, not flesh. Modern companion food – plant or flesh-based – relies on synthetic supplements for many of those nutrients, because processing destroys them. Taurine in flesh? It’s often degraded in cooking, so it gets added back in. Those same supplements work just as well in plantbased formulations.

Palatability studies show no significant difference in enjoyment between plant and flesh diets. If a plantbased food didn’t taste good to animals, it simply wouldn’t sell.

Beyond Plants – The Rise of Alternative Proteins

The most immediate and scalable fix is plantbased companion food. But other innovations are emerging:

▫️Cultivated flesh – real animal tissue grown from cells without raising or killing animals. BioCraft’s cultivated flesh for companions emits just 8.3% of the CO₂ of cow byproducts. One live mouse cell sample can, in theory, produce flesh indefinitely. The first cultivated dog food went on sale in the UK in February 2025.

▫️Precision fermentation – using microorganisms to produce specific proteins with tiny land, water, and carbon footprints. Calysta’s protein plant can produce 100,000 tonnes on just 10 hectares of land. Producing the same amount of soy would need 250,000 hectares.

▫️Yeast, fungi, and algae – nutrient-dense, low-impact ingredients that can be grown without farmland at all.

Not all “alternatives” are equal. Insect farming has been touted as sustainable, but questions around insect sentience, welfare, scalability, and actual environmental gains make it a poor ethical or ecological solution.

The Policy Gap

Despite the clear climate case, companion food is missing from national emissions inventories and reduction targets. Governments are still treating it as a private consumer choice – but we are out of time for that approach. The researchers behind multiple studies recommend:

▫️Reclassifying byproducts as coproducts to reflect their real economic and environmental value.

▫️Including companion food in climate targets.

▫️Mandating carbon labelling for companion food, like we’re starting to see with human food.

▫️Funding R&D for alternative proteins.

▫️Supporting manufacturers and retailers to transition.

Changing the Narrative

We don’t have to frame this as taking something away from companions. We frame it as giving them food that meets their needs without fuelling mass slaughter, deforestation, water depletion, and greenhouse gas emissions. Choosing smaller companion animals over large ones reduces environmental impact dramatically. Preventing overfeeding cuts both waste and obesity. Adopting animals instead of breeding them reduces overall population growth – and the resources they consume.

But the real win comes from replacing animal-sourced ingredients entirely. A global transition to plantbased companion food could happen faster than for human diets, because there’s less cultural baggage and no need to overcome the taste preferences of the consumer – the dog or cat doesn’t care about the politics of meat.

The Clock Is Ticking

We’re living through the most documented collapse of life in Earth’s history. Every tonne of CO₂ we can prevent matters. Every hectare of land we can free up matters.

The companion food industry is a multi-billion-dollar sector with the potential to deliver massive climate gains quickly. The science is in. The nutritional solutions exist. The market is ready – plantbased companion food sales are growing nearly six times faster than conventional.

What’s missing is the urgency.

Feeding the animals we love should not come at the cost of the planet we share. The choice is clear: keep pretending that bowls of flesh-based kibble are harmless, or start feeding them in a way that protects all life – theirs, ours, and everyone else’s.