In celebration of Earth Day, this week’s post continues to focus on sustainable cat care. One of your cat’s essential resources is his litter box. Litter boxes are typically made of plastic but there are many choices of litter box filler. How can your choice of cat box filler help in reducing your cat’s carbon pawprint?

What makes a cat litter sustainable?

  • Made from renewable resources
  • High absorbency to reduce the amount needed
  • Biodegradable

Reducing your cat’s carbon pawprint: sustainable cat litters

the scoop on kitty litter

Kitty litter is the brainchild of Edward Lowe. He began promoting fuller’s earth, an absorbent clay, as  a cat box filler in 1947. Previously sand and ashes had been used as cat box filler – neither had the absorbency of the new clay product.

Clay cat litters are still with us. The original kitty litter was a non-clumping litter. In 1984, Thomas Nelson developed clumping cat litter using calcium bentonite. Clay materials dominated the cat litter market in 2021 with a share of 83.6% per Grandview Research

Clay Litters are not sustainable

These materials come from strip mines. Not only are they not renewable (at least in our lifetimes), they wreak havoc on the environment. They are not biodegradable. They are, however, relatively inexpensive.

Alternatives to Clay Litters

Other types of litters include those made from silica, recycled paper, wood, corn, peas, walnut shells, coconut husks, and grass.

Cat litter made from silica (crystal litters) and diatomaceous earth also must be mined. Diatomaceous earth is the fossilized remains of tiny aquatic organisms called diatoms – again, these litters are not renewable and not sustainable.

Recycled Paper

Litters made from recycled paper come from sustainable sources. However, some paper litters are not very absorbent and have to be changed frequently.  This may contribute to increased mass in a landfill. Paper is biodegradable.

Clumping or non-clumping?
Clumping litters make it easier to scoop the litter box frequently (at least once a day!) The clumping litter sticks to the waste and keeps it from contaminating the remaining litter. It more likely that you will dump non-clumping litter more frequently because the soiled litter with  mixes the non-soiled litter.  Using non-clumping litter may increase the amount of litter in the landfill.

Plant-based Litters

Plant-based litters are made from corn, peas, wheat, wood, and even tofu by-products. Starch and plant fibers such as guar gum make these litters clump. These litters tend to be lighter, less dusty and more absorbent than clay litter and are biodegradable. They are unfortunately more expensive than the old clay standby but they are sustainable.

  • You can grow more plants to produce more litter.
  • The growing and harvesting methods do not damage the environment as much as strip mining.
  • Plant-based litters are more absorbent than clay and less plant-based litter is needed for the litter pan.

A Better Mousetrap?

The Tidy Cat Breeze system uses zeolite pellets on a grate with a disposable pad underneath to catch liquid waste. Per the manufacturer, the pad is changed every week and the pellets monthly.

Zeolite is another mined material so loses some marks in sustainability although some people wash and reuse these pellets. This can extend the life of the pellets by a few months. The absorbent pad is plastic-backed so this is more plastic to go in the landfill.  Another downside to this system is you may have to train your cat to use it – cats prefer softer finer particles in their litter.

litter in the landfill

 Disposal options for cat litters include landfills, flushing down the toilet, and composting.

  • Clay litters cannot be flushed down the toilet or composted.
  • Even biodegradable litters may not degrade much in a landfill.
  • Although much of the plant-based products can be flushed, there are the risks of clogged plumbing and introduction of pathogens into the water supply.
  • These litters can be composted although there are concerns about parasites and bacteria from decomposing pet waste.

Composting cat litter
This is a controversial topic. Although plant and paper-based soiled cat litters can be composted, home compost piles do not get hot enough to kill pathogens so you certainly do not want to use composted cat litter on vegetable gardens.

Reducing Your cat’s carbon pawprint using sustainable cat litter

As the sun sets on 2023 Earth Day, here are some conclusions:

  • Clay and other mineral based cat litters come from limited natural resources and are not sustainable.
  • Paper and plant-based litters come from renewable resources, are biodegradable, and more sustainable.
  • Paper and plant-based cat litters absorb more liquid than clay litters so not as much litter is needed in the litter tray.

If you are interested in reducing your cat’s carbon pawprint, consider trying the paper and plant-based litters.

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Can insect-based cat food help you reduce your cat’s carbon pawprint?

Sustainability is a word you hear a lot these days, as more and more people compete for natural resources and deal with the effects of climate change. Sustainability is defined as “meeting the needs of the present without compromising the ability of future generations to meet their own needs” (United Nations Brundtland Commission 1987). So, you recycle plastics, take reusable bags to the grocery store, and limit the use of your car to reduce your “carbon footprint”.

How can you care for your cat sustainably? How can you go about reducing your cat’s carbon pawprint? In this post, we will talk about one of the recent trends in pet food aimed at sustainability: the use of insects as a food source (Reference 1)

reducing your cat’s carbon pawprint

Do Insect-based Foods Provide Sufficient Nutrition for Cats?

Our cats are obligate carnivores and are designed to eat primarily meat. Since many of our cats live indoors with us, they are not out hunting – we provide them meat-based cat food. Raising food animals (chickens, cattle, pigs…) for pet food produces significant amounts of greenhouse gases (carbon dioxide, methane, water vapor…)  and so is not very sustainable.

Insect Nutrition

  • Meal made from insects has as much protein as animal meal.
  • Insects have amino acids that are very similar to those in animals and cats are able to digest these.
  • Insect larvae are a good source of energy due to their fat content.
  • Insects are rich in minerals and provide necessary dietary fiber.
  • Insects are more protein dense – per weight, it takes 3 times more chicken leg meat to provide the same protein as insect meal.
  • Insects make up 2% or more of a feral cat’s diet.

Reducing Your Cat’s Carbon Pawprint by Feeding Insect-based Foods

  • Insects require less water and land use than food animals.
  • There are lower greenhouse gas emissions when farming insects compared to food animals.
  • Mealworms and fly larvae convert 45-55% dietary protein into edible body mass compared to the 33% conversion rate of a chicken.
  • Insects can feed on fruit and vegetable by products, household waste, slaughter plant waste and convert this into edible food.

What Insects are Used for Pet Food?

There are three insects currently used in animal foods: black soldier fly larvae, mealworm larvae, and adult house crickets. Black soldier fly larvae are most commonly used in pet foods.

Are Insect Foods Safe for Our Pets?

The insect larvae are blanched, chilled or frozen, then dried and ground into meal. In the process, moisture is removed, reducing microorgansims and inactivating enzymes that cause spoilage.  Heat treatment of the meal when making pelleted foods helps reduce bacteria and microorganisms.

Most insect bacteria and viruses usually do not affect animals and humans.  However, insects can be vectors of some pathogens, parasites, and prions.  Feeding the insects on vegetable waste (and not animal waste) makes insect food safer.

More studies aimed specifically at cats eating insect-based foods are needed.

Do I want my cat to eat bugs?

In Asia, Africa and South America, it is not uncommon to find insects on the menu. Chapulines or fried grasshoppers can also be found in restaurants in Mexico and even in California and Texas. However, insect consumption is not widespread in western countries.

Researchers from Oklahoma State University conducted a survey of 1,021 Americans in 2021 to see if they would be more willing to consume food containing powdered crickets than raw oysters (a food that although widely eaten is viewed as “yucky” by some). The findings: about one-third of Americans are willing to both try and consume insect products on a regular basis, provided they are tasty and safe to eat. (see Reference 2)

Another survey (Reference 3) in the United States that targeted dog owners found that participants:

  • were more likely themselves to try food made with insect flour than to eat the whole insects
  • were  more willing to incorporate insect meal but not whole insects into their dogs’ diets.

Where Can I Buy Insect-based Cat Food?

A casual Internet search turned up a handful of companies marketing cat foods with insect protein.  Most of these are based in Europe and Asia.  The only cat food that I could easily purchase in the US is made by the Canadian company Catit.  Catit offers dry cat food mixes of insect protein with chicken or herring called Catit Nuna. I contacted Catit regarding feeding trials with these foods.  They responded that Catit Nuna is formulated by pet nutritionists and has undergone feeding trials per AAFCO protocols for acceptability, digestibility and palatability.

Insect-based cat foods certainly sound like they may offer some options in reducing your cat’s carbon pawprint. However, it looks like we will need to wait for more research and development before these foods become mainstream.


  1. Valdes et al., Insects as Feed for Companion and Exotic Pets: A Current Trend. Animals 2022, 12, 1450.
  2. Melissa Reed, Bailey F. Norwood, W. Wyatt Hoback, Angel Riggs, A survey of willingness to consume insects and a measure of college student perceptions of insect consumption using Q methodology, Future Foods,Volume 4, 2021,100046,ISSN 2666-8335,
  3. Jennifer E. Higa, Matthew B. Ruby, Paul Rozin, Americans’ acceptance of black soldier fly larvae as food for themselves, their dogs, and farmed animals, Food Quality and Preference,Volume 90,2021, 104119, ISSN 0950-3293,


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