Manisha Krishnan: So I think it’s kind of important to contextualize this because this is happening at a time where we’re seeing age verification being applied to a range of industries from porn to video games, and companies are going about it in different ways. And while I think there obviously is a lot to be concerned about with young people having unfettered access to ChatGPT, I think these efforts always raise a lot of questions like how is age going to be verified? Where’s that data going to be stored? Even the idea of something inappropriate flagging someone’s parents or the authorities, what is appropriate?

Zoë Schiffer: Right.

Manisha Krishnan: I can definitely see why suicide would be something that you’d want to flag, but maybe there’s other things that the authorities or someone’s parents may not be helpful in every situation. And I guess I’m thinking more about when we go into young people’s exploration of their sexual orientation, just as one example as the culture war topic that’s big right now. So maybe I’m getting too ahead of myself, but those are some of the questions that come to mind.

Zoë Schiffer: That was immediately what came to mind for me, especially because you specifically report on the adult content industry, and I feel like this issue always comes up there where it’s what’s the trade-off between privacy and keeping people safe? But when it comes to young people, it really feels like the privacy conversation goes out the window and regulators are much more inclined to be like, safety comes first, and we might not necessarily care if we’re degrading privacy in some kind of fundamental way.

Manisha Krishnan: Yeah, with the whole porn conversation too, Pornhub obviously has a litany of controversy, but at this point, because they’ve been in trouble so much, they’ve buttoned up a lot of their regulations. And now, in response to the age verification stuff, they’ve removed themselves. So you’re also like, “Am I opening up a vacuum to other maybe more nefarious or irresponsible sites?” There’s always something that will crop up in replacement of something else.

Zoë Schiffer: Well, we’ll wait to see how OpenAI continues to handle this. Staying on the topic of AI for one moment, our next story is about how US tech giants are investing billions of dollars in AI infrastructure in the UK. Our colleague, Natasha Bernal, reported that Microsoft and NVIDIA announced that they’ll be investing up to $45 billion in the form of data centers and AI research. This comes on the heels of another joint venture from NVIDIA, Nscale and OpenAI that’s also aimed at boosting AI infrastructure in the country. Earlier this week, OpenAI CEO, Sam Altman, and NVIDIA CEO, Jensen Huang, traveled with President Trump to the UK during his state visit and then we got a whole bunch of announcements about all of these billion-dollar investments.

Manisha Krishnan: Honestly, one of my first reactions was is this just another form of American tech imperialism spreading and how do the Brits feel about this and what is the underlying motivation for these tech companies to make all these announcements? Do they actually want to invest that much in the UK? That would make sense, but also is it to appease Trump?

Engineers in Australia have developed a new building material with about one quarter of concrete’s carbon footprint, while reducing waste going to landfill. The research is published in the journal Structures.

This innovative material, called cardboard-confined rammed earth, is composed entirely of cardboard, water and soil—making it reusable and recyclable.

In Australia alone, more than 2.2 million tons of cardboard and paper are sent to landfill each year. Meanwhile, cement and concrete production account for about 8% of annual global emissions.

Cardboard has previously been used in temporary structures and disaster shelters, such as Shigeru Ban’s iconic Cardboard Cathedral in Christchurch, New Zealand.

Inspired by such designs, the RMIT University team has, for the first time, combined the durability of rammed earth with the versatility of cardboard.

Lead author Dr. Jiaming Ma from RMIT said the development of cardboard-confined rammed earth marked a significant advancement toward a more sustainable construction industry.

“Modern rammed earth construction compacts soil with added cement for strength. Cement use is excessive given the natural thickness of rammed earth walls,” he said.

But cardboard-confined rammed earth, developed at RMIT University, eliminates the need for cement and boasts one quarter of the carbon footprint at under one third of the cost, compared to concrete.

“By simply using cardboard, soil and water, we can make walls robust enough to support low-rise buildings,” Ma said.

“This innovation could revolutionize building design and construction, using locally sourced materials that are easier to recycle.

“It also reflects the global revival of earth-based construction fueled by net zero goals and interest in local sustainable materials.”

Practical benefits

The cardboard-confined rammed earth can be made on the construction site by compacting the soil and water mixture inside the cardboard formwork, either manually or with machines.

Study corresponding author and leading expert in the field of structural optimization, Emeritus Professor Yi Min “Mike’ Xie, said this advancement can spearhead a leaner, greener approach to construction.

“Instead of hauling in tons of bricks, steel and concrete, builders would only need to bring lightweight cardboard, as nearly all material can be obtained on site,” Xie said.

“This would significantly cut transport costs, simplify logistics and reduce upfront material demands.”

Ma said cardboard-confined rammed earth could be an effective solution for construction in remote areas, such as regional Australia, where red soils—ideal for rammed earth construction—are plentiful.

“Rammed earth buildings are ideal in hot climates because their high thermal mass naturally regulates indoor temperatures and humidity, reducing the need for mechanical cooling and cutting carbon emissions,” he said.

The mechanical strength of the novel material varies based on the thickness of the cardboard tubes.

Ma said the team has developed the formula for this strength design.

“We’ve created a way to figure out how the thickness of the cardboard affects the strength of the rammed earth, allowing us to measure strength based on cardboard thickness,” Ma said.

In a separate study led by Ma and published in Composite Structures, carbon fiber was combined with rammed earth, proving it had a comparable strength to high-performance concrete.

Ma and the team are ready to partner with various industries to further develop this new material so it can be used widely.

After testing dozens of automatic litter boxes, I can say it’s been difficult to determine which is the best cat litter (or rather, if there is one). Most people will want to look for a low-tracking, clumping cat litter that’s compatible with their litter box. But there are other factors to consider, like allergens, material, the litter box itself, and how you’ll deal with the waste.

In recent years, there have been leaps and bounds in the pet tech sphere as a whole—including where our cats go potty and what litter they go potty in. In the past, the choices were an absorbent clay whose main compound was calcium bentonite, sawdust, or sand. Now, we have high-tech crystal litter, which aims to show health issues through changing color; eco-friendly tofu litter; and all types of clumping clay litter between. After a year of testing litter boxes and scooping tons of cat litter, let me sift through (get it?) the options so you can determine the best type of cat litter for you and your furry friend.

Should You Change Up Your Litter?

There are many reasons why you may want to change your litter. Your cat may be like mine, with sensitivities to strong odors or smells that can cause allergies or allergy-like symptoms like red eyes or itching. Or maybe your cat is long-haired, like mine, and you’re tired of litter sticking to their fur.

If you want to be more eco- (and budget-) friendly, a biodegradable tofu or wood pellet litter may be better, but for these, you’ll need to introduce the change slowly and oftentimes, you’ll have to change the box you’re using. (More on that below.)

As a helicopter pet parent who brushes their cats’ teeth and shaves their butts, I honestly just want to make sure I have a litter that keeps my cat (and me) comfortable, giving them a safe space to potty and an easier time to clean it for me.

I look for, and recommend folks do trial-and-error to find, a litter that has all of these elements:

• Clumping: Many brands claim to clump effectively, but you’ll need to monitor while scooping to see if they actually are, or if they’re leaving smaller bits that sneak through grates while cleaning.
• Scent-free or low scent: Cats can smell 14 times better than humans, and strong odors can irritate their respiratory system and lead to itching, watery eyes, and other symptoms, including not wanting to use the litter box at all because the scent is too overwhelming.
• Low–tracking: Same as clumping litters above, many litters claim to be low tracking, but I’ve found that the best way to lessen litter tracking around the house is to have a great clumping litter and add as much space between the box and the floor. This means that in addition to clumping litter, add accessories like stairs (if your cat is mobile enough), a ramp, or a litter-trapping mat to increase the distance between the box and your floor, to reduce litter tracking. Litters that aim to be low-tracking are generally better at dust control, which also help with general cleanliness and lower irritants.

I’ve tested several types of cat litter from Boxiecat, and although pricey, they have all managed odor well, had low dust/tracking, and scooped easily in clumps (and worked well with my automatic litter box).

Compare the Most Popular Types of Litter

As said before, there used to be super-limited litter options, now there’s tofu, wood, silica crystals, recycled paper, and even nut shells. While something like wood pellets is more-eco friendly and cheaper, you’ll have to factor in your litter box and whether your cat takes to the new litter. (Although slow introduction is key.)

• Clay cat litter: This is by far the most popular litter type, and most closely resembles what cats would be using in the wild. Clumping clay cat litter is what I recommend for most people, as it primarily uses a naturally absorbent bentonite clay. It expands when wet/soiled, making it “clump,” which is easier to scoop and generally more hygienic. However, it’s not as environmentally friendly because it’s not biodegradable and can contain carcinogenic silica dust.
• Tofu cat litter: This relatively new litter is great because it’s environmentally friendly. It’s made out of soybean fiber, making it naturally biodegradable, nontoxic, and way less dusty than traditional choices. If bought in pellet form (the most popular option), they clump well and can even be flushed in the toilet, although it can be pricey and can grow mold if in humid conditions.
• Crystal cat litter: This type of litter is made from silica mined from quartz sand and mixed with oxygen and water to make super absorbent pellets (akin to the absorbing powers of little silica gel packets found in many newly bought items). It’s lightweight and has great odor control. Crystal litter is pricey, not biodegradable or clumping (requires daily sifting), easily tracks, can be an uncomfortable texture for paws, and is difficult for some cats to get used to using. Popular brands like PrettyLitter actually use a special silica formula that aims to track health changes through changing colors based on urinary PH. Although I’m slightly cautious to use it because of reviews of the silica litter being ingested and harming cats and causing respiratory issues because of the particle dust.
• Paper or Wood pellets: Paper and wood pellets are cheap, have low dust and tracking, and are eco-friendly because they’re biodegradable. (Paper pellets are also great for injured or post-operation pets because the litter is low-dust and there’s less chance for litter to get stuck in wounds.) However, this doesn’t control odor well, is non-clumping, and needs to be changed frequently (you’ll probably need a sifting litter box). Wood pellets are also often made of pine and can have an overwhelming scent.
• Walnut shell cat litter: Made from crushed walnut shells, this is often used as a much lighter, more natural alternative to clay litter. It’s lightweight and has a similar texture to clay, and is biodegradable. Although it can track, spoil if in moist conditions, and requires frequent emptying/cleaning.
• We don’t recommend corn cat litter, as corn is prone to a toxic mold called aflatoxin. This can cause health issues for cats and in humans who have asthma or COPD and are immunocompromised or elderly.