A new type of crystal could enable refrigerators and air conditioners to keep us cool without warming the planet.

Refrigerators and air conditioners get their cooling power by circulating a liquid through the device, which absorbs heat and causes chilling through a cycle of evaporation and condensation. But many such liquids contribute to the greenhouse effect, causing further warming when they leak. Now, at Deakin University in Australia and her colleagues have made a climate-friendly alternative to these liquids using 鈥減lastic crystals鈥� 鈥� crystals with molecules that can move just enough to make them pliable.

Under enough pressure, these plastic crystals can transform. Their molecules go from being randomly oriented to aligning themselves into a neat grid. Then, when pressure is removed, they become disordered again. As part of this disordering process, the crystals absorb heat, effectively cooling their surroundings.

Such pressure-based cooling has been investigated before, but most materials capable of this transition could only do so at balmy temperatures, limiting their cooling power, says Pringle. In contrast, the heat-sucking ability of her team鈥檚 crystals kicks in at temperatures from -37掳C (-34.6掳F) to 10掳C (50掳F), a suitable range for household refrigerators and freezers.

However, the new crystals are not ready to leave the lab yet. That鈥檚 because the pressures needed to make them work are very high 鈥� hundreds of times greater than atmospheric pressure and equivalent to being thousands of metres underwater, says Pringle.

at the University of Glasgow, UK, says materials like those in the new study have 鈥渢he potential to almost completely decarbonise this huge [cooling] industry鈥�, but he shares the concern about the high pressures required.

There may be another practical issue with this approach, says at the Chinese Academy of Sciences. With every repeated use, each crystal may absorb less heat, as the grid the molecules form becomes more strained. Still, Li is optimistic and says he is confident the technology could be applied in the 鈥渘ear future鈥�.

You have probably never heard of John 鈥淏ud鈥� Benson Wilbur, but he is a low-key civil engineering legend. In the mid-20th century, he was chair of the civil and sanitary engineering department at the Massachusetts Institute of Technology (MIT). He built some major bridges in Massachusetts and helped prototype the first wind power systems in Vermont. But I first encountered his work in a silly-but-serious essay called 鈥淲hither civil engineering?鈥�, published in the March 1952 issue of The . In it, Wilbur claimed he and his colleagues had invented a crystal ball for seeing the future called the Paynterscope.

The Paynterscope, Wilbur wrote, revealed the distant-future world of 1977. Africa had become a Wakanda-like paradise full of farms, clean rivers and high-tech systems for weather control and water management. The US was criss-crossed with conveyor belts for rapidly transporting freight, while roads were surfaced with a sustainable, durable version of rubber, making the infrastructure more resilient. A transit tunnel whisked cars below the English Channel (yes 鈥� he predicted the Chunnel). There were dozens of other gee-whiz inventions, but most of them were like these: improvements to old, bog-standard tech to help humans stay comfortable and healthy.

At one point in his essay, Wilbur described his co-authors using the Paynterscope to peer into the future waterways of the US. They exclaimed happily: 鈥淒on鈥檛 those streams and lakes look fine? No more pollution!鈥� By the 1970s, they imagined that engineers would have figured out how to treat sewage quickly and cheaply.

Wilbur鈥檚 humble, self-satirising style of futurism is a stark contrast with our current era, where cutting-edge engineering projects are generally pitched as ways to maximise profit for corporations and optimise or eliminate human labour. Wilbur鈥檚 vision shows us science serving the public good.

He spent most of the 1950s working with a colleague at MIT, Robert Hansen, on that could withstand the blast of an atomic weapon. Wilbur made joking reference to this in his article, describing looking through the Paynterscope to see how many of their buildings survived into the 1970s. To his surprise, he discovered that few were in existence and that it 鈥渁ppeared atomic warfare was no longer a major consideration鈥�.

In Wilbur's distant-future vision of 1977, a transit tunnel whisked cars below the English Channel

Wilbur concluded that this, too, could be credited to good civil engineers: by the 70s, he imagined that advances in civil engineering would have increased sustainable energy and food supplies, improved the environment and created resilient public transport to distribute resources globally. 鈥淎ll of these activities had contributed directly to a higher standard of living throughout the world, and thus had helped to remove one of the major causes of war,鈥� he wrote. Living in the aftermath of war, Wilbur wanted to build a better world 鈥� literally 鈥� using resource abundance to steer people away from violent conflict.

Interestingly, Hansen wrote his for The Technology Review, years later in 1967, where he suggested a different solution to resource scarcity: using genetic engineering to create 鈥渟mall man鈥�, tiny people who used less food and energy. This idea, in , became notorious as an example of odious futurism, focused on controlling people鈥檚 bodies instead of making it easier for them to thrive in the bodies they have.

Unfortunately, a lot of futurism today sounds more like Hansen鈥檚 鈥渟mall man鈥� essay than Wilbur鈥檚 fanciful musings. Venture capitalists, who are essentially economic futurists, are hyping artificial intelligence with the promise of shrinking human creators down to nothing. Silicon Valley鈥檚 billionaire leaders are investing in separatist, libertarian 鈥溾�� run on cryptocurrency, while neighbouring areas experience housing shortages and drought.

Wilbur鈥檚 long-forgotten essay offers us a different way of thinking about what comes next. The mind-blowing engineering achievements of tomorrow could involve cleaning up the environment and making healthcare, housing and transport work brilliantly for everyone.

In the 1960s, Wilbur retired to Woodstock, a village on the border of New Hampshire and Vermont. He lived there until his death in 1996 and stayed active by creating a summer programme for civil engineering students who wanted to try their hands at solving real-world problems in an actual town.

For Wilbur, good engineering offered the promise of a healthy life, without war, on a planet with clean water and plentiful food for the public. It isn鈥檛 glamorous, and it probably wouldn鈥檛 get the big venture capital money. But it might just help us build a better world.

Annalee鈥檚 week

What I鈥檓 reading

Untethered Sky by Fonda Lee, the tale of a badass warrior and her giant attack bird.

What I鈥檓 watching

I鈥檓 checking out @coyoteyipps, or Janet Kessler, who has been photographing urban coyotes in San Francisco for almost two decades.

What I鈥檓 working on

Some essays on the history and future of futurism.

Annalee Newitz is a science journalist and author. Their latest book is Stories Are Weapons: Psychological warfare and the American mind. They are the co-host of the Hugo winning podcast Our Opinions Are Correct. You can follow them @annaleen and their website is techsploitation.com

An abundant mineral called olivine can help make carbon-negative cement. This process could help tackle cement鈥檚 large carbon footprint 鈥� the material contributes about 8 per cent of global CO2 emissions.

Olivine is one of the main components of Earth鈥檚 mantle and reserves sit on every continent. 鈥淚t鈥檚 one of the few minerals that is available at the gigatonne scale,鈥� says at Seratech, a UK-based company that has patented a process to turn olivine into cement.

Dozens of start-ups like Seratech are developing low-carbon methods to produce cement, such as supplementing with steel by-products or recycling the CO2 released in cement production. Most emissions occur when heating limestone to produce clinker, a binder in cement, along with burning fossil fuels to generate the heat.

Draper and his colleagues looked to the more abundant olivine to find a replacement for some of the usual clinker. Olivine contains silica, which makes cement stronger and more durable. Magnesium sulphate can also be extracted from it, and this salt reacts with CO2 to form minerals that sequester the gas.

The researchers extracted these compounds by dissolving powdered olivine in sulphuric acid. After separating the silica and magnesium sulphate, they bubbled CO2 through the magnesium slurry to form a mineral called nesquehonite. To scale up the process, Draper says a cement plant would use CO2 captured from an emissions source or from the air, rendering the entire process carbon negative. The leftover nesquehonite could be recycled into new construction materials like bricks.

Replacing 35 per cent of the regular cement in a concrete mix with silica from this process would produce a carbon-neutral cement, the researchers estimated, while subbing 40 per cent or more would make it carbon negative. Draper says current building standards allow this type of material to replace up to 55 per cent of cement, although he says they haven鈥檛 yet made enough of it for robust testing.

The process utilises well-known reactions, says at the University of Guelph in Canada, but offers a novel and 鈥渞easonable鈥� way to combine them. However, some of the chemicals involved may prove tricky to recycle, he says.