Cement isn't something most people notice, even though we all depend on it every day. The most common type of cement is called Portland cement. Portland cement is used to bind concrete, an essential component of roads, bridges and buildings.

Cement production is also a big contributor to global warming. Manufacturing Portland cement requires heating limestone to around 1,450 degrees Celsius (2,640 degrees Fahrenheit). The heating process uses fossil fuels, which release massive amounts of carbon dioxide into the atmosphere. Carbon buildup in Earth's atmosphere causes global warming.

Humanity made do without modern cement and concrete for most of its existence. In ancient China, fortresses, walls and buildings—including the Great Wall of China—were constructed from gravel, wood bundles, reeds, bricks and stone. Limestone-based mortar mixed with sticky rice was also used to bind materials like bricks together, similar to cement. In the city of Teotihuacan (now Central Mexico), most prominent between the first and seventh centuries, people used volcanic rock, mud and wood to build. The Teotihuacan Pyramid of the Sun, which still stands today, was built from volcanic rock.

Concrete-like materials have been around since ancient times. As early as 10,000 B.C.E., humans had discovered that burning limestone and mixing it with water created a paste that would eventually harden. By 6500 B.C.E., in what is now Syria, people were mixing lime with volcanic ash to create an even stronger material, which functioned much like modern cement. Though these early processes would have emitted pollution, it was not at the same scale as modern cement operations.

Modern concrete arose during the 19th century with the invention of Portland cement, which created a stronger product than lime-based formulas. Its use greatly increased with the innovation of reinforced concrete, which uses iron or steel to further strengthen concrete. However, its widespread use and climate-warming emissions have proven to be incredibly harmful to the natural world, necessitating a turn to nature for creative solutions.

A company called Fortera believes it has figured out a way to make cement that stores carbon instead of releasing it into the atmosphere. Fortera evolved from an earlier company, Calera, which combined flue gas released from power plants with seawater to make cement. This method of carbon storage is called carbon sequestration.

Brent Constantz, scientist and cofounder of Calera, came up with the idea for the company when researching how corals created reefs. He thought that if corals could make cement this way, then perhaps humans could do it too. Seawater contains dissolved carbon dioxide, calcium and other minerals, the same ingredients corals use to build reefs. These ingredients combine in a process called biomineralization to make calcium carbonate. Calcium carbonate is the material that makes up both coral reefs and Portland cement.

Calera was one of the first companies to use carbon dioxide to make cement. The company closed by 2015, but in 2019, former Calera employees decided to revisit the technology and founded Fortera. This time, instead of using seawater, Fortera uses a machine that captures the carbon dioxide emitted by cement-making kilns and mixes it with calcium oxide to create a cement-like product. This product is then used as part of the concrete-making process. In 2024, the company began using its technology to help create cement at the CalPortland plant in Redding, California, U.S.A. However, currently Fortera’s technology eliminates only 70% of carbon emissions and relies on the energy sources of the cement plants it works with, mainly fossil fuels.

Biomimicry

Using nature as a guide to build new technologies—like energy-efficient cement—is called biomimicry.

“Biomimicry is an innovation practice where we look to the natural world for designs, processes, strategies that we then try to emulate in order to create a more sustainable world,” Janine Benyus, the biologist who popularized the term biomimicry, said in an interview at Appalachian State University. “The core idea is that life has been on Earth for 3.8 billion years and has learned during that time what works and what lasts and how to fit in here.”

Applying the principles of biomimicry means taking ideas from natural systems, which have evolved to be efficient through millions of years of environmental pressures. And it’s not a new idea. Many Indigenous peoples have long held respect for what nature can teach us. Traditional ecological knowledge—a term that describes the accumulation of knowledge, beliefs and practices of Indigenous groups—focuses on an intimate understanding of local ecosystems.

Today, biomimicry is used in everything from medical technology to city planning and architecture. By studying nature, scientists have come up with new ways to fight harmful bacteria by creating surfaces similar to the antibacterial wings of dragonflies. Researchers are looking at how plants store energy to help design better solar panels. Biomimicry principles are used to produce more energy-efficient trains and cars, like the bird-inspired Shinkansen bullet trains in Japan, and to help manufacturing plants create products that use less energy and produce little or no waste.

Like coral reefs, termites are another example of living things that have inspired sustainable designs to fight global warming. In Zimbabwe, the architects who designed the Eastgate Centre—a shopping mall and office building—were inspired by termite mounds to create passive, energy-efficient climate control. The natural, chimney-like structure of a termite mound, with its porous surfaces, keeps internal temperatures comfortable and promotes air exchange. Similarly, the Eastgate Centre features building materials that store and release heat from the environment. It also has two interconnected towers with fans that push cool air from the ground level upward, hot air travels up toward the chimneys and out of the building.

In Brazil, building plans for the Votu Hotel feature inspiration from prairie dogs, cacti and toucans. Prairie dogs construct their burrows to promote constant airflow, which underlies the concept of the planned hotel’s natural ventilation. The ridges in cacti allow the plant to shade more of itself from the sun, a concept borrowed to increase shade in the building design. Lastly, toucan beaks provided a model for efficient heat exchange in the kitchen. The beak’s large surface area promotes heat exchange, and the bird can modify blood flow for heat radiation. The hotel kitchen mimics this system of thermal radiation with its roof garden. A copper pipe ventilation system snakes through the soil along the kitchen roof to radiate the heat before the cooled air reenters the kitchen.

While plenty of other species and natural processes can inspire sustainable solutions for building materials, biomineralization remains one of the most promising, as it provides plentiful inspiration for low-carbon building. Fortera and similar companies are looking to expand their nature-inspired operations for large-scale applications. For example, a startup company called ReefCycle also harnesses knowledge of coral and oyster reefs for more sustainable cement applications. They are using plant enzymes to carry out the biomineralization process in a way that is carbon-neutral, nontoxic and affordable. The company focuses on using their “bioconcrete” to restore reef systems off the coastal communities of New York City, New York, U.S.A. Reefs help protect coastlines from flooding by slowing waves, and ReefCycle hopes that its restored reefs will do the same while also providing opportunities for local communities. Their process doesn’t require industrial equipment, and according to the company, it could empower communities to restore local reef ecosystems and build resilience against storms.

The stakes are high for companies and governments to find effective solutions for preserving nature and slowing climate change and global warming. If not, climate-change–induced droughts, severe storms, wildfires, flooding and rising temperatures will irreversibly alter life on Earth, posing the greatest threat to people already facing poverty and low resources.