Author: Chloe O'Neal — Staff Writer
Date: August 23rd, 2025
Climate change is a phenomenon affecting the entire world, but here in the Caribbean it poses a particularly big issue. The Caribbean accounts for less than 0.60% of greenhouse gases emissions, but will suffer the most severely from its impact. Any development being made towards reducing the amount of greenhouse gases in the atmosphere should be closely followed as a matter of regional interest. Carbon sequestration is one such method of reduction, and a team of scientists based in Switzerland have found an exciting new way to explore this technique. The group have created a living material that can bind CO₂ from the atmosphere and transform it into carbon sequestration materials like limestone. Their hope is that one day this material can be used on the surfaces of buildings to help absorb carbon from the atmosphere.
This study comes out of ETH Zurich in Switzerland. The group of scientists merged a series of bacteria, algae and fungi to create an active, living material. To work, the matter only needs sunlight and artificial seawater treated with nutrients such as calcium and magnesium, as well as CO₂.
The material can be manipulated via 3D printing and reproduced through a series of structures. When it first starts out, it's gel-like and loose in nature, but that's when the magic happens. See, within these amalgamations of different matter is a photosynthetic bacteria known as cyanobacteria. Cyanobacteria is one of the oldest bacteria on the earth, and it's highly efficient at turning sunlight and carbon into oxygen and sugars.
The cyanobacteria absorbs around 26mg of carbon per gram of material, which is three times the amount of a more common material like recycled concrete, which absorbs around 7mg per gram.
It then converts the CO₂ to biomass and produces a series of solid carbonates, including limestone. As the minerals are deposited, the cyanobacteria strengthens the environment around it, turning its initially gel-like texture into a hardened structure.
This hardened structure that houses the gel is known as hydrogel—a complex, cross-linked polymer structure with a high water content. The structure of the hydrogel encourages transportation of water, nutrients, light and allows the cyanobacteria to spread out and grow without leaving the habitat. The structures are also optimized for surface area, maximize light penetration and encourage the flow of nutrients throughout the environment.
Researchers believe this material could eventually be added to buildings to help with carbon sequestration. A recent art-architectural exhibit, held in partnership with the scientists, integrated the cyanobacteria into tree-like structures. These structures were able to bind up to 18 kg of CO₂ per year—about as much as a 20-year-old pine tree.
There is still a long way to go, however, before this can be developed at scale. As the material is living matter, several considerations toward maintenance and survivability will have to be made. For example, the cyanobacteria's need for a consistent supply of seawater and minerals may pose a problem at an architectural design level. It should also be considered how these living buildings may react in different weather systems and climates.
Sources:
ETH Zurich
Nature Communications
Live Science
OECD Report
UWI IPCC Summary