Anita Gogia is an IPilogue Writer and a 2L JD Candidate at Osgoode Hall Law School.

Concrete jungles around the world illustrate the man-made burden on the planet. Concrete is a carbon-intensive ingredient in construction and makes up at least 8% of man-made CO₂ emissions. When it comes to industrial processes, cement manufacturing produces the highest amount of CO₂ emissions.

To resolve the issue and alleviate the output of greenhouse gasses, a cement-free concrete named EarthCrete is being developed by CarbonMeta. EarthCrete was recently assessed by researchers at Oxford and CarbonMeta Research who confirmed that EarthCrete is actually carbon negative on July 26, 2022. Particularly, using 1200 metric tonnes of EarthCrete with water can actually eliminate 132 atmospheric metric tonnes of CO₂ emissions.

The pace to carbon-free construction is also accelerated by engineers and researchers at the University of Illinois Chicago, University of Wisconsin-Madison, and Pennsylvania State University who are using their federal grants to approach carbon-neutral cement manufacturing. The researchers hope to turn building material into a “carbon capture system.” In the system, carbon would be captured from the air by distributed direct air capture with rapid mineral carbonation. This technique would recycle industrial waste into a cement alternative. The researchers hope to create a long-lasting building material that extracts more CO₂ from the air than it emits.

Another grant has been provided to UIC, UW-Madison, and Fort Lewis College for the sustainable production of calcium hydroxide. Calcium hydroxide is a crucial ingredient in cement, and the low-temperature calcium hydroxide procedure (LoTECH) would create calcium hydroxide from industrial waste. Such sustainable calcium hydroxide would reduce limestone demands (and the thermal decomposition of limestone), and act to further  reduce the carbon footprint of cement production.

At the University of Colorado Boulder, researchers have created a way to use algae to develop biogenic limestone, therefore creating another potential carbon-neutral concrete. The microalgae creates calcium carbonate through photosynthesis. Using sunlight, seawater or freshwater, and CO₂, microalgae produces calcium carbonate shells. The process is carbon neutral because the CO₂ emitted when used to make cement is equal to the CO₂ the microalgae absorbed. The biogenic limestone behaves the same as regular limestone which makes it feasible to incorporate into cement production. The researchers estimate that this biogenic limestone would save two gigatons of CO₂ emissions yearly. The researchers also illustrate that the 1-2 million acres of open ponds in the US make it possible to produce enough biogenic limestone to satisfy cement demands.

In review of progresses to environmentally friendly cement, federal grants have played a crucial role. At a global scale, carbon-neutral or carbon-negative innovations will be the key to offsetting the damage done and accessing sustainable resources.