On the floor of a cluttered office inside Boelter Hall stands a foot-high concrete block that may one day be exhibited in a museum. The unassuming masonry is commonplace on construction sites, though rarely deployed as office furniture. Yet, its guardian, Gaurav Sant, says this object is special: the first block in a green revolution that he believes could save the world. The Pritzker Professor of Sustainability at UCLA Samueli School of Engineering reveals how UCLA scientists are blurring the boundary between land and sea to tackle climate change.

This rough gray block, designed to absorb carbon dioxide emissions from power plants, won UCLA’s first XPRIZE in 2021. It is also a forerunner of an even bolder technological leap: the ability to remove carbon dioxide from the world’s oceans. So, there are two related technologies that could help clean up the world. Before we get to that, can you share your background, which was more hands-on construction than academia for many years?

I am a third-generation civil engineer who grew up in Goa, on the west coast of India. Figuratively, my grandfather built half the city of Pune, while my father built half the state of Goa. I was raised with an awareness about built things and how they can improve our quality of life. After studying in the Midwest [at Purdue University] and at the École Polytechnique Fédérale de Lausanne in Switzerland, I was either going to become an academic or go back into real estate in India with my father. It could have gone either way.

So what happened?

While at graduate school, I was swept up in the excitement of the 1997 Kyoto Protocol, which challenged engineers to find new building methods to reduce greenhouse gases produced during construction. Everyone was talking about the environmental threat from our carbon footprint, but there was little being done about it — particularly in the construction sector. I knew that it would be a heavy lift to find the fixes. But in 2010, after California had passed State Law AB32 [tackling greenhouse gases], I felt UCLA was the right place to make a real-world impact through focused research in science and engineering. 

In 2019, you helped set up the Institute for Carbon Management at UCLA, where you are now director, to develop technologies that will move us into a lower carbon world. It has grown fast: 22 patents and partnerships with the U.S. Department of Energy and industrial giants such as Boeing. Why is there such a thirst for big thinking from UCLA?


I see the world as an engineer: If you provide cost-effective, accessible solutions to dramatic problems, society will quickly adopt the solutions to resolve seemingly insurmountable challenges.


Simply because this is the only way. While the scientific community has developed a broad range of solutions, we have been far less focused on translating that knowledge into real-world, scalable, affordable solutions. The answers to climate change have to be smarter and cheaper than what exists today — otherwise businesses will not be interested. Technology is going to be the lever to mitigate climate change. And we are part of that. 

In 2021, the institute became the first university team to win the NRG COSIA Carbon XPRIZE, an award worth $7.5 million. Your entry was one of 47 submissions from 38 teams in seven countries, and you credited it all to … seashells. 

Amanda Friedman

Having grown up by the seashore, seashells were central to my childhood. I knew that seashells are made of calcium carbonate — nature’s original cementation agent. We were really motivated by the idea of how seashells are “cemented” together. And that started us thinking about new forms of concrete, and whether it could be made with carbon dioxide as an ingredient. This thinking, for which we won the XPRIZE, is now being commercialized by a UCLA/institute spinoff company, CarbonBuilt Inc. 

The Romans used concrete to build the Colosseum. It’s the second-most used substance in the world, after water. How can you improve such a fundamental substance — change its production process to make it cheaper while reducing its carbon footprint?

The block in this office is among the first of its kind, proof that we could take everything the Romans knew about concrete and make it better. We have two pilot schemes on barges that are nearing prime time. One is in Singapore; the second is in San Pedro, Los Angeles. We are sending electrical charge through seawater, which sets off chemical changes that remove carbon dioxide from the water, captures it and solidifies it into blocks. The blocks have a much smaller carbon footprint than conventional concrete. 

Apart from the sample in your office, the first 150 metric tons of your new style concrete blocks were finished at the Wyoming Integrated Test Center, which is a leader in the burgeoning carbon capture business. Then you donated the blocks to the Eastern Shoshone Tribe in Wyoming for new homes on the Wind River Reservation, which is a very UCLA thing to do. But back to San Pedro, and the barge surrounded by curious seals.  What happens to the seawater after the electrolysis?

Amanda Friedman

The water goes back into the sea, recycled. We are closely monitoring what happens to it after that. You know the ocean and the atmosphere are in carbon dioxide equilibrium. If you extract carbon dioxide from seawater, this prompts the ocean to soak up more carbon dioxide from the atmosphere. If we scale this technology up, we can reduce the level of greenhouse gases in the atmosphere significantly over the next few years. We shall soon deploy this prize-winning technology to remove 5,000 metric tons of carbon dioxide per year in Singapore. It decarbonizes our economies and powers them simultaneously. It also produces hydrogen, which interests Boeing as a new green fuel. 

The Intergovernmental Panel on Climate Change says that the removal of CO2 from the atmosphere is as critical as reducing car emissions. Are you hopeful that humanity, and your young child, can still avoid the climate catastrophe threatened by global warming? Some people are very gloomy about the future.

People display pessimism for one of two reasons: They think either that there is no solution to the massive problems we face and all hope is lost, or that there are so many impediments to the solution that nothing can be done. I see the world as an engineer: If you provide cost-effective, accessible solutions to dramatic problems, society will quickly adopt the solutions to resolve seemingly insurmountable challenges.

Where does that worldview come from?

There are many reasons for optimism. Look at how quickly, from the depths of despair, we found a vaccine during COVID-19! Success stories of this manner reinforce my optimism and highlight that given collective will, if we marshal our talents and treasures, we can invent and scale up solutions to address our climate issues. And it is our role as scientists and engineers to make sure that we keep on finding better answers to address our most serious societal challenges together.


Read more from UCLA Magazine’s Spring 2024 issue.