The Big Idea - Capture Carbon From the Air - Companies need to stop their emissions from polluting the skies. Direct air capture can help absorb what's already up there.

Companies need to stop their emissions from polluting the skies. Direct air capture can help absorb what's already up there. The world’s first DAC technology was developed by research groups at the University of Calgary and ETH Zurich about a decade ago. Canada is well positioned to be a world leader in DAC. The technology requires two main ingredients: plenty of that porous geologic storage and renewable energy infrastructure. Canada has an immense amount of storage capacity.

- By Phil De Luna - Illustration by Peter Ryan

I was a curious kid, always drawn to science. I mainlined episodes of The Magic School Bus, and even though I came from an immigrant family with little money, I begged my parents to buy me chemistry kits filled with test tubes and colour-changing pH strips. Those early chemistry lessons were the gateway to my understanding of climate change. I couldn’t yet grasp complex concepts like greenhouse gases and the carbon cycle, but I did know that the tools and technologies humans created had an impact on our environment. We could make messes, but we could also help clean them up.

I was in university when I first heard about direct air capture, or DAC—the idea that you could collect carbon dioxide that had already reached the atmosphere, instead of at sources of emission, like factories or power plants. The world’s first DAC technology was developed by research groups at the University of Calgary and ETH Zurich about a decade ago. I was in grad school at the time and started researching it myself. After completing my Ph.D. at the University of Toronto in 2018, I became the youngest-ever director at the National Research Council Canada, in charge of a $60-million program to find ways to convert captured carbon into plastic.

Direct air capture involves a multi-step process: first, large fans mounted on the sides of steel or aluminum cooling towers pull in the air. It then passes through a filter, made of a liquid (like potassium hydroxide) or a solid (like metal organic frameworks, which are similar to the activated carbon in Brita filters). Clean air goes back out into the atmosphere, but the CO₂ stays behind. It is removed from the filter using energy-heat, electricity or steam then compressed into a liquid, pumped and stored two kilometres underground, in ancient ocean beds made of porous sand.