Menu News

Digging into carbon sequestration with Guy Webb

Soil may not be exciting to everyone, but the ground beneath our feet holds great promise in the fight against climate change. By trapping the carbon dioxide that’s released by soil and keeping it in the ground, it benefits the atmosphere as well as farmers, who see a marked improvement in their soil health. This process, carbon sequestration, has been the focus of agronomist Guy Webb over the last seven years.

“Soil holds twice as much carbon as all the vegetation and all the carbon in the atmosphere combined,” he says. “What’s a problem in the air is a solution in the soil. It’s a resource to capture.”

Working with a team of volunteer scientists and farmers at SoilCQuest, Webb and his collaborators have developed a carbon sequestration solution that has the capacity to remove gigatonnes of carbon dioxide from the atmosphere. Now the technology is turning heads around the world, and SoilCQuest is on the cusp of a significant period of scaling up. Guy, one of the co-founders of SoilCQuest, explains how exactly the biotechnology works, how he became interested in it, and how we can ensure being green is a smart business choice for farmers.

How did you come to be involved in SoilCQuest and its hunt for a practical carbon sequestration solution?

In my agronomy career I focused on soil health. One component of soil health is soil carbon. I’ve really focused on all the ways that we can help build soil carbon to get that fertility up for farmers to grow better, more resilient crops. Concurrently, I also made the mistake of educating myself more on climate change issues over the years and became interested in what could be done about climate change. I started piecing together that idea of soils acting as a carbon sink to draw down carbon.

All that excess carbon that’s floating around in the sky that’s causing climate issues and extreme weather events actually has value to a farmer. More carbon in the soil means it holds more water, it holds more nutrients, it creates better structure and better aeration in the soil. It’s a really valuable asset to be building for the farmer, and it’s doing a really valuable job in trapping carbon out of the air. It’s truly a win-win situation.

How does the SoilCQuest biotechnology work?

We needed to work out how to take carbon from a gaseous state to a solid state that’s in the soil. I started looking for a solution that’s economic and practical for a farmer. Farming’s a business like any other. You can’t expect a business to make a loss for environmental gain. No one does that. It’s hard to be green when you’re in the red.

In 2012, I went to a carbon sequestration conference where a professor from The University of Sydney, Peter McGee, presented research on a particular fungus that was able to sequester carbon. Plant carbon breaks down very easily in the soil but the fungus is the magic part that converts it into a stable form of carbon. A farmer just has to inoculate the fungus onto a plant, which is very easy. All the infrastructure’s already there to roll out such a technology, it’s simply a matter of coating the seed with the spores of the fungus. When I saw that research it was like a light-bulb moment. This was a way that farmers could easily adopt that strategy.

Until now, farmers have really been paid to extract carbon from the land rather than put it back in. Think about clearing trees off a paddock or growing annual crops, instead of perennial crops. The soil gets tilled and moved around and it’s harder to sequester carbon. You’ve got all this against you where you’re leaking carbon out of the soil. How do you flip that on its head? How do you get farmers invested in putting carbon back into the landscape and out of the air? That became my goal.

Why is a gigatonne solution necessary?

The scale of agriculture is huge. Globally, we farm an area about the size of South America and we graze an area about the size of Africa. A small amount of sequestration in one hectare multiplied by the billion or so hectares that we farm globally means that all of a sudden you’ve got gigatonne capacity to pull carbon out of the air. The numbers add up.

What prompted your interest in the potential for soil and land management to help address climate change?

I was a farmer in central NSW for the early part of my career and we went through several droughts and extreme weather events. I remember hearing about climate change but not really engaging in the idea. But then I decided I’d go back to university as a mature-age student and got interested in some of the lecturers who were talking about the climate and the atmosphere and the changes that were being measured. When I saw this solution [carbon sequestration] pop up, it was like someone handed me the keys to the universe. There are a million different solutions out there, but this is something that I can push.

Carbon drawdown is an exciting prospect, as it’s almost a solution that’s in front of our very eyes. How effective can it be in the face of what’s now being called a climate disaster?

Very effective. The sort of conservative numbers that we’re working with show that if we could access the cereal market alone, we’d be pulling down in excess of six gigatonnes of carbon each year. But this has to be hand-in-hand with stopping putting the carbon in the air; we can’t fight a losing battle.

What would be your number-one piece of advice on land management?

To value carbon as an asset. The issue is, it’s underground and as it comes out of the soil it’s a clear odourless gas: you can’t see it, can’t smell it, can’t hear it. I often ask my growers to imagine if carbon dioxide was a purple gas that stunk like rotten eggs and you drove across your paddock and saw it was leaking purple gas and you could smell it in the cab of the ute. You’d say to yourself “Oh my god, we’ve got to stop doing this, we can’t let this valuable carbon disappear”. I want people to visualise what’s happening to the carbon in their soil. The word soil carbon is bandied around a lot more in agriculture now and people are thinking a lot more of it. We just need to continue that process, hopefully to a stage of monetising it for farmers so it becomes part of their industry. We grow sheep, we grow wheat, we grow cattle; why not grow soil carbon?

What’s your favourite fact about the food and agriculture industry?

The carbon footprint and water footprint figures for clothes. A pair of jeans is worth close to 10,000 litres of water, for example. Those facts that connect people and what they’re wearing and what they’re eating and what they’re doing back to the land are really powerful. There’s a cost there that we need to assimilate into society somehow. I would like to see more of an impactful economic price woven into the price of agricultural produce so that that would find its way back to the farmer to implement more sustainable practices.

There are many young people here at Global Table this week. What message do you have for them about changing our current trajectory?

It’s always darkest before the dawn. Change is going to be instigated by this generation coming up. I think you do need to feel that sense of despair, unfortunately, and go through those stages of grieving and come to that point where you think the future looks so bleak because the next stage is acceptance and action. I went through all those stages myself. For me, soil sequestration represents the action part of that whole process. I wake up every morning engaged in life, thinking we can actually do this and what a wonderful world it’s going to be when we have that breakthrough.

As a human race, it’s like we’re going through our teenage years at the moment where we’re really disruptive and angsty. But I can feel the growing up happening now with this younger generation. They’re saying we’re not going to accept the status quo; it’s too damn scary and we’re going to pull this back from the brink. I have great faith that we will. There’s lots of encouraging people starting to emerge that are our next leaders.

Find out more about SoilCQuest or get in touch at, or follow the latest news at @soilcquest on Twitter.

Related News