Living Soils: A Promising Lever to Mitigate Climate Change – In Conversation at the World Living Soil Forum

For far too long, humans considered the ground beneath their feet to be just “dirt”. What we’ve discovered is that the world’s floor is a complicated ecosystem that we’re only just beginning to understand. Soil is what makes life on earth possible and is being impacted by climate change. But at the same time, it may also offer a way to mitigate climate change, by being a place to sequester carbon.

Pauline Vicard, CEO of ARENI, led a plenary session to discuss the issue, at the recent Moët Hennessy World Living Soils Forum in Arles, Provence. Joining her were: Claire Chenu, director of research at INRAE, the National Institute of Agriculture, Food and Environment Research, who also teaches soils and science at AgroParisTech; Paul Luu, a notable agronomist and Executive Secretary of the “4 per 1000 Initiative: Soils for food security and climate”, launched at COP 21 in Paris; Jesper Saxgren, vice-chairman in Organic Denmarks Global Committee and founding member of the Regenerative Viticulture Foundation; and Nigel Greening, owner of the biodynamic Felton Road Wines in Otago, New Zealand.

Pauline Vicard

How can living soils themselves be a promising lever to mitigate climate change? How can soils potentially save us?  Claire, we know the ICCP released its latest report a few months ago. Can you tell us about the new items?

Claire Chenu

Well, I think the main message is that we have to act now, and we have to act really intensively. That’s the main message. Greenhouse gas emissions are still increasing. We’re not reducing emissions enough. What is needed is a drastic reduction in emissions.

What is also apparent, and what appeared in the IPCC report is that even with all our reduction emissions strategies, we will probably not reach the objective of limiting global warming by +1.5 degrees.

Capturing carbon from the atmosphere and nature-based solutions are one of the options. The recent report gives emphasis to these solutions—but only once reduction of emissions is underway.

Pauline Vicard

So if I understand, we still have a chance to limit global warming to + 1.5C degrees, but we have to act now, and reducing emissions is not going to be enough. We’ve got to decrease the historical load of carbon. Some scientists suggest if we use stores to capture carbon, not only that will help us reach the goal, but we can start decreasing and cooling the atmosphere as well. Is that possible?

Claire Chenu

I think that’s a dream. The realistic dream, I hope, is to stay at 1.5C [of warming]. We will never return to the climate before the pre-industrial age. That’s not possible. We have to get into action to reduce the global warming and reduce the consequences we already see.

Pauline Vicard

So even if we have a magic wand and we use all the soils in the right way to capture all the carbon that they can, we are not going to cool the planet.

Claire Chenu

We’re not going to cool the planet.  Nature-based solutions have a great potential. And soils are only one of the nature-based solutions. Forests are another one. The scientific communities are working a lot on making quantitative estimates of how much additional carbon could be stored in soils. What we do know is technically possible is to store between one and two additional gigatons of carbon. This would offset one third of the additional carbon that goes to the atmosphere. So it’s a very significant contribution, but it’s not magic.

We’re not going to cool the planet. What we do know is technically possible is to store between one and two additional gigatons of carbon. This would offset one third of the additional carbon that goes to the atmosphere. So it’s a very significant contribution, but it’s not magic.

Claire Chenu, director of research at INRAE

Pauline Vicard

We talk a lot about carbon, but I know that methane is also bad for global warming. So is soil or natural-based solutions also active for methane?  

Claire Chenu

There are two greenhouse gases that contain carbon: carbon dioxide and methane, but methane has a warming power that is 28 times greater than CO2. Nitrogen oxide has a warming power that is nearly 300 times more than CO2. So any strategy to reduce or to mitigate climate change must account for carbon storage and the carbon cycle, but also reducing emissions.

There are microbes that eat methane. But the main role of soils is to capture carbon dioxide. The vegetation stores it as organic matter.

Pauline Vicard

Paul, the ‘4 per 1000’ initiative was introduced at the COP21 Paris climate summit. Can you tell us a bit more about it and what it aims to achieve?

Paul Luu

We tried to make people understand what are the main challenges. The idea came from a back of the envelope calculation. If we increase the quantity of carbon in the soil by 0.4% each year, we may theoretically offset the addition carbon that human activity releases into the atmosphere every year.

We can change things. And that’s all we propose: changing the practice in agriculture, towards agroecology in order to improve soil health through carbon sequestration.

If we increase the quantity of carbon in the soil by 0.4% each year, we may theoretically offset the addition carbon that human activity releases into the atmosphere every year.

Paul Luu, Executive Secretary, “4 per 1000 Initiative

Claire Chenu

Soils in many areas around the world are losing carbon. So the absolute priority is to protect what exists in peatland and mineral soils. And then, if possible, increase soil carbon.

Pauline Vicard

One of the questions I would like to address is: how can soil impact climate? But the reverse question is how does climate impact soils? And what I get from Professor Schultz from Geisenheim is that temperatures are rising more in soils than they are outside. It’s very interesting to see how the level of carbon in the air also impacts the plants levels, and the number of insects and the size of insects.

Jesper, I’m going to turn to you now. Above all, you believe in “de-learning” things. Can you explain what you mean?

Jesper Saxgren

We all know these practices that we are doing now is releasing CO2 to the atmosphere, and of course we need to change the way we farm, the way we produce. But maybe the most difficult part is to change our way of thinking. A lot of our way of thinking is based on not only hundreds of years of understanding, maybe even a thousand of years. For example, ploughing. We learned that the plough was possibly one of the most important inventions of our civilization, and we have gone on with that for thousands of years. It might turn out that it’s one of the most destructive inventions we had made, but it’s very difficult to change that concept. We also think that bare soil is the correct thing to have, even though we never find bare soil in nature.

We need to reinterpret our understanding of Darwin, because we think Darwin said “survival of the fittest” and we misinterpret that, in my opinion, to mean the survival of the most competitive, the strongest. And therefore we think we need to remove everything else but the crop we want to grow. But what he is actually saying is the ones who fit in the best. If we look at, for example, the rainforest as the most productive system, we have plants do not compete for habitat. They share a habitat. In my opinion, if we do not change the way we think, all the technological solutions will not help us.

We need to reinterpret our understanding of Darwin, because we think Darwin said “survival of the fittest” and we misinterpret that, in my opinion, to mean the survival of the most competitive, the strongest. And therefore we think we need to remove everything else but the crop we want to grow. But what he is actually saying is the ones who fit in the best.

Jesper Saxgren, founding member of the Regenerative Viticulture Foundation

Pauline Vicard

Claire, do you want to react on tilling and ploughing?

Claire Chenu

What regulates the amount of organic carbon in soil is what enters by plant material, and what leaves via respiration by microbes. Ploughing is considered to limit the microbes. What we have found recently is the effect of ploughing on carbon storage is much less important than we though, especially in temperate countries. But ploughing is still associated with having bare soils, and bare soils are subject to erosion. So it is important to have covered soil.

Jesper Saxgren

Bare soil doesn’t sequester anything.

Pauline Vicard

Nigel, I want to turn to you know, because we’ve also talked about organic, biodynamic and those practices, but you’ve recently voiced a concern that these labels might do more harm than good. Can you tell us more?

Nigel Greening

As a farmer, I’m certified organic. I’m certified biodynamic, but I increasingly worry that these are not helpful labels. I think there’s a real danger that the people who have these labels think climate change isn’t about them. They think, “I’m already doing the good stuff,” so I don’t have to listen. I know from my own experience; you take a group of maybe 20 or 30 biodynamic wines. You weigh the bottles and they’ll be heavier than 20 or 30 regular wines. So just because we carry these labels, doesn’t mean to say we are doing the right thing. So we have to learn to learn about climate change and nobody gets a free pass in this one.

As a farmer, I’m certified organic. I’m certified biodynamic, but I increasingly worry that these are not helpful labels. I think there’s a real danger that the people who have these labels think climate change isn’t about them. They think, “I’m already doing the good stuff,” so I don’t have to listen.

Nigel Greening, owner of Felton Road Wines, New Zealand

Pauline Vicard

When it comes to climate change, it seems like you are battling two timeframes. There’s mitigation that you need to do now, but you also need to future-proof your vineyards.

Nigel Greening

This is another of my big concerns at the moment. There’s this label: “sustainability”. It means nothing. It has no definition, but it sounds good. And we have a real difficulty that people think sustainability and climate change are the same thing, and they’re not. Climate change is an emergency. Climate change is we have someone having a heart attack and sustainability is coming up and lecturing them. We need instant, hard urgent action. I’m looking for emergency solutions. What can I do the quickest?

People think sustainability and climate change are the same thing, and they’re not. Climate change is an emergency. Climate change is we have someone having a heart attack and sustainability is coming up and lecturing them. We need instant, hard urgent action.

Nigel Greening, owner of Felton Road Wines, New Zealand

Pauline Vicard

Jasper, when we talk about land ownership and making the land better for future generation, we have to talk about transmission and how we bring a new generation in to continue the work and in your country. That’s a problem because the land can be so expensive.

Jasper

You don’t need to go to Africa to experience land grabbing. We experience that in Denmark where when old farmers have to stop farming, their lands are grabbed by the nearby industrial farms and they become bigger and bigger and bigger. It’s very difficult for young people to come in and take over. We have created what we call an organic land fund, which goes in and buys up these farms. And then they lease them to young people, so they become steward farmers. They have to farm organically or regeneratively, and they do not have to buy the land.

You can actually go and buy shares to increase also the capital for buying up more and more land. Young people are not inspired or interested in the industrial way of farming. That is not what inspires them. They talk about permaculture, forest gardens, and so on, and then farming more in cooperatives where they will help also bring life back to land. Instead of having these lonely one-or-two-man farms.

This is a condensed and edited version of a much longer and livelier discussion, which you can watch HERE in English of French.

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The forum brought together researchers, experts, public institutions, journalists, trade associations and companies from the Food & Beverage industry for two days of conferences, round tables, masterclasses, and workshops.

This first edition of the World Living Soils Forum took place on June 1 & 2, 2022 in Arles-en-Provence. You can watch all the replays of the sessions HERE in both English and French. 

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This conversation is part of ARENI’s publication 12 Conversations: Different Ways of Looking at Sustainability, published in September 2022, available to all.