Academic: Phasing out fossil-based fertilisers necessary, but won’t happen overnight

Fifteen or twenty years will be needed “at the very least” to phase out fossil-based fertilisers and switch to bio-based solutions, says Kevin O’Connor. But it can be done with the right incentives, he argues in an interview.

Kevin O’Connor is professor of applied microbiology and biotechnology at University College, Dublin, and director of Ireland’s national bioeconomy research centre (BiOrbic). He is also a member of the scientific committee of the EU’s Circular Bio-based Europe Joint Undertaking (CBE JU).

O’Connor spoke to Euractiv’s Frédéric Simon on the sidelines of the CBE JU stakeholder forum 2023, on 6 December.

The CBE JU held a public debate recently on the research agenda for the bioeconomy up to 2050. What are the main themes that need to be addressed in your view?

The 30-year agenda seeks to challenge us in our thinking about what kind of research we should be doing to achieve the EU’s 2050 target of climate neutrality.

In my view, building biorefineries and making biobased products is very important and we need more biorefinery and scale-up demonstration sites across Europe to help scale and accelerate the transition away from fossil and towards biobased products.

However, the biobased sector can contribute much more in areas such as soil health, biodiversity and building sustainable communities, so its impact has the potential to be even larger.

Circularity is important so that we don’t replace a fossil economy with a linear bio-economy.

While this is already built into the CBE JU program, I believe there is more we can do – for example looking into the circularity of carbon-based materials or circularity around biobased fertilisers.

Research on the bioeconomy must expand right back into the farm, beyond just simply supplying biomass. For example, some farmers are spreading manure using a technique called “low emission slurry spreading (LESS)” where you spread manure directly onto the soil instead of onto the crop which helps to reduce emissions.

It is also about soil health: how do we ensure that the soil producing biomass now stays healthy so that it will be able to produce that biomass in 30 years time as well.

For instance, do we fully understand how the microbiome inside the soil works? Do we understand how we can actually enhance soil health through circular bioeconomy? The soil is an incredibly complex structure – it’s a living structure in fact, with bacteria, fungi, insects, as well as plant life. And it’s really important that we not just protect it, but actually enhance it.

Can you give examples of how agriculture can become more circular?

We first need to realise that agriculture was already circular in the past in many ways. Before the advent of fossil-based fertilisers, for example, we would have used animal wastes or seaweeds as fertiliser, which was commonplace in Ireland.

By using fossil-based fertilisers, we’re breaking that cycle and creating greater linearity. So we have to change how we do things, and put in place economic incentives to help agriculture and forestry actually implement strategies that are circular and better for the environment.

But these policies cost money. And you need policies to back farmers, mariners, fishermen and women to do the right thing. That is critically important.

Can fossil-based fertilisers be dropped entirely? And how quickly could this be done?

A phase-out is necessary, absolutely, but it won’t happen overnight.

One way of doing that is to use nitrogen-fixing plants. By introducing legumes, farmers can reduce the amount of fertiliser they use. You can also use protected fertilisers, like protected urea, which reduce the amount that you need to spread on the land, because it will sit there longer, last longer and slowly release into the soil. There are also bio-based alternatives to fossil-based fertilisers such as manures and seaweeds, which I have mentioned already, but also microbial bio-fertilisers.

But price is always the challenge. Again, the core issue is to incentivise change. If the bio-based alternative is more expensive, that’s where I think governments need to step in and drive those changes through financial incentives.

So the overall answer is yes, we can remove fossil-based fertilisers, but it’s going to take time, and it requires innovation, and investment.

Can you give a timeframe? Assuming policymakers do all the right things, how long would it take?

I think that’s a 15-20 year transition, at the very least, to make a 100% transition. But achieving a 20% or 50% transition as milestones is what you have to do to show this is possible. You have to bring people on a journey to change practices in agriculture, industry, government, and wider society.

And some of those practices are older practices that have to come back into existence.

Moving to plastics, do you think it’s achievable to replace all of it with bio-based? Or is there a scalability issue here that could hamper that transition?

I don’t think we should replace all the fossil-based plastics with bio-based plastics because the quantities are so huge. We have too much plastic in the world.

Rather, I would say we need to prevent plastic where we don’t need it, minimise it where we do need it, and use biobased as well as biobased biodegradable plastics when we do use plastics.

That way, we can envisage replacing fossil plastics with bio-based alternatives – for example by using bio-based biodegradable plastics such as those coming in contact with food, where food contamination, which interferes with mechanical recycling, is a high probability.

For others, like plastic bottles, recycling is going to be a more obvious choice.

What can be the contribution of the bioeconomy to EU’s 2030 climate target, which is around the corner?

Based on the projects that I’ve seen, it is clear that the bioeconomy can deliver carbon savings: they can reduce the carbon footprint of products, they can deliver new bio-based products.

It’s now about scaling those projects. Having one bio-refinery is great but we need many more of them – biorefineries that are multi-feedstock, that can take waste not just virgin materials, but also side streams from agriculture, from forestry, from society, like food waste, etc.

So it’s complex, but the lifecycle analysis is clear that if you take these biomasses and convert them into bio-based chemicals and higher-value products, you can make those carbon savings.

There are a few hundred biorefineries currently in Europe. How many of them are multi-feedstock?

A lot of them are mono feedstock or maybe use two feedstocks because of seasonality. But multi-feedstock bio-refineries, by their nature, are incredibly difficult.

What we currently have is individual bio-refineries taking single feedstocks. The next phase of development will be bio-refineries that can take multiple feedstocks, so they can hedge economically and take a certain bio-based resource that’s available for example from Spring until Autumn and other feedstocks in winter.

Is this something that requires still a lot of research?

Yes, because you have a setup of biological and chemical reactors that are processing the biomass and their operation will be affected by the feedstock that’s coming in. So then you have to have that adaptability and flexibility to changes in feedstock. And that’s a huge challenge.

Past experience with biofuels shows that environmental issues usually come up when trying to scale up production with dedicated crops. How can we avoid those pitfalls going forward with the bioeconomy?

This is why lifecycle analyses are so critically important – so that we can actually demonstrate and quantify what is the impact of a particular value chain on the environment.

For instance, we must make sure that we produce biobased products that are not going to harm the environment. If we know, based on the data, that producing these products is not the right answer, then we should stick to our guns and say that’s not the right answer but the same rules need to be applied to fossil-based products. We want biobased products to achieve the highest standards but fossil-based products already on the market need to be subjected to the same scrutiny.

Fuels are high-volume products and the negative impact of using high-volume biobased products on land use and competition with food has been reported many times.

However, the volumes of bio-based chemicals and bio-based materials are much less than biofuels. And the value of those is also much higher. So if you are going to produce a bio-refinery, it should be focused on bio-based chemicals and materials, because they require less volume in terms of biomass as well as carbon emissions.

That said, biofuels can also be produced as a side stream, as a result of producing these other materials. That’s okay in my view. But don’t make biofuels your primary product, otherwise you’re going to encounter environmental issues when going up to scale.

Society needs a mixture of energy solutions such as biofuels, bioenergy and renewable energy but we must produce them in a way that is sustainable and integrated with the production of higher-value products.

The European Commission made biofuels one of its policy priorities 15 years ago to reduce fossil fuels in transport. Now, they have made a U-turn and have placed a cap on the use of biofuels in transport…

Yes, and that’s because of the science, the life cycle analysis.

You know, we as Europeans have a more conservative relationship with failure than other parts of the world. And, to be fair to the European Commission, they want to invest in the right thing and when they saw the negative impact of biofuels, they changed position. I don’t see this as a failure but as learning from your experiences and moving in the right direction.

And so the future is bio-based materials and chemicals, then?

Bio-based materials and chemicals, because those are used as building blocks to make a multitude of products we use in our everyday lives.

Nature is fascinating because it has a complexity that fossils can’t make, and we need to tap into that complexity. This is true for materials made by nature and molecules that have biological activity.

For instance, mushrooms contain bioactives that are very good for our health, for reducing cholesterol for heart health, for brain health, etc. These types of products may be found only in the Mediterranean for example. But maybe through biorefineries, we can actually make them available to people also in Northern Germany, with the production of that bioactive ingredient in a biorefinery and that will help our ageing population, or young children.

So there are many ways to skin the cat as we say. But what’s really important is that the bioeconomy is about being in balance with nature – it’s about respecting nature and recognising that we are not in a bubble outside of nature.