Earth Talks: Nick Holden


Caitriona Devery talks to Nick Holden about food system resilience and sustainability, the global soil crisis and food waste

Nick Holden


UCD School of Biosystems and Food Engineering

UCD Profile

Q: Global and European Strategies, such as the EU's Farm to Fork, increasingly place sustainability as central to food system resilience. Would you see the Irish food system as resilient?

A: No. There are some very simple examples that tell you the food system isn’t resilient in all sorts of places. The one I use a lot in class, which is beginning to get a bit old now, is that the last time we had serious snow, the supermarket shelves were empty within about thirty-six hours. Our food system Is not resilient. We don’t like to think, as a well-developed economy in the global north, that we could run out of food, but the reality is that if trucks don’t drive along motorways and get onto ferries, we effectively can’t access a balanced diet within a couple of days. That would apply in lots of places. On a global scale, something like 80-85% of all the food in all the world goes through eight or nine ports. All you have to do is disrupt two or three of those and you have massive logistical problems with the global food supply. The system isn’t resilient.

My job as someone in a university isn’t to stroke the back of the system, reassuring it that everything is okay. My job is to be cynical and questioning. I don’t think we have a resilient, food secure system. If you look at what’s happening now with COVID-19, if many meat factories were shut for a month or two, we could potentially have a collapse of the meat industry. Dairy, because the product price is a bit higher, might be okay, but meat could be in serious trouble. Whenever I’ve had the ear of somebody in the Department of Agriculture, I’ve argued that we should be promoting policies for food security and I’ve been laughed at. It is being taken seriously in the last year or so, because the problem has become more apparent. There’s been a lot of scrambling behind the scenes to ensure that food stays on the shelves. However, one of my students calculated that Ireland could be self-sufficient in its food using only about 35% of its land.

Q: Let’s talk about soil. A few years ago, the UN warned that global soil is so degraded we may only have sixty harvests left. Are you hopeful or terrified when you hear these predictions?

A: I’m currently terrified, I’m very worried. In this article I summarised the case for why the food system isn’t sustainable. Now, that’s at a global scale. Remember that scale is really important here, and the resolution you look at. Soil is eroding perhaps ten times faster under production agriculture than it is being produced by natural soil forming factors. That’s where we get this figure of how many harvests are left. Ireland is a little different because of the predominance of grass. What happens on the Great Plains is not happening here, but because of the global nature of the food system, we’re so reliant on elsewhere in the world for our basic nutrition, that we can’t just say our soil is okay, so our food is okay.

There’s a problem around soil erosion. There’s a problem around soils’ function within the hydrological cycle, and the amount of water that we’ve abstracted and is required to grow our food. One of the biggest man-made features on the planet is now the central valley of California, driving the fifth largest agricultural economy in the world, and it’s sunk by over ten metres in places because of the abstraction of groundwater for cultivation. The abstraction of fossil water is a huge problem, if you look at China and the Beijing basin, it’s now pumping water from over a thousand metres deep in some places, and I have read suggestions that there are seventy to ninety years of accessible water left. India is predicted to run out of water in the next two hundred years at its current rate. Ireland is fine, we have plenty of rain. It may be destructive rain at times, but it is not a major issue.

Phosphorus, however, is a major issue. We’re running out of phosphorus. We will hit peak phosphorus in the next seven to thirteen years, according to some estimates. Without phosphorus, our agricultural productivity tanks. That’s why you see this European research focus on phosphorus recovery.

Q: What happens to phosphorus in the agricultural cycle, is it recoverable? How essential is it?

It ends up with a number of fates, but the key issue is the amount of phosphorus that is applied, which becomes part of agricultural products and then in the sewerage system, and finally in the ocean. So that means it isn’t coming back for terrestrial use for hundreds of thousands, millions of years. We need to recover much more at the end of the chain, in order to make it a cycle. On what phosphorus does, I’m not a plant biologist, but I know that it regulates the energy that flows through plant cells. It regulates photosynthesis by helping the plant to assimilate carbon and nitrogen to make dry matter, which makes the food that we eat. That’s why we add it; we couldn’t have crops and crop yields of the magnitude we do without phosphorus.

Nitrogen is the other big one. That’s actually the one planetary boundary which we are way, way in excess of.  Perhaps more damaging than climate, I’m not sure. It’s not that nitrogen is limited, we have an almost unlimited supply in the atmosphere, but we are transferring so much of it from the atmosphere into aquatic environments and other terrestrial environments, where it was never supposed to be. The Earth systems can’t buffer these amounts. Nitrogen in various chemical forms causes pollution and drives ill health. Increasingly, when I talk about these things to students, they are kind of aware of them but it’s almost as if it’s so worrying, they don’t want to acknowledge it.

Q: Do you sense a kind of paralysis around how ominous these kinds of projections are?

A: To some extent, yes. If I dealt with a company around these things and I said, ‘You really need to reduce your climate change impacts’, the response used to be quite dismissive. I remember talking to one major agri-food company in Ireland who I won’t name, and the director of the company said to me, I don’t care what you say about climate, if we don’t make the money, nothing else matters, the money always has to come first. I think in the last year or so, this attitude has started to change. Companies now recognise they have to address climate impact, but then you add on top of that the nitrogen, then you add on top of that the water, and the phosphorus, and the soil erosion impact and so on, and the problem seems to become almost insurmountable (which it isn’t). Then I ask, what’s the point of the money now, if the world is irrevocably damaged in a hundred years’ time?

Q: You have worked with Life Cycle Assessment in all manner of sectors over the past few years. Tell us what that means.

A: Life Cycle Assessment (LCA) is a method of quantifying originally environmental impacts associated with a product, process or service, across its entire life cycle. What makes it different from things like environmental impact assessment is that you’re not looking at the impact of an activity at a given location and time, you’re looking at the summation of the impact from the very first activity required for that product, process or service to exist, right until the very last activity that is required when it ceases to exist. While science underpins the method, it’s not a scientific method. It’s not like mathematical modelling, which would be used in biological or geological sciences, it is an accounting method, and there are accounting rules defined by an ISO standard. What this means is that you’re not estimating the actual impacts that occur for a given product. You’re estimating the potential or likely impacts.

I’m increasingly worried that as LCA has become a mainstream method in policy instruments and has fed into formal requirements in research programmes, it’s almost becoming regarded as if it’s a scientific modelling method. And it isn’t. It is science-based, but you can’t validate it. In scientific modelling, you collect empirical data, you parameterise, you calibrate, you validate, and then you say you’ve got a generalisable result. You can’t do that with LCA. It’s like financial accounting. You follow the rules that are agreed and then people agree the results are meaningful.

Q: Is it a useful technique for furthering sustainability?

A: LCA methods and the footprint methods that go with it, apart from the ecological footprint, which is a different thing, are eco-efficiency measures. This means that LCA calculates impact per unit of activity or output from a system. In an LCA, you always define the function of the system that delivers the product, process or service you are interested in, you put a unit on that function, and then you calculate the environmental impact. For climate impacts, you add up all the CO2 equivalents over the full life of the system, then divide by the amount of the functional unit that the system produces. That’s the number you report, in this case, a carbon footprint. So, Ireland has a low carbon footprint for dairy and beef products, but that doesn’t mean they’re sustainable. It just means they are eco-efficient. You could get a low carbon footprint by producing more without increasing the emissions or producing the same and decreasing the emissions. This doesn’t tell you what the local environment is capable of supporting in the long term. Therefore, it doesn’t tell you much about sustainability. Sustainability is an absolute concept, not a relative concept. I really dislike it when people talk about ‘more sustainable’, or ‘less sustainable’. A system is either sustainable or it’s not. This is the trouble with using indicators as measures.

Q: How is it applied to social considerations, as in Social LCA?

A: Social LCA uses the same approach, but what it does is use indicators of social activity or social impact. You define stakeholders of interest; they could be the general public, people in the value chain, workers in the factories, owners of factories. Then you identify indicators that represent their social wellbeing, as it were. So, for instance, we would use things like accident rates or salary above minimum wage to indicate social impact for workers. Key indicators we might use would be the costs associated with health impacts of an activity, child labour, aged labour, accident rates, profits, gross margins, salaries, these kinds of things, gender balance, ownership by gender, the right to further upskilling and education and the right to unionise.

We are using social LCA for a number of projects such as AgriChemWay and for the BiOrbic Centre. Social LCA raises the issue that you can’t trade capitals. If I’m doing something very environmentally inappropriate, I can’t offset that by doing that doing something socially good, which is traditionally what corporations do. They will flag some social initiative to distract the eye from something else. You also can’t trade capitals across geography either, so if my mobile phone is made using child labour and non-unionised labour in Asia, this can’t offset that by investing in an education programme in California.

Q: Do you believe in the premise that science and engineering will be able to fix environmental problems and deliver global sustainability?

A: There is a formal concept that describes two ways of looking at sustainability. There’s the strong sustainability model, which is what I advocate in principle and all my research is built around. This says everything must operate within the limits of planetary boundaries. Within that, it must operate within the needs of human society and within that it must be financially viable. Finance is the inner circle and the limit of activity is the planetary boundary. This is known as strong sustainability.

The contrary view, which is very much the kind of business view that has been used to justify current thinking, is called weak sustainability. What this says is that we don’t need to worry about the impact we have now because in the future we will innovate, and we will develop technological solutions. If we have more sick people, we will innovate more medicines. If we have an environmental problem, we will innovate a solution, for example if we have excess heat, we will innovate air conditioning. So, the question you need to ask is, if you project both of these ways of looking at sustainability into the future, what does a future look like with weak sustainability? And if you think about one of the most dystopian futures imagined, Blade Runner 2050…

Q: Mad Max?

A: Yes. That’s kind of where you get to. Now I would argue it’s not for us to say that this is what future generations should be consigned to, I like to think they should get to see life lived in a natural environment. We can innovate, we can come up with technologies, but fundamentally a measure of whether a technology is right in my view is, does that technology work in tandem with, complementary to, and supportive of ecological and environmental processes? If it’s complementary to and permissive of natural processes and natural systems, then I think it’s a valuable technology. If it’s contrary to, then I think it’s a poor technology. So, vaccination, probably complementary. Damming rivers, probably not.

The role of science isn’t to make the decisions, but to provide the evidence. One of the problems with working in sustainability is that the first response to a proposed measure is often to ask the question, would people do it, would they buy into it, would they accept the cost of doing it? I try to understand why the most environmentally efficient way of doing something isn’t the cheapest, which is because we do not place a cost on the externalities. For instance, we calculated the cost of a litre of milk in Ireland in 2015, and then estimated the cost of externalities, which nobody pays for directly. They’re estimated by looking at things like environmental emissions and what they might do to human health, and what we found were that the externalities that are not costed represent a similar amount, so milk is selling for around half the price it really should be if it were to account for its wider impacts.

External costs are not captured in the weak sustainability model. They need to be captured for people to really understand the implication of externalities.

Q: What are the implications of this kind of methodology for the food industry?

A: There are sectors of the food industry that are really driving towards using costing of externalities in order to understand their future liability. I am involved in a network called FoodSIVI that is focused on impact valuation. What they’re trying to do is drive green financing, and they’re trying to ensure that businesses don’t have future liabilities in the same way as the tobacco industry did. If you imagine in the 1960s, the tobacco industry knew it had a problem but nobody else did, then in the 1970s people were beginning to move against the tobacco industry for compensation, which is still running. The food industry knows it is doing global damage. The question is, in twenty years’ time, what will happen in the reckoning around that, who will be liable? There are issues of liability over health directly and liability over health due to environmental issues.

Q: Irish agricultural sector is heavily reliant on beef and dairy and often criticised for its high environmental impact. Can beef and dairy production ever be sustainable?

A: The answer to that is, it depends on the scale you look at. So, an individual farm might be sustainable, but all of the farms together might not. When I started doing the carbon footprint exercise on milk and beef, about fifteen years ago, we calculated these eco efficiency metrics. What I’m now asking is, how many cows should be in Ireland? Livestock isn’t inherently unsustainable, what makes it unsustainable is the amount of activity. There is a number of animals we should have. The question is what is that number, what is a fair share of our natural resource, buffering capacity and contribution to acceptable adverse impacts?

Q: How difficult would it be for Ireland to move away from beef and dairy to a more tillage based agricultural sector?

A: We are very reliant on these activities to support the national economy. I walk down the street on occasion, and I try to do a calculation (for fun and to keep my mind working) on how much money the car brings into the exchequer. For every car that’s on the road, the exchequer gets the import duty and the VAT, and then they get an annual tax, and they get the duty and the tax on the fuel, the VAT on all the servicing, maintenance and so on. If you calculate that for one car and then multiply it by all the cars on the road, we might conclude that we can’t afford to take cars off the road and still have public services. If we took dairying out of agriculture, we would perhaps have a similar problem. The reason we have cows is because they allow us to use grass, and on much of our land area, grass is probably the best crop we can grow. There are arguments for and against that of course too, but I won’t get into that. If I assume that livestock serve a purpose in certain environments and Ireland is probably one of them where it’s a positive purpose, then the question I would ask is, how can we make a viable system with the right number of cows?

The economic assumption has always been to make the system profitable, you just have to keep producing more, but maybe there are alternatives. All that milk and meat we produce is largely going into bulk product markets, high volume, relatively low value. Rather than producing bulk commodities and competing on a global market, why aren’t we at least asking about finding a business model which means we can make enough money with less animals? We might also consider the Sustainable Development Goals, particularly SDG 12 sustainable production and consumption. When is the day going to come that we don’t have the right to unlimited cheap food? We haven’t even talked about the whole issue of waste. I should get danger money for doing this work, because sometimes I get quite upset thinking about it.

Q: Let’s finish with that topic, then, as I know you’ve worked a lot on waste in terms of the bioeconomy and circular economy.

A: Yes. It’s the thing that’s caused me the most personal discomfort, the idea that we should make value chains from wasted food. I did some work a few years ago where we calculated the environmental impact of different options for dealing with wasted food. There were only two options that had a positive environmental impact. For the technology solution, the positive environmental impact was tiny, so small it could have been negative. The solution that had a massive impact was avoidance. Don’t waste. Once you’ve ‘spent’ the resource and you’ve made the food, there is nothing you can do with the food product to offset that ‘spend’. The impact has happened, you’ve caused all the emissions, consumed the resources. There is nothing that can be done to offset or negate those impacts that have been ‘spent’. I try to always use the phrase ‘wasted food and residue’. When you talk about ‘food waste’, people don’t necessarily know what you mean, it implies many different things. Wasted food is stuff that was grown to be eaten and wasn’t. Residues are things like potato peels or banana skins, stalks and so on, those are things that we should be valorising, because we get more from the initial spend. If I could get only one message across at the moment, it would be DO NOT WASTE FOOD and VALORISE YOUR RESIDUES.