28
Examination of witnesses
Dr Ulli Dragosits, David Baldock and Professor Kevin Hicks.
Q1 The Chair: Good morning and welcome to the Lords Committee on the Environment and Climate Change. Today, we will be taking evidence from our distinguished panel of experts for the first public session of our inquiry into the efficient use and management of nitrogen in the environment.
Before we start, I remind everyone that the session will be webcast on parliamentlive.tv and that a transcript will be taken and made public. Witnesses will have an opportunity to review the transcript and, if necessary, make minor amendments. Members are reminded that they should declare any relevant interests the first time they speak. I take that opportunity as I am a director of Peers for the Planet, which is an unpaid role. Could each witness introduce themselves?
Dr Ulli Dragosits: I am from the UK Centre for Ecology & Hydrology, which is an independent research organisation. I am based in Edinburgh and work on nitrogen, especially ammonia and the wider nitrogen budget issue, which is looking holistically at environmental issues across all parts of the environment and economy.
David Baldock: I am a senior fellow at the Institute for European Environmental Policy, UK, in this instance, which is a non‑profit organisation specialising in policy analysis. I was part of a team that prepared a report last year looking at the nitrogen cycle and challenges in reducing nitrogen across the board, which we prepared with Aether. I was only one of several authors and would not pretend to have the full bandwidth of knowledge on all aspects that we tried to cover in that report.
Professor Kevin Hicks: I work at the Stockholm Environment Institute, which is an international institute with centres all over the world and headquarters in Sweden, but we are based at the University of York. I am a researcher at the University of York and work on air pollution and climate change, and the co-benefits you can achieve by tackling them together in an integrated fashion. I have a very special interest in nitrogen pollution, especially in the UK, and its effect on terrestrial ecosystems.
The Chair: My first question is a general one to enable our witnesses to give an overview of the essential role nitrogen plays in the environment and in sustaining all life on earth. We often hear that the nitrogen cycle is out of balance. Before we look further into that, can you explain what the nitrogen cycle is and what it means for the cycle to be in balance, if being in balance is the right terminology? Please indicate if you would prefer different terminology.
Professor Kevin Hicks: Nitrogen is a very special element. It is essential for all life on earth; it is an essential nutrient for plants and animals. Nitrogen is very stable in the atmosphere. In this room, 80% of the air is nitrogen, N2. It is stable; you can breathe it in and out. To grow a plant or animal you need a reactive form of nitrogen. To do that, in nature you have lightning, combustion processes and bacteria fixing nitrogen in the soil. You have bacteria associated with root nodules and what we call biological nitrogen fixation. These are natural processes.
Before the 20th century, the nitrogen cycle was more in balance. These processes were producing nitrogen. We knew about nitrogen as a fertiliser for plants. Nitrogen is a very good thing as it can boost crop yields. Any farmer or gardener knows that nitrogen is a key asset, for example in the profitability of farms. Nitrogen is often used as an insurance policy by farmers; it is so good at growing crops that they put a lot on. I will come back to that.
Essentially, before the industrial revolution the system was in balance. For example, you had cattle producing manure in a field and that being recycled in a quite tight cycle. What happened to put the whole system out of balance is that getting nitrogen out of the air takes a lot of energy. We have become very good at that. In 1910, an industrial process called Haber-Bosch was developed. Under high temperature and pressure, that puts nitrogen and hydrogen together to make ammonia, which can be used for fertilisers and, interestingly, is a key ingredient of explosives. Nitrogen is a very fascinating element.
The energy to make fertiliser comes from fossil fuels, traditionally. Now we are moving more towards renewables. We are producing a lot of fixed nitrogen in an active form that can grow plants and animals, and putting that into the system. At the same time, we have combustion, especially in transport and the industrial sector. Any hot temperature fixes nitrogen from the air. We have become tremendously good at mobilising this reactive form of nitrogen, which is useful to us, but we produce it in quantities that leak into the environment. The nitrogen cycle is very leaky.
There are processes in nature called denitrification which take the nitrogen back into the air as N2 and that completes the cycle. But, globally, since the advent of the green revolution, the Haber-Bosch process, growing populations, transport and all the consuming we do, we have fixed enough nitrogen to more than double the amount of reactive nitrogen in the nitrogen cycle. We have perturbed the nitrogen cycle on a global scale. The planetary boundary study published in Science in 2023 talks about a safe operating space for humanity. We can go on to all the impacts of nitrogen, but, basically, nitrogen pollution, nutrients, climate change and biodiversity are all in the highest risk area of planetary boundary effects, so we are completely out of balance in the nitrogen cycle.
The other point, on which I will finish, is that there are different scales. That is the global scale. You can also think about a farmer’s scale and his field. If you are applying fertiliser to a field, you need to do it in such a way that it will not escape into the environment. One theme I will come back to is that, if you are growing crops, the efficiency of the nitrogen used in Europe can be, on average, about 50%, but it can be much more if you have really advanced processes. However, raising livestock—chickens, pigs and cattle—involves a lot less efficient use of nitrogen. It can be as low as 10% efficient when raising animals. In agriculture, the system is very leaky, which is one of the problems.
The Chair: We will come to that, but we need to move on.
Dr Ulli Dragosits: I can add a little bit to what Kevin said. Nitrogen emissions and their deposition back to the land increased substantially, especially between 1800 and 1990. Since the 1990s, nitrogen deposition has started to come back down again, mainly due to very successful international and national legislation on combustion plants and catalytic converters. We are making things a little better, but, as Kevin said, there is a lot of reactive nitrogen in the air and environment. For example, the UK population has grown from about 10 million in 1800 to nearly 70 million today. Nitrogen is a good thing to feed us all, but we need to be careful what we do with it and try to keep that cycle as closed as we can.
The Chair: Before I move on, there is a huge amount of concern among scientists, environmentalists and people who work in nature about the amount of reactive nitrogen that is not being used and goes to waste in the environment. Is it damaging the environment and, if so, to what extent? Should we be worried about the amount of nitrogen in the biosphere?
Dr Ulli Dragosits: There is an awful lot of additional nitrogen in the environment and it permeates all components of the environment: water, the terrestrial system and soils. It has big impacts, on not just the environment as such but also human health.
Lord Duncan of Springbank: I am trying to get an appreciation of the international bodies working on nitrogen right now. As a quick overview, who is doing what at global level rather than just the domestic level?
Professor Kevin Hicks: This is very much on the agenda of the United Nations Environment Programme. You will be aware that the United Nations Environment Assembly meets every year with member states. One of the resolutions agreed at UNEA-6 was the sustainable nitrogen management initiative. That encapsulates the aim to halve nitrogen waste around the world. By “waste”, it is nitrogen escaping into the environment. There is an ongoing UN process. Countries within that process are moving towards making national action plans to reduce the amount of nitrogen going into the environment.
There is also the very big issue of nutrients affecting biodiversity. Nitrogen is deposited from the air. It can change plant composition and affect the functioning of ecosystems, so it is very much on the radar of the Convention on Biological Diversity at a global scale. The Global Biodiversity Framework has just produced—you may have heard of it—a new target 7, which is to halve the amount of excess nitrogen going into the environment.
The Chair: We will come to targets more fully later. I would like to move on to question 2.
Q2 Lord Ashcombe: Mine is a very basic question. You talked about inert nitrogen in the air, but what are the primary sources of nitrogen pollution? Once we understand that, we can move forward.
Professor Kevin Hicks: I covered this very briefly at the start, but basically it is combustion, agriculture and ammonia production. In the UK budget, which in a way Ulli is working on, the biggest signal is NOx emissions from combustion. Just a bit lower is the amount of ammonia coming from agriculture. Those are the two big sources in the UK. There are various types of combustion sources, of which transport is the dominant one. As David will tell us, we have made great inroads in reducing the oxidised nitrogen signal in the UK, but we are struggling with the ammonia signal. Those are the two major sources.
Lord Ashcombe: When you burn hydrocarbons, which is where the great mass of emissions come from, where is nitrogen involved in that, because it is not involved per se?
Professor Kevin Hicks: In a car, a certain amount of nitrogen is in the fuel itself but the heat in the exhaust pipe fixes it; it is fixed from the air. It is a bit like the Haber-Bosch process in miniature, if you like. The advent of catalytic converters has helped us to reduce that amount of NOx. They capture that before it gets into the environment. It is being fixed from the air, basically.
Lord Ashcombe: That was pretty much my question. It is the very hot gases coming out of the internal combustion engine, meeting air as it comes out of the exhaust and creating reactive nitrogen.
Professor Kevin Hicks: Yes. I am not an expert on this but there is a component in the fuel itself. There is nitrogen in the fuel and from the air, as I understand it.
Lord Ashcombe: That forms what?
Professor Kevin Hicks: Nitrogen oxide or what we call NOx. In street canyons, when this emerges from the tailpipe it is usually in the form of nitric oxide, which is NO. That is quickly oxidised to NO2. You have probably heard about nitrogen dioxide, which is a major air pollutant in street canyons. The success of London traffic schemes and restrictions is in reducing the amount of NO₂ in the atmosphere, which is a health benefit for the population.
Lord Ashcombe: What does a catalytic converter do?
Professor Kevin Hicks: In simple terms, it filters out the nitrogen.
Lord Ashcombe: Does it keep it in the catalytic converter?
Professor Kevin Hicks: Yes. I am not an expert on catalytic converters but basically it reduces the amount of NOx coming out of the tailpipe of the car.
Dr Ulli Dragosits: There are other sources of nitrogen. The main ones, from the air pollution perspective, as Kevin said, are nitrogen oxides for combustion and ammonia for agriculture. There is also the greenhouse gas nitrous oxide, which is N2O, as opposed to NO2, the air-quality pollutant. That is a powerful greenhouse gas, nearly 300 times as effective as carbon dioxide for global warming. There is also pollution to water, mainly through agriculture but also from sewage and discharges. This can be in the form of nitrates and various other types of nitrogen that include dissolved organic and inorganic nitrogen and particulate nitrogen that gets washed off from the soil.
David Baldock: I think there is a question in the future about whether shipping will become a more significant source of nitrogen emissions than it is now, if we use ammonia as a fuel. I am not an expert on this, but this comes up now as a sector we have not looked at so much in the past. We might need to do more so in the future.
Q3 The Earl of Leicester: Following on from what we have discussed, I am fascinated by the different forms of reactive nitrogen. There are five listed here, including dinitrogen N2, N2O, NOx and ammonia NH3. Could you amplify on these different types of nitrogen and their impacts on the environment and human health?
Professor Kevin Hicks: I can add to what Ulli and I were saying as well. If you think about ammonium, half the ammonium going into the air—
The Earl of Leicester: What is the difference between ammonia and ammonium?
Professor Kevin Hicks: Ammonia is the gas emitted, mainly from fertilisers and manure as well as intensive animal houses. You get a lot of ammonia gas. It is very reactive and quickly forms—through atmospheric chemistry—ammonium, NH4. Fertilisers are ammonium nitrate, NH4NO3, which can be formed in the atmosphere through the chemistry once ammonia is emitted.
The Earl of Leicester: That is fertiliser.
Professor Kevin Hicks: Essentially, it is fertiliser, but you can also get ammonium sulphates and urea—
The Chair: So ammonia reacts in the atmosphere as a preference with one of the oxides of nitrogen or with water to form ammonium hydroxide.
Professor Kevin Hicks: There is atmospheric chemistry in which hydroxide is involved. I am not an expert on the chemistry.
The Chair: It is a pathway through to forming more stable ammonium nitrate.
Professor Kevin Hicks: Yes. It has changed over the years because back in the 1970s and 1980s there was a lot of sulphate in the air from the burning of high-sulphur fuels in power stations. Ammonium sulphate in the atmosphere was quite common, but, as we have done a lot to control sulphate, ammonium nitrate has become more common and the chemistry has changed. There is now a phenomenon of alkaline air where the reduced nitrogen, which is the ammonium, dominates. That has a whole host of problems.
Quickly on ammonium, because it is so reactive it is deposited at short distances around the farm. You often get a problem with chicken farms and intensive pig farms where you have a radius where ammonia is deposited, damaging sensitive vegetation. Some of that will be deposited there and some will go further afield. There is evidence that ammonia from a farm situation can end up in particulate matter. Ammonium nitrate, NH4NO3, in a tiny particulate form called an aerosol is PM2.5, which we hear is causing health effects. It has been shown that about 20% of the annual average PM2.5 concentration in London is due to ammonia from agriculture, so it is a very complicated business.
The Chair: The source can be traced back to the agricultural environment.
Professor Kevin Hicks: Yes. I could show you the paper where that is modelled.
Baroness Whitaker: That is extremely interesting. As you say, it is complex. I wonder whether it would be possible for one of the witnesses to send us a slightly different chart from Dr Dragosits’s very interesting nitrogen balance sheet, which sets out the different forms that nitrogen takes, where these come from and what they do. That is where I feel slightly at sea. I know various forms of them but not all. It would be helpful to clarify it.
Professor Kevin Hicks: Yes, I will do that with pleasure. If you are adding things to the soil to fertilise it—that could be with urea, ammonium sulphate, ammonium nitrate or manure—soil chemistry is going on all the time. Depending on the time, place and what you put on, you will get ammonia going into the air or, through soil chemistry processes, N2O would be formed. If it is not applied correctly and is in too large a quantity, you could end up with surface runoff of nitrate into a river. Whether it is one of those three things is dependent on soil management. Management and making farmers aware of how these pollutants emerge is key to solving the issue.
Baroness Whitaker: If you can factor that into the chart in a three-dimensional way that would also be very useful.
Professor Kevin Hicks: We shall try. With soil management processes like that, when you add fertilisers to grow crops, which may be for human or animal consumption—we will come back to that—50% of the signal in the UK arises in that way. Then obviously you have cattle manure and other sources. Ulli was correct: N2O is a major gas. The big five are: NOx, which are the nitrogen oxides related to combustion; ammonia coming from agriculture; N2O coming predominantly from agriculture, though we could go further into that as well; and nitrate, which is the main species going into the rivers and causing problems there, although organic hydrogen is also involved.
The Earl of Leicester: That nitrate, NO3, is from fertilisers but also human waste and sewage.
Professor Kevin Hicks: Correct.
The Earl of Leicester: What is the percentage between those two?
Professor Kevin Hicks: According to the Environment Agency in December 2024, of the total nitrate going into water sources in the UK 70% is from agriculture and 20% to 30% is from sewage effluent as a secondary contributor.
The Chair: How much ammonia comes from burning biomass?
Professor Kevin Hicks: It is a proportion but not the largest one.
The Chair: A small proportion.
Professor Kevin Hicks: A smaller proportion.
The Chair: Is it significant?
Professor Kevin Hicks: It is significant. Ulli is nodding, I think. Diesel cars also have an ammonia signal, but the technology has improved in reducing that. Combustion produces ammonia and N2O. Industry has reduced N2O emissions considerably in the UK through combustion and manufacturing processes.
Lord Rooker: Is the runoff from the use of fertiliser because too much is being put on or is it being put on in a non-precise way? Could precision delivery of the fertiliser assist here? Is that a technique that is used with fertiliser? I know it is used for herbicides.
Professor Kevin Hicks: Absolutely. On bigger intensive arable farms in the UK, a lot of technology is used for precision application of fertilisers. A lot of the crops grown have specific requirements for fertilisers able to deliver nutrients at a particular time. That is a big issue.
The Chair: I remind members that we have two questions on agriculture further down the line. If they can wait until then, that would be appreciated.
The Chair: Before we move on, acidification of soils is often mentioned as one of the undesired effects of too much nitrogen. Could you say a little bit about that and why it is bad?
Professor Kevin Hicks: In the 1970s and 1980s, there was the phenomenon of acid rain, which led to something I did not mention earlier: the UNECE Convention on Long-range Transboundary Air Pollution. That is all about acidification. Sulphates and nitrates in the air acidify rain, with hydrogen making sulphuric and nitric acids in the atmosphere through chemistry. That is deposited on to the land. There is then a very dynamic process that depends on the buffering capacity of the soil. By “buffering”, I mean whether you have alkalinity in your soil that combines with the incoming acidity. Depending on where you are and the nature of your soil, you can have very serious acidification, as they did in Sweden because of the soils there, or you can have quite well-buffered soils where it is not so much of a problem. In the chemistry in the soil, you get processes going on where base cations, which give the soil alkalinity, are stripped away. Because of neutrality they leave together in what is called leaching from the soil profile. That acidity can end up in rivers. In Scandinavia, that led to a lot of fish kills, which led to the issue of the UK exporting pollution.
Q4 Lord Lennie: My question is about how we combat this. First, what recent changes in policy or practice have reduced nitrogen pollution in the UK, and from what sources? Secondly, is policy addressing some forms of nitrogen more than others? You mentioned that shipping for the future has not been addressed. What are the top three where we have been successful and what is outstanding?
David Baldock: As Kevin said, we have seen some major changes in practice across the whole economy in recent decades. That brought down emissions from combustion processes in power. To a large degree, we switched from coal and fossil fuels to renewables. We have tackled the transport sector to some degree in increasing the efficiency of vehicles, reducing their emissions and switching a portion of the vehicle fleet to electric-powered vehicles. At the same time, industrial processes have become more efficient. That has been driven partly by policies originating in integrated pollution control, as well as air pollution-focused measures and greenhouse gas emission measures. The whole move towards reducing the greenhouse gas footprint has been helpful, as have some local measures such as clean-air zones in cities. There is some evidence that this is a complicated area but some of those have definitely been associated with reducing emissions.
In agriculture, as we heard, there have been fewer reductions in emissions and fewer policies focused on reducing emissions generally. It is not that the most efficient farms have not changed; they definitely have, and they have been encouraged to do so by measures such as ELMS and other incentive schemes, and some legislative changes regarding things like slurry management. Yet the trajectory is still towards fairly flat emissions of ammonia, for example.
We have seen intensification in parts of agriculture and clustering of investment in very intensive livestock units in certain catchments, which can mean that the pollution load in localities is quite large. Generally, the record of pollution load on the most sensitive habitats in the UK, including in England, shows that 99% still experience nitrogen levels above their critical loads. I think that indicates that our ability to focus policies on the most sensitive sites has made very limited progress.
Lord Duncan of Springbank: That sounds like it would make a very good map. Is there a map available for the UK and potentially for Europe so we can see where the densest impact is?
David Baldock: There are such maps. I think Kevin could expand on that point. You are absolutely right. We see areas of Europe with heavy concentrations of industrial plants such as in Germany, or with heavy concentrations of intensive livestock as in parts of the Netherlands and Denmark. We see some differences in policy within Europe. It is not all determined by pan-European EU legislation. There are local initiatives alongside the bigger EU policy dynamics.
Lord Duncan of Springbank: Is there a global map as well? I am conscious that Europe may be quite distinct from South America, North America and so on. Is it possible to expand that around the globe so we get a real sense of where the concentrations are?
David Baldock: There will be a new International Nitrogen Assessment out this year. That will have details about all the world regions, the major trends and the success stories or otherwise in controlling nitrogen in those regions. So there is a global assessment coming out.
Lord Duncan of Springbank: When is that coming out?
David Baldock: Ask Mark Sutton, who is chair of that assessment.
Lord Duncan of Springbank: How fortunate.
Lord Lennie: If you had a policy wish, what would you wish this Government to do to address current levels of nitrogen?
Professor Kevin Hicks: That is a good question.
David Baldock: One thing we lack at the moment is a comprehensive approach to nitrogen which attempts to look at all the tentacles that we have briefly touched on this morning and comes up with a more synthetic approach that tries to identify the most environmentally pressing and cost-effective pathways to reducing nitrogen across the piece, rebalancing the effort so there is more focus on agriculture. Within that, one could envisage more of a cross-cutting agricultural emissions reduction programme that could go from local farm level, encouraging nutrient management there, through to catchments and up to national level.
The Chair: Would Dr Dragosits like to comment on any of that?
Dr Ulli Dragosits: There are an awful lot of maps available for the UK, Europe and globally showing emissions from different sources of nitrogen, concentrations in the air and deposition where it lands. The UK, in particular, has annual reports on environmental impacts and concentrations produced for Defra. We often refer to those as the Trends Reports.
In terms of policy, I agree with David. An integrated approach would also be my wish. Nitrogen exists in so many forms that transform into each other in soil processes and in the air, so it is important to look out for win-win solutions where you do not accidentally let nitrogen escape in another way by mitigating one particular form of it. If not paralysing, that is certainly slowing down effective work.
The Chair: Can you give an example of that?
Dr Ulli Dragosits: With agricultural nitrogen, if you plough in your slurry and manure, you remove it from the surface of the soil so there is less ammonia emission coming off; but by having it in the soil you can have more nitrous oxide, the greenhouse gas emissions. If it sits in there for long and you get lots of rain on it, it can leach into the soil. You need to be careful and apply your nitrogen in such a way that the maximum amount is taken up by the plants and the minimum is lost. That includes weather conditions, application methods and all sorts of things. Unfortunately, it is complicated.
Professor Kevin Hicks: My wish would be for a more circular-economy approach. It takes energy to make this reactive nitrogen. Once we have it, how do we make the best use of it and make sure we recycle it where we can? Perhaps we can go into that later, but that would be my wish.
Lord Trees: Taking a step back, I have perhaps a naive question, but we are at the beginning of the inquiry. There is a lot of complexity here, but there is also some simplicity. We spend a huge amount of money and effort creating reactive nitrogen in making fertiliser. We dump it out there and spend a huge amount of effort trying to deal with what is, in the broadest sense, waste nitrogen, which causes problems. As you have just put it, can we be optimistic? This sounds like a very soluble problem. If we just make less and better utilise the waste, job done. Am I being very simplistic?
Professor Kevin Hicks: That is the vision. Some of the technologies for stripping nitrogen out of wastewater and so on are still in their infancy, but there are lots of examples in Europe and the world where that is starting to happen. One big problem with combustion is reclaiming the nitrogen. With catalytic converters, where does the nitrogen go? Can we get it back from combustion processes to make it into useful forms? That technology is starting to emerge, so the vision could come true. That is one part of it. I had another part, but it has completely escaped me.
Lord Trees: Is the fertiliser industry a huge issue? Is there a huge economic question there?
Professor Kevin Hicks: Yes. We have made steps towards this sort of circular approach in the UK. Since the 1990s we have reduced the amount of artificial fertiliser that we use and have started to use more amendments. Anaerobic digesters produce slurry, so we use that; we use manure. About 21% of the manure coming out of cattle and dairy mainly is spread on land. That is not synthetic. It is only 21% at the moment. We are the biggest user in Europe of biosolids reclaimed from water treatment plants. That is human sewage which is treated and then added as an amendment to the land as part of the fertiliser. I think we use about 80% of the biosolids produced in the UK in agriculture.
The Chair: We will cover that later in one of the other questions.
Q5 Lord Jay of Ewelme: We have talked quite a lot about agriculture already. Do you want to add anything about the way in which current agricultural practices contribute to nitrogen pollution, both to air and water?
Dr Ulli Dragosits: Fertiliser prices are quite a big driver. With the energy crisis in 2022, fertiliser prices went up a fair bit and that caused a visible reduction in the use of fertiliser and emissions from it. That changed practice. As Kevin said, farmers now see manures, slurries and other organic amendments as a resource rather than just waste that needs to be spread.
Another issue is that urea fertiliser is cheaper in the UK than other fertilisers such as ammonium nitrate, but it has a higher ammonia loss. You have a cheaper fertiliser but more of it goes up in the air as an emission. Urea now makes up about one-third of the ammonia emissions from mineral fertiliser in the UK. If we could bring down that price differential and make more use of fertilisers that emit less ammonia, that would bring down emissions.
Another important thing is that if you can feed animals the right amount of protein that they need to optimise their production but no more, they excrete a lot less nitrogen. If they get too much protein, that just comes out as excreta, which opens a cascade of losses from livestock housing, manure storage, landspreading and grazing. Once what comes out of the back of the animal—excuse my language—is in the environment, it cascades through and has all these effects. There are other measures such as breeding animals to become more efficient and the feed efficiency, which I mentioned, where we can make slow progress. It is all part of the bigger picture of less nitrogen going into the environment. As one of the committee mentioned earlier, if we can stop it going out and reuse it as much as possible, that is the best way forward.
David Baldock: If it would be helpful, I could mention a few policy gaps in the agriculture sector.
The Chair: We are coming on to that in the next question.
Lord Rooker: Let us do that now. It makes sense if the clock is running.
The Chair: Lord Rooker, shall we take your question straightaway?
Q6 Lord Rooker: We are going to get the answer before I have asked the question. Tell us about the policy gaps then, please.
David Baldock: First, one answer to the question was supplied by the Nutrient Management Expert Group that Defra commissioned to look into this topic a few years ago. It reported in 2001 with a catalogue of measures, which I commend you to look at, most of which have not been implemented.
I will refer to two or three specific pieces of legislation, one of which is the environmental permitting regime that applies to intensive pig and poultry units above a certain size. That has had an impact on reducing emissions; the evaluation suggests that quite strongly. That could and should, in our view, be extended to intensive cattle units—not just pig and poultry—including dairy farms, so that we have a firmer regulatory grip on those emissions.
There is definitely a role for better enforcement of the existing regulations such as farming rules for water. When you look at the Environment Agency’s reports on the results of farm-level inspections, which it is primarily responsible for following the removal of cross-compliance in England, you see a very high level of non-compliance with environmental regulation, particularly in farming rules for water.
We could also maximise the use of ELMS—the incentive schemes we have—to make that more targeted and better designed to bring about specific environmental outcomes. The sustainable farming incentive, which is the biggest part of ELMS, is a bit of an à la carte measure. Farmers are not led to a position of adopting those sets of practices that would be most beneficial in environmental terms in that particular locality. There is quite a lot of scope for using the money we spend through the intense voluntary incentive schemes in ELMS to bring about a more targeted result.
Finally, we could also encourage more effective nutrient management at farm level by helping farmers and including an increased advisory effort. We know from the advisory work put in place in the past that catchment- sensitive farming reduces emissions. An intensified form of advice would also allow emissions to be reduced considerably over time.
Lord Rooker: Are many of these measures voluntary? In other words, are they not a statutory requirement? You talk about enforcement, but if they are voluntary, we have a problem.
David Baldock: Some are voluntary. The ELMS, which are where we spend the bulk of the resources, are voluntary. There are also regulatory requirements. Environmental permitting, as I mentioned, applies to only a portion of farms. Farming rules for water, which are a significant measure, are binding. That is where we see a particularly limited level of compliance on farms. For example, slurry stores do not comply with the requirements for levels of storage and sealing, whether they have a top or are the right distance from water and so on.
Lord Rooker: Why is that allowed, then? If the slurry stores are either not big enough, in the wrong place or not even covered up, who allows that to happen?
David Baldock: There is a whole issue of how stringently the Government wish to apply environmental regulations on farms. This is a politically sensitive area. The choice up to now has not been to seek anything like 100% compliance with such regulations on farms. The Environment Agency inspects what it regards as the highest-risk farms. It might inspect 3,000 or 4,000 farms a year. That is not that high a proportion and it was a lot less than that. We do not have a regulatory culture at the moment where there is an expectation of high levels of compliance, if I can put it that way.
Lord Rooker: We have identified the problem.
Lord Jay of Ewelme: When you say a high-risk farm, does that mean one that the Government somehow would judge as not behaving properly, or is it risk in the sense that it is close to water? How do you judge a high-risk farm?
David Baldock: You may have to ask the Environment Agency, but it will, I think, take account of the past record of the farm, its characteristics, whether it has a very large concentration of animals, whether it is near a water works, whether there have been reports from other agencies and so on. I think it has a number of indicators to identify high-risk farms.
Lord Jay of Ewelme: Professor Hicks has not commented on this yet. Going back to the original question, does more need to be said about the role of agriculture? Secondly, you talked earlier about what other countries are doing. Are there any lessons, good or bad, that we can or should learn from what other countries are doing?
Professor Kevin Hicks: Yes. One thing I was going to say about controlling nitrogen is that it is a very spatial problem. In the Netherlands, they pay farmers to shut down their enterprises and move elsewhere. This is an issue with manure. In the UK, there is a lot of arable farming in the east and a lot of animals in the west, and there is a disconnect. Years ago, you would have a horse, not a tractor, producing manure and it would be a much tighter, more in-balance system, as we said at the beginning. Now there is a disconnect and farmers end up with a lot of manure. They might have the best intentions with farming rules for water and things like that. They might have manure that they cannot put on the land at that time of year, so they have to store it. Then they might not have anywhere to store the manure. The SFI scheme that David mentioned now pays farmers to have these stores. In the voluntary landscape, we are approaching the problem, but there needs to be a bit of a rethink about whether we use manure well enough.
The Earl of Leicester: On Lord Rooker’s question and which farms, we have talked about regulation but there is also a financial incentive. The more advanced farms are looking at nitrogen usage and ways to save it. At home where we have applied it, I said to my team, “Let’s see if we can reduce artificial inputs”. My potato manager, with 450 hectares of potatoes, reduced it voluntarily by 10%. We still got the same yield; the next year, another 10% and still the same yield. The next year, we changed our planters, which applied the fertiliser next to the seed potato. In three years, we saved 37% in nitrogen, a huge saving, particularly as the Ukraine war then started. A lot of advanced farms are looking at this to improve margins.
The Chair: Thank you, Earl of Leicester. It might be a good time to declare whether you have any relevant interests.
The Earl of Leicester: Yes; farming interests in Norfolk. My apologies.
Q7 Baroness Whitaker: I should declare that I live in a national park but do not farm it. Returning to the scientific background rather than what we ought to do about it, what is the role of the food that we eat in the nitrogen cycle and what is the link between diet and imports and the potential to contribute to nitrogen pollution? I am conscious that in Professor Hicks’s very interesting paper when he talks about the FAO category of food—lots of different kinds of food—I am not clear what form of nitrogen is in them, how it is produced and what it does. When you talk about emissions to air, if I could extrapolate a bit from food, there must be some of that air in kitchens where food is prepared. What kind of nitrogen is that and in what concentrations? Presumably, it is NOx. Does it matter, basically?
Professor Kevin Hicks: In a kitchen? That is a good question. Those are three good questions. I am not an expert on indoor air pollution in terms of NOx, but cooking on gas involves a combustion process there so you will be exposed to NOx. My main expertise is in developing countries where they are burning biomass and you have sooty smoke, which has a big health impact.
Baroness Whitaker: That is in the lungs.
Professor Kevin Hicks: Yes. Small particulates are inhaled, especially soot as well as other things. Small particles can cause a host of effects. There is a whole literature on the wide range of effects: cardiovascular, respiratory and their link to cancer, dementia, autism and things like that.
Baroness Whitaker: We will have a session on human health later so I should probably confine this to nitrogen.
Professor Kevin Hicks: Your question is really good. On foods, processed foods use nitrate and nitrite in the process and there is some link there to a higher risk for cancer—not the numbers but it is a risk. On ingesting water with nitrates in it, we control the amount of nitrate in our water in the UK but at high levels it can cause problems. There has been a recent study of 60 big studies of cancer from nitrate in water. There is a link to gastric cancer from ingesting water with nitrate in it, the details of which I can send to you.
Baroness Whitaker: Yes. In particular, what form of nitrate is that? I understand that it turns into nitrite. Is that a process within the body or within the production of the food?
Professor Kevin Hicks: The study I read was about the nitrates in water. Yes, they are processed in the body, which I am not an expert on. Nitrites are implicated in that as well.
There is a big point to make about diet. In the Netherlands and Denmark, where they had a lot of intensive animal rearing and a really big nitrogen problem, they have done a lot with technical measures such as putting the fertilisers in the right place in the soil by injecting it and things like that. There is a whole host of technology that you can use, and they have made big advances. Now they have got to the stage where they are having to do more what we call transformative measures, which relates to people’s diets. It has been estimated that people in the UK eat about 50% more protein than is recommended by the WHO; in Europe overall, it is 70% more protein than they need. There is an obesity problem linked to health effects, and that is related to your diet.
I will try to be as quick as I can. The main thing to get across, as I said before, is that, if you are growing an animal, you have to grow the plants to feed the animal first—whether it is soy or maize or whatever you feed your animals, or even grass. You have to fertilise the grass as well, and that is not a very efficient process. If you want to really squeeze the nitrogen balloon so that you are losing less to the environment, healthy diets with less meat are a really good way to go.
Lastly, a demitarian diet where you halve meat and dairy—you do not give up meat and dairy; you just have one chop instead of two—has been modelled for Europe. If you halve meat and dairy, you can have a 43% reduction in ammonia emissions to the air, a 35% reduction in leaching and run-off, and a 31% reduction in N2O emissions. There is a lot of modelling to show how you can have a transformative change in how we produce nitrogen and leak it into the environment through diet. For me, the big benefit of that is that the health bill would be reduced because people eat more healthily. But there is a whole journey to go on to get to a place where we have more healthy, nitrogen-sustainable diets, which is a huge topic.
Baroness Whitaker: Thank you. Is processing food in the factory, in these great things that provide junk food for supermarkets, something that we should be looking at from the point of view of harmful forms of nitrogen? I appreciate that that is also quite a big subject, so if somebody has something they would like to write in—
The Chair: Dr Dragosits, would you like to tackle that as succinctly as you can?
Dr Ulli Dragosits: I am not an expert on what happens with different forms of nitrogen as you ingest them, but, yes, there is some mixed evidence as to what nitrates and nitrites do to the body.
The Chair: Before you go on, can we just clarify that nitrites are added to meats such as pork and bacon to preserve shelf life? Is that the main route into the human food chain?
Dr Ulli Dragosits: Yes, to preserve the meat and to kill off things like botulism, which is really dangerous. Other types of preservatives are now available, which mean that you do not have to use the nitrites any more, but that is not widely done yet. I have no idea about the cost implications. It is probably more expensive than nitrites.
Baroness Whitaker: That is really helpful. I would appreciate a note on everything else that you know about that.
Dr Ulli Dragosits: Very little, if anything.
The Chair: Thank you very much.
Q8 Lord Trees: My question is about the reuse of human waste. There appear to be two forms of this: wastewater, which is liberated usually into aquatic environments, and sewage sludge. What is the relationship between those two flows in terms of quantity of nitrogen? Do we have opportunities to recycle more of our waste? Is nitrogen pollution from wastewater properly addressed or going to be addressed by existing policy changes around sewage pollution more widely? That is, of course, a big issue.
Professor Kevin Hicks: There is further opportunity, as I said, to strip nitrogen out of wastewater. Biosolids are being quite well used in the UK already, but then you have to think about how they are applied to the land. There are also other chemicals getting in there.
Lord Trees: Is how they are applied in terms of nitrogen consistent with the optimum way of applying them to reduce methane? I do not think it is.
Professor Kevin Hicks: It is not. It is ammonia that is the problem. You get methane emissions from soils but it is not a huge source.
Lord Trees: If we inject manure deep into an anaerobic situation, that favours methane production.
Professor Kevin Hicks: You do get methane production.
Lord Trees: But it is better for nitrogen pollution. Is that what you are saying?
Professor Kevin Hicks: Yes. There is pollution-swapping potential there. Methane is not a huge signal from soils; it is more problematic from livestock with enteric fermentation.
Lord Trees: Yes, I understand.
Professor Kevin Hicks: The biosolids need to be applied in the right way and that is not always done, as you said. The Nitrogen Management Expert Group suggested that there needs to be awareness-raising and education so that farmers understand this. They know better than anyone how to manage their soils, but there are some instances where this pollution swapping can occur. There needs to be more information shared between farmers to help with that type of situation.
Lord Rooker: When I served my time in MAFF and Defra in the past, I came across food production companies and drinks companies that did not allow any form of human waste on the fields where their crops were going to be grown. Is that still the case?
Professor Kevin Hicks: I do not know the answer to that.
Lord Rooker: We told them the science. They said, “We’re not having it”. They made sure that their contracts with farmers were such that there was no human waste put on the fields where they were growing.
Professor Kevin Hicks: All I know is that the biosolids are applied widely but I am not sure if there is anybody who does not.
David Baldock: I think there are companies that still have those provisions and they are due to concerns about contamination of biosolids with heavy metals particularly. In some parts of Europe, you have to incinerate all biosolids. This is unfortunately not a totally straightforward situation.
Lord Duncan of Springbank: In an earlier response you said that 80% of biosolids were utilised within the UK. I am curious if that is driven forward by regulation or if there are market forces where there is a profit within that utilisation.
Professor Kevin Hicks: I look to you, David, for this.
David Baldock: I do not honestly know. It is efficient in economic terms. I do not think there is a requirement on sewage operators to do that but I may be wrong.
The Chair: Thank you. It has just been pointed out as well—I was wondering about this—that we have talked a lot about biosolids but not about the wastewater stream, the effluent. How much are nitrates or other forms of nitrogen in wastewater that is released to our waterways? We hear so much about pollution in our rivers and so on. Maybe Dr Dragosits wants to contribute to that first.
Dr Ulli Dragosits: I can make a start. Yes, there is a lot of nitrogen and phosphorus in human waste. Most human waste in the UK goes through sewage treatment, which strips out a lot of the nutrients but leaves some of it in there. Further proper stripping before discharge could help some more. There are also septic tanks for buildings that are not connected to the sewage network, which makes lots of little local diffused sources. I can probably get from a colleague—but not right now—what proportion of human sewage is coming through the sewage system versus septic tanks.
The Chair: Excellent, thank you. Professor Hicks, I am sorry to have interrupted you. While answering the question, would you also address denitrification of the wastewater stream and whether there is more we could do with that?
Professor Kevin Hicks: On farmers’ fields there is an issue of compaction. Whenever you get compaction, you get the right conditions for denitrification and N2O emissions. We talked about trade-offs before. To reduce the nitrate flow into rivers, some people have wetlands installed with reed beds to stop nitrogen going into the river. That can mean a situation where you have denitrification and you can have an N2O source. It is about having the integrated approach where you can see where any management solution should or should not be put because of the trade-offs that you might get. Any water body can be a source of N2O as well through denitrification.
The Chair: A source of N2O?
Professor Kevin Hicks: Yes, nitrous oxide, the greenhouse gas. The thing about denitrification is that it depends on how the chemistry proceeds in the soil or the water. It can proceed all the way to N2, the stable form, but if the conditions are such sometimes it is the greenhouse gas that is produced. It is understanding how those conditions produce the gas.
The Chair: I was really interested in trying to understand whether there is an applied process of denitrification to treatment works before wastewater effluent is released into the environment. Does that take place?
Professor Kevin Hicks: I am not sure. Ulli, would you know?
Dr Ulli Dragosits: No, sorry.
The Chair: Okay. I thought there was a process. All the nitrates and ammonium that is in wastewater is released into the environment.
Dr Ulli Dragosits: No. Some of it is filtered out, but it is not completely filtered out. There will be some residual nitrogen in the discharge that could also be removed. I am not 100% sure about the proportion that is taken out. That is the nitrogen that is then contained in the sewage sludge that is being applied. All of that is removed from the wastewater and then goes into the sewage sludge, and then the sewage sludge is applied. It is not just nitrogen but also a lot of phosphorus. There is technology to split the nitrogen and phosphorus apart and take them out. Then you can apply them in the right proportions properly, separately, to whatever somebody’s soil needs rather than a fixed ratio of nitrogen and phosphorus, where you are then overfertilising, potentially, with one or the other and not giving the soil what it needs, causing more losses.
The Chair: Okay. I understand from what you said that you are talking here again about the biosolids from the waste stream.
Dr Ulli Dragosits: Yes.
The Chair: Excellent. In water, is there any scope at the moment to take out the nitrogen for reuse before it is released to the environment?
Dr Ulli Dragosits: There is technology but I am not an expert on how widely used that is in the UK currently.
Professor Kevin Hicks: I do not think it is widely used yet but I see it as a potential solution.
The Earl of Leicester: I believe that the water companies are doing that now when they reinvest in large new sewage plants, but it does not happen in old systems and in very small, rural sewage plants that cannot justify the cost. A lot of rural rivers and chalk streams are getting little bits of excess nitrogen.
Q9 Lord Rooker: We have discussed a lot about air pollution, so I will not go through the question in detail, but, basically, is there more that needs to be done compared to what is happening at the moment with decarbonisation to reduce nitrogen pollution from transport, given the fact we are going for low-emission vehicles and electric vehicles? Are there other things that can be done?
Can you also give us a view about the contribution of nitrogen from domestic boilers? One way for sure that the Government will have a hell of a problem in getting rid of domestic gas boilers and persuading people to use heat pumps is from a practical point of view, let alone an economic one. What is the contribution to nitrogen emissions from our domestic gas boilers?
Professor Kevin Hicks: I am sorry, what was the first part?
Lord Rooker: What more could we do in terms of emissions from transport compared to what we are doing now with low-emission electric vehicles and whatever?
Professor Kevin Hicks: Yes, thank you. There is the move away from the combustion engine. The Government have a policy to remove petrol and diesel cars and reduce the numbers on the roads, moving towards electric vehicles. Then the whole thing is about where you get the energy from to charge the cars. That is the key thing. If it is green energy and renewables, that is a really good win-win solution, but if you are making the energy to charge the cars from dirty fuel that is another thing.
The other thing is that we have done a lot with readily available technologies for NOx emissions and transport. We are into the harder yards now. As I said, things like ammonia from agriculture are becoming a bigger proportion of the urban signal even as we clean that up.
For the boilers, I will refer to Dr Dragosits in a moment because she does the national inventory, which I think she will be able to talk about. From the London perspective, at the moment gas boilers are the second largest contributor to the NOx signal that is causing urban air pollution and health effects. Some studies say that in the next couple of years that could overtake transport as the biggest proportion to urban air quality. There is an air quality dimension to using gas boilers as well as we move towards decarbonisation of the heating sector. I will stop there and let someone else come in. There is some more to say about net zero and the link between nitrogen and carbon, which could be interesting.
Lord Ashcombe: I would just like to follow up. You have domestic boilers, car transport and then heavy transport. My understanding is that heavy transport is a much bigger issue as car transport is slowly being solved. The differential seems to be amazing. Where do we go with the heavy transport?
Professor Kevin Hicks: I am not an expert in that area but I know there are various initiatives like the green freight initiative. Around the world in particular, there is a lot of action going on to reduce the emissions from heavy transport. You are right, it is a big signal. I do not know the figures in the UK but there is definitely a problem. I do know there is a gap in the policy for farm machinery and things like that. That is relatively unregulated as well. That is one of the gaps that could be filled: off-road machinery and the fuels that they use. I am not enough of an expert to be able to tell you the proportion of cars versus heavy-duty trucks.
David Baldock: Going back to the first part of Lord Rooker’s question, there are still some gaps in the transport and industrial emissions sector. With industrial emissions, a number of much smaller plants are outside the emissions trading scheme. They represent a much smaller proportion of nitrogen emissions than the larger plants, but they are not regulated in the same way and they are not under the same incentive structure to reduce their emissions. A certain amount of mobile machinery is not vehicles, which you find on building sites and so forth. That represents a source of emissions that is not very specifically regulated.
One of my colleagues on the report that we worked on in the summer said that there are also possibilities for reducing emissions from ships when they are in harbour by increasing their access to electricity so that they can turn off combustion sources and so forth.
In the transport sector, initiatives can be taken at the local level. This includes clean air zones. Local authorities are meant to have their own local clean air plans. These are slightly variable plans with varying levels of implementation. So there is scope for action in some of these areas.
Lord Rooker: Some manufacturers are converting internal combustion engines to run on hydrogen. Does that affect the nitrogen angle?
David Baldock: It will—
Professor Kevin Hicks: It depends on how you make the hydrogen, I guess.
The Chair: Thank you. Before I give Dr Dragosits a chance to come in, air pollution obviously impacts human health quite a lot. It happens in the urban environment quite a lot where people are living. We had the very sad case—it really brought home to us how devastating it can be—of Ella Adoo-Kissi-Debrah’s death being attributed partially to pollution in the part of south-east London where she lived. This issue is really pertinent to human health and one that we need to get on top of. Dr Dragosits was nodding at that. I will give you all a chance to come back on that very briefly.
Dr Ulli Dragosits: As you said, in terms of human health, the high NOx concentrations tend to be in a lot of areas where there is combustion, which happens to be where people live, with delivery vehicles and people going about in their cars. Obviously, there is less emission of fossil fuels with the conversion of the fleet to electric. The sooner combustion-powered vehicles are taken out of cities the better for human health. It was said earlier that it does not just affect the respiratory system, but cardiovascular, dementia, diabetes, low birth weight and cognitive development as well. Literally everything is impacted by air pollution and we keep finding out more and more just how damaging it is. In particular, people who cannot afford to live in the nice, leafy suburbs and end up living close to major transport arteries do not have a chance. Often, they also have other health conditions that make it worse. Asthma is also a big issue. With pre-existing conditions such as asthma, you get a lot more hospital admissions when there is high air pollution. That is well proven from NHS data. Taking combustion vehicles and other combustion out of cities would be really wonderful for human health.
There are initiatives such as last-mile delivery by electric vans or cargo bikes rather than letting the big lorries ride into city centres. If you give people increased public transport capacity and frequency, especially outside London, which is very well served, make rail journeys more affordable, have monthly or annual rail passes for next to no money such as in Germany or Austria, people do not need their own cars. Have safe and well-lit infrastructure for pedestrians and bikes. When new properties are built, often estates do not have any infrastructure and act like dormitory towns. They do not have shops, doctors’ surgeries, nurseries and so on. People just end up having to drive because there is no alternative. There is a lot that could be done with proper planning. The 15-minute neighbourhood is a really good idea from the human health perspective for getting combustion out of cities.
In terms of boilers, I am not the right expert. Kevin said I work on the National Atmospheric Emissions Inventory but I am not on the combustion side of it. I had a quick look at the national inventory and there are natural gas emissions from what is termed “domestic space heating”, which I think is domestic central heating, “domestic water heating”, which would be boilers for hot water, and “domestic cooking and other”. Overall, if those are the right terms—I need to double-check them with the experts—that would be only about 3% of the total NOx emissions in the UK. If you look at it spatially, there will be areas where that is a much bigger problem. Data in a report from 2020 from the Energy and Climate Intelligence Unit, which I just glanced through briefly, shows that about one-fifth of London’s NOx emissions—it is probably similar in other major cities—is from commercial and domestic boilers, and 12% is from gas boilers in London. It is expected to rise to nearly 50% in terms of the actual NOx emissions in London because of the reduction of transport emissions.
The Chair: Thank you. It is now 11.19, and we have three more questions so we need to speed up. May I just ask our witnesses if they can spare an extra few minutes after 11.30? We will not take up too much of your time. Baroness Whittaker, you had a question. Can it wait or is it urgent?
Baroness Whitaker: It is very quick.
The Chair: Professor Hicks, I know you wanted to come in. Maybe you can answer while taking Baroness Whittaker’s question.
Baroness Whitaker: In regard to air pollution generally outside in the street, is it only nitrogen and its forms that are the damaging parts of pollution? If there are other elements, we need to be able to say, “There are these things, of which nitrogen does X”. By all means, write to us about that.
David Baldock: Yes.
The Chair: Yes, write to us about that. Professor Hicks, did you want to say something, or could you write in as well?
Professor Kevin Hicks: Very quickly, there is nitrogen dioxide, which I mentioned before, from the back of cars. There is particulate matter, which has many sources of nitrogen as part of it. NOx in the atmosphere in the presence of sunlight, methane and other chemicals produces ozone, which you might have heard of, and that also has a health effect. Nitrogen is implicated in that, so you have to think about that. The thing about ozone is that it causes health effects, it reduces crop yields—there is a lot of work in Europe on that—and it is a greenhouse gas. So it is even more complicated.
The Chair: Do write to us about the formation of ozone as a consequence of NOx emissions. It would be very helpful.
Lord Duncan of Springbank: I have a follow-up for Dr Dragosits. You mentioned that gas boiler emissions will rise to 50% if transport emissions fall, but presumably that is in relative terms. In absolute terms, you are suggesting that—
Dr Ulli Dragosits: Yes, it is relative. It becomes more important.
Lord Duncan of Springbank: There would be a decline almost certainly in the gas boilers if we are moving towards heat pumps and other things as well, or are you suggesting it is also going to rise in absolute terms?
Dr Ulli Dragosits: I do not know the answer to that. I was just quoting numbers from that report. Presumably, as London grows, as empty land gets filled in with lots and lots of new accommodation, there will also be additional sources arriving, but hopefully they will be cleaner sources. I am not an expert on that.
Q10 Lord Duncan of Springbank: That is helpful. Next, I have a question on the nitrogen balance sheet. This has been initiated by the Scottish Government, I understand. There are three parts to the question. What made them initiate this—that is, what was the impetus behind it? Once they have the balance sheet, what will they do with it? How will it then link into policy reform or change?
Dr Ulli Dragosits: Initially, the balance sheet was established as part of the Climate Change (Emissions Reduction Targets) (Scotland) Act 2019. It was seen as a really good idea to better understand where all the nitrogen is coming from and where it is going across the whole economy and environment within Scotland, and then to think about increasing nitrogen use efficiency, depending on the evidence available, and to link up better across all policy areas. To our knowledge, Scotland is the only country with a nitrogen balance enshrined in law and the legal obligation to update and report this to the Scottish Parliament every year. The reports can be found online. The balance sheet basically provides transparent knowledge on nitrogen in all its forms and across all its flows across the country and by sector. It is really useful for future planning.
The main development since I left my secondment in the Scottish Government where I produced the initial balance sheet is that there is now a national-level working group that involves the Scottish Government policy leads from all departments and all the relevant agency partners such as the Scottish Environment Protection Agency, SEPA, and NatureScot. That working group is co-ordinating work on the further development of the balance sheet, the annual reports and future policies towards promoting greater nitrogen efficiency.
I should also say it came about as part of the greenhouse gas policy area, but, as we have shown quite clearly today, it is much wider. The greenhouse gas nitrous oxide is just one of the many aspects of nitrogen. If the Scottish Government had run it as part of agriculture, that would have perhaps given the wrong impression that nitrogen is just an agricultural problem. By coming at it not from the agriculture side or the environment side, it enables a much wider conversation.
Lord Duncan of Springbank: The Scottish Government have a reputation for creating working groups across a whole range of areas. Can you give examples of where the working group has delivered a change in policy that had meaningful impact on the question that we are looking at now?
Dr Ulli Dragosits: It is still early days. The first nitrogen balance sheet was published only in 2021. I am no longer part of the Scottish Government but I can give you contacts and you can ask them directly, or I can ask them.
Lord Duncan of Springbank: Yes, that would be helpful.
The Chair: Thank you. I have a quick supplementary on that. I am trying to tease out where responsibility for managing nitrogen lies with each of the UK nations. It is excellent to hear of the work that Scotland has been doing. Where does responsibility lie with the other nation states? Are they meeting that responsibility?
David Baldock: Essentially, environmental policy is devolved in the UK, as you know. A lot of the issues that we have been talking about are devolved. On the other hand, there is some UK-wide legislation as well. If we have things like product standards for electric vehicles and so forth, they are set at a UK level. There is a mixed competence, in effect, in responsibility for different aspects of nitrogen. There is a substantial amount of responsibility for each of the devolved authorities, including clean air zones and so forth. It is clear that the overall trajectory of a lot of policies, including the agriculture budget, are set at a UK level. One has to look at those two elements together.
The Chair: Would it be a good idea for each of the nations to produce their own national nitrogen budget in the way that Scotland has, to make a stab at quantifying nitrogen in the environment?
David Baldock: It is a precursor to choosing the right parts of the system to try to manage better and then to develop policies to do so.
The Chair: It is essential, you would say, if we are serious about managing nitrogen in the environment. Dr Dragosits, would you like to comment?
Dr Ulli Dragosits: Yes. The four countries all have their own policies, as I said, in terms of environment and agriculture specifically, which is one of the biggest drivers of the nitrogen budget. It would be really helpful if all the countries could see the different nitrogen flows and how they differ between the four countries. One example for Scotland is the aquaculture sector—all the salmon farming. That is mostly in Scotland and it is a relatively large part of the Scottish nitrogen budget compared with, say, the UK nitrogen budget or other parts of the UK. Combustion happens to different degrees. Northern Ireland is much more agriculture-focused in its nitrogen flows than England, which has a lot of agricultural flows but also has a lot more on the industry side. Each country should recognise where its biggest flows, its biggest losses and its biggest issues are.
There is also the issue of nitrogen flowing between the countries and beyond them, internationally. We must not forget that, especially with air pollution, a lot of international nitrogen import and export goes on, and what happens in one country within the UK or beyond the UK really affects elsewhere as well.
The Chair: Thank you. Professor Hicks, could you also address this question: if you had one message that you wanted to send to Defra—maybe David Baldock could also come in on this—what would it be?
Professor Kevin Hicks: It is to change the narrative on nitrogen from waste to a valued resource. I am very keen on balance sheets because it can show you the major flows of nitrogen. Where is your fertiliser coming from? Are you importing it? Is it coming from the UK or not? That is one question that you can answer. In terms of animal feed, of which we use a lot—a lot of that is imported as soy in particular—what are the implications of that on the world stage and things like that? There is potential in the UK, as we have discussed, for the nitrogen to be used more effectively, efficiently and wisely. It is very much my wish to change the narrative in that way.
The Chair: Thank you. Did you want to say anything, David?
David Baldock: Yes, if I may. There is an opportunity to put nitrogen in its right place in the pantheon of environmental measures and policies in the UK. It does not appear prominently in the Environmental Improvement Plan. It does not tend to appear in measures such as the land use framework consultation that came out on Friday. You do not see recognition of nitrogen as a cross-cutting, widely permeating issue that needs to be tackled as a whole. There is an opportunity perhaps to address that in the EIP review and to learn lessons from Denmark, where there has been an effort to get farmers, environmental authorities and the industry in the same room and try to tackle the permeating problems they have related to greenhouse gas emissions from agriculture and nitrogen, and think about package deals of measures that address more than one element of a problem at once. That is clearly what needs to happen with nitrogen. It is not something that you can pursue purely through individual tentacles of the issue.
Q11 Lord Mancroft: This is a catch-all question. Government policy on nitrogen to date has been described as fragmented. In your view, what are the priority policy gaps that need addressing to have the most impact?
David Baldock: Fortunately, we have talked about a number of those gaps already. On the one hand, it is getting that bigger picture, the better framework, recognising that we need a strategy on nitrogen. It is also recognising that we have a particular concentration of issues in the agriculture sector and therefore deploying the measures that we have in a way that allows us to meet the quite important target that we have for reducing nutrient pollution from agriculture. Most authorities, including the OEP, are very sceptical that we will be able to meet that at the moment with existing policies.
It is also putting into the picture the longer-term dynamics that Kevin has mentioned with the food system. Changes on the demand side in the food system would allow a contribution to reductions on the supply side. In the same way, we talked about domestic boilers. These are important.
A nitrogen policy map needs to include technical measures where we can make improvements and an attempt to look at the more systemic reasons for the current levels of nitrogen waste and pollution. It must try to put those together in such a way that we can see a rational efficiency in use, and tie that into other objectives such as reducing greenhouse gases and improving biodiversity. If you overlaid maps of the greatest concentrations of local nitrogen problems, they would undoubtedly have some relationship with biodiversity hotspots, with greenhouse gas emission hotspots and so forth. We can use the nitrogen lens to look at related issues as well.
Professor Kevin Hicks: I just add that you can link nitrogen to all the government priorities: clean rivers, lakes and seas, zero-waste economy, food security, nature recovery and flooding. Flooding is about soil management and the structure of soils and so on. Nitrogen is very much in the first four, as we have discussed. There is a real opportunity here if you can have a joined-up approach.
In regard to working groups, there needs to be a way of helping the departments work together to get the optimal solutions. The seventh carbon budget is just coming up now. It is going to be released any day, if not already. I hope there is an opportunity within that to see that carbon and nitrogen are intimately linked. If you are going to make a transformation for the decarbonisation of the food sector, diet is another major player for carbon. Carbon and nitrogen need to go together in respect of net zero. I can provide a note on how that might work.
Finally, there are emerging challenges. There has just been a major report on the global nitrous oxide situation. One of the major findings in that was that nitrous oxide is now the major ozone-depleting substance in the world. That is when it gets into the stratosphere and creates the ozone hole, which is then linked to skin cancers and human health. The solution to nitrous oxide is about sustainable nitrogen use, especially of fertilisers. The whole thing is very linked. Seeing it in the round in a very joined-up, integrated way is definitely the only way forward to really get the huge benefits that would be achievable.
Earl Russell: Thank you very much for a really interesting session. It seems important to have an overall policy for nitrogen. Every Government to date have failed to do that. Could you just say a quick word about some of the barriers here? Is it that the nitrogen cycle is extremely complex? Is it government departments working together? Is it that there have been key issues that have been picked up and people have not had overall strategies? Finally, is a greater appreciation of the need to do something on biodiversity also key to resolving nitrogen problems?
David Baldock: I will have the first go at that. It is a very good question as to why we have not moved in the direction that you outlined. It is partly because we have tended to address a lot of environmental problems in a more sectoral way and looked at them individually, whereas nitrogen is rather pervasive. When EU policy was driving UK environment policy, there was no major pan-European initiative. There is this complex balance between the local and the national and the multi-sectoral aspects, which make it more difficult to tackle. It has not had the political profile that some other measures have. Frankly, it is quite difficult to get one’s head around the whole nitrogen octopus and see it as a whole. It has not necessarily appealed to politicians to go out and champion a nitrogen approach. I am sure there are other reasons, too.
Professor Kevin Hicks: I agree with all that. You can see that there has been improvement on the combustion side with technology. Bolt-on technologies, end-of-pipe and things like that have been relatively successful. When we talk about the ammonia signal, it is stagnant around the world, not just in the UK. That has a lot to do with the agricultural sector and the perception of nitrogen as a very available resource. You need a lot of education and awareness to put on less, as the Earl of Leicester said. He has put on less and found that it can work out. Awareness, education and a culture shift is needed in that aspect before we can really embrace it, because there is sometimes a lot of reticence and misunderstanding.
The opportunities with diet are the other elephant in the room, which is another politically hot potato, to make a terrible pun. Again, that is culture. We love bacon. We love these things. It is very much in our culture to have a fried breakfast and things like that, which we should all still have. I am not here to say, “Don’t eat your fried breakfast”. Surely, healthy diets are something that we can really push because there are tremendous benefits for a healthy life.
The Earl of Leicester: David Baldock, you said that there are many octopuses of nitrogen. Governments have to tread very carefully. The Sri Lankan Government fell when they put an edict out saying, “No more artificial nitrogen”. When the Dutch tried to do that about a year ago, they had to back down because farmers protested. I would suggest that it has to be more nuanced, with a lot of carrot and less stick.
David Baldock: Yes. We can only agree that you need the carrot as well as sticks. We have a certain number of carrots in the policy armoury already. We could deploy them in a more effective way in addressing the nitrogen issue than we do now. I am sure there is scope for more carrots. Potentially, more targeted investment aid on farms would probably help speed things up. I do not think we would advocate a purely regulatory approach here. We need to create some economic incentives as well for people to do the right thing.
The Chair: Absolutely. Dr Dragosits, and then we will call this part of the session to an end.
Dr Ulli Dragosits: Yes, nitrogen is everywhere and it is also often invisible, which does not help. There is a real advantage in joining up different policy areas and finding out what the benefits are across departments, while at the same time avoiding the drawbacks for nitrogen policy. Government budgets obviously play a role as well in where the money is spent. Nitrogen really needs joined-up investment. If you do not join up, I do not think you can tackle nitrogen properly or effectively. We have called it an octopus. We can also call it a slippery customer because it changes shape, or is a shape shifter or something. It just needs holistic tackling.
I would hope that all departments could sign up to overarching targets such as reducing nitrogen losses across the environment and the economy. You can help increase nitrogen use efficiency and help farmers save money by being more efficient. It is not just that they have to pay to reduce nitrogen losses; there can be advantages to them as well. It is about making clear and disseminating what these opportunities are.
The Chair: Thank you. Could you bring your remarks to a close?
Dr Ulli Dragosits: There is also a lot of innovation that can still be done in terms of new processes, especially for separating out the nutrients from materials and better recycling.
The Chair: Excellent, thank you and a huge thank you to all our expert witnesses. You have been very helpful and generous with your time. I bring this public session of the meeting to an end.
