PUBLIC LECTURE
Food security in a changing climate
By 50th Anniversary Selby Fellow
The Shine Dome, Canberra, Tuesday 20 October 2009
Oaks on Collins, Melbourne, Friday 23 October 2009
Professor Peter Gregory
Director and Chief Executive
Scottish Crop Research Institute
Peter Gregory was appointed Director and Chief Executive of the Scottish Crop Research Institute at Invergowrie, Dundee, Scotland, in 2005. In the decade before that, Peter was leader of a research group at the University of Reading investigating root/soil interactions and the introduction of integrated nutrient management into systems of crop production. The main areas of research were in characterising the physical and chemical environment of the rhizosphere, investigating the appropriate use of fertilisers and manures in Nepal, modelling water and nutrient uptake in agroforestry systems in Kenya, and characterising the movement of the weevil Sitona lepidus to roots of white clover.
Peter’s current research includes: non-invasive imaging of roots and root-soil interactions with x-ray CT; improving resource use efficiency at the root-soil interface; effects of dwarfing and semi-dwarfing genes on root growth of temperate cereals; root growth in response to soil drying; and global environmental change and food security. His research is conducted at two scales: the rhizosphere – a very active region for physical and chemical changes in soils – where his research is concerned with the quantification of the processes leading to these changes; and the global scale, with interests in global environmental changes and food security. This research is undertaken as part of the activities of Global Environmental Change and Food Systems (GECAFS) and with staff at the University of Dundee.
Peter Gregory: Thanks to all of you for coming to this lecture this evening.
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I am going to talk about food security in a changing climate. I will talk about climate change, obviously, but I will also talk about other elements of the climate that are changing.
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For somebody like myself coming to talk about agriculture, agriculture has not been a topic of polite conversation in English society for some 20 years now. But suddenly it is back on the political agenda. Even at casual dinner parties at my own house it is clearly a matter that has got public imagination fired up, helped by the new Chief Scientist in the UK, John Beddington, who has made it a major theme of his current tenancy.
This is the front page of the Economist in April of last year when the 'food crisis' was at its height and there was a great deal of public engagement, particularly with the issue of the price of food. So it is back on the agenda, not just in the UK but around the world.
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In my talk this evening what I want to do first of all is talk about climate change, the change in climate, and also some of the issues that are affecting the debate around food and food policy.
Then I want to say a little bit about food security. I cover this as a biophysical scientist. But of course food security is also the remit of economists and social scientists, and over the last few years, in a program known as GECAFS, we have been trying to bring together the perceptions of biophysical scientists and social scientists to come to an understanding of food security, and in particular the importance of food systems within that.
Then I will go on and give a few examples of elements of the food system and then reach a few conclusions.
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Environmental changes induced by the activity of humans are many. The obvious one, I suppose, is the atmospheric composition, in particular the increase in CO2, but of other gases as well.
An obvious change, particularly in the country that I come from and here in Australia, has been the change of land cover, change of vegetation and indeed of soils.
Changing climates, changing climate variability and changing water availability are important issues related to this evening’s talk. These other issues I am not going to talk about this evening.
So the background in terms of environmental change and climate change is now quite well appreciated.
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Indeed climate change is not something which is down the line. Climate world‑wide has changed – depending on which period you take, but certainly since about 1960 onward – these are the actual changes in surface temperature in the 30-year period between 1976 and 2006. As you might expect, the temperature has not changed uniformly over the whole globe. Most warning has occurred up here in the north.
The average temperature rise across the globe over that 30‑year period has been around 0.7to 0.8 of a degree.
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From the Australian Bureau of Meteorology website, that is almost exactly the change of mean temperature that has occurred here in Australia; 0.7 to 0.8 of a degree.
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If we go to my own institute in Dundee, the temperature rise from 1960 through to mid‑2000s has been 1.2 degrees average temperature rise on a base of around 8. So that is quite a substantial change. I will allude to some of the changes that that has induced, particularly in relation to crop production, later on in this lecture.
So the point that I’d like to start with is that the change is already here. We know from what the climate modellers tell us that even if we turned off all the CO2 taps tomorrow there is at least another half a degree in the pipeline on its way.
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There are computer models which look forward and project changes into the future. This is from the Hadley Global Climate Model, but we could equally use the one from Australia – there are obviously differences in the outputs. By and large they project roughly the same sort of changes. Again, they show non‑uniform distribution of temperatures over the globe, with substantial warming in the north by at least 5 degrees or so by 2050 to 2060. Mean global temperature changes of the order of 3 degrees or so.
Agricultural scientists have then used these models, together with standard crop growth models, to try and project what that would mean for the production of cereal crops in particular, say in 2050. This is an example of the output of those sorts of models.
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It was something that was produced for the Food Summit in Johannesburg in 2002 by the International Applied Systems Analysis Unit in Vienna in Austria. It had a major impact at the time it was released because it showed that in parts of the world such as sub‑Saharan Africa, much of sub‑Saharan Africa, over here in Brazil, parts of Australia, India, China, and sort of a bit of poetic justice, I suppose, on this area here in the United States, there would be projected decreases in crop production – quite substantial decreases in yield. But it also showed or purported to show that in other parts of the world there would be winners.
This comes with a big health warning because actually these aren't going to be many winners, because the soils here are not going to support cereal production in the foreseeable future, unless of course that carbon is oxidised away, and we don't want that to happen. What is more likely is a substantial compression of the zone over which substantial agricultural production can occur.
Now the point that this makes, and the reason that this achieved such publicity at the time, was that it clearly showed that there were going to be losers and that the losers were largely going to be in those parts of the world where we already have problems supplying enough food, where we have issues of hunger. And it was the poorest who were likely to suffer most. The beneficiaries, to a large extent, of this change were going to be here and across the northern latitudes. Arguably in this zone of eastern Kenya as well, although recent events there make one question that, I think.
But the major issue was that there were going to be winners and losers, and many developing countries were going to be significant losers.
We might question the value of this, but I think politically at the time it was quite important.
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Climate change arguments are reasonably well-worked in relation to production. There are some other aspects which I hoped we might get into a discussion later on this evening about the climate in which this debate is now occurring. It seems to me that there are at least three major ways of looking at food, and depending upon the audience that one is talking to you find greater or lesser interest in one or other of these three ways of thinking about food.
These are gross simplifications, but I think it is a useful division. The first one is food is quite simply a commodity to be moved around. Trade will sort it out. We live in a globalised market. Let's move the stuff around, just as we do computers or any other commodity. Multi‑national corporations, for example, are already starting to do this, let's continue that trend. The World Trade Organization, with appropriate safeguards, would be able to resolve the issue of distributing food around the world. So food is quite simply a commodity, like any other.
Then another way of thinking about food, and one which has become reasonably popular I think, particularly amongst agricultural and environmental scientists over the last couple of decades, is to say, okay, what do we want from land? There are many services that we rely on land to provide. We rely on land to provide food, but there are also other services that we get, such as fresh water. There are aesthetic values in land. There is biodiversity that we want from an area of land.
So we will think about food as one of a number of services that land provides. There are a number of trade‑offs in order to be satisfied, to get the so‑called ecosystem goods and services. This argument is developing quite a scientific currency. Carbon, in particular, or carbon and water are often used as currencies to normalise all of those services that are required.
The third way of thinking is as food as a human right. So, a human has rights, and one of them is food. You also have a right to determine how that food is produced and where it is produced. This raises issues, for example, of food sovereignty. And it tries to balance up the rights of individuals as consumers and producers. That is a view of food which is quite popular and quite current, particularly in areas which have, as it were, trademarks associated with food. It is a way in which some producer groups can earn added economic value.
These three views of food actually affect quite profoundly the way the issues are presented in newspapers and within the media.
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Another issue which I think profoundly affects the way we view food is the way we actually get it these days. This slide is taken in Nairobi. Nairobi is in an under‑developed country, but 25 per cent of all the food consumed in the cities of Kenya is supplied through four supermarket chains. In the UK 70 per cent of the food bought by households is supplied by five supermarket chains.
The growth of large retailers supplying food, particularly into urban markets, has profoundly changed the way that we access our food and our views, I think, of what food is.
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You can go on the website of the supermarkets and see how they view themselves and the market that they are dealing with. If you go to the Woolworths' website, as I did last week, it is quite clear that Woolworths regards the fact that 70 per cent of its fruit and veg is grown and consumed here in Australia with some pride. They will tell you where they get it from.
In UK supermarkets now, if you go on their websites, they will even give you the profile of the farmer producing the pig that you have just eaten.
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Another issue which I think affects the way that this debate around food is occurring, is that at one end of the spectrum we have the spectre of malnourishment, but at the other end of the spectrum over‑nourishment. Certainly within Europe and America the concern now with the expansion of the population – I picked these numbers off the website – 52 per cent of the population of Australia is now either overweight or obese. Interestingly, in Australia it is the men who tend to be the more obese than the women. In Europe it is the other way around, for some reason. There's an interesting social distinction.
But this debate too is particularly concerning governments. I haven't seen whether it is an issue here in Australia, but it is certainly affecting governments both in North America and Europe as to how you deal with the issues of over‑nourishment and overweight and the health problems that follow as a consequence of that, and the cost to the state of providing those health resources.
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All of that is background material to the way in which we are going to have to face up to this issue of food security.
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What is it? There are a number of definitions. Basically most organisations tend to use this one, or something like it, which comes from FAO. Interestingly it doesn't actually talk about producing food at all. It talks about having access to food. It talks about the food that you have access to meeting your needs both in dietary terms and the preferences that you have for certain types of food.
Within GECAFS we found this quite a useful way to at least start approaching a research program on food security. And we have, over the last 10 years, developed the notion that the food security that we are talking about, and is politically important, is underpinned by food systems.
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It has been useful, in our thinking about food security, to think of it as made up of three major elements. First of all there is the issue of availability of food. Does it exist in the first place and how is it distributed? So production is certainly important. The manner in which the food is distributed gives some measure of the availability of food. Then there is this whole question of access, which I described in passing just now. Who can afford to buy this food or get access to it in some other way, either through preferences, in some societies there are distinct hierarchical social arrangements which determine who gets access to certain sorts of food, or through various allocation processes. And then finally there are a whole series of issues around, the utilisation of food, what nutritional value it has? If you go, for example, to the west side of Glasgow, in Scotland, people certainly have access to food but it is actually very low quality food and there are enormous health problems as a consequence of what people there are eating.
There are issues of societal value and food safety too. If you look at, for example, the definition of food security coming out of the UK at the moment, it puts a lot of emphasis on food safety because of past political problems in that field.
This security that everybody is aiming for is underpinned by a series of activities. It is these activities which within the GECAFS research program we focused on as being elements of the food system. The series of activities are: we do things to produce foods. We grow it. There are inputs and there are various technologies that we use. We process and we package it. There is a whole big industry around that. Then there’s the issue that I have talked about before, the distribution and the retailing and how it gets to us. Then we consume it. These activities together form a chain, sometimes called the food chain, whose outcomes contribute or otherwise to food security.
These in turn interact with elements of social welfare. I have already talked about the issue of access to food, to a large extent, being a reflection of the income that people have. The wealthy people generally spend a much lower proportion of their income on food than very poor people. So that on average in Nigeria, for example, some 70 per cent of income is spent on food. In the UK, until the year before last, the average spend on food was 8 per cent of income.
Environmental welfare is reflected in the ecosystem goods and services that I went through earlier. There is a series of environmental issues as well relating to ecosystem goods and services, particularly about the access or otherwise of poor communities to natural capital. Can they actually get access to the forests? Can they use products from forests and so on, to supplement their income in other ways?
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All of this is what underpins the research program GECAFS. The website, GECAFS.org gives more details. It is supported by these international programs: the International Geosphere/Biosphere Program, the World Climate Research Program, and the International Human Dimensions Program, which is the social and economic sciences, the FAO, the World Met Office and the CGIAR centres are all sponsors of this research program. The aim of the program is shown on the slide.
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What we have done within that program is to focus on three major questions. The questions are summarised in this little triangular diagram. Essentially we have a series of environmental and social conditions that have produced our current food systems. We can look at the impact, for example, that changing climate will have on our current food systems.
In many places, but not all, these systems will adapt as a consequence of things that are thrown at them. They will change, and hopefully they will adapt to cope with the changes, for example in climate, and produce new and adapted food systems, which themselves will feed back to produce a new set of conditions.
So the program is concerned with looking at the impacts on, and the vulnerability of, present food systems. How might food systems be adapted to cope with change, what are the feedbacks, and what are the consequences of those adaptations?
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This approach changes the picture that I presented right at the outset. The classical view has been to say there is environmental change going on which will have an impact on food production.
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That is the sort of view of the world that produces a map such as this. It really just takes climate and what we know about food production and puts them together into a projection.
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What we are saying is that we need to have a much more holistic view. We need to take account of social and institutional changes that will also occur.
Institutions and the accessibility of resources can have a major effect on the result of exposure to environmental change. In some parts of the world the resilience of the system may be improved.
In other parts of the world there will be increased vulnerability. That leads to a capacity, or not, to cope with and adapt to environmental change. The ability to cope and adapt is a major factor in determining whether the map that we showed earlier – given its imperfections in terms of soils – turns out to be so, or whether institutional changes and other changes will allow the population to cope with and adapt to that change.
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So I just want to give a few examples of some elements of the food system. I am going to start with the whole question of producing food in the first place.
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We know that the population of the world is increasing. Since I was born in 1951 the population of the world has grown from just over 2 billion to around 6.5 billion today. Should I reach my biblical three score years and 10 it will be around eight billion or so.
So during my lifetime, the population of the world will have more than tripled. That's an astonishing number.
That’s coupled with the fact that lifestyles have changed. In particular, last year we reached the cross‑over point where, for the first time, more of the population will live in urban areas than in rural areas, with enormous consequences, for example, for the provision of food and the access to food, because it now has to be taken in ever greater amounts to cities where people are living.
You can see on this graph. The projection is that most of the new people inhabiting the Earth are going to be living in cities, not in rural areas.
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The consequence of the changing population, particularly the increase in population from about 1700 onwards, has been to clear land to grow not just crops. The area devoted to crops has increased, but proportionately a lot more of the land has gone into pasture and animal production. A lot of the recent deforestation that has occurred around the world has been for animal production. So there has been a change in land use.
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But for the future we expect most of the increase in food production to come about through increases in yield. This is some data from FAO demonstrating that in most parts of the world the increase in production has got to come from increasing the amount produced per unit area of land. In some parts of the world, south and east Asia, in particular, there isn't a great deal more land that can be taken into production. So 80‑odd per cent of the increased production has got to come from increasing yields.
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We have seen substantial increases in yields in the recent past, particularly from about the mid fifties onwards. This slide starts in 1965. It shows the increases that have occurred globally in maize, rice and wheat yields. Roughly, maize has increased by about 60 kilograms per hectare per year, rice by about 54, and wheat by 41. You find that for quite a large number of countries, particularly North America, Europe and parts of Asia, the increases there have been linear.
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I put this slide up from Scotland, where my current institute is based. The yield of barley has been increasing since 1940 at about 55 kilograms per hectare per year. The fresh weight of potatoes has been going up by 420 kilos per hectare per year. A lot of it is water, of course. But there is nothing God given about increases in yield. Rape yields have stayed stubbornly constant. In fact, there was some trials done with rape back in the 1960s and the same level of yield was being achieved.
I like to put this slide up because my own institute SCRI gets money to work on barley and potatoes, but we don't get a penny to work on rape.
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Increases in yield have been driven by multiple factors. I think the best explanation comes from writing on this subject by Lloyd Evans here in Australia. He put together all of the many technological factors that have contributed to those increases in yield. Multiple factors have driven the increases in yield. You might also add to this list of technological changes the economic and institutional changes that occurred at those times that enabled crops and so on to be marketed, and that enabled extension services and knowledge transfer to occur.
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But it hasn't happened everywhere. Australia is a good example of that. This is a slide from John Angus in CSIRO; there appears to have been step changes in yield. The linear increases that I showed you earlier suggest that there's been a gradual adoption of different technologies. No one thing has produced all of the changes. But here in Australia there have actually been several marked step changes as new technologies have been widely adopted over relatively short periods of time.
But these things don't go on forever. The linear increases that I showed you don't appear to be plateauing globally or indeed in Scotland. But in some parts of the world they clearly are.
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This is a slide from John Sheehy for rice yields in Asia, suggesting that the rapid increases in yields which occurred during the sixties and seventies are now tailing away. That is, of course, of considerable concern.
The other issue which we have to face up to is that although we have been able to increase yields, and we have done a very good job of that, will we be able to sustain them over prolonged periods of time? We have quite worrying evidence, I think, that we may not.
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In terms of climate, the other set of issues around which there has been, to my mind, very little advance on in the last 10 years or so has been the whole question of plant diseases and pathogens. These are two new cereal diseases in Scotland. One of them is coming from the south to the north, as warming occurs: brown rust is moving from England northwards to Scotland. We can plot that. Ramularia has moved east to west: it has moved from the continent, the Netherlands, into Scotland, and is now becoming a marked disease.
The other thing which is occurring is the increase of temperature by about 1.2 degrees. That, we think, is contributing to some of the increase in yields, particularly in potatoes that we have seen in Scotland, because it basically means that we can get a crop canopy intercepting radiation earlier in the year. Intercepting radiation gives a faster bulking rate of the tubers.
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However, it is not all positive gains. One of the things that we have seen, for example, in the warm winter that we had in 2007 is that some plants, particularly perennial plants, actually have to have a degree of cold in order to synchronise the breaking of buds. These are blackcurrants; this is Ribes. You get uneven breaking of the flower buds. These buds have not produced leaves, while the tips here, which got cool, have produced new leaves. This is an issue because it means you don't get uniform production of the berries. This is a crop which is harvested mechanically. It makes it impossible to harvest these berries in any cost‑effective manner.
We are approaching this issue by bringing in germplasm which we originally sent to New Zealand. It is now coming back to Scotland. That germplasm has a much lower chilling requirement, and so we are reintroducing that back into our own breeding programs.
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So that is, if you like, a little snapshot around production and availability. Let us take a look at some issues around access.
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I mentioned earlier that until the increase in food prices, which occurred last year, access to food in the UK has been improving all the time. The proportion of household expenditure that people in the UK spend on food has gone down consistently from when I was in my teens. Roughly a quarter of household income would have been spent on food then but this has decreased to around 8 per cent in the early 2000s. It went up above 10 per cent last year. What political repercussions that had. That is why it is back on the agenda.
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Food prices went up. Here in Australia, the statistics say you are spending 17 or 18 per cent of average household income on food. That looks quite a lot to me, and it has not changed since 1983/84.
That's the average of course. Again, as I said earlier, those on lower incomes tend to spend a greater proportion of their household expenditure on food.
So there are a whole set of issues around the way in which income is spent in order to secure supplies of food.
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To go back to retailers again, one of the things that we are quite involved with now is looking at who determines what you see on the supermarket shelf. It is certainly a considerable societal concern in Europe – much more so, I think, than in America – about the power that people have on the buying desks. This is a slide which comes from 11 OECD countries where they quantified the number of farmers and producers. 3.2 million farmers and producers, 160‑odd million consumers in these 11 countries, and 110 people on the buying desks.
These people tell these other people what they are going to produce and how they are going to produce it, because they control what you see, and the price that these people are going to pay for those products. This raises a big set of questions.
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Also, if you think about your own consumption of food, what is it you want from your food? Most of us require multiple things from our food, and different things at different times. This is a slide that comes from a professor of food retailing who works in his spare time as a consultant to Sainsbury, a big supermarket chain in the UK.
He likes to portray what we, as consumers, want in terms of what he calls 'a migration to extremes', 'a migration to poles'. Sometimes we are quite proud to buy local food. We quite like the feeling of buying stuff that has been produced locally. But also there are times when we quite like to have imported products, less so in Australia, given what Woolworths says. This is the case in much of Europe, and particularly in the UK.
Do we want it produced by high‑tech means or so‑called traditional means? Do we want it ready to eat? In the UK the average evening meal took 40 minutes to prepare in the 1970s. Now it is between 10 and 15 minutes. We use that time to do other things.
Do we want it for a low price or are we prepared to pay a premium price? Until last year the fastest growing brands in supermarkets in the UK were premium priced products, because people were prepared to pay for something that said it had been produced locally or produced by Farmer Joe. There is the healthy food, the ‘good for you’, and then there is the ‘naughty but nice’. Again if you go into supermarkets you will find that they tend to stack those ‘naughty but nice’ products just before the cashier point.
There are things on this list that you can all identify with: at different times and in different moods you quite like all of these things. One of the reasons which supermarkets are popular is that you can actually get them.
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Finally, thinking about food utilisation. I am just going to say a little bit about nutritional value and go back to this question of over‑weight and obesity. This is a major public health concern in many parts of the world, particularly amongst the affluent.
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We have seen a marked upward trend from something like around 5 to 8 per cent of the population being obese in the 1980s heading towards now 20 to 25 per cent. Projections say that if nothing is done it will reach around 35 to 40 per cent by 2020 to 2025, with major consequences in terms of diabetes, heart disease and so on.
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Why has this come about? There is a great deal of debate around this. One of the nutritionists, who I have the greatest of respect for, points out that it is not that we are eating more, but actually we are not burning energy. So in the UK houses have become centrally heated over the last 25 or 30 years. We have changed the climate in which we, as humans, live. We don't walk upstairs any more. We use escalators. We have put central heating in our houses. We don't walk, we drive cars. Children don't go out to play any more, they sit at the computer and do things.
So we have substantially changed our whole energy balance by changing the environment in which we live, particularly in the UK, by heating our houses.
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This is a rather crude slide but I think it illustrates a point, that we have moved from burning fossil fuel. Instead of burning our own energy we have accumulated it. There is some quite good evidence for this.
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Again I couldn't get the numbers for Australia, but this data from the UK will make the point, looking at the energy consumption, or the food that has been taken in by people. You are probably aware that in the 1940s the government had quite a concern about the number of malnourished people there were in England around the war time. During the fifties, in my early childhood, there was quite an effort made to improve the amount of energy consumed by people. It stabilised during the sixties and early seventies.
North Sea gas came on stream. We started to install central heating in our houses. Many more people got cars in the early seventies. You can see that since the seventies, gradually the amount of energy we have been consuming in food has gone down.
The message is that it needed to keep going down. It hasn't gone down fast enough to cope with the way in which we have modified our environment. We probably only need to eat around six megajoules per person, given our current lifestyles.
That hasn't been reflected in the way in which, on average, we tend to consume food, particularly the poorer sections of society. Governments are now concerned not just with food security but also developing new policies around food. In a number of countries – and I heard about the interest in doing this in Australia today – food policy, which is not just how you produce the stuff, and how you distribute it and have access to it, but what effect it is going to have on people who buy it. That is a major, major element now of food policy development in governments.
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It is important we get this right, because if we don't it leads to violence. There were protests around food in 2008. A number of people were killed in the riots that occurred. A lot of property was certainly damaged.
Of course that makes governments extremely nervous. It didn't happen in wealthy countries because they could get access to the food, because they had money.
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But these three different views of food, which I alluded to earlier – commodities, the human right and ecosystem goods and services – following these three things through in an uncoordinated fashion increased food insecurity. The policies which a number of governments pursued last year ostensibly to relieve food insecurity actually had the opposite effect to that intended. So that banning, for example, exports of foods actually led to less being produced in the home market.
So somehow we need to reconcile these different views. We need to understand the system as a whole and maybe that will then lead us to non‑violent government systems and food security and equity.
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I would like to thank a number of people for providing me with information that has gone into this lecture, briefly listed here. John Ingram and Polly Ericksen from the GECAFS project, who have led a great deal of the thinking in that project, some of my staff at SCRI, Christine Williams, who is Professor of Human Nutrition at the University of Reading, and colleagues around the world.
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Finally, the changing climate is placing pressure on food systems. We have seen that the demand for food is going to increase, not least because of the change in population and our different demands for food. That is likely to lead to greater pressure still for crop production to be intensified.
I think that regional food security is going to be a major issue over the next decade or so. We are already starting to see governments engaging in that and developing food security policies and food policies both for their countries and in larger trading blocks and in regions.
For those interested in the production side of things, quite clearly in relation to climate change there are going to have to be changes to crops and the diseases may migrate. I showed you a few. There are also, I think, new opportunities emerging as those changes occur.
With that I would like to stop and I would be pleased to answer any questions. Thank you.
Discussion
Question: I hark back to an early comment you made that climate change arguments are reasonably well worked in relation to production. It is production that I want to think about. I want to use Australia as an example which has a highly variable agricultural system and low cost structures. Meaning we are managing risk at this point in time.
Most of the comments in relation to that comment of yours relate to trend in climatic factors, whereas there is a fair bit of information to say that variability in a number of factors is going to increase. Increase variability, higher risk. Greater problems for such areas of the world as Australian food production.
Now, what are Australia's options? Maybe to markedly increase cost structures, which will end up meaning Australia and other countries similar to it will import a lot more food from elsewhere rather than have food security in country. Big policy issues.
Secondly, adapt the species, both plant and animal. That's not particularly easy in a lower rainfall temperate system. Thirdly, move food production to those parts of the country, such as further north, which would be a massive change, and from experiments we have already done over the last 40 years brings with it some major production problems. I would like you to just comment on that scenario, not only as it relates to Australia because I realise there are a number of places on other continents that have similar issues.
Peter Gregory: By my remark I intended to imply not that the consequences of the temperature change were well defined, but that the science behind the temperature change was reasonably worked out.
Your comment about, I think, changes in variability is very apposite indeed. I was having a conversation with people this afternoon about that – I don't think we have yet fully worked it out – well, we haven't quantified what that change of variability might be and, therefore, what its consequences might be, particularly in the systems of production that you have been talking about.
Will we shift zones of production? Well, as I understand it that has already occurred, or is in the process of occurring for one crop in Australia. In that, as I understand it, a peanut company has already decided that it is going to move northwards its major sites of production.
That, of course, is not possible for all crops and all elements of the food system.
One or two might be able to do that. So coping with increased variability, I think, is going to be a major concern in the future. It is clearly an issue here. That variation is an issue in Europe, particularly in southern Europe, but less so in the part of the world that I'm operating in at the moment.
Question: Against all my expectations I hope we do achieve food security. However, against that Charles Feather [?] in 1937 mentioned that as agricultural lands became productive population would increase to counteract that.
Now for 10,000 years agriculture has been making lands more productive, over the green revolution and so on. Do you expect any change in this?
Peter Gregory: Well, I do what I do because I thought that it would be possible to sustain the high population that was being projected in my teens and I am by nature an optimist. So I tend to feel that we have a good chance of doing some of these things. However, I have to say that by the time a population reaches 10 or 12 billion, I think it is pretty risky. We may be able to do it for a time, but the thing that really concerns me, and this is where I start to use my soil specialism, is how we sustain it, how to keep those levels of production.
The thing that concerns me is that for many parts of the world, not necessarily the UK, but in the soils of the tropics and semi‑arid regions, most of the longer‑term experiments that have been done on trying to sustain crop production demonstrate that you need quite large inputs into the system of organic materials at some point. So that fertility is a consequence of chemical, physical and biological activity.
The concern that I have is that I'm not sure that we can do that over sustained periods of time at the levels of yield that will need to be achieved. From the production end of things I think that that is a very serious issue. So my optimism is tempered with that specific set of questions and realisations.
If I can inject an even more pessimistic note, when biologists see an exponential increase in the population of an organism – most exponential population increases end in quite large and catastrophic declines.
Again, I don't think we know the point at which that might occur. But I guess that at a population of 10 and 12 you are a lot closer to it than you are at six. So I think the problem becomes increasingly difficult.
Question: I have two questions, one relates to fossil fuels and the other to obesity. There is a concept of peak oil, and that seems to me to relate to fertilisers and the sustainability of increased yields. I wonder if you could comment on that. The second question regards obesity, which you talked about in terms of too much food per energy requirement. But I am wondering whether it might come from too little high quality food. That is, if you have to eat an awful lot of stuff to get your basic nutrients. Maybe you get too much energy per basic nutrient.
Peter Gregory: On the first one, yes, there is this concept of peak oil. There is also a concept – which I knew about which is obviously on the agenda here in Australia – of peak P [phosphorus] as well. There are those of my colleagues who think that peak P is going to occur in agricultural systems and be much more of a substantial issue before peak oil is.
I was doing a review recently on the way in which we have used fossil energy to boost yields. The return that we are getting on the energy put in now is not great. I think the real question coming to the fore, in the context of wanting to somehow reduce greenhouse gas emissions – actually it was on the front page of The Australian today – is that agriculture is going to have to play its part.
In Europe, for example, 20 percent of greenhouse gas emission comes from agriculture. Agriculture and the food industry is not going to be exempt from making a contribution to reducing greenhouse gas emissions. As soon as you say that you get into the question of how the energy is being used in agriculture at the moment. We are not getting a very good return for the energy that we are putting in. How we do that better is a moot point at the moment, but it has to be faced.
In relation to the obesity question, you are absolutely right. Obesity isn't just confined to the poorer sections of society, but it is much more prevalent there. Actually, it tends to be the poorer sections of societies spending a greater proportion of their money on food and they are buying high energy food, a lot of carbohydrates and not necessarily many other vitamins and so on within their diet. And the other extreme, it is down to alcohol consumption amongst the rich.
Question: Thank you very much for a very interesting talk. I was just reflecting on the slide that you put up that showed that the proportion of pasture is now at the expense of crop. I'm also thinking about some of the other comments that have been made. I am wondering is there a dialogue going on that is looking at this decreasing resource of land. Instead of just talking about increased yield, talking about an increase in terms of the nutritional yield and the choices of land-use to that might help counter‑balance some of this security issue?
Peter Gregory: Yes, there is a very active – not just debate – but a very active desire now to take a look at land-use policies. Again, I am not familiar enough with what has been going on here in Australia. But when I was a student, certainly in the 1970s in the UK, there were areas of land that you couldn't build on because they were regarded as being of high agricultural value. There were planning restrictions placed on that land. All of that was largely swept away in the eighties and nineties.
But now the question is coming back again as to whether that is a sensible policy and as to whether – given that no‑one is manufacturing any more land, and indeed it might disappear under the sea – we shouldn't be taking a look again at land‑use policies not just in relation to producing food but in relation to renewable energy and also for sources of fresh water.
So I think it is a very, very active debate, and I would imagine that what is going to come out across the world, in many countries, is not only a food policy which relates to many of the questions that we have talked about, but also improved policies regarding land-use for multiple purposes.
Question: A technical question. You mentioned that there needed to be an input of organic matter to sustain food production. Where is that organic matter likely to come from, and will an increase in soil organic matter be a win/win situation both in environment and food production?
Peter Gregory: Historically the organic materials have largely come from two sources; either from mixed farming systems, where grass and clover have been part of the rotational sequence. A large number of those have disappeared as farms have become either purely arable or purely animal. That is one source.
Another source which is used in countries like Nepal and large parts of sub‑Sahara in Africa is that nutrients are effectively mined from forests, and feed is brought from forests onto farms and small holdings. That has been a source of nutrient inputs, and the dung then has been incorporated as a source of organic materials.
So basically it has been achieved by, in that case, bringing in nutrients from others sources and then putting it into the land via an animal.
But animals have been historically very important, as means of conserving soil organic matter.
Question: I am beginning to see movements of large numbers of people. I was wondering how you felt migration might interact with factors that you have been talking about? Will we see enormous numbers of people moving to places where there is food, and will that completely disrupt the world order?
Peter Gregory: I am not an expert in this, but I know a man who is, and I am working with him and a PhD student at the moment. The answer to the question, I think, is yes, people are going to move. They are already moving, which is why the Indian government is building a very large fence around Bangladesh. So it is already happening. It is already happening to your own boat people. Obviously we see it in Europe to a very large extent. And part of the reason that governments in Europe are now expanding their aid programs to Africa is basically to try and keep people in Africa. Otherwise they are going to move into southern Europe at considerable rates.
There is enormous movement going on both in relation to food and in relation to climate shocks, also in relation to government, or the lack of governance, and the institutional arrangements in many of these countries. So it isn't just climate. That is often the label put on it. The whole question of appropriate institutions, appropriate governance is a major factor influencing migration patterns. The answer to your question is definitely yes, people are going to move.
Question: I had a vaguely related question. As well as your excellent talk we hear a lot about efforts to improve the production side of the equation. As you point out, we can all see it can't go on forever and it will be difficult to sustain. So we ultimately, as a society, have to tackle the demand side, which means stabilising and hopefully reducing global population.
You mentioned that the GECAFS research program includes social scientists. Is this side of the equation something you are addressing, and if not who is?
Peter Gregory: Very much so. Yes. I mean, the question of population, as you can imagine, a very vexed and emotive topic because it is never one of us who shouldn't be here.
So that is a difficult issue. But, yes, the whole demand side is being considered in that element of the program. I think one of the exciting things about this research program fro me, over the last five or six years, has been how we have managed to bring those communities together around this particular issue. One of the things I am going to say in my talk in Melbourne, to the [Think Tank] group there, is that one of the pleasing things of this particular research project has been that the thinking around that has now been picked up in a number of policy documents, for example, one of the latest FAO documents. There is an EU document, and there is a Defra [Department for Environment, Food and Rural Affairs] document in the UK, which are starting to pick up on this food system way of thinking about the issues.
Graham Farquhar: Thanks Peter. Having just come from a conference on the production side of this problem it has been fascinating for me to hear your comments not only on that but on processing and packaging, distribution retailing and consuming.
The Academy has taken quite an interest in this area. Indeed, we put a submission to Parliament to draw attention to the work of TJ Higgins in this area as well, pointing out that these problems have solved themselves in the past but of course they have solved themselves because people have eventually got active. At the basis of getting active there has to be research into production. There is research in a whole string of topics. Peter, I found it really interesting and fascinating the way you have explained them to us and explained the issues of how climate change will affect the full food chain.The Selby Fellowship
The Fellowship is financed through the generosity of the trustees of the Selby Scientific Foundation. In 1980 the Director of HB Selby Australia recognised the need for a continuing source of funds to help finance education, research and development in the fields of science and medicine, with which the company had been involved for some 80 years as a supplier of scientific instruments, laboratory apparatus and chemicals. Accordingly, the Selby Scientific Foundation was established with contributions from HB Selby Australia Ltd, members of the Selby family and a number of shareholders in the Selby company.
Fellowships are awarded to distinguished overseas scientists to visit Australia for public lecture/seminar tours and to visit scientific centres in Australia. Fellows are expected to increase public awareness of science and scientific issues and accordingly will be outstanding lecturers to the general lay public.
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