[insert slide 1] I have been asked to speak about managing in a - - PDF document

[insert slide 1] I have been asked to speak about managing in a variable and changing climate, and the basic theme is both variability and the change. And I’ve got to try and do that very quickly. [insert slide 2] This is a simple graphic from Roger Jones from CSIRO that many of you have probably seen before, but I think it summarizes the issue, that we have a variable

• climate. It wiggles up and down, and in a changing or non-stationary climate, we

move in that. I guess what we are really trying to argue about is that managing this variability is very important, partly because we would expect with a changing climate more variability, but I think that is a bit of an over-simplification, a bit of a bumper sticker. In some cases, we will get less variability, mainly because the main way to cope in a changing climate is how we manage variability. Variability is going to be what hurts us, there is going be these peaks, and as we try and expand this coping range by adaptation, one of those ways to adapt along with better varieties, along with better farming practices and so on is understanding the variability and the climate science behind that. I guess I would see that there is probably two extremes in views in farmers and other people I speak to. One is that, “Look, we’ve managed this incredible variability. We’re bullet-proof. We can handle anything into the future.” The other view seems to be held by some NRM people and others that the first little bit of change is going to knock farmers out. With my colleagues, we will try to run this perfectly rational middle ground that is somewhere in between those two. So it is going to present new challenges and important challenges but we can overstate the impact of climate change in the short term, so I guess at a very simple level, compared to some other commentators, I think I am more optimistic about 2030 and more pessimistic about 2070; time matters in these projections. [insert slide 3] But just to be clear here that we are acknowledging climate change; this is an important study by William Klein, and if we were to get four degrees warming with business as usual along with ecosystem destruction, along with many, many dispossessed people, we will have significant food shortages. But an important point is that that is four degrees warming and 2080. That is well into the future and really is telling us where we must not go, where we don’t want to go. How we can adapt to four degrees is very difficult. When I was at uni in the ‘80s, I remember one person

PETER HAYMAN

did a PhD on how nuclear war would be bad for wheat growth, and I think sometimes studying the notion of what four degrees will do to agriculture is a bit similar. [insert slide 4] This diagram here from the IPPC shows this notion of a coping range, adaptive capacity and vulnerability. Notice this goes from 2000 to 2300. Sometimes, in climate change discussions, these are the world’s – nothing is going to go past 2100. It goes well into the future there. It has this idea of this one to six / one to seven degrees of different sectors having vulnerability and an adaptive capacity and a coping range. And if you look for agriculture there, there is a fairly large – there is a coping range but there is a big adaptive capacity. We can work in this area. This is not pre-defined, but again – let’s stress again that the discussion we are having here is about the next few decades, and that is right back here, okay? And so we are talking about this bit here. There is no question, no doubt, that if we get up into here there is major problems, and the huge amount of information about the tipping points and everything else there. So we are talking about this variability, how we manage that in a non-stationary climate? And there is an interesting argument that so much of our understanding of risk, how we talk about risk, how we discuss risk, how we talk about deciles and everything, assume a stationary climate. We have assumed a stationary climate in how we do that and how we are trained at university and how we have discussions. Maybe that was never the case; we’ve always had a non-stationary climate and climate change is highlighting that. [insert slide 5] So in the Managing Climate Variability Program, there has been a lot of work in Australia on the basis of this, on that variability, and an emphasis on ENSO, [insert slide 6] but also in more recent work and there is information out in the foyer there about the important, as Wenju Cai talks about, the important three headed dog of ENSO, Indian Ocean dipole and the Southern Annular Mode and how they all work in a complex way to effect our climate. You can see that on Water in the Land from the Bureau of Meteorology. Climate change will be delivered to us through climate, through seasonal climate, through weather, and how these interact, and so on. So it is an important part of how we do that and how we prepare for that. [insert slide 7] Background to this is that it has been incredibly dry in Southern Australia. So this is October 1996 to September 2008, so for someone like Ian McClelland, he’s got to go back to October before he remembers decent rainfall. So it has been an incredibly

PETER HAYMAN

long dry spell through there. Obviously, there has been a few wet times in between there, but there has been this long term drying there. And that becomes a pertinent and difficult question. [insert slide 8] So in my new adopted home of South Australia, I just wanted to make this point that we really are about a very small group living on the edge of this very, very wet bits at the bottom – well, relatively wet bits with this huge dry desert just to the North. [insert slide 9] Goyder talked about this in the 1860s / 1870s, drew this line which has been remarkably – had a huge amount of foresight, and there is a lot of discussion if that was to shift, if we were to have a drying trend. If you like, Clare is double the rainfall

• f Orroroo. If you were ever going to say rainfall was going to halve at Clare, one

idea would be to get in the car and drive from there to there, and it is an amazingly different sort of country, and especially as you go through these sort of transects and so on. But one other point is that we all live on a boundary, and in the 2006 drought, visiting people down in the bottom end of the Yorke Peninsula and in Kangaroo Island, and there is an old guy in Kangaroo Island. They were the most shocked by that drought of anybody, compared to people up here, who were dealing with droughts all the time. So in one sense, we all have systems that are adapted to the edge there. [insert slide10] As you can see here there are many farms, many grain farms, north of Goyder’s line and on Goyder’s line and north of Goyder’s line. And we are doing a bit of work to try and understand is this due to soils and other situations as well. So there is a large amount of farming that has gone north of that and one area is Minnepa which is on the Eyre Peninsula. [insert slide 11] This is just a quick run through the growing season rainfall at Minnepa, and you can see this run of very poor seasons recently. I guess one point here is that we look at these troughs, these droughts, but one of the really important points is this; it’s just the lack of good years in between the droughts. So there has not been this bounce back, if you like. We tend to bounce back to this sort of median, rather than going above. So I think we talk about the droughts but

• ne of the main issues is the lack of good years. And so a good friend in my short

time in South Australia, he went back farming and he picked 2005 to go back farming, and so he’s basically just had this – he’s young, university educated, had a

PETER HAYMAN

job working in my little group and he went back farming and he’s just had this run of really difficult years. [insert slide 12] So this is a question that comes from – this is the EPARF group, a group of farmers and some university people and others, but the question then comes; is this drought

• r aridity, drought or drying, variability or change, is it a cycle or is it a shift? So this

is a pertinent question, and it’s a question, I guess, if in one sense if people are leaving and agriculture is always going through constant adjustment, that is normal business, if people are leaving and someone says, “Look, I’m just sick of this drought,” that’s understandable. But if someone says, “I’m leaving because of climate change,” you are sending a very different message to the people who are staying behind. And so this question is, and it is very pertinent. In one sense, you can think of this and this is – Stephen Schneider talked about this, [insert slide 13] – you can ask this question; what destroyed the sandcastle; the wave or the tide. And you can stand at the beach and ask that for a long time. In a variable and changing climate, it will always be hard to distinguish between the extreme events, the waves, and the trends, the tides. You are always going to have these two

• processes. And it is going to be complex. And maybe this detection and attribution

in terms of these waves is always going to be difficult and always going to be a contested area. But the waves are important, because they tell us about resilience. They tell us about vulnerability. They are very important for climate science to try and work them

• ut, but these heat waves we have had, these runs of droughts and so on, tell us a

lot about resilience and so on. And we can do a better job of learning from that. But in one case it’s always going to be an open question. [insert slide 14] So we look at this sort of run of seasons. One thing we can do is with a bit of recreational spread-sheeting is take that same data and colour it for the different deciles. [insert slide 15] So deciles, if you like, are the language of risk that agronomists and farmer will use. When a farmer says a decile three year, they are saying something. They are saying three years out of ten have been drier than this, and seven years out of ten have

PETER HAYMAN

been wetter than this. And so it’s pub talk that actually captures the notion of risk quite well, in terms of what would we expect for this area in terms of different expectations for growing season. And you can see here the last three years have been down here, and remember you know, when you are down around 100 millimeters and so on, it’s very, very hard to grow a decent – grow anything in that area and the significant NRM issues, and so on, in the sense of erosion and so on there. You can also see that the last time that it was a decile ten year was quite some time

• back. And so one of the issues about this assumption of a stationary climate is we

sort of talk sometimes as if in every decade you should get a decile one, decile two up to decile ten, and you should be doing your nitrogen budgeting and so on, on that. If your nitrogen budgeting is very dependent on these few very good years, you can see the situation where that just has not happened there. And we can get fooled by runs of good years and poor years, and that is probably, in one sense, the history of Australian agriculture. [insert slide 16] I think you can explain most things in life with a pie chart, so I have – you take that same data and you colour it as a pie chart. So in one sense, in a stationary climate, you just spin that wheel, so in any year you are managing in that. And so you are basically doing your basic stats of you budgeting and so on with a probability weighted average of the different outcomes. But that is very, very skewed to some of the very good outcomes. Also, in terms of the themes of this conference, in terms of productivity growth, I would suggest that much of what people like me as agronomists and so on talk about at GRDC updates to farmers are really about things that kick goals in this blue, rather than this area,

• kay?

So a lot of our productivity growth is about capturing those good years where you say nitrogen pays more in the good years than it costs in the bad years, and so on. We’ve had that sort of sense. So a lot of the productivity comes from these sort of kicks from there, and that is in a stationary climate. [insert slide 17] In terms of how does climate science talk about risk and talk about change, it uses the language of percent reduction and mean rainfall. So we’ll say – so this is from the Climate Change in Australia Report, and this is saying the median projection for 2030 annually is around this five percent reduction.

PETER HAYMAN

Now, you can go to different – and the one in ten driest models is this sort of – tend to blow ten percent or worse and the one in ten wettest models is a slight wetting. So it is that sort of range. So we are taught that. I guess the question then comes; what does ten percent drying mean, and so on, mean in terms of deciles? [insert slide 18] And so this is one way we can look at that, is we can say that if that is your stationary climate, what does a five percent, a ten percent and a twenty percent decline mean in terms of deciles? And so even if a five percent decline, it basically changes the

• ratio. So a ten percent decline would have this sort of change of ratio.

So in terms of discussing this with dry land farmers and so on, I guess that is what we are sort of at, is saying that we’re not – I mean, the very simple message from the media is 2006, 2007, 2008, this is what we’re getting, get used to it. That’s your new

• future. But that is confusing means and extremes. What we need to do is talk about

the fact that the ratio of good years to bad years would change, and work on farming systems to manage. And to an extent, what the agronomists and so on will say is, “Look, we think we can make good money out of these green years. We obviously can’t cope with these, but we can come up with ways to have, if you like, a soft fail

• systems. We can’t have fail safe systems but we can fail – we can have a sort of a

better way of managing some of these worse years in terms of cutting costs and so, but also coping with the good years.” The other important point is even under this 20 per cent decline, these good years become more important in terms of when they do come along, how do we capture

• them. I just want to quickly make the point that that is true for rainfall, this is for – and

Ian McClelland will talk about this in - much more eloquently, [insert slide 19] but basically if you look at the same thing, you can do the same thing for growing season temperature through a model like APSIM so the blue is a very cool year and the red is a one in ten warmest year. Out of one degree warming, and you’re going to be very much into this much warmer conditions, must faster crop development. Two degrees warming and that becomes the norm. [insert slide 20] So I wanted to finish with a diagram that my boss said I should never show in public, but this is basically the deciles and the run of deciles for Minnepa. This is a decade

• level. For 2008, if you go back and compare the last 10 years there, there have been

two decile ones, one decile two, some decile fours and fives and eight and some

• nines. So to an extent, as you go back in time, you can see that what – how does

PETER HAYMAN

this compare with previous times, and farmers are very quick to point out that there was this terrible time in the ‘40s with many, many runs of decile ones and twos and so on. So this sort of, if you like, this decadal area, I think, it’s a – it tells – it’s very important in terms of vulnerability, in terms of resilience, and it’s also a very important area for research to try and understand our decadal changes over the immediate future over the next two decades, again, repeating the point that extreme climate change, there is no way we can adapt to it, but over the next few decades, how we manage this decadal stuff is pretty important. Thanks.

PETER HAYMAN