SCIENCE AT THE SHINE DOME canberra 7 - 9 may 2008

Symposium: Dangerous Climate Change: Is it inevitable?

Friday, 9 May 2008

Dr Graeme Pearman, AM, FAA, FTSE
Sustainability Science, Monash University

Graeme Pearman trained as a biologist and was chief of the CSIRO Division of Atmospheric Research for ten years. He is an author of more than 150 academic publications, primarily on aspects of the global carbon budget, and has acted as a science adviser to former US vice-president Al Gore. His current interests and activities include: energy futures; sustainability and sustainability science; scientific capacity building; public communication of science; and the role of science in modern societies. He is a Fellow of the Royal Society of Victoria, and has been awarded a United Nations Environment Program Global 500 Award, a Medal of the Order of Australia and a Federation Medal.

Can we avoid dangerous climate change?

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Thank you very much, Geoff, and thank you all. This is the last shift in this symposium. The one good thing about that is that a number of the things I wanted to say have already been said, so hopefully it will allow me to move a little bit more quickly than I might have otherwise.

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I want to go back to the issue of urgency, just briefly, to reiterate some of the things that have been talked about today. I want to speak a little bit more about the concept of managing risk, which came up in some of the questions. And then I want to concentrate on energy futures, more from a scientific perspective than perhaps from the economic perspective, and talk a little bit about working with complexity. We had in the session this afternoon some comments about the degree to which complexity impedes progress or in fact might even make it impossible, so I want to speak a little bit about that.

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The question in the mind of some of us who have been in this field for almost 40 years has been: have we actually underestimated how much change will occur, or the risk associated with these changes? Even since the IPCC [Intergovernmental Panel on Climate Change] report there have been a number of scientific findings – you have heard about some of them today – which have made some of us feel a bit uncomfortable. I think particularly in the biological field there has not been a clear understanding of just how sensitive some species are to climate change. But certainly ecosystems are sensitive, illustrated by the kinds of changes that we are seeing all over the world and I believe you will see in your newspapers every few days over the next few years.

We have talked about and heard about the deglaciation issue, and mention was made of the political issue. In fact, there was a paper only a few weeks ago in the Journal of Foreign Affairs in which an economist took an economist's view about the deglaciation of the Arctic and said, 'Isn't this fantastic! We'll be able to take our ships all over the Arctic, we'll be able to trade and we'll be able to get to all the resources that are up there.' Then the economist said, 'Oh, but we actually we don't have any agreement between the nations as to how this will be shared' – and then concluded that there was the possibility for political instability in the region. We don't know how these things are going to actually pan out.

We have heard from Mike Raupach about the emissions being high relative to what was being used as projections earlier, and we have also heard about the fact that there has been a change of capacity of the ocean to absorb CO₂ – and only a few weeks ago there was a paper published in Geophysical Research Letters in which the non-productive areas of all of the four major ocean basins of the world, as measured from satellite (sensing chlorophyll) are growing, at about 1.4 per cent per annum. This is most probably, but not certainly, due to the fact that the oceans are stabilising and the supply of nutrients to the surface is diminishing.

And, finally, we have heard that some of our previous predictions may have been at the lower end of what we are observing. It doesn't really matter about which of these observations is conformed, but it raises the question: are we at risk that in fact some of these things are occurring faster than we thought?

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This diagram, a form of which actually was in Roger Beale's presentation, is the one that struck me most. This came in the synthesis report of the IPCC late last year, looking at six different 'futures' where we had different levels of carbon dioxide increase with different levels of the other gases, adding up to different levels of effective carbon dioxide levels, and then a series of temperature estimates associated with those, and sea-level rises associated with the thermal expansion.

The point about this was that the European Union target at the moment for avoiding dangerous change is 2°, and only one of these scenarios suggested that in fact we would get near that. And that was the 450 ppm target. And so people are talking about 450 ppm. They were not talking about 450 ppm only two or three years ago, and I will come back to that.

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This is a picture, also modified but out of the IPCC, looking at Australia. The numbers up the left-hand side of the panel are the temperature changes in degrees. This is highly qualitative, but it is meant to try to give a feel for where the science suggests we might be headed. The green areas are the areas where, because of the adaptability of each of these areas of potential impact on Australia, we think we can adapt to some of these changes readily, or we can cope with them within the normal coping range. The yellow areas are where we really will have to intervene to adapt – the kinds of things that a number of people have spoken about today, where we have to intervene and be adapting. And the red areas are the best estimate of when we actually hit what is regarded as a vulnerable area, where we may in fact go beyond what we think we can do to adapt in these particular areas.

Much of this is qualitative, and it depends on the kinds of questions that Neville Nicholls was asking – that is, how certain are we about water availability in Australia as we go forward in time? But it does suggest that in water availability, in natural ecosystems and in coastal communities Australia is likely to be vulnerable when we hit about 2° change.

This is reiterated partly because in this audience that magnitude is probably reasonably well appreciated, but in the wider community it isn't. And I will come back to that also in a minute.

The bars on the right-hand side of the diagram are the estimates at different times into the future when we will actually hit these levels of temperature. They show why we are talking about 450 ppm now in our discussions. That is, 450 ppm by 2050 gets us to just under 2°, and some time by the end of the century above 2°, with the colours indicating the uncertainty ranges that exist within those areas. Whereas for the other targets – 550, 750 or a business-as-usual – we go way beyond this. I think at the moment that is the message that the scientific community is trying to provide.

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I think that the science has tended to stress the 'likelihood' of particular events occurring. That is what drives us. We want to try to understand whether we have a capacity to actually project a particular likelihood. But when you are managing risk, like the risk of the drought at the moment, then it is not just the likelihood but it is the consequences if it happens that actually become just as important, and we in our everyday life are actually managing this. There are things that we will not do anything about unless the probability of their occurring is one in a million, because the consequences are high – like getting into an aeroplane to go home to Melbourne tonight. What people are actually doing now is to try to think about where they sit within this framework. Since I have become a consultant, this last year, I have done briefings to 140 different groups, of which about two-thirds to three-quarters are companies. The good news, I think, is that they know about risk management and they are actually in this framework right now, trying to understand not whether we know things perfectly but what we do know and what the consequences are if some of these things come home.

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This statement was made by one of those people, Rupert Murdoch. He has said, 'I do know to assess a risk' – and most of these businesspeople do. That is what they are doing all the time. And he said, 'We may not agree on the extent, but we certainly can't afford the risk of inaction.' I think that is the position of many companies in Australia; perhaps in many ways ahead of government responses.

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The other point that I want to make before I get into the energy is one that has been alluded to a couple of times and was made by Ross Garnaut. That is, it is not only about what we are trying to avoid in terms of temperature, but about how we will share the responsibility.

This is a highly inequitable problem. No two persons or two nations in the world will be impacted in the same way by climate change. No two persons or countries in the world contribute or have contributed equally over time to the effect that we have already had and no two persons or countries in the world actually have the same capacity to respond to these changes. This is a highly inequitable problem, and the net result of that is that Ross Garnaut is talking about building into this the inequity and therefore the share that is more reasonable from an Australian point of view in reaching some global targets in this regard.

There are serious questions, though, and some of these I think were alluded to by Roger, about whether we can find reasoned or reasonable options within existing government structures, and on what time-scales we can actually do that.

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The other day, when some people were talking about equity, I rescued this diagram, which I drew in 1995. It addresses two things.

It tries to say, 'Let's suppose we were really attempting, as a global community, to get equity in 100 years' – which to me at the time I drew this seemed like a reasonable target. Do we really want the world's communities to be inequitable for another 100 years? Equity in this case meant an equal share of emissions per capita around the world, and so it drew out the issue that has already been made, that OECD countries (and Australia in particular) have to reach a peak in their emissions early, and the rest of the world, including the Chinas of the world, may have to grow for some time, but never to the level of emissions that we did.

The second point that this diagram makes is that this was for a doubling of CO₂, more like a 550 ppm. Why did I choose that? Because in 1995 I thought that was actually not dangerous, whereas I think we have changed our minds – we think now that anything beyond about 450 ppm is potentially dangerous.

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So what about the energy futures?

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This is from the McKinsey report that was mentioned in the previous presentation, and I want to say straight away, having been involved in a project that has tried to do this kind of thing, that anyone who has done this knows it is very, very difficult, and therefore these numbers have all sorts of uncertainties associated with them.

But what they have said is that Australians emit 547 megatonnes of carbon dioxide per year and that they anticipate that by 2030 this will grow by 235 Mt. Actually, we are almost halfway there now. Whilst land clearing reduction has been used as the means to slow our rate of emissions growth, our power generation and other sectors of the community have grown massively over the last 10 years or so. So business-as-usual, from their perspective, is something like 782 Mt.

Then MrKinsey have calculated that they can achieve a reduction of 563 Mt – that is, a reduction of 60 per cent below 1990 levels – at a cost of $65 a tonne of carbon over this period of time. How do they do that? I will come back to that in a moment.

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The IPCC, on the other hand – in 800 pages that I am going to summarise in about three points – says firstly that if we don't mitigate, the concentrations will continue to go up and the climate will continue to change. I have to mention this, not in this forum but in some fora, because there are people out there that don't understand that this is basic geophysics. It is the kind of stuff that Mike Raupach does. That is, it is because the real system can only move about 2000 million tonnes of carbon from the upper layers of the ocean to the deep ocean each year, and so unless we stay below that point then we actually don't stabilise the concentrations and we don't stabilise the climate.

The second point is the good news. In analysing what we do, the IPCC found that our use of energy is very inefficient. The market has not worked very well. It doesn't work in my house, and I'll guarantee it doesn't work in this building, and it doesn't work in most buildings, for many different reasons. As a result, this is the good news, because we have opportunities to lower our emissions in a cost-effective way.

The third point is one that also was raised earlier, that the cost of actually getting reductions, in a macroeconomic study such as that done by the IPCC, is less than about one-tenth of a per cent of annual GDP.

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Some of you will have seen this diagram, which is not a projection for the future but is a way of thinking about the issue of energy futures first used by Princeton University people, Socolow and others, some years back. It simply says that globally we are currently emitting, as Mike has pointed out to us, about 8000 million tonnes of carbon a year, and if we meet all of the demands of the world over this century we will be emitting 10 times that by the end of the century – if we use the technologies that we have at the moment. Yet we have just been saying that we have to get down to 2000 million tonnes, because that is the geophysical limit of the world, assuming that this limit itself doesn't actually decrease as we change the climate.

This diagram simply says that there is no simple answer. There is a series of things that we can do, and some of the technologies that might be your favourite technology might not even be on this diagram; it is just illustrative in that sense. But it includes the big blue area at the top, which is energy efficiency, and down at the bottom it includes carbon capture and sequestration, with a number of other options in between, including nuclear.

There are two things about this. First, this diagram does not represent what we should do. In fact, even between the states of Australia this portfolio of action might be different. It would be sensible if it was. The best thing to do is for each jurisdiction to do what they best can to reduce their emissions. So we come back to the McKinsey report: isn't it much more complicated than that and much more detailed?

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What McKinsey have done here is to break out in more detail some of the things that we in Australia can do. This diagram indicates on the abscissa the amount of avoided emissions (in this case in million tonnes of carbon dioxide). So it goes up to 350 Mt – not out to where they are talking about by 2030, but it shows the first part of this. It shows that about the first 70 Mt, on their assessment, can be done at positive economic gains. So that is the good news. The difficulty is that each little segment of emission reduction – and there are many segments there – may require totally different engagements, maybe even interventions or regulation, or education processes, to actually get people to redeem the advantages.

The green areas are things that can be done within the biosphere, and the width of these things clearly is how much they contribute. But they cost, and so we go onto the positive cost side of the curve. We can break even – as a community, not necessarily as an individual company, because some may be more exposed than others – when we get out to about 250 Mt, about half the distance we need to go, in their study, by 2020–30.

Beyond that there are things like carbon capture, nuclear power and so on that can be added, and the cost rise as we go to those options.

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But the important point about this is that that diagram says we know what the costs of these are, but actually we don't know this with certainty. And therefore we have to manage that. That is part of the complexity. Even with burning brown coal to generate electricity, do we know what the cost of doing that will be in 10 years' time? No, because we don't know what the carbon emissions costs will be; we don't know how much intervention with technologies will change the price of those things. And that applies to all of these options.

Secondly, there are some technical feasibilities associated with these options. And, thirdly, the capacity to deliver some of these options on time, both to deliver the energy and to deliver the emission reductions, varies quite a lot. That is part of the reason why McKinsey do not have some of these things in the first part of getting emissions down. And it is one of the faults of the Socolow diagram. The wedges should not be linear. They should evolve quickly for some areas, early, and later for some of the other areas, depending on the way the technologies develop and so on.

And there are issues, of course, around acceptability. There are people that don't like windmills in their backyard, any more than they like nuclear power plants.

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The other thing that makes it more difficult to actually assess the cost of these things is that there are collateral benefits from some of them. For example, IPCC identified that if we lowered the emissions from motor vehicles there would be substantially reduced air pollution and health issues. And these should not be ignored. They should be part of the assessment, but they make it that much more complex in determining what our portfolio should look like and where we should put the efforts.

As the last point I just want to stress working with developing countries, and the co-benefits. Particularly I think of Papua New Guinea and Indonesia. Indonesia is now the third or fourth major greenhouse-gas emitter because of its land-clearing practices. It may be much useful for us to work collaboratively with them, coming from a good base ourselves, to assist them not only to lower their emissions but to create sustainable industries in place of what are unsustainable industries of cutting down forests that are gone, potentially, forever.

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The cost of abatement, according to McKinsey, is achievable: 30 per cent below 1990 levels by 2020 and 60 per cent below by 2030, without major technological breakthroughs or lifestyle changes. Isn't this a very different message from the one we were hearing only late last year in the lead-up to the election? We were told by one minister that we were 'going to go back to the caves' to reduce emissions like this.

These numbers deserve to be treated with caution, such estimates are difficult to make, but there are many studies now that give similar kinds of results. We need to be careful about the vested interests that might frighten us and weaken our courage to go in these directions. The estimate of McKinsey is that it will cost about $300 per household increase by 2020 to achieve those big reductions.

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There is a whole range of complexities, which, I think, magnifies our exposure to danger.

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The first thing is that people do not understand what 1° or 2° planetary warming means. There are many ways of illustrating it. This shows, in a very simplistic way, the latitudinal movement in Australia of the climatic zones with the kinds of changes associated with these emission scenarios. They are hundreds to 1000 kilometres southward movement for such levels of warming. These are big movements that are important for the natural ecosystems and for our productive systems.

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To set Australian targets is very, very complicated, because we have to asking the questions that we have been asking today about the physical possibilities; we then have to ask questions about what is dangerous in the sense of an uncertain future; we can ask questions about what is acceptable, and how we weigh our expenditure on adaptation, on mitigation; and finally, how we share this emissions reduction challenge internationally and what is equitable. That is what confronts the Australian government as they make decisions about targets as we go through this year. This is complicated.

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I will skip over this slide, which contains the three pillars approach. But I will give an example of some of this complexity.

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This is the example that has been in the newspapers, that we actually have a food shortage globally and it has these possible consequences, the grey areas on the left-hand side. We have people saying this is due to population growth, it is due to drought in countries like Australia, or it is due to bio-fuels. Well, it is probably some mix of that, but do we know? No, we don't. And how each of those possible causes are actually impacted by population growth itself, by the climate state or by the peak oil problem is also difficult to assess.

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So let's just take one aspect of that, as an argument. I don't want to get people upset about this; some might see bio-fuels as a useful part of our energy portfolio, but I use it just a particular example. People are going down the bio-fuel option, mainly on the fuel security argument but also using the climate change issue as an argument. There are a number of factors that need to be quantitatively or at least qualitatively satisfied before we do that, in my view.

The first is: would you go down this track if you were going to have a drier climate?

The second thing is: would you replace the current biomass storage that is in the systems, which is what they are doing in Indonesia, to put in oil plants instead of the existing forests, which store large amounts of carbon compared with what we could ever save from bio-fuels?

Would you apportion the viable land-use differently? You use land for many purposes.

What are the net energy benefits? Actually, in Australia, of the energy that is contained in grain that leaves the farm door, about 35 per cent has already been used in the production system. So how much is then used in transportation and in the process of producing the fuels and then getting it back to the vehicles? We need to know that before we go down this track. This is complicated.

Do we know the contribution, particularly of the greenhouse gas nitrous oxide, in the full cycle of actually using these fuels?

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And so it goes on.

The point about this is simply that these are the kinds of complex structures that we need to underpin with science – and I talk now of science in its broadest sense of economics, physical science and social science – to actually be able to provide some guidance. It is not good enough to have a disciplinary-based view on this issue. It is not good enough to have one sector of the society driving Australian policy in one of these directions.

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In conclusion, avoiding 'dangerous' change is possible, I think (I'm an optimist) yet very challenging.

Uncertainty means it is contingent on the treatment of the complexity, the integration of multiple outcomes as well as the multiple purposes and the multiple time-scales that are involved in this issue. It is contingent on treating the urgency and dealing with the inertia that exists within the climate system but also within our social systems, and balancing markets and intervention where we have to. And it is contingent on having a strategy of deciding where we want to be. I think a few speakers have referred to this: where do we really want to go with this?

How do we build in resilience? We don't know and we will never know all we really would like to know about that issue as we go forward. And without resilience we won't get to where we want to be; we will get to some other place.

Thank you.

Prof. Michael Dopita: Thank you very much, Graeme. Because of time constraints I don't think I will open this one up to questions. We have probably consumed our question time, and I suspect that in view of the passion with which Graeme delivered the last half dozen slides the questions might be detailed.