Director UK Climate Impacts Programme
On: Climate Risks: How to manage them
1 October 2004
“Thank you for your invitation; I’m going to talk about climate change, moving from the now familiar debate about whether or not it is real and what causes it to consider what are the risks associated with climate change and what we can do about it. First, to be clear, I am talking about climate and not weather. “Climate is what you expect, but weather is what you get”. Mark Twain complained “everybody talks about the weather, but nobody does anything about it”. Well it now appears that we have been doing something about it by messing about with the climate engine that delivers out weather. We have behaved like a small child twiddling with the knob on our spaceship’s life-support system labelled “Do not adjust without consulting the operating manual!” Mrs Thatcher said, in a speech to the Royal Society in London in 1998, “We may have unwittingly begun a massive experiment with the system of the planet itself”.Reality of climate change
So, why do I believe, as do nearly all scientists, that climate change is a reality? Let’s start with the long view. Antarctic ice cores have shown that for half a million, maybe a million years, the earth has shifted between ice ages some 6ºC cooler than the present and inter-glacials with temperatures like those of today. In the normal course of events, we could expect another ice-age in around 30,000 years. Are we now stepping outside the familiar world of “happened before” into the dangerous jungle of “unprecedented”?
Let’s look at the last 10,000 years, since the sudden end of the last ice-age. This period has been characterised by a nearly constant stable global temperature, in which the 0.7ºC rise during the 20th century is remarkable. (Slide 2)I wonder if it is only coincidence that civilisation has become established in this stable climate. The temperature increases itself and the rate of change in that “industrial” century was unprecedented. Moving closer to today, if we look at the frequency of record hot years, we find that globally, the ten hottest years on record have all occurred since the beginning of the 1990s. This would be extraordinary, unless a change was underway.
Let’s turn to the natural world. Penology is the science of recording natural annual events, and it already offers real evidence that climate change is happening and that it is having an effect on nature. You will all have seen these yourselves. Trees are coming into leaf sooner; spring flowers are blooming in December; butterflies are appearing earlier; swallows now arrive a week earlier than a generation ago (Slide 3); other usually migratory birds now over-winter in Britain; Frogspawn has been found before Christmas.
Why though, do these obvious signs and clear numbers not get accorded the weight that perhaps they should? Part of the reason is that the small signal of climate change is drowned by the huge noise of the weather. In one day in this country, we can experience a 20ºC range, while in a year it could be three times as great. Against this background, the 0.7ºC increase during the 20th century seems footling, until we recall the geographic scale over which it is found – on every continent, the same signal has been recorded.Causes of climate change
I shall not try to cover all the causes of climate change, but shall focus on one cause – the greenhouse effect – that accounts for around 75% of the change. There are other natural and human causes that are significant but smaller. Before I point any accusatory finger, let’s look at the natural history of two chemical elements: carbon and oxygen. These two have a natural affinity; left to themselves they will combine to form a stable gas called carbon dioxide. Much of the carbon in the universe is in this stable form. However, on a planet circling a star, some organisms, which we will call plants, found a way to separate these two elements using the radiant energy of their star; they used the carbon to build their bodies and expired the oxygen as a waste product; their dead bodies formed deposits in the planet’s crust.
Later on, other organisms on that same planet – animals – found a way to make a living extracting the energy released when plant carbon was re-combined with the atmospheric oxygen. Now we, the latest descendants of those animals on that planet, have elaborated on this to use the energy released when that buried fossil carbon is re-oxidised to form more carbon dioxide. As a civilisation, and especially as a consumer society, we are now pathologically dependant on the use of that fossil carbon, as coal, oil, and gas. We should remember that carbon in this form is rare in the universe; we are relying on a very local reversal of normal conditions to power our society.
This only causes a problem because three factors combine. These are the way that the temperature of a body in a vacuum is controlled, the variable transparency of apparently clear gases, and the enormous scale of our carbon addiction.
So, consider that planet circling a star. The star radiates visible light that heats the planet. The planet starts to radiate longer wavelength radiation (heat) into space until the incoming and outgoing radiation flows balance. At this point of balance, the planet’s temperature is stable. If some agency blocks part of that outgoing radiation, an energy imbalance occurs, the temperature rises (causing more outgoing radiation) until a new point of radiative balance is achieved.
Let’s leave that planet, and consider some scientists who considered the transparency of gases and how some act as “greenhouse gases”. Horace Benedict de Saussure (1740-1799) was a natural scientist from Geneva, whose statue you can see in Chamonix, with his guide pointing to the summit of Mont Blanc. De Saussure was puzzled by the fact that the sun felt as hot on his face at the summit of the mountain as it did in Chamonix, yet the temperature was much colder. He reasoned that the atmosphere between these two heights must work differently on the incoming and the outgoing radiation to retain more heat in Chamonix. De Saussure had identified the blocking agency.
John Tyndall (1820-1893), an Irish surveyor turned practical polymath, demonstrated that molecules of water and carbon dioxide were indeed opaque to infrared radiation, and argued that trace amounts in the atmosphere maintained the earth at a pleasantly warm temperature. Tyndall had identified the trace gases involved and how they operated as a “greenhouse”.
Svante Arrhenius, a Swedish physicist (1859-1927) from Uppsala calculated the sensitivity of the planet Earth to a doubling of carbon dioxide. He undertook “the most laborious calculations of my life” to produce a range of sensitivities between 4ºC and 6ºC. These are similar to current model-derived values. Arrhenius took the first step in quantifying the scale of the effect and linking it to fossil carbon consumption.
All this might be merely of academic interest were it not for the immense scale of the emissions of carbon dioxide put into the atmosphere. Let me first introduce you to a unit – the Gigaton of carbon. Imagine a coal pile, conical in shape, and a kilometre high (that’s four Canary Wharfs, three Eiffel Towers, or two Empire State Buildings); that would be a Gigaton of carbon, and we are putting six of those into the atmosphere as carbon dioxide every year. Under present conditions the green plants on land and plankton in the oceans can absorb around half of that, so 3.5 Gigatons of carbon accumulate in the atmosphere every year.
Is this significant? Let us return for a moment to those ice-ages and the question about whether we are still on familiar territory or venturing foolishly into the unknown. During ice-ages, the concentration of carbon dioxide in the atmosphere was around 200 parts per million – it sounds small, but John Tyndall showed that these sorts of concentrations were significant – while during the warmer inter-glacial, concentrations rose to around 270 parts per million. The concentration now is around 370 parts per million.
We have indeed strayed from the familiar into the unknown. Such concentrations have not been experienced for half a million years at least. By our burning of fossil carbon, we have altered the radiative balance of the planet. One obvious outcome is a general rise in temperature. This rise in temperature causes sea level rise because water expands with heat, but the detail of other consequences of running the complex global climate system at a different temperature are still imperfectly understood, and form the subject of a huge international research effort because what may be a detail of the global climate may be literally a matter of life and death to some community.Risks associated with climate change
Climate change appears to be a slow shift of the average conditions we experience, and it is tempting to view this shift as beneficial, especially to those of us in temperate latitudes, but our society, its built infrastructure, and the natural systems we depend on, are all tightly adapted to a historical climate. It is not, though, the average conditions that cause problems, it is the extremes, of temperature, rainfall, or wind, that cause damage and disruption, and projections of climate change indicate that extreme events will occur more frequently, and the absolute extremes will become even more extreme. This is one class of risk, and one that can be managed; I will return to how later.
In Britain and in America, weather extremes are always newsworthy; Reporters often ask me if a particular event is caused by climate change. I usually answer that one particular event cannot be blamed on climate change, but that this sort of extreme may become more frequent. In Britain, France, and Germany, the press and the public are ready to make the connection between climate change and any weather-related catastrophe. It constantly surprises me that their American counterparts don’t seem to link the increasing incidence of, say, forest fires to climate change. It is now becoming possible to ascribe a proportion of the risk of extreme weather events to climate change, and through a causal chain still untested in the courts, to actions or decisions taken by governments or corporations. Court cases based on this connection are starting, mostly in the United States, where litigation is a more developed art than here.
Another class of risk is foreseen in the ultimate objective of the United Nations Framework Convention on Climate Change: “stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.” We cannot yet agree what constitutes “dangerous” in this context; for some communities round the world we have already caused dangerous climate change; for others we may have done, but not yet know it. Complex natural systems often respond gently to a gentle perturbation, and then may suddenly respond in a non-linear, catastrophic manner when some threshold is passed. A frog in a frying pan provides a trivial example: gentle heating will produce no response, but at some unpredictable point, undetectable to the observer, the frog will jump. It is possible that a number of global-scale ecosystems or climate components may have this sort of response to gradual warming. The south Asian monsoons, the Gulf Stream, The Amazon rainforest, underwater methane deposits, and major ice-caps are examples.
Similarly, a number of human situations may share this capacity to switch from a linear to a non-linear response. Examples that ought to raise concern include conflicts over access to water in the Middle-East, the possibility of large scale migration from Bangladesh into India, from North Africa into southern Europe, or from Latin America into North America.
The US defence secretary Donald Rumsfeld was widely condemned in 2002 for making a most valuable point about knowledge. He won the Plain English Campaign’s Foot In Mouth trophy for his attempt to distinguish between known knowns, known unknowns, and unknown unknowns. Sea level rise is a good example of a known known, though we still cannot quantify the rate. The examples I have quoted of candidates for catastrophic change are known unknowns – we have some idea of what could happen, but no way of knowing when or if they will occur. What seems to me to be clear is that there are still other natural or human systems whose sensitivity to climate change has yet to be identified. These are the unknown unknowns that we cannot even imagine yet.Managing climate change
There are two responses to climate change; we can try to reduce the greenhouse effect that is causing it (mitigation), or we can deal with the consequences as they occur (adaptation). Individuals, organisations, or governments that do not want to address the issue have used this apparent choice to avoid action. In truth, these are not alternatives; they are both necessary and address different aspects of the issue. I draw a parallel with the different responses to illness.
A public health response to remove a disease vector or cause is one approach while a medical treatment of the symptoms is another. Nobody would advocate an either/or approach; both, working in synergy are essential. The same is true of climate change. The climate change we expect in the next 30-40 years will be due to our past greenhouse gas emissions. Climate change later this century is being determined by the emissions we allow now. We need to alter our way of life so that we can adapt to the changes that are already in the climate system, as well as limiting our future greenhouse gas emissions.
In the recent past, mitigation was seen by the UNFCCC as the primary response; adaptation was even seen by some as a distraction from the “real task”. Because mitigation needs to be undertaken with most urgency by the richest nations while adaptation was seen as more necessary for developing countries, there was some polarisation: “the rich mitigate; the poor adapt”.
Now, the two are accorded more equal weight, as it is realised that all will need to share both tasks. The two responses may differ in the actors responsible, and crucially do differ in where and when the benefits are realised. Mitigation actions have to be undertaken on a global scale, and climate benefits are realised by the whole world, but only after a lag of some thirty to forty years: “Your mitigation dollar benefits the grandchildren of someone in a developing country”. However, mitigation actions may yield other more immediate environmental and social benefits. There are many aspects of a post-carbon world economy that are most appealing. Adaptation, by contrast, can yield a benefit that is more local and may be immediate, and which persists and grows for little extra investment. No altruism is demanded of anyone adapting – self-interest drives adaptation.Mitigating the causes of climate change
You already know how to mitigate climate change, because we have talked about the cause – as a species, we need to cut greenhouse gas emissions by burning less fossil carbon fuel. It’s so simple to describe, yet it seems so hard to do. The wonder of the Kyoto protocol, when it works, will not be in what it achieves directly for the climate, but in getting so many countries working together. When a train moves out from a station, you don’t complain it’s only gone a few feet; you remark on the fact that motion has replaced immobility. The technologies required to deliver non-fossil-carbon energy are already here; what is lacking is the will to bring them into production. Perhaps though, inter-Governmental agreement is not the only route to cutting emissions; after all it’s not governments that emit. Industry will move very fast when and if its customers, insurers, or investors require it to.
There are other routes to mitigation, not involving a switch of energy source, but they are either limited in scope, wildly impractical, or unimaginably dangerous. It is possible to condense out or separate carbon dioxide from chimneys or from the atmosphere and sequester it away in underground rock formations, or in the deep ocean, but the side-effects of doing so on a planetary scale over millennial timescales have not been quantified. Even small rates of leakage remove much of the potential value of this sort of approach. Other suggestions, generally grouped under the harmless-sounding term “geo-engineering” include altering the reflectance of the planet’s surface or shading it from the sun. These seem to me to have much of the sense of keeping a tiger in the house to keep it clear of mice.
I want to look at two of the barriers to mitigation action, and consider what might overcome them. Firstly there is the issue of costs. I speak as someone whose grasp of economics never got past jam-jars and pennies, so be warned. In the natural sciences, there has been considerable movement towards consensus through the mechanism of the Intergovernmental Panel on Climate Change (IPCC), and consequently a focus on the important areas of ignorance and disagreement. In the economics sphere, I don’t see that progress towards consensus; I see a tendency to clump into mutually antagonistic groups centred round incompatible belief systems. IPCC gives a range of global temperature rises for this century from 1.4ºC to 5.8ºC, with future emission uncertainty the main cause of the range.
When the Government held a seminar last year on the social cost of carbon, figures offered per ton of carbon ranged from a few to hundreds of dollars. Translated into barriers to mitigation, this range represents the spectrum from insignificant to prohibitive.
There is a tendency to “talk up” the costs of switching from fossil fuel to renewable energy. It may seem expensive, especially to those with vast amounts of capital of various sorts tied up with the machinery for extracting fossil carbon from the earth. I would suggest they are comparing these costs with a false baseline – a “do nothing” or “business as usual” option to which they ascribe no cost.
In my opinion, not only is the sustainability of the “business as usual” option in serious doubt (quibble all you like but fossil carbon has only a limited future) but also the hidden external costs of the “business as usual” option are significant and increasing. Using fossil carbon seems cheap because we only pay for a fraction of its real costs – we don’t pay for its creation, nor for all of the social or environmental costs of its extraction, nor for the long-lasting costs of its combustion. Small wonder then that renewable energy sources, that internalise much more of their costs, seem expensive, and that nuclear power generation with social and environmental costs incurred over millennia, is so hard to judge.
I am reassured that this switch is possible on a useful timescale when I look back to changes in the past.
At the start of the 20th century, the internal combustion engine took over from the horse as a prime source of motive power in much of Europe and America in only a few decades. At the time a huge infrastructure of horse housing, horse food, horse waste disposal, and horse support industries existed, and yet in one working lifetime they were nearly all swept away to be replaced by an entirely different set of motor-related infrastructures. More recently still, in only a few years, the mobile phone has replaced…what? letters? silence? thought? Every other shop in the high street now sells nothing else. These revolutions happened without society crumbling; the transition to a low-carbon economy is bigger in scale, but surely not impossible.
A second issue is the one of fairness or equity. The USA and other developed countries point to the obligations under the Kyoto protocol that require them to reduce emissions, yet do not require the same action from developing countries, whose emissions will soon outstrip those of the developed world. This they perceive as unfair. Those same developing countries perceive a requirement for them to contain their emissions as unfair, when it is past emissions from developed countries that have caused the present problem. Bringing these views together is going to be an enormous task, which may be addressed by a process of “contraction and convergence” which requires faster reductions by developed countries to allow developing countries to develop, but then moves towards a situation where every individual on the planet has an equal right to emit greenhouse gas.
To put this into context, each citizen of Bangladesh causes 50kg of fossil carbon to be released into the atmosphere each year. The figure for the UK is 2.5 tons, while the average citizen of the USA, after a century of cheap energy, releases some 5 tons. How much, if you like, should past inequities influence current and future behaviour? I believe that, over the next few decades, the most developed countries will come to appreciate more fully the costs to them of poverty and inequity around the world. At present, the costs are not obvious and so are under-valued.Adapting to the impacts of climate change
Natural systems can only adapt in a purely reactive way; sometimes adaptation can maintain the status quo; otherwise reactive change is itself an adaptation. The fast rate of change anticipated and the way humans already impinge on natural systems may limit the adaptation possible for natural systems. The polar bear has only a few generations to evolve not to depend on seals breeding on arctic ice.
The UK Climate Impacts Programme, which I am privileged to lead, is funded by Government to help organisations assess how they might be affected by climate change, so they can prepare for its impacts. We offer a number of tools, such as climate scenarios and methodologies to look at handling uncertainty and risk and costing impacts. Adaptation is not something we can do for any of our stakeholders; they have to do it for themselves, but we aim to help them with the task. We are now assembling our tools into an “Adaptation Wizard” that leads users through a four-stage process: scope the impacts; quantify the risks; develop adaptation strategies; monitor and revisit. To adapt, an organisation may have to develop its adaptive capacity before it can successfully undertake adaptation actions.
Proactively adapting to the impacts of climate change is something new for the modern human species. We have neither the vocabulary nor the conceptual framework to describe much of it, still less to learn how to do it. A number of actors round the world are piecing together the science and the practice by borrowing from adaptation to climate variability, from managing other sorts of change, and from other fields of risk management. There is a pervasive tendency in the best-run organisations to use the past as a guide to the future. Much of our work involves uncovering this tendency, and offering a more rigorous risk-based approach.
Let me give some examples of adaptation: A small company in the West Country looked at its exposure to a possible increased frequency of flooding, and identified loss of access to its records system as the most business-critical impact of such floods. An afternoon’s work saw their computer moved to the first floor; the company had climate-proofed its operations.
On a larger scale, water companies must plan to be able to meet water demand over a number of decades. Working together, they have examined the possible changes to demand for water over the next 30 years, and individually, the ability of their reservoirs to collect and hold sufficient water to meet that demand. This forward thinking is essential, because if extra reservoir capacity is required, the planning, funding and construction of such significant infrastructure takes decades.
To illustrate this long period of development, consider the Thames Flood Barrier at Woolwich, which was built following the lessons of the devastating floods of 1929 and 1953. A decision to build it was made in 1966; construction was started in 1974 and the Barrier first operated in 1983. Climate change, through rising sea levels, will reduce the protection provided by the Barrier below its designed level (against a one in a thousand year event) by 2030; you will be reassured to know that the Environment Agency is already planning a replacement flood management system.
Adaptation then is something new for society to undertake, but many of the skills and knowledge required already exist. Our task then is to bring the need for and the practice of climate change adaptation out into the open so that it can be properly addressed, but then, as it becomes normal business practice, to incorporate it so completely into every aspect of life, that it again disappears. A hopeless or hopeful future?
So, am I hopeful about tackling the issue of climate change, or despondent about the gap between aspirations and action? We must face up to some awesome obstacles: the enormous power and inertia of the energy supply sector; the snail-like pace of intergovernmental agreement; the very different perspectives around the world on what is fair; the grotesque mismatch in scale between the climate change problem and any individual’s contribution to the solution. This may be the first issue we need to address as a species on a truly global scale.
However, we do have the necessary technology; we have an extraordinary record as a species for innovation; and we have no shortage of radiant energy arriving from the sun to power our economy. There are also enormous, but unheralded, positive features to a post-carbon global economy. Cleaner, more sustainable communities and a properly valued environment will make life more pleasant for all. Finally, a world that has decided to move from fossil carbon energy to one powered by sunlight will necessarily be one in which the tropics will gain a valuable, widespread, and inexhaustible resource, and one in which global equity will be accepted as a goal and will have begun to happen. That alone would be reason enough to be hopeful.”