Half a lifetime had gone by since Arthur Holmes had lain in his tent in Mozambique, racked with fever, dreaming of developing a geological time scale and wondering how he could reconcile the age of the Earth as determined by radioactivity with that calculated by the old established methods of sedimentation rates. While progress on a geological time scale had been made over the following years, it had largely been in the physics arena: improved understanding about the atom; the discovery of isotopes; development of the mass spectrometer; and recognition of the four stable isotopes of lead. The geological side, however, lagged far behind. A rock assigned an age of 300 million years, for example, still could not be classified as ‘Carboniferous’ with any confidence because it was still not known how long, in geological time, the Carboniferous ranged. So, as we saw with the helium results from the Whin Sill, extreme errors could be accepted as reasonable values because no limits could be placed on the extent of the Carboniferous. Clearly, what was needed was a time scale that said ‘the Carboniferous starts here at this age and ends there at that age, therefore any age in between must be Carboniferous’. But that was still a long way off.

If gratitude could be measured on the geological time scale, then what I owe Hugh Torrens, historian of technology and Professor of Geology at Keele University, would stretch beyond the age of the dinosaurs and survive the Permian extinction, only to disappear down the black hole of the Archaean still feeling inadequate. Without the benefit of his invaluable advice this novice historian would have taken aeons to find all the relevant materials, and this book would probably still be sitting on a word processor.

Finding out about another person's life is like writing a detective story – except that you are in it. Arthur Holmes left few clues about his private life and the ‘garden shed mystery’ was never fully resolved. A shed at the bottom of Doris' garden in Hove was believed to contain all Holmes' papers, but quite what happened to its contents when she died is not clear. I found some, but certainly not all. Although Geoffrey Holmes, Arthur's son, sadly died before I had a chance to meet him, I was delighted when I finally tracked down Geoffrey's wife Karla, and their four children.

Margaret Howe was nearly thirty when she married Arthur Holmes at Gateshead United Methodist Church on Tuesday the 14th of July, 1914. The daughter of one of the famous Howe Brothers, a printing firm started very modestly by her grandfather in 1863 which had grown to be one of the biggest employers in Gateshead, Maggie was the youngest of three children. Her father, a master printer, was now comfortably retired but Maggie still lived with her parents in their fine Victorian house in Saltwell View, Gateshead, overlooking the park. Her brother and sister had both married and moved away so it fell to Maggie to stay at home and look after her parents.

It is unclear how the relationship arose, Arthur being five years Maggie's junior, but he wrote to her from Mozambique so they must have known each other for some time previously. Having been ‘squashed’ by Edie it appears Arthur's attentions turned to Maggie on his return from Mozambique. In a letter to Edward Wayland dated 8th October 1912, he shed some light on the subject:

I had, as a matter of fact, wanted a girl at home for a considerable time but … someone else appeared to be in the field. Fortunately he was unsuccessful, for the girl also wanted me but was under the impression that I was not available.

Progress on dating the age of the Earth was slow. Years, even decades went by without any significant advance being made. But science is like that. What is often not realised when the breakthrough finally occurs is that for years previously a few individuals had been diligently working in the background, thinking and writing about the problems, quietly and persistently pursuing their goal. Arthur Holmes was one. Every few years he took it upon himself to write an article summarising the current state of play with regard to the age of the Earth. In simple and lucid language he explained to the scientist and layman alike the history of radioactivity, its application to dating minerals and the age of the Earth, and included any recent developments. Year after year he said much the same thing: Kelvin's arguments were shot down in flames, the ‘hour-glass’ methods were swept aside, and radioactivity emerged victorious. Slowly, bit by bit, this one-man campaign spread the word about the great antiquity of the age of the Earth.

He also continued to build up the database. As early as 1923 a committee had been set up in America for ‘The Measurement of Geologic Time by Atomic Disintegration’, its objectives being to collate and monitor all the dating of rocks being done around the world.

Summary

Natural catastrophes – rare, high-consequence events – present us with a unique conjunction of problems so far as risk is concerned. Firstly, they can have an extremely long recurrence interval – so long that the greatest may not have occurred within human memory. Secondly, the effects of events with which we are all too familiar, for example earthquakes, floods, volcanoes and storms, are easily trumped by the impacts of objects – comets and asteroids – that reach Earth from outer space; and thirdly, the largest of these events have a global reach, in principle threatening not just our way of life but perhaps life on Earth itself. However, recognising that such events occur very rarely, should we ‘make hay while the sun shines’ and ignore, ostrich-like, the significant actuarial risk; or should we seek to understand the underlying phenomena and develop strategies to mitigate the threat, and perhaps technologies to avert it? Our individual response often depends less on a purely rational assessment than on personal circumstances and how we have been brought up. In any case the nature of the risks, which are poorly understood, means that we must be prepared to handle the law of unintended consequences (that is, could our actions make things worse?). We must also be prepared to explore what happens if, perhaps inevitably, our current scientific understanding turns out to be less certain than many experts believe.

Introduction

Rare, high-consequence events present society with exceptional difficulties so far as risk assessment is concerned. The infrequency of the most extreme events means that their causes are often among the most poorly understood among environmental issues and their impacts are – fortunately – poorly known from direct experience. In addition, natural catastrophes may have an origin either entirely within the Earth-system or from outside: from the Sun, solar system or wider Universe of which the Earth is a part. It is widely accepted that the potentially devastating effects of cosmic phenomena are likely, in the long term, to far outweigh any purely Earth-based cataclysm.

Introduction

In a series of paintings from the walls of a bar in Pompeii – painted sometime in the ten years before Vesuvius erupted in ad 79 – is a scene of two Roman men playing a game of chance (Figure 5.1). They have a board between them balanced on their knees, and we can just about make out some counters on it. The man on the left has just been shaking the dice in a shaker, and, in the ‘speech bubble’ above his head, he is claiming a winning throw. ‘I’ve won’, he shouts (‘Exsi’ in Latin). ‘No’, says his partner and opponent, ‘it's not a three, it's a two’ (‘Non tria, duas est’).

The other paintings in the series show other activities you might expect to find going on in a bar: drinking, brawling, sex and flirtation (Figure 5.2). In fact, it is a line-up of exactly the kind of things that Roman puritans (who saw an obvious connection between alcohol, sex and dice-games) were very keen on deploring. It is perhaps hardly surprising that in the next painting (and so in the final episode of this little visual narrative), the game is leading to blows. Although the panel is badly damaged, it is clear enough that the two men have left the table and are trading insults in some almost incomprehensible speech bubbles. What we can understand is predictably rude: ‘Look here cock-sucker (fellator) I was the winner.’ Almost completely lost is the figure of the long-suffering landlord (or alternatively the hard-nosed supremo of the gambling den, depending on how we choose to see him). But his speech bubble survives. He is saying, as landlords have said for thousands of years: ‘If you want to fight, get outside’ (‘itis foras rixsatis’).

Putting numbers on risks

Risk is a strange concept. Different disciplines have tried to define it precisely, but perhaps it is better to be informal and follow more popular usage. I shall take it as anything to do with situations where ‘bad’ (or ‘good’) things may, or may not, happen. The crucial elements are that there is uncertainty, and that the outcomes may be nice or nasty.

A wealth of recent psychological research has shown that we mainly use ‘gut feelings’ to deal with such situations, rather than carefully weighing up the consequences and assessing numerical probabilities, as more formal approaches would have us do. Our feelings are influenced by culture, our experiences and those of people close to us, media coverage, emotional feelings of dread, or hope, and so on, but we manage to get by most of the time, and it is noticeable how recently, in historical terms, the theory combining probability and ‘rational’ decision-making was developed. Even when evidence is available about the ‘size’ of a risk, in sufficiently stressful situations it may be ignored. Cass Sunstein, a senior adviser to Barack Obama, claims that people display ‘probability neglect’ when confronted with vivid images of terrorism, so that ‘when their emotions are intensely engaged, people's attention is focused on the bad outcome itself, and they are inattentive to the fact that it is unlikely to occur’. So the ‘true’ risks are ignored; it's been shown that people are, rather illogically, willing to pay more for insurance against terrorism than insurance against all risks (which implicitly include terrorism), just because the use of the word conjures up dread.

Puzzling over gaps between practice and declared principles in government and public services

It is often said that high officeholders in government, both elected and appointed, live chronically time-pressured lives with many urgent and competing claims crowding in on their limited time and attention. Such individuals often, indeed routinely, declare that they want to focus on the big picture and on the pursuit of their grand visions, and that they are mainly concerned with achieving results that bring substantive social value rather than with small-print details of process and structure or with the trivialities of day-to-day media gossip.

Yet careful analysis of how those high-level officeholders in government use their limited time often reveals that they spend a remarkably large proportion of it – 50 per cent or more, on some estimates – on matters of media presentation and that they often devote a surprising amount of their time as well to small-print details of legislation and government organisation.

Social scientists tell us we live in a ‘world risk society’. But what does this mean post 9/11? By any account the risk to our collective security and, no less importantly, our subjective sense of security, was altered radically by the tragic events of that day. Of course terrorism was far from unknown before 9/11, but it did not occupy the public imagination in the way it has done since. Risk commentators were quick to add terrorist threat to the catalogue of environmental, health and engineering risks, and natural catastrophes already said to characterise the world risk society. But the risks born of terrorism are very different from those posed by climate change and ’flu pandemics. If risk is to avoid becoming an undifferentiated amalgam of unnamed perils we need to think a little harder about what or who is at risk.

This is all the more important because seeking security from terrorism has the quality of a trump card. Play the security hand and countervailing interests, not least our civil liberties, lose out. Despite their rarity, acts of terrorism pose a risk of catastrophic harm that inclines us to accept whatever policies seem to offer some prospect of protection. Although counterterrorist measures may discriminate unfairly and erode civil liberties unwarrantedly, the urge to reduce risk prevails. Balancing liberty and security assumes a zero-sum game in which by eroding liberty we can reduce risk. In place of balancing we would do better to think about the whole range of risks associated with terrorism and consider how seeking to avert risk may have the effect of introducing new hazards. By focusing on the obvious risks – threats to life and property, and subjective insecurity or terror itself – we risk overlooking the fact that countering terrorism carries its own hazards: risks to political and economic life; risks to social cohesion, community and race relations; risks to rights (rights to freedom of speech, privacy and freedom of the person) and risks for the rule of law. Add to this the risk of marginalising and alienating those we target and we arrive at the paradoxical situation that counterterrorism policies may make further attack more, not less, likely. So we need to consider what risks are really at stake when we seek to counter terrorist risk.

The ability to make good decisions about future courses of action under conditions of uncertainty is essential for the survival of most animals, including humans. Whether it is deciding which item to choose from a restaurant menu, when to cross a busy road or what career path to follow, we are constantly faced with the need to make decisions of varying degrees of importance in terms of their implications for our future well-being. Often the outcomes of such decisions are highly uncertain, and we must therefore take into account not only the pros and cons of the outcomes associated with different courses of action but also the uncertainties or ‘risk’ attached to such outcomes. On the whole, humans are rather good at making decisions, as exemplified by our incredible success as a species. The root of that success necessarily lies in the machinery contained in our brain, a highly efficient computer weighing approximately 1.36 kg that has been shaped by evolution to allow us the flexibility to make good decisions in diverse and rapidly changing environments. In this chapter, I will give a broad introduction to a new interdisciplinary field of study called ‘neuroeconomics’, which is concerned with elucidating how the brain is capable of enabling us to make such good decisions. I will outline our current understanding about how decisions are made by the brain, and I will highlight some of the outstanding questions for future research in this still nascent field of study.

Neuroeconomics

The field of neuroeconomics has emerged through a fusion of approaches found in more traditional disciplines. These include not only neuroscience and economics, as one might have guessed from the perhaps clumsily put-together title, but also cognitive and behavioural psychology, computer science and artificial intelligence, engineering, robotics and behavioural ecology, among others (Glimcher et al., 2009). A core assumption behind neuroeconomics is (in common with much if not all contemporary neuroscience) that the brain can be treated as a computational device transforming input in the form of information reaching our sense organs (vision, touch, audition, smell and taste), into output in the form of the generation of behaviour. This transformation is mediated by the billions of highly interconnected neurons (nerve cells) contained in our brains. The main goal of neuroscience is to describe precisely how these neurons act on the incoming sensory information in order to produce a particular output, or, to return to the brain-as-computer analogy, to resolve the algorithms (or mathematical functions) used by the brain to achieve such transformations.

Overview

Most countries are attempting to achieve environmentally and socially sustainable economic growth, coupled with food, water and energy security at a time of enormous global changes, including environmental degradation at the local, regional and global scale. Key issues include climate change, loss of biodiversity and ecosystem services (provisioning, regulating, cultural and supporting), local and regional air pollution, and land and water degradation.

There is no doubt that the Earth's climate is changing and it is very likely that most of the observed changes in the last fifty years are due to human activities. Cost-effective and equitable approaches to address climate change exist or can be developed, but will require political will and moral leadership. A combination of technological and behavioural changes, coupled with pricing and effective policies (including regulatory policies), are needed to address this global challenge at all spatial scales, that is, local, national and international, and across sectors.