Managing risks involves balancing amongst concerns, safety, profits, and reputation in the context of the assessed risks. In general, risk management evaluates a collection of alternatives, considers pros and cons, and then reaches a decision that best achieves the decision-makers’ priorities.

Risk management is closely related to policy analysis and creation. A policy acts as a belief or plan to guide decision-making toward favored outcomes for international organizations, governments, private sector organizations, or individuals. The development and operation of policies are often influenced by risk management practices and decision theory.

Risk assessments often include a combination of strategic risks (long term), tactical risks (medium term), and operational risks (short term). Management priorities and strategies for risks on each of these time scales are typically different, with conflicts arising when near- and long-term strategies have the potential to worsen either the longterm or near-term impacts.

Risks associated with climate change are characterized by large uncertainties and emergence, with complex interplays between emergency and incremental, long-term risks. For such situations, there is a growing focus on dynamic risk assessment and management rather than on conventional risk management and control.4 Particularly for emergent risks, the risks as well as the risk management responses need to be monitored and adjusted.

Risk Management Principles

Risk management starts with reviewing the results generated by risk estimation, characterization, and assessment. Acceptable risk requires no further management. With intolerable risk, benefits aside, management involves phasing out or eliminating the risk if at all possible. If that is impossible, then mitigation and increasing resilience come into focus. With tolerable risk, while there are perceived benefits, there remains a call for risk reduction. Public risk management for such risks should focus on designing and implementing actions that result in either acceptable risk or create sustainable longterm tolerance via reduction, mitigation, or increasing resilience. and implementing actions that result in either acceptable risk or create sustainable longterm tolerance via reduction, mitigation, or increasing resilience.

The Foundation of Buenos Aires

The Spanish Pedro de Mendoza (1487–1537) founded the port called Nuestra Señora Santa María del Buen Ayre on 2 February 1536. The settlement was the result of various Spanish expeditions searching for a passage connecting the Atlantic and Pacific oceans, a connection of strategic importance given the possibilities of shortening trading routes and the discovery of new lands. Juan Diaz de Solis (1470–1516) commanded the first expedition in 1512; the voyage had such tactical significance that it was secretly organised to avoid leaking information to foreign sailors and nations. The result was the European exploration of the River Plate and the Paraná River, and although Solis died during a defence of the territory mounted by local indigenous groups, the area soon attracted the attention of other sailors.

The second expedition was that of Ferdinand Magellan (1480–1521), a Portuguese at the Spanish service, who sailed down the River Plate in 1520 but left the area when he realised that the river did not provide a passage to the Pacific, continuing the journey south and eventually succeeding in his quest. The importance of these expeditions is not only the success in finding a connection between the two oceans, but also the new knowledge that was gathered and shared in the attempts. By pushing the Spanish's boundaries further south, the River Plate area begun appearing in European maps, particularly as survivors of the expeditions recounted the stories of a legendary king with enormous wealth, known as the White King. Indeed, port taverns and bars were the perfect place to exchange travelling stories. The English Sebastian Cabot (1474–1557), who was also at the service of the Spanish king, heard the story of the White King while docked in Pernambuco (today Brazil), deciding immediately to set sail south in search for the treasure in 1526. The expedition was unsuccessful, although it resulted in the foundation of the fort of Sancti Spiritus, the first settlement in today's Argentinean territory. However, the colony did not last long as it was soon destroyed by local indigenous groups who were defending their territories. Cabot returned demoralised to Spain, where he nevertheless spread the legend of the White King that captivated the imagination of other Spaniards.

There is a growing realization that global climate models are not fit for the purpose of predicting twenty-first century climate variations and change, particularly on decadal and regional scales (Sections 6.3.4, 6.4). Climate model simulations under the auspices of the CMIP program and the IPCC are not providing the full range of scenarios of plausible climate outcomes. The CMIP simulations include very limited scenarios of volcanic eruptions and solar variability. Further, the climate models have inadequate representations of solar indirect effects and multi-decadal to century scale variations in the large-scale ocean circulations. Natural internal climate variability is of particular importance for scenarios of regional climate variations.

There is a need for alternative science-based frameworks for developing scenarios of climate futures, particularly with regard to regional extreme weather and climate events. The framework presented here has an indirect role for climate model simulations in developing scenarios of climate futures, but utilizes a broader range of methods for generating scenarios. Statistical and network-based models, data-driven scenarios, and speculative but physically-based what-if scenarios are also used in scenario generation. This alternative scenario framework reflects a shift away from median and likely values to a possibility framework for scenarios that accepts all outcomes that are not judged to be implausible by our current background knowledge.

The rationale for the scenario generation methods described in this chapter is provided by the risk governance framework that is discussed in Part Three of this book. A broad range of justified scenarios, along with expression of uncertainties, provide inputs for robust decision-making. Robust decision-making incorporates scientific uncertainty into the decision-theoretic framework as knowledge, not ignorance.

Escape From Model-Land

“Model-land” is a world in which mathematical simulations are evaluated against other mathematical simulations. Decision support in model-land implies taking the output of model simulations at face value, and then interpreting the frequencies from model-land to represent probabilities in the real world.

Climate change mitigation refers to efforts to control the concentration of atmospheric CO2 and other greenhouse gases by reducing or preventing emission of greenhouse gases and enhancing sinks of carbon. By contrast with adaptation, which manages the local impacts of a hazard, mitigation seeks to prevent the hazard from occurring.

Carbon Mitigation and Management

Carbon management is targeted at limiting the atmospheric concentration of CO2 and additional compounds that comprise carbon-based air pollution (e.g., methane and soot). Several comprehensive schemes have been formulated for atmospheric CO2 emissions and carbon-based air pollution, including the IPCC AR6 WGIII Report,4 Climate Stabilization Wedges, and Project Drawdown. While the emphasis has been on atmospheric CO2, management of other carbon pollutants is important in efforts to reduce warming. These mitigation schemes focus primarily on the sources of emissions: energy systems, transportation, industry, agriculture and forests, buildings, and urban systems.

Reducing CO2 emissions has become an end in itself, with the implicit assumption that reducing CO2 emissions will rapidly decrease atmospheric CO2 and improve the climate. However, rigorous detection and attribution of the climate impacts of even very strong emission mitigation efforts will be very challenging. Emergence of a climate mitigation signal beyond natural variability can never be proven, as we would be comparing it to an unknown, counterfactual world. The challenge is to understand how atmospheric carbon will evolve in response to emissions reductions, and how the fast and slow components of the climate system will respond.

Global Carbon Cycle, Feedbacks and Budget

Reservoirs of carbon in the earth system include the atmosphere, land ecosystems, the ocean, sediments, and the Earth's interior. Excluding rocks, by far the largest reservoir of carbon is the ocean. Exchanges of carbon between reservoirs occurs via various chemical, physical, geological, and biological processes. These exchanges establish a dynamical equilibrium over time in the absence of large external perturbations to the system. Since the advent of agriculture, humans have gradually influenced the carbon cycle by modifying the vegetation in land ecosystems.

Government Regulations and the Development of Private Buildings

Phillip II's Ordinances of 1573 stipulated that private architecture in colonial cities should be homogeneous and have uniformity. This principle was still debated during the eighteenth century when theorists at the time discussed the lack of uniformity in cities. A prominent architectural theorist expressed in 1753 that towns in France were ‘a mass of houses crowded together haphazardly and without system, planning or design’. While in Spain, another recognised authority, Abbot Antonio Ponz Piquer (1725–1792), published a book titled Travels in Spain (1772), where he critically revised peninsular architecture while advocating for ordered and homogeneous cities. Similar arguments were circulating in the colonies. According to Manila's governor, the street line in this city in 1792 was a collection of different houses including elegant buildings and poorly built ‘cabins and huts’. The governor was appalled by these conditions, adding that these huts were built on an irregular plan that damaged the geometrical layout of the city. Without a doubt, in Europe and the Spanish American colonies, the ideal cities of the Enlightenment were ordered, with unbroken street lines and with houses following a similar style and quality. What theorist wanted and admired was regularity, and while European cities struggled with their medieval layouts and crumbling housing stock, the colonies in the New World had the advantage of been developed following the gridiron system, which provided a solid platform for ordered geometry.

In Buenos Aires, the introduction of planning permissions for private buildings was consistent with the ideas of Abbot Antonio Ponz, who declared that no government should allow complete freedom to people for building their dwellings. The reason for this statement was that, according to him, no citizen had the right to ‘make the city look ugly’ emphasising that governments should control both planning permissions and architectural styles. Such system of planning permissions appears thus as the ultimate tool in government control of the urban space and personal choice. Equally and in the context of the enlightenment, ideas like the ‘benefit for all’ had to prevail over individuality. Therefore, all citizens had to regularise their façades in order to display in the whole, a magnificent city, characterised by unity and order, showing harmony and support for the monarchy, thus sending in turn a strong message of power to all rival nations.

The climate change response challenge is often portrayed as simple: increasing CO2 emissions causes problems, therefore stop fossil fuel emissions. Our failure to stop fossil fuel emissions, after decades of international policies, is often blamed on a lack of political will. Well, political will is lacking at least in part because CO2 emissions are the byproduct of dependable energy delivered by fossil fuels that has underpinned two centuries of human and economic development.

In a 2018 interim Special Report requested by the UNFCCC, the IPCC mapped out a pathway to limiting the temperature increase in 2100 to 1.5°C above pre-industrial levels. Limiting warming to 1.5°C is assessed to require dramatic emissions reductions by the year 2030 and complete carbon neutrality by around 2050. This would entail unprecedented transformations of energy, transportation, agricultural, urban, and industrial systems. However, no feasible and effective pathway has been identified to achieve any of these objectives in such a short time frame.

Human-caused climate change has been characterized as a “tragedy of the horizon” that imposes a cost on future generations that the current one has no direct incentive to fix. The possibility of delayed global rewards is challenged as inadequate justification to take action and incur immediate costs. However, this has led to the concern that we are operating a multigenerational Ponzi scheme by continuing to burn fossil fuels.

Additional background factors that influence the decisions of individual nations to participate in collective action to urgently reduce emissions include: uncertainties and complexity surrounding the underlying climate change science, the priority of economic development, and the unknown impacts of future technologies. There is substantial uncertainty about the magnitude, rate, regionality, and timing of adverse climate impacts, which is confounded by natural climate variability.

Economist Robert Pindyck argues that this uncertainty creates insurance value, pushing us towards early and stronger actions to reduce CO2 emissions. However, the very uncertainties over climate change that create insurance value prevent determination of exactly how large that insurance value is.

As I write this final chapter in mid-summer of 2022, the world is embroiled in geopolitical and financial instability from the COVID-19 pandemic and Russia's war on Ukraine. In the midst of this instability, we are seeing the inevitable clash between alarming proclamations about the climate crisis, the priorities of food and energy and poverty reduction, and the costs and difficulties of transitioning to net-zero CO2 emissions.

Recent headlines include:

• • “German cities impose cold showers and turn off lights amid Russian gas crisis”

• • “Hungary declares state of emergency over threat of energy shortages”

• • “Almost half of UK adults fear falling into fuel poverty before the years end”

• • “The West's Green Delusions Empowered Putin”

• • “Russia's war is the end of climate policy as we know it”

• • “Trudeau moves forward with fertilizer reduction climate policy”

• • “Why Dutch farmers are protesting over emissions cuts”

• • “Ireland debates a 30% emissions cap on farmers”

• • “Green dogma behind fall of Sri Lanka”

• • “Rich countries’ climate policies are colonialism in green”

• • “Barbados Resists Climate Colonialism in an Effort to Survive the Costs of Global Warming”

• • “African nations expected to make case for big rise in fossil fuel output”

• • “UN climate talks end in stalemate and ‘hypocrisy’ allegation”

How to respond to the climate “crisis” in the midst of genuine crises associated with food and energy shortages and the humanitarian crisis in Ukraine is best reflected by the response of the New Zealand government. In defending its decision to issue fossil fuel prospecting permits in spite of declaring a climate emergency, the New Zealand government stated that the climate crisis was “insufficient” to halt oil and gas exploration. Climate change is indeed a crisis of insufficient weight that is now being all but ignored by many countries as they grapple with the basic human needs for energy and food.

In 2015, the world's nations agreed on a set of 17 interlinked Sustainable Development Goals to support future global development.16 These goals include, in ranked order:

1. No poverty

2. Zero hunger

7. Affordable and clean energy

13. Climate action

Should one element of Goal 13, related to net-zero emissions, trump the higher priority goals of poverty and hunger and the availability of energy?

The relationship between scientific knowledge and political action is far from straightforward. Scientific knowledge invariably has blind spots and is provisional. Policy for complex issues is ever more reliant on knowledge, while science can deliver ever less certainty for society's most complex problems. This tension creates a paradox that is normally resolved through political decisions, and not through the dissemination of “truth” in the sense of uncontested knowledge. Political considerations include public opinion, fiscal priorities, diplomatic considerations, and assessment of political and economic risks and rewards.

Policy decisions related to scientific findings can be fairly straightforward (tame problems), or they can be highly contentious (wicked messes). Good decisions are those that lead to desired outcomes. However, the climate change problem provides much scope for disagreement among reasonable and intelligent people as to what constitutes desired outcomes, let alone how to achieve them.

In politicized arenas, science has become increasingly like litigation, where truth seeking has become secondary to advocacy on behalf of a preferred position or policy solution. Encroachment of politics into socially-relevant science is unavoidable. Problems arise when:

• • Driven by external pressures or for their own political purposes, scientists ignore data and research paths that would make their political point weaker or undermine their ideological perspective.

• • Politicians interfere with the activities of science.

• • Narrow framing of the scientific problem by policy makers, whereby government funding draws the efforts of scientists towards a narrow range of projects that supports preferred policies.

• • Politicians, advocacy groups, journalists, and even scientists attempt to intimidate or otherwise silence scientists whose research is judged to interfere with their policy preferences or political agendas.

Models of the Science-Policy Interface

The science-policy interface is comprised of social processes that encompass relations between scientists and other actors in the policy process, with the aim of enriching decision-making.

Change in the Earth's climate and its adverse effects have always been a common concern of humankind. The current challenge of climate change is typically formulated as:

• • The Earth's climate is warming.

• • A warming climate is dangerous.

• • We are causing the warming by emitting carbon dioxide (CO2) from burning fossil fuels.

• • We need to prevent dangerous climate change by rapidly reducing and then eliminating our CO2 emissions.

In spite of the perceived urgency of the problem and international climate treaties and agreements that were first signed in 1992, global CO2 emissions continue to increase while targets and deadlines continue to be missed.

Most people feel that climate change is a very serious issue. Depending on your perspective and values, there will be much future loss and damage from either climate change itself, or from the policies designed to prevent climate change. Conflicts surrounding climate change have been exacerbated by oversimplifying both the problem and its solutions.

Acknowledging disagreement is not the same as rejecting climate change as an important problem. In the context of the international treaties and agreements on climate change, both the problem of climate change and its solutions are framed as a global issue. This framing of the central challenge that focuses on reducing global carbon emissions has allowed technical fixes such as geo-engineering and low-carbon energy to take center-stage. This focus has come at the expense of a host of wider visions for social, economic, and political change, particularly at the national and local levels.

Part One describes how the challenge of climate change has evolved in the context of a complex interplay among scientists, the organizations that support research, government-sponsored assessments of climate research, national and international climate policy, politics, and the needs and desires of peoples and nations in a rapidly changing world. Polarization has deepened in a fog of confusion about what we know versus what we do not know and what we cannot know. A populace that is trying to understand climate change is left confused by international and national policies and commitments that do not seem doable or politically feasible.

Land Control Changes

Colonial Spanish cities had three well-defined areas that radiated from the centre where the main square or plaza mayor was located, extending from here to the periphery and the surrounding fields. The first inner area was the urban core and where public buildings were located and where the original settlers had their dwellings. This core was usually divided into square blocks of 140 varas side (approximately 120 metres). Surrounding this, was the ejido, which was land shared by the community and administered by the town council, all settlers with a house in the core had a right to use these com¬mons for grazing the farmstock that they had in the town (most families had a couple of livestock for daily milk and eggs consumption). Beyond the ejido was the land divided into agricultural plots – called suertes (luck). The suertes were randomly allocated to the first settlers and used for agriculture. Beyond this area, the lands belonged to the Spanish Crown and were known as tierras realengas.

In order to ensure that the settlers remained in the colony, the Crown required that a minimum of five years residency cultivating the land and maintaining a dwelling in the core, earning full possession of the property after this period. However, some settlers migrated to other more hospitable areas of the empire, leaving behind empty plots in the city along with uncultivated suertes. The problem was that by the sixteenth century, there was a surge in empty urban plots, and it became difficult to monitor which owners were forfeiting their rights to the land or if they intended to return. The Crown therefore resolved that those who had reasons to leave a settlement but did not intend to emigrate had to appoint a ‘fully armed’ person in their place in case of enemy attack. This problem of settlers abandoning colonies was common particularly during the sixteenth century, when Spain was expanding its dominions and settlements. This prompted the Crown to order that settlers build houses as soon as possible, preferably in stone. Presumably intending that a capital investment would tie people to the land.

In the linear model of expertise and decision-making (Section 4.1.1), uncertainty and doubt are enemies of action. Attempts to hide or simplify uncertainty are at the heart of some of the most acrimonious debates over climate change.

Uncertainty is a state of incomplete knowledge arising from a lack of information or from disagreement about what is known or even knowable. The fundamental mischaracterization of the climate change problem as a tame rather than a wicked problem (Section 3.4) has resulted in institutionalized efforts to ignore, simplify, reduce, and control uncertainty.

In frontier research, the objective is to extend knowledge in ways that change how we think about a particular topic. Doubt and uncertainty are inherent at the knowledge frontier. Researchers using the same data and hypotheses can come to different conclusions in the context of a vast universe of different possible research designs. While extending the knowledge frontier often reduces uncertainty in some dimensions, inevitably it leads to greater uncertainty in other dimensions as unanticipated complexities are discovered. Careful consideration of uncertainties is not a central element of frontier research.

However, uncertainty assessment and characterization are paramount for science that is targeted at policy-making. The greatest challenges are presented by frontier research that is policy relevant, such as climate change.

This chapter presents a consilience of diverse ideas about uncertainty, which provides the foundation for a strategy to accommodate uncertainty at the climate science-policy interface and in decision-making.

The Uncertainty Monster

With a heritage in monster theory, Dutch social scientist Jeroen van der Sluijs introduced the concept of the “uncertainty monster” in context of the different ways that the scientific community responds to the monstrous uncertainties associated with environmental problems. The “monster” arises from the confusion and ambiguity associated with knowledge versus ignorance, objectivity versus subjectivity, facts versus values, prediction versus speculation, and science versus policy. The uncertainty monster gives rise to discomfort and fear, particularly with regard to our reactions to things or situations we cannot understand or control, including the presentiment of radical unknown dangers. Specifically, in the context of decision-making, the uncertainty monster is perceived as something to be feared and avoided.

The concept of risk is an outgrowth of concerns about coping with dangers. For most of human history, the assessment and management of risk occurred informally by trial and error. More than 2400 years ago, Athenians articulated the capacity of assessing risk before making decisions. As the influence and scale of technology expanded, it became evident that society needed to assess risks proactively. Science has increasingly allowed us to recognize and measure more subtle hazards, which has been coupled with a general decreasing tolerance for risk in modern industrialized society.

Risk assessment and management as a scientific field is only about 40–50 years old. There are many different perspectives on risk, and some of these perspectives represent substantially different frameworks. However, there is broad agreement on the basic ideas and principles of risk understanding, assessment, communication, and management.

Risk may have positive or negative outcomes or may simply be associated with uncertainty. Fire and accidents only have negative outcomes, and they are often referred to as hazard risks. Taking a risk can also result in a positive outcome. Risk can also be related to uncertainty of outcome. However, most applications of risk analysis focus on adverse outcomes.

Climate change presents a challenge to risk assessment that is uniquely complex, uncertain, and ambiguous. This chapter provides perspectives on risk and its perception, how risk is characterized, and why climate change is such a challenging problem for risk analysis.

Risk and Perception

Climate risk is generally regarded as a hazard risk, although there are potential positive outcomes as well. The related terms “threat” and “hazard” refer to something that could cause harm, with the possibility of trouble, danger, or ruin. The hazard may be something that is impending and imminent, or something that is likely, or merely possible.

The King's Presence in the Colonies

In most cities across the Spanish world, royal ceremonies covered a range of events associated with the royal family. They included the arrival of new infants, birthdays, commemoration of royal patron saints as well as simple gatherings at the local church to pray for the well-being of a particular member of the royal family who was unwell. Undoubtedly, among all these events, the most important was the death of the king and the subsequent proclamation of his successor. On these occasions, the routine of eighteenth-century city life was disrupted; market activities ceased and streets in the city centre transformed giving way to processions and parades. Citizens were compelled to attend the festivities and even if they did not, the ceremony brought to a halt their everyday routines, making them aware of the events.

Royal proclamations and city arrivals are closely related and have been traced back to the entrance of Christ into Jerusalem and therefore linked to Christian rituals. It was during the Medieval Ages when Christianity spread, creating centres in Europe where political power and Christian rituals intertwined. This was particularly true in catholic Spain, where rituals of power and ideas of civitas soon merged and rooted in society. In medieval Castile and in the event of the death of a monarch, the custom was that the nobility met in private to make funeral arrangements and select a new ruler, with a public proclamation following soon afterwards. As rituals were based upon familiar actions, gestures and movements that were meaningful to a given society, they were understood and mostly acknowledged without debate. By the time of the conquest and colonisation of the Americas, rituals were well established in the Spanish society and seen as a powerful tool for domination. Elaborate religious and political acts were therefore transferred to the colonies during the foundation of new cities (see Chapter 1), becoming regulated as soon as the administrative geographies were organised and the relevant offices in charge of events established. Notwithstanding, the issue of how to make the presence of the king felt by all subjects during royal ceremonies became an important question for overseas administrators.

While the public may understand little about climate science, nearly everyone has been exposed to the statement that there is a consensus among scientists regarding dangerous climate change. This chapter explores the history and consequences of the scientific consensus building activities undertaken by the Intergovernmental Panel on Climate Change (IPCC).

For genuinely well-established scientific theories, the concept of consensus is irrelevant. For example, there is no point in discussing a consensus that the Earth orbits the sun, or that the hydrogen molecule has less mass than the nitrogen molecule. While a consensus may arise surrounding a specific scientific hypothesis or theory, the existence of a consensus is not itself the evidence.

There is a key difference between a “scientific consensus” and a “consensus of scientists.” A scientific consensus is a relatively stable paradigm that structures and organizes scientific knowledge. By contrast, a consensus of scientists represents a deliberate expression of collective judgment by a scientific institution or a group of scientists, often at the official request of a government or other organization.

Under the auspices of the IPCC, the international climate community has worked for the past 30 years to establish a scientific consensus on human-caused climate change. The IPCC has codified consensus seeking into its assessment procedures: “In taking decisions, drawing conclusions, and adopting reports, the IPCC Plenary and Working Groups shall use all best endeavours to reach consensus.” The IPCC consensus has been described as a “manufactured consensus” (or a consensus of scientists), arising from an intentional consensus building process.

Among the best indicators to nonexperts about climate change is the existence of a consensus among experts. Messaging on the climate consensus went viral with this 2013 tweet from US President Obama:

President Obama's tweet linked to a paper by Cook et al. that analyzed the abstracts of almost 12,000 climate-related papers.