Energy for a Sustainable World E-Book

Vincenzo Balzani

• Herausgeber: Wiley-VCH
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 714

Veröffentlichungsjahr: 2010

Beschreibung

An easy read, balancing the pros and cons, this book surveys the energy issue from a broad scientific perspective while considering environmental, economic, and social factors. It explains the basic concepts, provides a historical overview of energy resources, assesses our unsustainable energy system based on fossil fuels, and shows that the energy crisis is not only a tough challenge, but also an unprecedented opportunity to become more concerned about the world in which we live and the society we have built up. By outlining the alternatives for today and the future, it gives an extensive overview on nuclear energy, solar thermal and photovoltaics, solar fuels, wind power, ocean energies and other renewables, highlighting the increasing importance of electricity and the long-term perspectives of a hydrogen-based economy. An excellent source of updated and carefully documented information on the entangled aspects of the energy issue, this book is a guide for scientists, students and teachers looking for ways out of the energy and climate crisis, and the problems and disparities generated during the fossil fuel era.

Leseprobe

Table of Contents

Cover

Table of Contents

Half title page

Related Titles

Title page

Copyright page

Dedication

Preface

Notation

Part One: Living on Spaceship Earth

1 The Energy Challenge

1.1 Our Spaceship Earth

1.2 An Unsustainable Growth in an Unequal World

1.3 Energy and Climate Crisis

1.4 Dealing with Change

1.5 Unavoidable Questions

2 Concepts and Misconcepts

2.1 The Elusive Definition of Energy

2.2 A Taste of Basic Principles

2.3 Converting Primary Energy into Useful Energy

2.4 It Takes Energy to Make Energy: the EROI

2.5 Embodied Energy

2.6 Energy Units and Conversions

2.7 The Immense Energy and Power Scales

2.8 Some Energy Key Parameters

2.9 Energy Pervasiveness Versus Energy Illiteracy

2.10 Key Numbers: an Abacus for Energy Literacy

3 Energy in History

3.1 Historia Magistra Vitae

3.2 Animal Power

3.3 Human Slaves and Energy Slaves

3.4 Waterwheels and Windwheels

3.5 From Wood to Coal

3.6 Steam-Powered Machines

3.7 Road Vehicles

3.8 Aircraft

3.9 Electricity

Part Two: Fossil Fuels

4 Oil

4.1 What is Oil

4.2 Oil History, Exploration, Drilling, Production

4.3 Oil Transportation

4.4 Oil Refining

4.5 Oil Storage

4.6 Unconventional Oil

4.7 Petrochemicals

4.8 Oil as a Fuel

4.9 America’s Addiction to Oil

4.10 Oil Price

4.11 Oil Peak and Reserves

5 Natural Gas

5.1 What is Natural Gas and Where It Comes From

5.2 Gas Properties and Definitions

5.3 Brief Historical Notes on Gas Exploitation

5.4 Gas Production, Consumption, and Reserves

5.5 Liquefied Natural Gas (LNG)

5.6 Natural Gas Processing

5.7 Transport, Storage, and Distribution

5.8 Gas Uses: Energy and Feedstock

5.9 Unconventional Gas

6 Coal

6.1 What is Coal

6.2 Coal Extraction

6.3 Coal Transportation and Industrial Uses

6.4 Coal Gasification

6.5 Coal Production, Consumption, and Reserves

6.6 Carbon Capture and Sequestration (CCS)

6.7 Integrated Gasification Combined Cycle (IGCC)

7 Fossil Legacy

7.1 The Energy Dark Sides

7.2 Alteration of the Carbon Cycle by Fossil Fuel Combustion

7.3 Anthropogenic Climate Change

7.4 Air Pollution and Global Warming

7.5 Counterbalancing our Climate Influence

7.6 Putting a Limit to CO2

7.7 Air Pollution and Human Health

7.8 Land and Water Degradation

7.9 So, What?

Part Three: Nuclear Energy

8 Nuclear Energy

8.1 Principles of Nuclear Fission and Fusion

8.2 Power from Nuclear Fission

8.3 Civilian Use of Nuclear Fusion?

Part Four: Renewable Energies

9 Solar Energy Basics

9.1 The Origin of Sunshine

9.2 Solar Radiation and Attenuation

9.3 Abundant, Fairly Distributed, Vital

9.4 Sun’s Limits: Dilution and Intermittency

9.5 The Conversion of Solar Energy: Heat, Fuels, Electricity

10 Solar Heat and Electricity

10.1 Passive Solar Harnessing in Buildings

10.2 Thermal Conversion: Unconcentrated Solar Flux

10.3 Thermal Conversion: Concentrated Solar Flux

10.4 The Birth and Rise of Photovoltaics

10.5 Inorganic Photovoltaics: Key Principles

10.6 Silicon Solar Cells

10.7 Thin Film Solar Cells

10.8 Organic Solar Cells

10.9 Concentrated Photovoltaics and Other Innovative Concepts

10.10 Photovoltaics: Global Installation and Market Trends

10.11 Solar Energy: Sustainable and Affordable

11 Solar Fuels

11.1 Introduction

11.2 Natural Photosynthesis

11.3 Biomass and Biofuels

11.4 Future Options for Transportation Fuels

11.5 Artificial Photosynthesis

11.6 Dye-sensitized Solar Cells

11.7 The Solar Fuel Challenge

12 Other Renewables

12.1 Hydroelectric Energy

12.2 Wind Energy

12.3 Ocean Energies

12.4 Geothermal Energy

Part Five: Energy Carriers

13 Electricity

13.1 Basic Concepts

13.2 Illumination

13.3 Traditional Power Generation

13.4 Traditional Electricity Grid

13.5 Power Generation from New Renewables

13.6 Energy Storage for Electricity Supply Networks

13.7 Plugging-in Transportation

13.8 Smart Grid

13.9 Towards an Electricity Powered World

14 Hydrogen

14.1 Introduction

14.2 Properties and Industrial Uses

14.3 Hydrogen as an Energy Carrier: The Scale of the Task

14.4 Methods for Producing Hydrogen

14.5 Hydrogen Storage

14.6 Hydrogen Transportation and Distribution

14.7 End Uses of Hydrogen Fuel

14.8 Hydrogen Powered Vehicles

14.9 Towards a Hydrogen Economy?

Part Six: Scenarios for a Sustainable Future

15 The Challenge Ahead

15.1 Reflection on the State of Our Planet: Now We Know

15.2 Energy Demand and Supply

15.3 Energy and the Quality of Life

15.4 Saving the Climate

15.5 Phasing Out Fossil Fuels

15.6 Avoiding Nuclear Energy

15.7 Ecological Sustainability

15.8 Why We Need to Develop Renewable Energies

15.9 Conclusion

Appendix

Did You Know That … ?

Websites

References

Index

Nicola Armaroli and Vincenzo Balzani

Energy for a Sustainable World

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The Authors

Dr. Nicola Armaroli

Ist. ISOF/CNR

Molecular Photoscience Group

Via Gobetti 101

40129 Bologna

Italy

Prof. Vincenzo Balzani

Dept. of Chemistry G. Ciamician

University of Bologna

Via Selmi 2

40126 Bologna

Italy

Cover idea:

Fausto Puntoriero

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Cover Formgeber, Eppelheim

ISBN: 978-3-527-32540-5

To Claudia and Carla

Preface

“With no foresight into the future

one is bound to find troubles at hand.”

Ancient saying

In recent decades, by observing the Earth from space, we have fully realized that we live in a spaceship that cannot land and cannot dock anywhere to be refueled or repaired. We travel alone in the Universe and we can only rely on the resources available on the surface or in the hold of our planet, and on the energy coming from the Sun. We have also realized that the Earth is a system of intricately connected parts and that human activities can affect biogeochemical cycles. In fact, our 4.5 billion year old planet has entered a new epoch, Anthropocene, characterized by a dramatic increase of the size of human ecological footprint.

Energy is embedded in any type of goods and is needed to produce any kind of service. What makes the modern life of affluent people apparently so easy compared to that of our ancestors, or even to that of billions of individuals still living in poverty, is a steady flux of cheap and plentiful energy in the form of fossil fuels. We know, however, that these resources will not last forever and we have also learnt that their use has caused, and is still causing, severe damage to the Earth’s atmosphere. Furthermore, fossil fuels have indirectly contributed to establish disparities and iniquities in human society: almost half of the total primary energy supply is consumed by about 10% of the population living in rich countries, while the poorest 25% of mankind consumes less than 3% of global energy.

Nowadays, everybody wants to have more and more energy, an attitude that poses a variety of entangled problems. When a blackout takes place in a country for whatever reason, the solution proposed by politicians who are seeking to be (re)elected is that of making new power plants. Is it the right solution? Many economists seem to believe that well-being correlates with energy consumption, that energy prices reflect all significant costs and that any societal problems can be solved by enhanced economic growth. Is it true? Several scientists are convinced that technology will solve the energy problem as well as the problems that technology itself is creating. Can we trust them?

The aim of this book is to show that we live in a fragile world and that the world’s fragility can be strongly reduced or increased depending on how the energy problem is tackled. According to Stephen J. Gould, the fragility of the world is related to an intrinsic law of Nature that he called “the great asymmetry principle” (Gould, S.J., Science, 1998, 279, 812): “The essential human tragedy, and the true source of science’s potential misuse for destruction, lies in a great asymmetry in our universe of natural laws. We can only reach our pinnacles by laborious steps, but destruction can occur in a minute fraction of the building time, and can often be truly catastrophic. A day of fire destroyed a millennium of knowledge in the library of Alexandria and centuries of building in the city of London.” Within this general principle, the destruction force depends on place and time. Leaving aside the menace coming from nuclear weapons, presently the biggest danger for spaceship Earth comes from too much consumption of natural resources, too much waste generation and too many disparities among the passengers. Energy plays a key role in controlling Earth’s fragility because most of mankind’s problems, including food, water, health, wealth, climate, heating, lighting, cooling, transportation, communication, and, of course, wars are strictly related to the energy issue. The way out of the difficulties and disparities generated during the fossil fuel era is a global problem: the supply of secure, clean, sustainable energy to all of the passengers of spaceship Earth is the most important scientific and technological challenge of the twenty-first century.

Fortunately, the energy crisis is not only a tough challenge, but also an unprecedented opportunity. It offers a unique chance to become more concerned about the world in which we live and the society we have built up. Whereas it used to be axiomatic that civilization would always progress over time, because science and technology would have solved any problem, now we are no longer sure about that. Human progress is neither automatic nor inevitable. We have to take urgent and responsible decisions right now: tomorrow might be too late. The quest for ecological and social sustainability requires every single citizen to become aware that consuming resources above a threshold of his/her real needs does not help to create a better world. Earth is in our hands: are we wise enough to develop, with the help of science and technology, an ecological sustainable civilization capable of reducing disparity and creating a more peaceful world?

An old Italian proverb says that the only difference between an optimist and a pessimist is that the latter is better informed. A short-sighted optimism based on unawareness will not allow mankind to move toward a real progress. Pessimism, which arises from the consciousness of the gravity of the situation, is the right starting point: to propose solutions, we must acknowledge that there are problems and we must know them in any possible detail. There is a great need for spreading information about the unsafe conditions of our planet.

Finding a solution to the energy problem is a challenge of utmost difficulty, but also an extraordinary opportunity. Perhaps we are still in time to change and create an Anthropocene epoch based on resource conservation, waste reduction, human relationships, and global solidarity. To achieve this epochal result, we need to educate public opinion and to find visionary leaders capable of looking far, over the planet and into the future.Our generation will ultimately be defined by how we live up to the energy challenge.

Acknowledgments

No book can be written in isolation and this one has, indeed, benefited from the work of the thousands of authors of books and articles that allowed us to gain a deeper understanding of the problems we have tried to illustrate and discuss comprehensively. We strived to acknowledge their work and we apologize beforehand if we have missed someone.

We are glad to thank the members of our research groups, including PhD students, for support, discussions, suggestions, and, even more, for their friendship. Special thanks are due to Gianluca Accorsi, Giacomo Bergamini, Francesco Bari­gelletti, Paola Ceroni, Sandra Monti John Mohanraj, and Margherita Venturi for their critical reading of several chapters of the manuscript. Public debates, many lectures in high schools and universities and intelligent questions by many students and colleagues have helped us to focus several topics better.

We also wish to thank Fausto Puntoriero for drawing the cover page of the book, Filippo Monti for preparing with great care and ability all the graphics and illustrations, and Andrea Listorti and Abdelhalim Belbakra for searching and gathering literature. We would also like to thank the staff of Wiley-VCH for their highly professional and valuable assistance.

Last but not least we wish to thank our families, and in particular our wives Claudia and Carla, who have provided inspiration, sustained encouragement, and, definitely, a great deal of patience during the writing of this book.

Nicola Armaroli and Vincenzo Balzani

Bologna, August 2010

Notation

Prefixes

exa (E)1018peta (P)1015tera (T)1012giga (G)109mega (M)106kilo (k)103milli (m)10−3micro (µ)10−6nano (n)10−9pico (p)10−12femto (f)10−15atto (a)10−18

Abbreviations

bblbarrel of oilDwt deadweight tonppm part per milliontoe ton of oil equivalentWththermal wattWpwatt peakWelelectric watt

Acronyms

AC Alternating CurrentAFC Alkaline Fuel CellASPO Association for the Study of Peak Oil and GasASTM American Society for Testing and MaterialsBHJ Bulk HeterojunctionBP British Petroleumbpd barrel per daybpy barrel per yearBTU British Thermal UnitsCAES Compressed Air Energy StorageCBM Coalbed MethaneCCS Carbon Capture and SequestrationCFC ChlorofluorocarbonsCHP Combined Heat and PowerCNG Compressed Natural GasCPV Concentrated PhotovoltaicsCR Concentration Ratio (in CSP)CSP Concentrating Solar PowerDC Direct CurrentDME Dimethyl EtherDOD US Department of DefenseDOE US Department of EnergyDSSC Dye-Sensitized Solar CellDU Depleted UraniumEEA European Environment AgencyEES Earth Energy SystemsEI Energy IntensityEIA US Energy Information AdministrationENI Ente Nazionale Idrocarburi (Italy)EPA US Environmental Protection AgencyEROI (EROEI) Energy Return on InvestmentEU European UnionEUROSTAT Statistical Office of the European CommunitiesEV Electric VehicleFAME Fatty Acid Methyl EsterFIT Feed-in TariffsGDP Gross Domestic ProductGHG Greenhouse GasGWP Global Warming PotentialHFC HydrofluorocarbonIAEA International Atomic Energy AgencyICE Internal Combustion EngineICF Inertial Confinement ApproachICT Information and Communication TechnologyIEA International Energy AgencyIGCC Integrated Gasification Combined CycleIPCC International Panel on Climate ChangeIR Infrared (radiation)KERS Kinetic Energy Recovery SystemsLCA Life-Cycle AnalysisLNG Liquefied Natural GasLPG Liquid Petroleum GasNASA US National Aeronautics and Space AdministrationNEA Nuclear Energy AgencyNGO Non-Governmental OrganizationNIR Near-Infrared (radiation)NPT Non-Proliferation TreatyNREL US National Renewable Energy LaboratoryOECD Organization for Economic Cooperation and DevelopmentOSC Organic Solar CellOTEC Ocean Thermal Energy ConversionOWC Oscillating Water ColumnPCET Proton-Coupled Electron TransferPEM Proton Exchange MembranePM Particulate MatterPSII Photosystem IIPV PhotovoltaicQUAD quadrillion BTU (1015 BTU)RC Reaction CenterRMFC Reformed Methanol Fuel CellSEGS Solar Energy Generating SystemSHP Small HydropowerSI International System of UnitsSMES Superconducting Magnetic Energy StorageSUV Sport Utility VehicleTPES Total Primary Energy SupplyUCG Underground Coal GasificationUCTE Union for the Coordination of the Transmission of ElectricityUNEP United Nations Environment ProgrammeURFC Unitized Regenerative Fuel CellUSGS US Geological SurveyUV Ultraviolet (radiation)Vis Visible (radiation)VOC Volatile Organic CompoundWEC World Energy CouncilWHO World Heath OrganizationWNA World Nuclear AssociationWWII World War II

Part One: Living on Spaceship Earth

1

The Energy Challenge

“Pay attention to the whispers,

so you won’t have to listen to the screams.”

Cherokee Proverb

1.1 Our Spaceship Earth

On Christmas Eve 1968, the astronauts of the Apollo 8 spacecraft, while in orbit around the Moon, had the astonishment to contemplate the Earthrise. William Anders, the crewmember who took what is considered one of the most influential photographs ever taken, commented: “We came all this way to explore the Moon, and the most important thing is that we discovered the Earth” [1] (Figure 1.1).

Figure 1.1 Earthrise: a photograph of the Earth taken by astronaut William Anders on December 24, 1968, during the Apollo 8 mission while in orbit around the Moon. This picture is one of the Life’s 100 Photographs that Changed the World. Credit: NASA.

The image taken by the Cassini Orbiter spacecraft on September 15, 2006, at a distance of 1.5 billion kilometers (930 million miles) shows the Earth as a pale blue dot in the cosmic dark (Figure 1.2). There is no evidence of being in a privileged position in the Universe, no sign of our imagined self-importance. There is no hint that we can receive help from somewhere, no suggestion about places to which our species could migrate. Like it or not, Earth is a spaceship. It’s the only home where we can live.

Figure 1.2 Photograph taken by the Cassini Orbiter spacecraft on September 15, 2006, at a distance of 1.5 billion kilometers from Earth. The dot to the upper left of Saturn’s rings, indicated by the arrow, is the Earth. Saturn was used to block the direct light from the Sun, otherwise the Earth could not have been imaged. Inset: expanded image of the Earth which shows a dim extension (the Moon). Credit: NASA.

Spaceship Earth moves at the speed of 29 km s−1, apparently without any destination. It does not consume its own energy to travel, but it requires a huge amount of energy to make up for the needs of its 6.8 billion passengers who increase at a rate of 227 000 per day (the population of a medium-sized town), almost 83 million per year (the population of a large nation) [2]. Spaceship Earth cannot land and cannot dock anywhere to be refueled or repaired. Any damage has to be fixed and any problem has to be solved by us passengers, without disembarking. We travel alone in the Universe, and we can only rely on the energy coming from the Sun and on the resources available on the surface or stored in the hold of our spaceship.

Earth’s civilization has always depended on the incessant flow of solar energy that sustains the biosphere and powers the photosynthetic production of food. Until a few centuries ago societies obtained their energy from sources that were almost immediate transformations of solar radiation (flowing water and wind) or that took relatively short periods of time to become available (wood) [3]. The feature that distinguishes modern industrial society from all previous epochs is the exploitation of fossil fuel energy. Currently over 80% of the energy used by mankind comes from fossil fuels [4]. Harnessing coal, oil, and gas, the energy resources contained in the store of our spaceship, has prompted a dramatic expansion in energy use. Powering our spaceship Earth with fossil fuels has been very convenient, but now we know that this entails severe consequences [5, 6].

Firstly, fossil fuels are a nonrenewable resource that is going to exhaust. We have consumed 1 trillion barrels of oil in the last 140 years, and currently the world’s growing thirst for energy amounts to almost 1000 barrels of oil, 93 000 cubic meters of natural gas, and 221 tons of coal per second [7]. How long can we keep running this road? Secondly, the use of fossil fuels causes severe damage to human health and the environment. It has been pointed out [8] that the energy challenge we face relates to “the tragedy of the commons” [9]: we treat fossil fuels as a resource that anyone anywhere can extract and use in any fashion, and Earth’s atmosphere and oceans as a dump for their waste products, including more than 30 Gt per year of CO2. A third critical aspect concerning fossil fuels is that their uneven allocation, coupled with the unfair distribution of wealth, leads to strong disparities in the quality of life among the Earth’s passengers.

1.2 An Unsustainable Growth in an Unequal World

1.2.1 Population Growth and Carrying Capacity

In the last 100 years there has been a rapid population growth due to medical advances and massive increases in agricultural productivity. In 1950, the world population was 2.6 billion, with an increase of 1.5% per year [10]. In 2010, it was more than 6.8 billion, but with a lower rate of annual increase (1.1%), that is expected to decline further until 2050, when the Earth will be populated by about 9.2 billion people. At that time, the median age of the world population will be 37.3 years, up from 26.6 in 2000 [11].

The population size of a biological species that a given environment can sustain indefinitely is termed carrying capacity. Overpopulation may result from growth in population or reduction in capacity. The resources to be considered when assessing the carrying capacity of a given ecological system include clean water, clean air, food, shelter, warmth and other resources necessary to sustain life. In the case of humans, several additional resources must be considered, including medical care, education, sewage treatment, waste disposal, and, of course, energy.

Clearly, spaceship Earth has a limited carrying capacity, but it is quite difficult to assess the maximum number of humans who can live on it in satisfactory welfare conditions, also because “satisfactory welfare” is a somewhat subjective concept. An alarm bell, however, comes from the estimation of the ecological footprint, defined as the amount of biologically productive land and sea area needed to regenerate the resources a human population consumes and to absorb and render harmless the corresponding waste [12]. In global hectares per person, in 2006 the Earth’s biocapacity was 1.8, while the average footprint was 2.5. In 2009, the Earth Overshoot Day, that is, the day when humanity begins living beyond its ecological means, was September 25 [13]. In other words, mankind uses biological services faster than the Earth can renew them.

1.2.2 Economic Growth and Ecologic Degradation

The expansion of the human enterprise in the twentieth century was phenomenal, particularly because of the availability of low-cost energy. Unfortunately, however, it has caused bad consequences that we have now to face. Ecologists emphasize that dominant patterns of production and consumption are causing environmental devastation and a massive extinction of species [14]. Climatologists warn about anthropogenic climate change [15]. Geologists point out that we will soon reach, or maybe we have already surpassed, the peak of oil production [16]. Seismologists wonder whether natural disasters, like the devastating earthquake which in May 2008 killed 80 000 people in China, are triggered by exaggerated human constructions [17]. International agencies inform us that about 6 million hectares of primary forest are lost each year [18]. People are worried about nuclear waste [19], and in affluent countries even disposal of electronic waste causes domestic and international problems [20, 21]. Last but not least, food security is a growing concern worldwide [22, 23].

Some scientists have pointed out that global effects of human activities, directly or indirectly related to the use of fossil fuels, are producing distinctive global signals. Accordingly it has been proposed that, since the beginning of the Industrial Revolution, we have entered a new epoch that can be called Anthropocene [24], in which the Earth has endured changes sufficient to leave a global stratigraphic signature distinct from that of the Holocene or of previous Pleistocene interglacial phases [25].

In spite of these alarm bells, growth remains the magic word of narrow-minded economists and politicians. They believe that the economic growth must continue indefinitely, and therefore they incessantly press for increasing production and consumption. In affluent countries, we live in societies where the concepts of “enough” and “too much” have been removed [26]. We do not take into account that the larger the rates of resource consumption and waste disposal, the more difficult it will be to reach sustainability and guarantee the survival of human civilization.

1.2.3 Inequalities

The goal of ecological sustainability is even more imperative if we consider the problem of disparity [27]: the passengers of spaceship Earth travel, indeed, in very different “classes.” As an average, an American consumes about 7.11 toe of energy per year, a quantity approximately equal to that consumed by two Europeans, 4 Chinese, 17 Indians and 240 Ethiopians [28]. The uneven consumption of fossil fuels and the related generation of waste products are accompanied by uneven consumption and consequent uneven waste generation of any kind of nonrenewable store, for example, metals [29, 30].

Disparity is indeed the most worrying feature of our society. The poorest 40% of the world’s population account for 5% of global income, and the richest 20% account for three-quarters of global income. According to the World Bank [31], the Gross Domestic Product (GDP) at purchasing power parity per capita is higher than $30 000 in at least 25 countries ($46 400 in the US), but it is below $3000 in more than 50 countries and less than $1000 in 15 African nations [32]. The three richest persons in the world have assets that exceed the combined GDP of the poorest 47 countries.

Income inequality is vast and is reflected in all aspects of life: health, education, food, energy, and so on. Life expectancy at birth is higher than 79 years in most of the affluent countries with a peak of 83 years in Japan, but in several African nations it is below 50 years, for example, 47 years in Nigeria [2]. The adult literacy rate is close to 100% in many countries, but it is below 50% for at least 15 nations, mostly African. In more than 45 nations at least 20% inhabitants do not have access to a reliable water source. Large differences are also found in the ecological footprint, that is 9.0 ha per capita in the US, 11 times higher than that in India [33]. It has been calculated that if all the world’s 6.8 billion inhabitants were to live at current American ecological standards, we should look around for another four Earths to accommodate them [33].

There are also strong inequalities among citizens within each nation. The gap between rich and poor is larger in developing nations, but is increasing in almost all the affluent countries. The ratio between the household incomes of the richest 10% to the poorest 10% is 168 in Bolivia, 51 in Brazil, 16 in the US, and 11 in Italy [34]. In spite of the presence numerous billionaires (356 in 2009), poverty in the US is endemic, with roughly 13–17% of the people living below the federal poverty line [35]. In 2008, 11% of American households were food insecure, with 30% of African American minors living below the poverty threshold [36]. Health disparity is a big problem in several countries including the US [37]. Domestic disparity is a difficult problem to solve in a society where the way of life is based on consumerism, and international disparity is a problem set aside by politicians of affluent countries to please their supporters. In the long run, however, both problems have to be tackled because disparities destabilize human society. If things do not improve, sooner or later the poor will rise up against the rich. The boost of “illegal” immigration in affluent countries that lie at the boundary between the North and the South of the world (e.g., United States, Italy, Spain) is indeed a forewarning of what will happen in the international scene. Any action to restore equity should likely pass through lowering resource consumption (in particular, energy) by the rich while attempting to raise that of the poor.

Our time is characterized by an unsustainable growth in an unequal world. We should try to decrease disparity, while being aware that growth based on consumption of nonrenewable resources is poised to be an ephemeral illusion.

1.3 Energy and Climate Crisis

In the last 100 years the strong increase in population and the availability of large amounts of fossil fuels have led to an average primary energy consumption rate of almost 15 trillion watts (i.e., 15 TW) of power worldwide [7]. Current global trends in energy supply and consumption are environmentally, economically, and socially unsustainable. We need more energy to fill the gap between the industrialized and the developing countries, but at the same time we will not be able or allowed to consume more fossil fuels for several reasons: their limited amount, their increasing cost, and, above all, the need to reduce CO2 emissions.

According to the fourth assessment report of the United Nations Intergovernmental Panel on Climate Change (IPCC) [15], an increase in carbon dioxide concentration leads to an increase in the greenhouse effect that, in turn, causes climate change. This will impact food security [38], water availability [39], fish production [40], and global forests [18]. Other not less dangerous effects will be ocean acidification [41] and permafrost melting [42]. Indeed, climate change caused by an increase in the CO2 concentration in the atmosphere might result in much more than a simple stratigraphic signature of the Anthropocene epoch: it could lead to devastating effects on humanity.

Recently, two important steps in the right direction have been made: Europe signed its own climate agreement committing the region to a 20% cut in emissions by 2020 as well as a doubling of use of renewable energy and boosting energy efficiency by 20% over the same period, and US President Obama decided that combating climate change is a priority of his administration. These positive signals are counterbalanced by the great difficulties encountered when trying to set global and concerted policies to curb atmospheric carbon pollution [43].

1.4 Dealing with Change

In the last few decades we have become aware that we live in a fragile spaceship, with limited resources. We realize that we are in danger and that risks derive from two main features: too much consumption and too much disparity. In a restricted and perhaps overpopulated system like spaceship Earth, opportunities discovered and exploited by a generation can cause challenges to the subsequent ones. Fossil fuels have offered outstanding opportunities during the twentieth century in the rich countries of the western world, but now mankind has to face the challenges arising from fossil-fuel overexploitation. We need to reduce progressively the production of CO2, while providing a suitable energy supply to allow a decent standard of life to all of the people around the world. This means that we have to learn to save energy, to find more intelligent ways of exploiting traditional energy sources and to develop new ones. From the supply side, there are several options, including (i) the use of fossil fuels (in particular, coal) with carbon capture and sequestration, (ii) expansion of nuclear energy with third- and fourth-generation power plants, and (iii) development of a variety of unexploited or underexploited renewable sources like solar energy, wind energy, geothermal energy, ocean energy, and biofuels. On the demand side, the opportunities include (i) saving energy in every action of our life, (ii) limiting energy wastage in heating and cooling buildings, (iii) increasing the efficiency of internal combustion engines and electric motors, (iv) moving from fossil fuel-powered automobiles to electric vehicles, and perhaps (v) developing a hydrogen economy. But energy supply and demand have implications that go far beyond technical features. In developing countries billions of people work hard to improve their standard of living and need much energy to succeed. They look forward to reaching a welfare level comparable to that enjoyed by the citizens of the countries that developed in the past century. To reach this goal, they constantly increase energy consumption and CO2 production, but these parameters continue to increase also in affluent countries, where people falsely believe that the quality of life increases linearly with energy consumption.

In the last few decades the world has undergone big changes, and we should deal with them. We need new thinking and new ways of perceiving the world’s problems.

1.5 Unavoidable Questions

For several reasons, we are deeply interested in finding solutions to the climate and energy crisis. As passengers of spaceship Earth, we need energy for satisfying our fundamental needs while living in a pleasant environment. As parents, we wish to leave our planet in a good shape for the benefit of future generations. As passengers traveling in the first class, we feel obliged to help passengers living in much worse compartments to find a better accommodation. As members of mankind, we have the moral duty of contributing to solving the energy problem as a decisive step towards creating a more peaceful world. And if we are scientists, we have a great responsibility that comes from our knowledge and educational duty [44].

We are at a crossroads, and decision on the path to be taken lies with policy makers who, unfortunately, usually look only at the interest of their own nation and at the next election. What we would need are politicians capable of looking far-off in space and time, statesmen thinking over the whole planet and the future generations. To play as statesmen, politicians need to be counseled; this is particularly true in the case of important and complex problems like energy that need to be tackled globally, with the wisdom deriving from an interdisciplinary approach. Advice should come from scientists of the various scientific and humanistic disciplines, who are less conditioned and better informed than politicians on the present state of spaceship Earth and on what will likely happen in the next few decades. It is indeed their duty to find answers to several entangled, fundamental questions like the following:

Can we afford to stop burning fossil fuels or at least reduce their consumption?How long can we continue to treat the atmosphere and the oceans as a carbon dioxide sewer?Can scientists find any new energy source capable of replacing fossil fuels?Is it wise to develop nuclear energy?Can renewable energies supply us with all the energy we need?How can people living in poor countries improve their quality of life?Will it be possible for all Earth’s inhabitants to reach the standard of living of developed countries without devastating the planet?Should the citizens of the affluent countries change their lifestyle and look for innovative social and economic paradigms?Is it possible to reach the goal of ecological sustainability?Will decreasing resources lead to a destructive collapse of economy or can we manage to descend without too much damage?To what extent is well-being, or even happiness, related to energy consumption?Is it possible to do more with less?Can we afford to wait for the end of the crises, that follow one after the other, before addressing the energy problem and the related climate change?Will science and technology alone take us to where we need to be in the next few decades?

These are, indeed, hard questions. History teaches that the pressures of the great, hard questions can bend and even break well-established principles, thereby transforming difficult challenges into unexpected, astonishing opportunities [45]. But we should not forget that the challenge of saving spaceship Earth and its passengers needs the engagement of all of us.

And we have to start right now.