Energy for a Sustainable World

From the Oil Age to a Sun-Powered Future

Vincenzo Balzani, Nicola Armaroli

• Publisher: Wiley-VCH
• Year: 2010
• Print ISBN: 9783527325405
• eBook ISBN: 9783527633616
• Edition: 1
• Topic: Scienze fisiche
• Subtopic: Chimica

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.

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 [4...

Table of contents

• Cover
• Half title page
• Related Titles
• Title page
• Copyright page
• Dedication
• Preface
• Notation
• Part One: Living on Spaceship Earth
• Part Two: Fossil Fuels
• Part Three: Nuclear Energy
• Part Four: Renewable Energies
• Part Five: Energy Carriers
• Part Six: Scenarios for a Sustainable Future
• Appendix
• References
• Index