Preface

1Preface: Before Taking the Plunge¶

This book somewhat mirrors a personal journey that transformed my life, altered the way I look at the great human endeavor, and redefined my relationship to this planet. The transition that took a couple of decades for me is unlikely to be replicated for the reader in the short span of time it takes to absorb the content of this book. Nonetheless, the framework can be laid down so that readers might begin their own journeys and perhaps arrive at some profound realizations. This preface explains the approach and some overarching principles of the text.

We live in a physical world governed by physical law. Unlike the case for civil or criminal law, we are not even afforded the opportunity to break the laws of physics, except in fiction or entertainment. We do not need to create a physics police force or build physics jails or plead cases in front of some physics court. Nature provides perfect, automatic enforcement for free.

The domains of energy, the environment, economics, etc. are no exceptions, and can be put on a physical footing. It is worth exploring the emergent framework: reflecting on scale, efficiency, and thermodynamic limits of the human enterprise. By understanding the boundaries, we can begin to think about viable long-term plans in a way that too few are doing today. Thus far, heeding physical boundaries has not been necessary for the most part, as the scale of human endeavors has only recently become significant in a planetary context.We are now entering into a new reality: one in which our ambitions are on a collision course with natural limits on a finite planet. It is a slow-motion trajectory that has been apparent to some for an embarrassingly long time Meadows et al., 2004, but not yet acute enough to have grabbed the lasting attention of the majority.

The delirious ascent in energy and resource use witnessed over the past few centuries has been accomplished via the rapid, accelerating expenditure of a one-time inheritance of natural resources—a brief and singularly remarkable era in the long saga of human history. It has produced a dangerously distorted impression of what “normal” looks like on this planet. The fireworks show on display today is spectacular, fun, and inspirational, but also exceptionally unusual. Just as a meteorologist somehow born and trained within a 15-minute fireworks display likely cannot make useful predictions about weather and sky conditions over the next week, we are ill-equipped to intuitively understand what comes after the present phase. Luckily, science offers tools by which to transcend our narrow, warped perspectives, and can assist in discerning likely from wishful visions. The aim of this textbook is to set quantitative bounds on the present era as a way to better prepare for the possibility of a much different future. Our eventual success depends on serious attention to planetary limits.

This book is written to support a general education college course on energy and the environment. It was formulated as a physics course, but is written in the hope that it may also be accessible beyond this narrow setting. Physics is built on a mathematical foundation, and the domain of energy demands quantitative assessment. As a consequence, the book does not shy away from numbers. The math that is covered is presented in a way that aims to integrate intuition and the formality of equations. While math and quantitative elements are present throughout the book, Chapters 1, 3, and 6 are perhaps the most math-intense, featuring exponential functions, logarithms, and the lightest exposure to differential equations. But students need not master math beyond simple arithmetic operations, being able to rearrange equations, compute logarithms and exponentials, and raise a number to a power. Appendix A may serve as a useful math refresher.

An attempt is made to prevent students from equation-hunting, promoting instead development of a core understanding and intuition. This can require an adjustment on the part of students, who often treat equations as algorithmic tools to file away for use later when solving problems rather than as the embodiment of concepts to be internalized. Students often want a clear recipe so that when presented with a problem for homework, they can mimic a parallel example clearly laid out in the book. Doing so may be convenient and time-efficient, but short-circuits actual learning—bypassing the neural development that would accompany mastering the mental processes that are involved in solving a problem. Only the student can form these neural connections, and only through some struggle and effort. In this sense, learning is like climbing a hill: the only way to get to the top is by investing the effort to gain elevation—no shortcuts can bypass the inevitable climb.

Problems in this book are formulated to emphasize understanding the underlying concepts, rather than execution of a mathematical recipe. When students say they have math difficulties, it is usually not a problem carrying out the operations ($+, -, \times, \div$), but in formulating an approach. Therefore, the main difficulty is a conceptual one, but blamed on math because casting a problem in a mathematical framework forces a mastery of the conceptual underpinning: nowhere to hide. Given two numbers, should one divide or multiply them to get the answer sought? Resolving such questions requires a deeper understanding of the meaning behind the numbers in the problem (and associated units, often). By focusing on what the numbers represent and how they relate to each other, problems aim to build a more meaningful and permanent understanding of the content.

In soliciting feedback from students about problems, comments frequently pointed out that “Problem X used exactly the same math approach as Problem Y, so was redundant.” This exposes a glaring difference in how students and instructors might view a problem. To the student providing such feedback, the problem seems to merely mirror an algorithm, devoid of contextual meaning. To the instructor, it is a window into a richer world: insight and personal ownership of the material is at stake. Problems are an opportunity to learn, as students are perhaps most actively engaged, mentally, when attempting to solve them. Instructors are trying to recreate their own learning experiences for students, through the imperfect mechanism of assigned work.

A similar revelation stems from comments that express the sentiment: “this problem has unnecessary information that is not required to solve the problem.” Is the point to churn out a number, or to embed the result into a deeper context (i.e., learn)? It’s a matter of context over algorithm. Context is where the real learning happens. It’s where deep and lasting connections are made to the real world. The point is not to exercise a student’s ability to perform mathematical operations, but to absorb a greater insight into the issue through its quantitative analysis. Math is like the airplane that delivers a skydiver to the jump. The jump/dive is the whole point, but the airplane is a necessary conveyance. When it comes time to jump, clinging to the familiar safety of the plane won’t accomplish the goal. A student who bypasses the context for just the math operation has not embraced the intended experience and attendant mental growth.

The book’s format sometimes weaves math and numbers into the text, which is unfamiliar to some students who are accustomed to clear delineation between math and text. Students are advised to approach sections containing mathematical developments by treating equations as statements of truth (within the appropriate context and assumptions) that help define and complete logical arguments. Or, think of equations as short-hand sentences that encapsulate a concept. Experts work to understand the concepts, by reading rather than memorizing equations. What is the equation trying to say? What truth does it impart? What relationships does it elucidate? Equations in the text are surrounded by sentences to help bring the equations to life as guides to intuition. Students who just want a step-by-step recipe to utilizing equations in an algorithmic autopilot mode are missing an opportunity to internalize (“own") the complete argument and concept. Once the concept is mastered, the equation is a natural consequence, and can be generated at need from the concept when solving a problem.

Most textbooks on energy and the environment for a general education audience stick to dry analyses of energy resources, their implementations, and the advantages and disadvantages of each. This textbook also does so, but is less reserved about providing contextual interpretations, like saying that resources such as waves, geothermal, tidal, or ocean currents are probably not worth serious attention, due to their small scale. In this sense, the book bears some resemblance to David MacKay’s fabulous and inspirational Sustainable Energy: Without the Hot Air MacKay, 2009. In fact, the decision to make this text fully available for free in electronic form as a PDF (available at https://escholarship.org/uc/energy_ambitions) was completely inspired by MacKay’s first doing the same. The topic is too important to allow financial interests of a publisher to limit access. The price of the print version of this book—available at https://www.lulu.com/—is intended to cover production costs only. If using as a textbook for a course, consider its adaptation at https://www.kudu.com/physics_of_energy, allowing customization and unlimited editing of the course copy.

This text also differs from others in that it attempts to frame the energy story in a broader context of other limitations facing humanity in the formof growth (physical, economic, population) and also limitations of people themselves (psychology, political barriers). In the end, students are given quantitative guidance for adaptation and encouraged to find any number of ways to reduce consumption of resources as an effective hedge against uncertainty this century. Such advice is “bad for business” and may be seen as risky in a textbook subject to financial interests and coached by market analysis—which might explain why many textbooks come off as anodyne.

The tenor of this textbook might be characterized as being pessimistic, intoning that the coming century will present many difficulties that may not be dispatched by tidy “solutions,” but instead borne with resigned adaptation.We entered this century graced by a few-hundred year run of mounting prosperity—and resulting sugar high—unlike anything previously experienced in human history, but may not exit this century in such a state of privilege. This sort of message may be off-putting to some (see also the Epilogue). But the stakes are important enough that it may be worth challenging assumptions and making students uncomfortable in a way that other texts might purposefully avoid. By the time students reach the end of Chapter 8, they are perhaps a little alarmed, and desperate to know “what’s the answer?” Even though the book does not completely satisfy on that front—because it can’t, in good faith—this is arguably exactly where an instructor would like students to be: attentive and eager. Having them carry the tension into theworld is oneway to help humanity take its challenges seriously and work to find a better way. Soothing their discomfort so they can emerge thinking it’s all in hand is perhaps at best a wasted opportunity to create a better possible future for humanity, and at worst only contributes to humanity’s fall by failing to light a fire equal to the challenge.

Tom Murphy December, 2020 San Diego, CA