The Nexus of Population, Energy, Innovation, and Complexity

• Author: Joseph A. Tainter,Temis G. Taylor
• Published date: 01 September 2016
• Date: 01 September 2016
• DOI: http://doi.org/10.1111/ajes.12162

The Nexus of Population, Energy,

Innovation, and Complexity

By TEMIS G. TAYLOR* and JOSEPH A. TAINTER

†

ABSTRACT. For the past 200 years, humans have benefited from the

abundant, inexpensive, and easily obtained energy of fossil fuels. Energy

surpluses such as this are unusual in human history. In systems with little

surplus energy, population growth is low and complexity emerges slowly

due to the energetic costs it carries. On the rare occasions when energy is

readily available, societies respond by growing rapidly. They must

become more complex in response to the social, economic, and resource

challenges of dense population. More complex societies are more

expensive, requiring greater energy per capita. The process of increasing

complexity necessitates greater energy production, creating a positive

feedback cycle. Past societies have collapsed under such pressures.

Population and complexity grew rapidly when the Industrial Revolution

replaced economies based on annual solar radiation with economies

fueled by fossil energy. The Green Revolution of the 20

th

century is

credited with preventing mass starvation, but it has made food production

and sustaining population ever-more dependent on high-energy (low-

entropy) inputs. Some believe innovation will overcome the limitations of

resources and permit unchecked growth. However, increases in

complexity, innovation, and fossil energy are all subject to diminishing

returns, and cannot continue to support population at current levels.

Introduction

Since the time of Malthus, it has been common to treat population as a

function of food supply, and subsistence as a function of population

pressure (e.g., Cohen 1977). As concern has grown over how many

*PhD candidate in the Department of Environment and Society at Utah State Uni-

versity with a Master’s in Bioregional Planning. Her current work centers around ener-

gy and perceptions of risk. Email: Temis.Taylor@usu.edu.

†

Professor of Sustainability in the Department of Environment and Society, Utah

State University, Logan. Author of The Collapse of Complex Societies and other works

exploring his interests in complexity and energy. Email: Joseph.Tainter@usu.edu.

American Journal of Economics and Sociology, Vol. 75, No. 4 (September, 2016).

DOI: 10.1111/ajes.12162

V

C2016 American Journal of Economics and Sociology, Inc.

people the earth can support without damaging life-support systems and

ecosystems irreparably, population has been seen as a critical factor in

sustainability. This led to the now-classic formulation of IPAT, where

environmental impact is a function of population, affluence (level of con-

sumption), and technology (Ehrlich and Holdren 1972: 20). Building on

this traditional line of discourse, we present an analysis that links popula-

tion to energy, energy gain, innovation, and societal complexity.

Denser human populations create scalar stress (Jennings 2016), which

is resolved through increasing complexity for such matters as provision-

ing, maintaining order, and ensuring security. In the face of the Second

Law of Thermodynamics, however, complexity can only be maintained

by expending energy. More complex societies are more expensive,

requiring greater energy per capita (Tainter 1988). Yet it takes energy to

gain energy. Dense human populations and complex societies can be

sustained only where net energy, or energy returned on investment

(EROI), is sufficiently high. Nonrenewable resources are finite, and as

we use the best sources, net gain declines. Technology and innovation

are conventionally thought to offset resource depletion, but knowledge

production is subject to diminishing returns. Over time, innovation grows

complex and costly, and the returns to investment decline (Strumsky

et al. 2010; Tainter et al. n.d.). This fact calls into question whether tech-

nology and innovation can forever offset resource depletion. Population,

energy, innovation, and complexity form a nexus that has only recently

begun to be examined. Exploring these factors in combination raises

questions about whether population, affluence, and technology can be

sustained at their current levels, let alone their current trajectories.

Energy exerts a fundamental influence on the formation, growth, and

transformation of human societies. All living systems require energy inputs

for basic subsistence and for maintaining organizational and regulatory

functions commensurate with their complexity. Complex adaptive sys-

tems must further provide energy for learning and problem-solving tasks.

At scales from the individual organism to the global human network, com-

plexity provides benefits but also incurs costs. Complexity and the energy

that supports it now underpin the material, economic, and political sys-

tems that provide for the needs of more than 7 billion individuals.

Until a few centuries ago, the 2,000–2,500 kilocalories necessary for

daily human subsistence were supplied by the solar energy falling on

The American Journal of Economics and Sociology1006

earth, converted by photosynthesis into forms that people can use.

Since the Industrial Revolution, our caloric consumptionhas undergone

radical change. Energy use per individual peaked in the United States

during the mid-1970s at around 230,000 calories per day, primarily in

the form of hydrocarbon resources (Mattick et al. 2010). Over time,

people moved from meeting their energy needs by way of food and

human labor through a period where animals and fodder (and occa-

sionally water and wind power) supplemented human power, to the

present circumstances in which fossil fuels and machines provide the

majority of the heat, power, and light necessary to modern life. Organic

production still feeds us, but it, too, has come to depend on

nonrenewable resources. In the industrialized nations, 10 calories of

fossil fuels now produce one calorie of food (Giampietro and Pimentel

1993). The human population today is transformed fossil carbon.

Malthus (1798) believed that food was thelimiting resource to human

population, and, as a basic need that is non-substitutable, this holds

true. Food remains central to maintaining the well-being of individuals

and the stability of the societies they live in. There have been recent

reminders that food prices can lead to civil unrest (Lagi et al. 2011),

take global markets by surprise (Timmer 2010), and cause economic

bubbles and panics (Piesse and Thirtle 2009).

Much has changed since Malthus’s time, and it is important to under-

stand why his predictions of food and population crises have not been

realized. Were they wrong, or have they only been delayed? There is an

unresolved tension between the neo-Malthusian perspective of material

constraints, and the adaptive capacities that have thus far prevented a glob-

al crisis. The idea that human population cannot continue to grow indefi-

nitely without exceeding resource limits runs counter to the cornucopian

view that technology and innovation will forever allow us to overcome

those limits (Strumsky et al. 2010; Tainter et al. n.d.) We propose that the

conflict between neo-Malthusian and cornucopian views can be addressed

through the nexus of population, energy, innovation, and complexity.

Energy and Growth

Alfred Lotka (1922a,1922b) theorized that living systems able to capture

and use the most energy will have an evolutionary advantage. As

Population, Energy, Innovation, and Complexity 1007