1.2.3 Impact of the fossil fuel energy pulse

Helpful prior knowledge and learning objectives

Helpful prior learning:

Learning objectives:

The economy is all the human-made systems we use to transfer and transform energy and matter to meet human needs. 

The embedded economy model (Figure 1) shows the solar energy inputs into Earth's ecosystems and the flow of various forms of energy from ecosystems into society and the economy. It also shows waste heat leaving the economy and society. 

The embedded economy model

Figure 1. The embedded economy model

(Credit: Kate Raworth and Marcia Mihotich)

How do we transfer and transform energy to meet human needs?

Humans use various forms of energy to survive and do work. Our bodies use chemical energy stored in the foods we eat. When we need more energy than our bodies can provide, we take it from the external environment. 

Humans cannot use most energy forms directly, so we often transform energy to a usable form with machines. For instance, the dense chemical energy stored in coal becomes thermal energy through burning, a process known as combustion.

Everyday we use hundreds of machines either directly, like flipping an electricity switch, or indirectly, through the processes that make the things we use, like the shirt on your back. A T-shirt requires dozens of machines in various production stages , like the spinning machine that makes thread (Figure 2).

Spinning machines

Figure 2. There are many machines involved with producing a T-shirt

(Credit: Janko Ferlič CC0)

How did fossil fuels and machines bring about The Great Acceleration?

Centuries ago, all human-used energy was renewable: ships sailed with wind power, horses pulled carriages, water mills turned turbines, homes were built by human labour, and oxen ploughed fields (Figure 3).

From the mid-1800s, we replaced many renewable energy sources with nonrenewable energy sources like coal, oil, and gas. This shift to fossil fuels massively increased the amount of work we could do and increased the amount of products we could produce to meet human needs and wants during the Industrial Revolution. 

An ox and a man ploughing a field

Figure 3. Man and ox ploughing a field in China, ca.1900

(Credit: USC Digital Library CC0)

The energy pulse of fossil fuels created a reinforcing feedback loop: more energy led to more machines, increasing work and product output and energy-intensive lifestyle changes which further increased fossil fuel extraction.

Figure 4 shows this reinforcing feedback loop expressed on its own, and in a stock and flow diagram, which are explained in the Systems topic of this resource.

Figure 5 shows the increase in gross domestic product (GDP), the total value of all goods and services produced in a year, after introducing energy rich coal to the energy mix in the mid-1800s. When you look at the shape of this behaviour-over-time graph (Section S.x), can  you understand why the period from the 1950s onward is called the Great Acceleration?

Figure 5. Global GDP since 1600

(Credit: Our World in Data)

The fossil fuel energy pulse also enabled humans to overcome limiting factors to human population growth. The energy from fossil fuels enabled the production of chemical fertilisers through the Haber-Bosch process, which requires a lot of energy.  These fertilisers improved crop yields, so fewer people starved or died of malnutrition. The energy pulse also enabled advances in medicine and technologies that improved health, increasing life expectancy. 

Figure 6 shows that before 1800, the human population remained below 1 billion people. But the energy pulse from fossil fuels triggered rapid population growth. Notice how similar the population graph in Figure 6 looks to the GDP graph in Figure 5.

Figure 6. Population since 1600

(Credit: Our World in Data)

This growth, shown in both the population and GDP graphs, significantly increased demand for Earth's material resources which is discussed in the next Section 1.2.4, with negative consequences for the ecosystems on which we depend. 

Figure 7 show graphs of social and economic trends and Earth system trends over time. They all show the same ‘hockey stick’ shape of rapid growth.

Figure 7. The Great Acceleration in human activity 

and the negative impact on Earth’s systems

(Credit: International Geosphere-Biosphere Programme)

How did the Great Acceleration change our views of the economy and energy?

From the mid-1800s, cheap and abundant fossil fuels led to rapid economic growth in many parts of the world, and changed how we view the economy. Economists, businesses, and politicians started to expect economic growth every year and worked to stimulate more growth. 

The positive numbers in Figure 8 indicate a growing economy, though at different rates. The peak growth rate was 6.6% in 1964 compared to the previous year. In 2020 during the Covid-19 pandemic, there was a rare decline of -3.1%, indicating a decline in economic production compared to the previous year.

Figure 8. Global GDP growth (annual % change)

(Credit: World Bank)

Even low economic growth rates can quickly double the economy's size. Using the rule of 70, or doubling time, at the current global economic growth rate of 3%, the size of the global economy doubles in about 23 years!

Doubling time (rule of 70) in years= 70 / growth rate

70 / 3% = 23.3 years

Most people are unaware of how these growth rates impact the overall size of the economy and our use of energy and material resources. It is highly questionable whether Earth systems can support a doubling in size of the global economy by 2050.

Over time, we have become blind to our use of and dependence on energy for all this economic growth. Economic models developed during this period, many of which are still used today, did not consider energy, because it was so abundant. In addition, the use of machines in our daily life separates us from seeing or understanding energy production and consumption. For example, artificial intelligence technologies are predicted to massively increase our energy use in the coming decade, but most people are not aware of the energy impact of these new technologies.

What can we do?

SDG7 Affordable and clean energy symbol

Figure 9. UN SDG 7 aims to ensure access to affordable, reliable, sustainable and modern energy

(Credit: United Nations)

Supporting over 8 billion people with growing economies is increasingly challenging. Our use of fossil fuels and machines has boosted human health, populations, and living standards. But our consumption of energy and materials, as well as waste pollution and CO2 emissions driving climate change, threaten ecosystems.

Fossil fuels are limited and damaging, so they must be phased out of our economies. Accelerating renewable energy production, with state support, is crucial. Additionally, improving energy efficiency to use less energy for our economic output is key and will require new technologies. But there is a risk that any new efficiencies and technology will be used to simply increase GDP and energy use further, known as the rebound effect, or Jevon’s paradox. 

SDG12 Responsible consumption and production symbol

Figure 10. UN SDG 12 aims to ensure sustainable consumption and production patterns.

(Credit: United Nations)

So it is equally important that Global North countries reduce unnecessary consumption. This will reduce the need for fossil fuels, enabling renewable energy sources to provide a larger proportion of our energy needs. Reducing consumption in the Global North where human needs are largely met, leaves room for Global South countries to grow their economies to improve standards of living for the world’s poorest, a matter of environmental justice.

If you read Section 1.1.4, you already know that regenerative economies aim to meet people’s needs within Earth’s limits by being circular, distributive, caring, needs-based and sufficient, all of which can significantly reduce energy use.

Activity 1.2.3

Concept: Systems

Skills: Thinking skills (critical thinking)

Time: depends on the option

Type: Individual, pairs, group depending on option

Option 1 - Making our dependence on energy and machines visible

20 minutes

Option 2 - Actions to reduce energy use

40 minutes

The text points out that in addition to moving to renewable energy, we also need to reduce energy use. Do some quick research online about the most effective individual strategies to reduce energy use. You can also combine this information with research you might have done in Activity 1.2.2 on the energy consumption of various machines you use.

Make a list of concrete actions you and/or your family could take and use an impact-feasibility matrix to classify them. High impact means that the action will reduce energy consumption by a lot. High feasibility means that you or your family are likely to do it. Which one(s) seem the best to try out?

Option 3 - Understanding the machines involved in T-shirt production

30 minutes

These days, making something even as simple as a T-shirt involves a vast number of machines and energy.

Option 4 - Data interpretation practice

40 minutes

Examine Figure 11 below. Use a data interpretation strategy suggested by your teacher or your course to form some conclusions about the relationship between energy use per capita and GDP per capita.

If you do not have a data interpretation strategy, you could use these prompts:

Figure 11. Energy use per person vs. GDP per capita - Graph belongs with Activity Option 4

(Credit: Our World in Data)

Ideas for longer activities, deeper engagement, and projects are listed in Subtopic 1.5 Taking action

Checking for understanding

Further exploration


Blain, C., Jancovici, J. (2021). Welt Ohne Ende. Berlin: Reprodukt.

Daly, H., Farley, J. (2011). Ecological Economics (2nd ed.). Washington, D.C.: Island Press.

Hagens, N. (host). (2023, August 16). Jean-Marc Jancovici: Our Global Energy Predicament [Audio podcast episode]. In The Great Simplification. https://youtu.be/-EHCguJp9eQ.

Raworth, K. (2017). Doughnut economics: seven ways to think like a 21st century economist. London: Penguin Random House.

Stockholm Resilience Centre (n.d.). New planetary dashboard shows increasing human impact. https://www.stockholmresilience.org/research/research-news/2015-01-15-new-planetary-dashboard-shows-increasing-human-impact.html

Terminology (in order of appearance)

Link to Quizlet interactive flashcards and terminology games for Section 1.2.3 Impact of the fossil fuel energy pulse

economy: all the human-made systems that transfer and transform energy and matter to meet human needs

transfer: to move something from one place to another

transform: a change in the state, energy or chemical nature of something

energy: the ability to do work or cause change

matter: anything that takes up space and has mass

embedded economy model: an economic model showing that the economy is shaped by society and dependent on nature

ecosystem: the interaction of groups of organisms with each other and their physical environment

chemical energy: energy stored in the bonds of chemical compounds and released during chemical reactions

thermal energy: energy related to heat; it increases as things get hotter

combustion: a chemical process in which a substance reacts rapidly with oxygen and gives off heat

renewable energy: energy from sources that are continuously available or regenerate quickly

nonrenewable energy: energy from sources that cannot be regenerated in a human timescale, such as coal, natural gas and oil

fossil fuel: a non renewable energy source including coal, oil, and natural gas, formed over millions of years in the Earth's crust from decomposed plants and animals

energy pulse: the burst of energy that human economies experienced when they started to use fossil fuels

reinforcing feedback: a situation where change in a system causes further changes that amplify the original change which can lead to tipping points in a system

extraction: taking something away from somewhere else, especially using effort or force

gross domestic product (GDP): the total value of all goods and services produced in an economy in a time period

energy mix: the share of the different energy sources used

behaviour-over-time graph: a graph that shows increases or decreases in something over time

Great Acceleration: a period of dramatic increase in human economic activity and impact on the Earth's systems since the mid-20th century

limiting factor: a factor that limits a population or humans, other organisms or things

fertiliser: a chemical or natural substance added to soil or land to increase its fertility

Haber Bosch process: an energy-intensive production method for producing ammonia from nitrogen and hydrogen

crop yield: the quantity of plants grown in a period of time

economic growth: an increase in the total value of goods and services produced in a period of time

rule of 70: a formula used to determine the number of years it takes for a variable to double, by dividing the number 70 by the variable's growth rate

doubling time: the number of years it takes for a variable to double

model: simplified representations of our world used to communicate ideas, understand complex processes and make projections or predictions

abundant: when something is available in large quantities

climate change: a change in the temperature and precipitation patterns in an area, in recent times due to human economic activities

energy efficiency: the amount of energy used per unit of economic output

consumption: using resources and products to meet needs

Global North: a group of countries with high incomes and more industrialisation and service-based economies; these countries are most responsible for exceeding planetary boundaries

Global South: a group of countries with low-middle incomes and less industrialisation; most of the global population lives in these countries, but these countries bear little responsibility for exceeding planetary boundaries

environmental justice: the fair distribution amongst social groups of environmental benefits and burdens

rebound effect: a situation where efficiency gains in an input are counteracted by increased consumption and production, resulting in even greater use of the input

regenerative economy: an economic system that meets human needs in a way that strengthens social and ecological systems

circular: having the form of a circle; in this course, closing the loop on linear economic systems

distributive: when something is widely or evenly shared or divided among individuals

care: the act of providing what is necessary for the health, welfare, upkeep, and protection of someone or something

sufficient: an amount of something that is enough

impact-feasibility matrix: a tool that helps classify actions according to their impact and feasibility

energy use per capita: the energy use of a country, divided by the population

GDP per capita: the total value of all goods and services produced in an economy in a period of time, divided by the population