Energy Demand and Sources

The following section looks at human uses of energy to enhance lives. Since energy has been central to human existence and development from prehistory to the present, understanding the evolution of the production and consumption of energy is essential in making balanced energy choices which will impact upon our lives today and for many decades to come.

The compelling motion picture 2001: A Space Odyssey begins with a dramatization of how man differentiated himself from other animals early on; namely, in the understanding of tools — the use of a club to aid in combat and the harnessing of fire. Over a long stretch of history, advancements in technology and the sources of energy to support it have contributed to economic development. Such development has also been redirected by changes in technology or available energy. An example from the 16th century is the once-thriving iron-making industry in England. Shortages of wood eventually restricted its capacity to make charcoal, causing the industry to shift from England, first to Ireland and later to Scotland, in order to access abundant supplies of wood. Later still, in the 19th century, charcoal succumbed to coal, and in the 20th century coal has faced significant displacement from many of its uses by oil. Today, oil is under pressure from natural gas.

Many hope and believe that renewable sources of energy will soon largely displace fossil fuels which, when combusted, release carbon into the atmosphere. Due to the effects excess carbon may have on the planet, society no longer views this practice as acceptable. It is recognized that it would take significant policy stimulus through subsidies to fully embrace renewable sources of energy. The long-term energy future may well lie in potentially clean hydrogen-based technology, but currently it costs more energy to produce than it provides. And many believe that nuclear fusion — safe, limitless, and clean — will eventually make a major contribution to energy supplies, although technology is not likely to reveal a path to it for many decades, if not longer.

And so it goes. Looking back on these changes it is possible to see what led to them and to trace their impact. But looking forward is a different matter. Forecasting is recognized as a sometimes necessary, always difficult, activity that is most useful as a way to discuss possibilities.

Interaction of the Economy and Energy

From an economic viewpoint, energy is one among many factors necessary to produce goods and services. Human labour, raw materials, and productive machinery are other factors of production. Technological advancement has been important in allowing us to use energy more effectively to get what we want. Access to energy is vital in enabling technology to play its role. It has been a very friendly circle, indeed. In primitive societies, oxen pulled simple tools to assist in agriculture. Today, one person in a single modern tractor — sitting in air-conditioned comfort with music on the CD or MP3 player — can do the work of hundreds of oxen and people.

The world is not, however, a single community where everyone benefits from such progress. Those in developed economies have access to the fruits of scientific and organizational advances. But there are many developing countries in the world today that for various reasons have not matched the technological evolution of the developed world and who do not, as yet, share in the resulting bounty. Developing countries for the most part hold the view that they have the same right as developed countries to use fossil fuels, and they will not forego prosperity because developed societies now see the combustion of fossil fuels and the release of carbon as a negative. In these developing countries, less access to energy is common.

One-third of the world’s population, some two billion people, do not have access to electricity in their homes. While there are slow but continuing improvements, one of the challenges of the modern world continues to be how to enhance the lives of the less fortunate. Nonetheless, even developing populations have seen some benefits from technological progress. For lucky residents of the developed world, many tasks are now simpler and work has altered in nature because of technological advancements and the availability of usable energy, which in turn has made life easier, longer, and more comfortable for those with access.

A simple economy: no contraints
A simple economy: no constraints.

The preceding discussion glosses over the complexities of the relationships involved even in one region or country, let alone the entire world. The following figure is a much-simplified model of economic activity which sets out the broad relationships, omitting the details of the interactions.

Unfortunately, the global picture now has been complicated by an inevitable development: accumulating waste products. Over the course of history, the Earth and its environment have been providers of good things, such as fertile land, energy resources, water, and air, as well as receptors for the residual waste of human activities. This simplified picture must add another element, the capacity of the environment to absorb the residue of human activity in the form of solid, liquid and gaseous waste products.

A Simple Economy: Limited Waste Absorption Capacity
A simple economy:
Limited waste absorption capacity.

The capacity of the Earth to adapt to the results of ever-growing human activity is not infinite. The figure above illustrates a simple economy that has some limits on what it can absorb from the activities it induces. The smokestack stands in for all the sources of solid, liquid, and gaseous waste that are the by-products of modern economies. For most of human history, these limits were effectively non-existent, since our activities were small relative to the capacity of the biosphere. Today, there is increasing concern for future generations about the implications of continuing our ways of doing things. Although solid waste in all its forms, from metals to electronics to plastics, is a growing problem in most regions, gas emissions, in particular greenhouse gases (GHGs), are the more worrisome global issue. This worry stems from the concern that GHGs accumulating in our atmosphere will eventually, through the greenhouse effect, increase the average temperature of the Earth. That increase in temperature will in turn melt the polar icecaps; raise the level of the oceans, submerging some coastal areas, and have an unpredictable impact on both short-term weather extremes and the long-term climate.

Climate Change

ice caps
Melting sea ice is the result of climate change.

To use a heroic simplification, there are two opposing points of view on the issue of climate change. One group believes that in the worst case, these changes could make our world uninhabitable. Therefore, we should take rapid and strong action to reverse the trend. This includes individual and national initiatives to reduce our use of energy now — even at some significant economic cost — decreasing current emissions while we seek effective and permanent solutions.

Polar bear
Climate change affects such species as polar bears which rely on sea ice to hunt, breed, and den.

Others point to our limited understanding of global climate, and question whether there is an imminent danger. They argue that reducing energy use decreases economic activity and has a high cost in terms of forgone investment in technology. Reduced investment in technology limits our ability to respond effectively to climate issues. This group believes it is important to avoid unnecessary reductions in economic activity and that we must look to technological development to solve the greater part of the problem. We need to achieve a delicate balance in our response.

A related problem is the prospect that efforts on the climate change front in the developed world may be completely offset by activity in the developing world, where there is reluctance to forgo economic growth while they are still so far behind. That is, in fact, another pressing issue with respect to the global management of resources: equity among nations.

The global outlook for energy depends on a number of factors, including population growth, economic development, environmental limits, and all of the things that affect them. There is a natural and obvious distinction between developing and industrialized countries that must be recognized when considering how strongly disparate regions will differ, as will the resulting implications for energy use.

World Population and Human Development

World population is projected to increase by some 2.5 billion people, from its current level of 7.2 billion in 2014, by the middle of the 21st century. Since almost all of the increase will be concentrated in developing countries — thirsty for energy — energy demand will grow even faster. Although modern economies are critically dependent on a reliable and affordable supply of energy, roughly 2 billion people currently do not have access to electricity in daily living. The developing world is not likely to accept limitations on either the form or the quantity of energy it uses prior to reaching a standard of living commensurate with other countries. That means international demand for reliable energy supplies will increase over the foreseeable future.

In the graph below we see historical data for population growth and forecasts based on estimates from the United Nations. In 2000, the world’s population was estimated at a little over 6 billion people. Under all forecasts, population is growing. The range of forecasts is substantial, from approximately 7.8 to 10.8 billion people by 2050.

world population
World Population, 1950 – 2050 (billions).

The major sources of uncertainty in population forecasts are assumptions regarding fertility rates, which are defined as the average number of children born per woman. A total fertility rate of 2.1 is needed to replace current populations. Current estimates indicate that in many developed countries the total fertility rate is now significantly below this level.

Estimates also indicate an unprecedented decline in fertility even in some developing nations. This largely unexpected decrease has led to the lowering of population forecasts.

In the graph below we see the relationship between an index of human development and estimated total fertility rates in the periods 1970–1975 and 2000–2005. The United Nations Development Programme defines this index as a combined energy average achievement by country in longevity, knowledge, and standard of living. This graph shows a clear decline in estimated total fertility rates from the period 1970–1975 to 2000–2005, particularly among the countries near the middle in terms of Human Development Index rank.

total fertility
Total Fertility Rate and Human Development Index.

The graph also demonstrates that even though fertility rates have declined significantly, large differences still persist between the most developed and least developed nations. The total fertility rate for Canada is estimated to be 1.5, indicating that without continued immigration Canada’s population would likely begin to decline. For the US estimated total fertility is 2.0, indicating that without immigration the total population would remain relatively stable. Overall, the UN expects that by 2050 population in Canada will have risen from approximately 32.6 million to 42.8 million. The US population is expected to rise from 301 million people to 402 million people by 2050.

World Energy Sources will introduce you to the world of energy, how electricity generation works and how each source impacts upon the environment.


“World Energy: The Past and Possible Futures” pp 20-22,