complete - Pearson | The world's learning company | Canada...290 Chapter 19 Environmental Sustainability Paul Hawken, in his book The Ecology of Commerce [3], explained sustainability

Chapter19EnvironmentalSustainability

For centuries, human societies regarded Earth’s resources as inexhaustible. Previousgenerations concerned themselves only with discovering resources and finding conve-nient locations to dump waste. It was assumed that the environment would absorb anddissipate all the human and industrial garbage, sewage, and other waste that was pro-duced. In recent years, we have come to realize that these assumptions are false (seeFigure 19.1). Our resource consumption and waste disposal are not sustainable. Thissimple fact has immense consequences for present societies and for the next generations

Figure 19.1 Billowing smokestacks were once considered signs ofprosperity, but now are recognized as evidence of waste-ful operations, health risks, and part of the cause of globalwarming. (Copyright c© De Klerk / Alamy; used with per-mission)

of engineers, who will be faced withsolving many of the resulting prob-lems. This chapter investigates thefollowing questions:

• What is sustainable develop-ment?

• How is sustainability relatedto climate change and energyconsumption?

• What do the licensing Associa-tions expect professional engi-neers to know and do aboutsustainability?

• What can individuals and engi-neers do to make our futuresustainable?

19.1 Defining sustainability

Sustainability is an old concept, summarized in the ancient proverb: “We do not inheritthe planet Earth from our ancestors; we borrow it from our children.” The basic goalof sustainability is to ensure the continuing quality of the environment. In 1987, theBrundtland Commission of the United Nations defined sustainable development in itsreport, Our Common Future:

“Sustainable development is development that meets the needs of the present,without compromising the ability of future generations to meet their ownneeds” [1].

The Brundtland Commission definition of sustainability was included in 2008 inCanada’s Federal Sustainable Development Act (FSDA) [2].

289

290 Chapter 19 Environmental Sustainability

Paul Hawken, in his book The Ecology of Commerce [3], explained sustainabilitymore simply in terms of a “golden rule,” which says, in effect, that we should take fromnature no more than what we need and leave the world better than we find it.

To achieve sustainability, we must answer two fundamental questions: What kindof planet do we want for our children, and what kind of planet can we get? The firstquestion depends on personal values leading to ethical implications, while the secondquestion is both technical and societal. Engineers, scientists, and economists can solvemany but not all of the technical problems, but society must also be willing to acceptmajor changes in lifestyle. Furthermore, society must act quickly because decisions byprevious generations have already limited what we can get.

Sustainable living and development are essential today, because the welfare of futuregenerations is threatened by two vices of the past and the present: careless disposal ofwaste and excessive consumption of resources. These are separate problems, but theyare linked because emissions from burning fossil fuels contribute to global warming andclimate change. Countries with high energy consumption generally have a large grossdomestic product (GDP) that, in turn, is linked with large amounts of emissions andwaste. For example, a large GDP typically involves manufacture of vehicles, machinery,and appliances that consume much energy when in service.

Figure 19.2 illustrates the links among GDP, energy consumption, and carbon diox-ide (CO2) emissions. These quantities are generally strongly related, as indicated by thenearly constant slopes before and after 1973. Furthermore, massive societal change ispossible with minimal effect on standard of living (GDP), as shown by the reduced slopesfor energy consumption and CO2 emissions, which indicate a massive shift to more effi-cient energy use following the 1973 Organization of Petroleum Exporting Countries(OPEC) oil embargo (also called the 1973 OPEC energy crisis). However, the 1973

1960 1970 1980 19900

20

60

100

140

180

Year

GDPEnergy consumption

CO2 emissions

Rel

ativ

eva

lues

(197

3va

lue

=10

0)

Figure 19.2 Canadian GDP, energy consumption, and CO2 emissions relative to 1973. A deliberate reduction in oildeliveries known as the OPEC oil embargo occurred in 1973 (data from Chapter 11 of [4]).

Section 19.2 An overview of sustainable thinking 291

change in energy consumption rate occurred primarily from conservation measures suchas driving smaller cars, not from improved energy conversion efficiency. The latter canactually increase total consumption, as discussed on page 306.

Understanding the link between economics and engineering achievements, such asincreased efficiencies, is critical as we strive for a sustainable future, and is part of themultidisciplinary engineering described later in this chapter.

19.2 An overview of sustainable thinking

When the Second World War ended in 1945, Canadians looked forward to an era ofpeace and prosperity. Industries that had been geared for war converted their factories toproduce appliances and vehicles. Petrochemical industries provided a selection of mag-ical new materials—plastics—made from petroleum feedstock. Agro-chemical indus-tries promised that new pesticides, herbicides, and fertilizers would bring profitability tofarms and the end of world hunger. The average person could fuel a car and heat a homeeffortlessly, using oil or natural gas drawn from massive reservoirs in the Canadian West.

A new era of electrical generation and distribution also started, as newly devel-oped nuclear generating plants were built to augment electric power produced by hydro-electric and fossil-fuel plants. Visions for the future contained utopian predictions aboutnuclear energy, such as, “It is not too much to expect that our children will enjoy intheir homes electrical energy too cheap to meter” [5]. In the 1950s, cheap electricpower was made available to almost everyone in Canada. Jet engines, which were atan early experimental stage before the war, provided easy international travel, and vaca-tions abroad became affordable. Air-conditioning units and television sets, which werevirtually non-existent in pre-war days, became common. At the same time, the worldpopulation continued to grow, from less than 1 billion people in 1800 to over 7 billiontoday. Many people aspired to a lifestyle that consumed more resources in a month thanour pre-war ancestors consumed in a year. For decades, no one saw problems with suchconsumption-oriented lifestyles.

Silent Spring, 1962 In 1962, Rachel Carson described the dangers of pesticide use in her book SilentSpring [6]. Carson, a trained biologist, was investigating why songbirds did not returnin the spring. She discovered that bird populations were dying because pesticides suchas dichloro-diphenyl-trichlorothane (DDT) were being applied indiscriminately. Car-son’s book led to recognition that indiscriminate use of agricultural chemicals can behazardous to bird, fish, animal, and human life.

The PopulationBomb, 1968

Paul Ehrlich’s book The Population Bomb predicted that population growth may even-tually outpace agricultural food supply [7]. In a later book, Ehrlich linked populationgrowth to environmental problems such as global warming, rain forest destruction, andair and water pollution [8]. Population growth is a basic challenge to sustainability,but it is an ethical and societal problem, beyond the control of engineers. However, asmembers of society, we all have a responsibility to monitor the problem and suggestsolutions.


The Limits toGrowth, 1972

In 1972, the Club of Rome, an organization concerned with the problems of humankind,published a report entitled The Limits to Growth. The report warned that uncontrolledhuman consumption had the potential to make our planet uninhabitable [9]. The reportdescribes one of the first computer simulations of the behaviour of human populations. Asimple “world model” simulated the creation or consumption of five basic elements overtime: population, capital, food, non-renewable resources, and pollution. The “standard”run, which simulated behaviour from 1972 into the future, showed industrial output percapita peaking about the year 2000, with the production of non-renewable resourcesdecreasing sharply thereafter. This computer analysis is naıve by current standards, butit is significant because it stimulated further research into global sustainability.

Gaia, 1979 James Lovelock’s book Gaia: A New Look at Life on Earth likened our planet Earth toa self-regulating living being, with abilities to adapt and heal itself, like other organ-isms [10]. Many challenged the Gaia concept on the basis that the assumed healingphenomena did not exist very clearly. However, Gaia is a good metaphor. It emphasizesthat we are the custodians of a living organism—planet Earth—and we should manageit as we would a cherished family home that we want to pass on to future generations. Ifwe damage the environment, we will regret our negligence.

The Brundtlandreport, 1987

The Brundtland Commission, charged by the United Nations with the task of respondingto growing concerns about the environment, issued a report: Our Common Future [1].The Brundtland report defined the concept of sustainable development and proposeda compromise that accepted continued industrial development provided that it did notimpair the ability of future generations to enjoy an equal level of prosperity. The reportpopularized the term “sustainable development.” It is a well-accepted concept, but def-initions still vary: to environmentalists who emphasize the word sustainable, it meansthat we must protect the environment from harmful change whereas to many others whoemphasize the word development it means that business can continue as usual.

IPCC, 1988 The World Meteorological Organization (WMO) and the United Nations EnvironmentProgramme (UNEP) established the Intergovernmental Panel on Climate Change (IPCC)in 1988. The IPCC members are scientists, experts from all over the world. Thepanel reports are comprehensive, scientific, and balanced. The IPCC does not conductresearch, but monitors research around the world and attempts to provide an objectiveopinion on climate change, its causes, its consequences, and how to reduce its effects oradapt to them. IPCC reports are essential documents for guiding discussions of globalwarming and climate change. The IPCC Fifth Assessment Report was released in 2013and is discussed later in this chapter. The IPCC is a co-recipient of the 2007 Nobel PeacePrize.

Internationalconferences: Rio,

Kyoto, Bali

Because of growing understanding of the grave consequences of climate change, a seriesof international conferences has been held to try to reach international agreement onsteps to be taken. At the “Earth Summit” in Rio in 1992, 165 nations including Canadaand the United States voluntarily agreed to reduce greenhouse gas (GHG) emissions. InKyoto in 1992, more than 80 countries agreed to reduce their emissions to an averagelevel of 5.2 % below 1990 levels by the year 2010. Canada endorsed the Kyoto protocol

Section 19.2 An overview of sustainable thinking 293

but later withdrew from the commitment. In 2007, the “Bali Road Map” set out a pro-cess for negotiating an accord to follow the Kyoto agreement. In the Bali negotiations,Canada pushed for equal responsibility for developed and developing countries alike.The success of these conferences has been mixed, but they will continue as countriesseek to deal with the long-term consequences of climate change without disadvantagingthemselves unduly in the short term.

CopenhagenSummit, 2008

The United States was not a signatory to the Kyoto Protocol, but, in December 2008,the U.S. agreed to the Copenhagen Accord. While the Accord is non-binding, Canadapledged to a target emission level reduction of 17 % in GHGs below 2005 levels of737 Mt by 2020, equivalent to 3.5 % above 1990 levels [11]. Similarly, the United Statesagreed to the same 17 % reduction target by 2020. Many of the countries most vulner-able to climate change got less than what they wanted in the Copenhagen Accord, as itcontained no firm target for limiting global temperature rise, no commitment to a legaltreaty, and no target year for peaking emissions. Later in 2010, however, governmentsagreed that emissions should be reduced so that global temperature increases are limitedto below 2 degrees Celsius [12]. Outside the Copenhagen Accord, the provinces of Que-bec, Ontario, and British Columbia announced GHG reduction targets below 1990 levelof 20 %, 15 %, and 14 %, respectively; in contrast, Alberta is expecting an 58 % increasein emissions [13].

Figure 19.3 shows emissions in relation to Canada’s Copenhagen target. The figurealso contains Canada’s intensity-based GHG emissions (Mt per $billion of GDP), show-ing a downward trend consistent with Canada’s Clean Air Act commitment presented atBali in 2007 [14].

0

500

600

700

800

Em

issi

ons

(MtC

O2

equi

vale

nt)

0

0.4

0.5

0.6

0.7

0.8

Em

issi

ons

Inte

nsity

(MtC

O2

equi

vale

ntpe

r$

billi

onof

GD

P)

1990 1995 2000 2005 2010 2015 2020Year

Emissions intensity

Emissions

Copenhagen target:17 % below 2005emissions level

Figure 19.3 Canada’s GHG emissions and emissions relative to GDP from 1990 to 2020 [14].


19.3 The process of global warming and climate change

The Industrial Revolution led to improved living conditions in the 1800s, but, at the sametime, it led to the beginning of human-induced global warming. Coal-fired steam enginesreplaced human and animal labour, making life easier. Trains, mills, and factories ran onsteam power, and billowing smokestacks were a sign of industrial activity and prosperity.The use of coal grew so rapidly that it blackened many of the buildings in the industrialtowns of central England—at the time this seemed to be a negligible effect comparedwith the benefits of steam power. However, the blackened buildings were omens ofglobal warming, a general name for a four-step sequence that begins with burning fossilfuels and ends in climate change, as follows.

Gas emission The combustion of coal, oil, natural gas, and other hydrocarbon fuels produces waste gas,mainly carbon dioxide, which is released into the atmosphere. Decaying foliage, respira-tion, and flatulence have always emitted carbon dioxide and methane, while living plantsabsorbed the carbon dioxide through photosynthesis, resulting in approximate equilib-rium, known as the carbon balance. However, after the Industrial Revolution, humanactivity began to produce more carbon dioxide than was absorbed, thereby upsetting thebalance. Figure 19.4 shows that atmospheric carbon dioxide remained nearly constantat 280 ppm (parts per million) for 2000 years until approximately 1800, when it beganto rise to current levels, crossing the threshold of 400 ppm—a value often mentioned assymbolic of increased concentrations—in May 2013 [15]. Furthermore, current atmo-spheric concentrations of carbon dioxide, methane, and nitrous oxide exceed the rangeof concentrations recorded in ice cores over the past 800 000 years [16]. The lifetime ofcarbon dioxide in the upper atmosphere (stratosphere) is many decades; consequently,the effects of past and current greenhouse gas emissions will continue for decades.

Greenhouse effect Components of the radiation from the Sun pass through the atmosphere and warm Earth’ssurface. The absorbed energy is eventually re-emitted as thermal radiation, which is

0 500 1000 1500 2000Year

0

100

200

300

400

0

500

1000

1500

2000

Carbon dioxide

Nitrous oxide

Methane

Symbolic 400 ppm CO2May 2013

Car

bon

diox

ide

(ppm

)N

itrou

sox

ide

(ppb

)

Met

hane

(ppb

)

Figure 19.4 Concentrations of important long-lived greenhouse gases over time. The units are parts per million(ppm) and parts per billion (ppb). (Data from Chapters 2 and 6 of [17])

Section 19.3 The process of global warming and climate change 295

partially blocked by carbon dioxide, methane, and other greenhouse gases in the atmo-sphere. This transparency to some types of radiation and blocking of other types is calledthe “greenhouse effect.” Figure 19.5 shows global atmospheric heat flows relative to theincoming heat from the sun, which is shown as 100 %. The atmosphere-emitted infrareddepicted in the figure shows that the greenhouse effect is actually slightly larger thanincoming solar radiation energy.

Earth’s surface

Atmosphere

Outerspace

100 %

47.4 %surfaceabsorbed

23.2 %atmosphereabsorbed

22.3 %atmospherereflected

7.1 %surfacereflected

30.6 %atmosphericprocesses

117.1%

surfaceemittedinfrared

70.3%

outgoinginfrared

100.6%

atmosphereemittedinfrared

Sun (1361 W/m2 solar flux)

Figure 19.5 Solar energy flows showing the atmosphere-emitted radiation greenhouse effect that warms Earth’satmosphere. Percentages are relative to solar radiation. (Adapted from [16, 18])

Global warming Because of the greenhouse effect, the expectation that products of combustion and otherhuman activity will continue to increase, and the long times that greenhouse gassesremain in the atmosphere, it is reasonable to expect Earth’s surface temperature toincrease over the next half century or more. There is now widespread scientific agree-ment that global warming is occurring [16], although the severity of the consequences arestill under debate. One expectation is that average global temperatures will remain aboveany seen prior to 2005 starting in 2047 (±14 years), under a “business-as-usual” assump-tion, or starting in 2069 (±18 years), assuming that emissions will be stabilized [19].

Climate change Global warming represents only a small deviation in Earth’s solar energy balance, asexplained in the following section, but it can produce dramatic climate changes, includ-ing severe storms, droughts, and floods [16].

19.3.1 The solar balance

The greenhouse effect illustrated in Figure 19.5 is essential to human life, since it cush-ions Earth from the temperature extremes that exist on planets without an atmosphere.However, small deviations in Earth’s solar energy balance can produce large effects,


leading either to global cooling, as occurs in ice ages, or to global warming. To explainthis sensitivity, an approximate model will be developed.

We shall write S for the solar flux shown in Figure 19.5 and the solar-balance modelof Figure 19.6, and RE for the radius of Earth. The total power striking the atmosphereis, therefore, S ·π R2

E, of which, from Figure 19.5, 22.3 %+7.1 % = 29.4 % is reflected.Therefore, the absorption coefficient is 1 − 0.294 = 0.706, which will be written as α.

Sun 100 %

S = 1361 W/m2 RE

29.4 % reflected

70.6 % absorbed

S · α · π R2E

(α = 0.706)

Earth

εσ T 4E · 4π R2

E emitted

Figure 19.6 The solar balance model showing power absorbed and emitted by Earth.

The solar energy absorbed by the planet is eventually converted to thermal infraredradiation emitted to outer space. The amount emitted is described by a law of physicscalled the Stefan-Boltzmann law [20], which states that the power emitted as heat froma perfectly black object per unit area is proportional to the fourth power of its Kelvintemperature; that is, the power per unit area of Earth will be εσ · T 4

E , where TE is thesurface temperature of Earth, σ is called the Boltzmann constant, and ε is a fractioncalled the emissivity factor, which accounts for Earth’s surface not being black.

Although Earth’s surface and near-surface characteristics change continuously withthe seasons, the atmosphere is in a relatively stable equilibrium, so that global averagetemperature changes little from year to year. For the purpose of developing a simpli-fied, approximate model, we shall assume that Earth’s absorbed solar energy equals thethermal energy emitted, or

S · α · (π R2E) = εσ · T 4

E · (4π R2E), (19.1)

where 4π R2E is the surface area of Earth. Solving for TE gives

TE =(

α S

4εσ

)1/4

=(

S

4σ

)1/4

α1/4ε−1/4. (19.2)

This formula can be used to investigate the sensitivity of TE to changes in absorption α

and emissivity ε, using the methods described in Section 12.2 of Chapter 12, as follows.The right-hand side of (19.2) is an algebraic term in which α has exponent 1/4 and

ε has exponent −1/4. From Section 12.2.4, these exponents are the relative sensitivitycoefficients for α and ε, respectively, so the formula for relative change in TE with respectto changes in these two variables is

ΔTE

TE� 1

4

Δα

α− 1

4

Δε

ε. (19.3)

Section 19.4 The consequences of climate change 297

To determine the relative change (Δα)/α in absorption that would produce the envi-ronmentally significant change of one degree in TE with constant emissivity (so thatΔε = 0), we solve to get (Δα)/α = 4(1 K)/TE = 1.4 %, where TE = 287.5 K. Asimilar calculation for (Δε/ε) gives −1.4 % for a 1 K change in TE, the negative signshowing that an increase in ε decreases TE.

These results show that small changes in α and ε, well within seasonal variations,can have a significant effect on Earth’s temperature. Consequently, there is concernover changes that affect α and ε, such as changes to atmospheric composition shownin Figure 19.4, land surface changes such as desertification and receding polar ice caps,and suspended cloud particles resulting from fossil fuel combustion. To understand thesignificance of a one-degree global temperature change, one need only realize that aone- to two-degree drop plunged the planet into the “Little Ice Age” of medieval history,while a five-degree drop buried North America under a glacier of ice 20 000 years agoduring the last Ice Age [21].

The previous model assumed that the emitted heat equals absorbed radiation, butother sources of energy also exist, as shown in Table 19.1. Since wind, wave, lightning,and hydro energies are driven by solar energy, it is clear that solar energy and solar-derived energies dominate any transition to a future of sustainable renewable energy.

Table 19.1 Major energy sources for Earth’s solar balance. Societal consumption includes fossil fuels and nuclearpower. (data from [22–24])

Source Power (W/m2)Fraction ofsolar input

Solar radiation 240 1Geothermal energy 0.092 1/2500Tidal energy 0.0073 1/33 000Societal consumption 0.029 1/8300

In summary, there are two key features to the solar balance shown in Figure 19.5:first, solar radiation energy dominates all other energy inputs, and second, Earth’s sur-face temperature is sensitive to small changes in atmosphere and surface absorption andreflection properties.

19.4 The consequences of climate change

The research into global warming and climate change has had detractors and skep-tics. In 2001, Bjorn Lomborg’s book The Skeptical Environmentalist challenged widelyheld conclusions from environment research and predicted a rosy life for future genera-tions [25]. The book continues to generate debate about climate change predictions.

In 2006, Al Gore, former U.S. vice-president, produced the award-winning docu-mentary film An Inconvenient Truth: A Global Warning, based on his book of similartitle. The film and book explain environmental research so that it is understandable by


the average citizen, and the key message is that global warming is a real and presentdanger to our way of life [26]. Gore was a co-recipient of the 2007 Nobel Peace Prizefor his efforts “to build up and disseminate greater knowledge about man-made climatechange, and to lay the foundations for the measures that are needed to counteract suchchange.”

19.4.1 Ending the debate about climate change

The debate about climate change effectively ended when the Intergovernmental Panelon Climate Change (IPCC) issued its comprehensive Fourth Assessment Report (AR4)in 2007 [27]. The Fifth Assessment Report (AR5) was released in parts in 2013 [16] and2014, and strengthened the evidence for climate change with substantial new data andanalysis. The IPCC reports are long and technical, but summaries are freely available inreferences [27, 28] and companion documents found on the IPCC website [29].

The IPCC reports show great certainty, based on extensive evidence, that climatechange is directly linked to global warming caused by greenhouse gases that resultmainly from human burning of fossil fuels. A few of the many IPCC conclusions aresummarized as follows:

Human cause Worldwide atmospheric concentrations of carbon dioxide, methane, and nitrous oxidehave increased markedly as a result of human activities since 1750. Current levels nowgreatly exceed pre-industrial values.

Temperature rise Global temperatures will increase by 0.3 ◦C to 4.8 ◦C by 2100 compared with the meanfrom 1986–2005 [28], depending on future fossil fuel use, technological change, eco-nomic development, and population growth in the absence of climate-control initiativessuch as the Kyoto Protocol. This expected temperature increase will not be uniform;the greatest temperature increases will be observed in the Arctic and Antarctic. Even ifgreenhouse gas concentrations are kept constant at year 2000 levels, a warming of about1 ◦C will occur in the next century as a result of GHGs already emitted. The temperaturerise may not appear to be great, but the effects are surprising.

Sea level rise Observations of the decline in ice volume around the world lead to predictions thatsea levels will rise by 26 cm to 82 cm by 2100 compared with the mean from 1986–2005 [28], a change that would produce the risk of floods in vulnerable coastal cities.Sea level predictions are less precise than those for temperature rise because of incom-plete data on the melting of the Greenland ice sheet. If the entire sheet were to melt, thesea level would rise 7 m, but that is not expected although recent observations suggestfaster melting than previously expected.

Presentobservations

Meteorologists and other scientists have observed numerous long-term climate-relatedchanges. These include changes in arctic temperature and ice, ocean salinity, wind pat-terns, and extreme weather conditions, including drought, floods, heat waves, and intensetropical cyclones. Each of the past three decades has been warmer than all the previousdecades in the instrumental record [16]. Curiously though, the observed global meansurface temperature (GMST) has shown a much smaller increasing trend over the past

Section 19.4 The consequences of climate change 299

15 years than over the past 30 to 60 years. Nevertheless, even with this pause in GMSTtrend, the most recent decade of the 2000s was still the warmest in recorded-temperaturehistory, and the pause does not change any of the conclusions that global temperaturewill rise over the next century.

Otherconsequences

The IPCC lists many possible consequences of climate change, including severe inlandflooding and drought, melting of sea ice, insect plagues, extinction of species, bleachingof corals, and possibly even major changes in ocean currents.

Feedback An important factor in the science of global warming and climate change is the effectof feedback [16, 17, 28, 30]. Feedback is studied in mathematical detail in advancedengineering courses, but it can be described roughly as the two-way interaction betweendifferent objects or quantities. The result of the interaction can be stabilizing or desta-bilizing, desirable or undesirable. Two examples of destabilizing, undesirable environ-mental feedback are the following. First, forest fires release carbon dioxide and otherGHGs into the atmosphere, leading to global warming and drier conditions in whichmore forest fires occur. As a second example, sea ice is very effective in reflecting sun-light back into space, but as the ice melts, the darker water absorbs more energy fromthe Sun, thereby causing more ice to melt.

Irreversibility A book by George Monbiot claims that if average global temperatures increase by 2 ◦C,which the book states to be probable, then vast peat bogs in the sub-arctic, presentlyunder permafrost, will begin to decay and release greenhouse gases, leading to evengreater warming that is irreversible [31].

Summary The emission of greenhouse gases is changing our environment, and unless seriousefforts are made to reduce these emissions, climate change will lower the quality oflife of future generations. The burning of fossil fuels (coal, oil, gas) is the main sourceof increasing GHGs.

19.4.2 Ethical implications of climate change

The Brundtland Commission was concerned about environmental degradation becauseit leads to poverty and economic disparities among societies. The 2007 and 2013 IPCCreports show that global warming exacerbates disparities because the economic losscaused by climate change will fall hardest on the poorest nations. This disparity raisessome very basic questions of fairness.

• Is it ethical or fair for richer countries to burn fossil fuels indiscriminately, therebycreating GHG emissions and indirectly imposing climate change on poorer coun-tries?

• Is it ethical or fair to require poor or undeveloped third-world countries to meet thesame emissions standards as Western countries, which have emitted about 20 timesas much GHG per capita for the past century?

• How will the industrialized nations respond to the millions of “climate” refugeescreated in Africa when droughts reduce crops, or in the Netherlands, Bangladesh,and the Pacific islands when sea levels rise and flood these low-lying countries?


Ethically, sustainability is simple fairness. It is unfair and unethical to harm othersthrough negligence, inefficiency, greed, or abuse. In this case, the “others” are futuregenerations, including our own children. If the present generation fails to combat globalwarming, it will cause a serious reduction in the quality of life for future generations,particularly those living in the poorer countries.

19.5 Excessive consumption and the depletion of oil and gas

Climate change is not the only serious problem affecting sustainability. Our planet’sresources are large but finite. We are consuming some resources so quickly that, withinthe lifespan of the present generation, these resources will become scarce and potentiallyvery expensive. If we cannot reduce consumption or find substitutes, our society willface serious disruption. Examples of such resources are fossil fuels (such as oil and gasbut excluding coal), fresh water, fish stocks such as the Canadian East Coast cod fishery,and various species of wildlife. How can we maintain our standard of living withoutdepriving future generations of the benefits of these resources?

Growth rates World population increased from 1.26 billion in 1850 to 6.83 billion in 2010, at an annualaverage growth rate of 1.06 %, so that the 2010 total was 542 % of the 1850 population.Figure 19.7 shows that over the same time interval, world per capita energy consumption

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Tonn

esof

oile

quiv

alen

tper

capi

ta

0

1

2

3

4

5

6

7

8

9

10

Wor

ldpo

pula

tion

(bill

ions

)

1850 1900 1950 2000Year

WoodHydro

Coal

Oil

Gas

Popu

latio

n

⎫⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎬⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎭

89%

non-

rene

wab

le

}

11%

rene

wab

le

Nuclear

Total energy consumption

894 % of 1850 energy consumption

542 % of 1850 population

Figure 19.7 Primary annual world energy consumption and population 1850 to 2010 [32–34]. A tonne of oil equiv-alent equals 42 gigajoules (GJ) or 12 megawatt-hours (MWh) of thermal energy.

Section 19.5 Excessive consumption and the depletion of oil and gas 301

grew to 894 % of the 1850 level, at an average rate of 1.36 % per year [33, 34]. Popula-tion topped 7 billion in 2012 and is expected to exceed 8 billion by 2026 [32].

Doubling time Multiplying per capita energy consumption by population yields the world’s total annualenergy consumption. Between 1850 and 2010, the total annual energy consumptionincreased by a factor of 48; that is, an astounding 4800 %. This total growth correspondsto a average annual growth rate of about 2.4 %, and if energy consumption continues togrow at this rate, total world energy consumption will double the 2010 rate of energyconsumption before 2040. Furthermore, assuming no major shift in the proportions ofenergy sources, the total amount of fossil fuels we will consume during this approxi-mately 30-year interval will equal all the fossil fuels consumed by humans in all of thepast prior to 2010! Whether or not such predictions turn out to be precisely true, theglobal warming caused by greenhouse gas emissions should be obvious from the pre-vious discussions: energy consumption will trigger irreversible climate change. Theseobservations magnify the importance of the question of how our future energy demandswill be met. To start answering this question, we first investigate whether fossil fuelproduction can meet this demand.

Peak production Natural gas and oil are the most important economic resources that are approachingtheir predicted peak production rates. These resources are fundamental to our currentlifestyle: they provide energy to refine, manufacture, and distribute the commoditiesrequired by developed societies.

Oil and gas production rates have known physical limits because the discovery,exploitation, and depletion of oil and gas wells follow known patterns. Oil productionfrom many major oil reserves around the world has already peaked, with world produc-tion of conventional crude expected to peak by 2030 or earlier [34, 35], followed by aproduction plateau before an unavoidable drop in production. Since 1984, world crudeoil production has exceeded new crude oil discoveries, as illustrated in Figure 19.8. The

Production exceedsdiscoveries(since 1984)

Conventional oil discoveries

Conventional oil production

Total oil production

1930 1950 1970 1990 2010 2030Year

10

20

30

40

50

60

0

Oil

prod

uctio

nan

ddi

scov

erie

s(b

illio

nof

barr

els

per

year

)

Figure 19.8 The growing gap between world oil production and discoveries. Total production includes oil sands andshale oil. (Data from [34])


growing disparity between conventional crude oil supply and demand is compensatedby sources such as tar sands oil, shale oil, and coal liquefaction, known as “unconven-tional” production. This growing deficit between production and discoveries is the mostimportant evidence confirming that a world oil-production peak is approaching. Thereis no doubt that oil and gas production will peak; the uncertainties are a matter of whenand of how prepared society will be.

Price-technologylimit and

energy-technologylimit

As oil and gas production shifts to unconventional sources, prices will trend up, as illus-trated in Figure 19.9, to the price-technology limit supported by markets, but there alsois a further limit. Ultimately, the extraction of oil or gas on a large scale cannot be jus-tified when, for example, the energy required to produce a barrel of oil approaches theenergy contained within a barrel of oil; this is the energy-technology limit. To gain anappreciation of the price-technology limit, consider the vast reserves of shale oil, a formof tight oil being accessed on an increasing scale through the technology of “fracking.”Fracking creates fissures in the shale, enabling trapped oil to flow. U.S. shale oil pro-duction increased six-fold between 2006 and 2013, yet a peak or plateau in productionis expected around 2020 [36]. One reason that shale oil is more expensive to producethan conventional oil is the need to continually drill many wells to maintain productionrate as individual well production rapidly drops. For example, in one of the largest shaleoil deposits in the U.S., the Bakken Formation on the northern prairies, the average wellproduction drops 69 % in the first year and 94 % after five years [37].

In summary, the price-technology limit ensures that oil and gas production peaks arecoming within many of our lifetimes.

Energyresource

Productionenergy

required

Conventionaloil and gas

Unconventional productionshale oil, tar sands, coal liquefaction . . .

Technical limitproduction energy

= recovered energy

Current price-technologylimit

Increasingproduction cost

Figure 19.9 The price-technology limit determines the oil or natural gas resources that are economical to produce inthe existing market, while the energy-technology limit establishes the dividing line between resourcesthat can provide a net energy benefit and those that take more energy to produce than they provide [34].

Reducing fossil fueldependence

We have only two choices if we want to reduce society’s dependence on fossil fuels.Both will take a long time. We can:

• decrease our energy consumption to a level that can be sustained with renewablesources such as solar, wind, and geothermal energy, or

• exploit another non-renewable energy resource such as nuclear energy, which,being non-renewable, will itself eventually peak.

Section 19.5 Excessive consumption and the depletion of oil and gas 303

Both of these choices involve great engineering challenges and opportunities, but wemust realize a critical truth: we consume enormous quantities of energy, so there is noquick fix.

Nuclear energy is the classic example of a rapidly developed energy technology.Political and military interests sped its development, with approximately 40 years elaps-ing as the technology developed from scientific feasibility to engineering feasibility,through to commercial feasibility, utility integration, and, finally, significant use, as illus-trated approximately in Figure 19.10. All other energy source technologies, includingwind and solar energy shown in the figure, have followed slower development paths.

1930 1950 1970 1990 2010 2030 2050

Sta

geof

deve

lopm

ent

Year

ScientificFeasibility

EngineeringFeasibility

CommercialFeasibility

UtilityIntegration

SignificantUse To

day

Nuclear1942

Solar(Electric)

1953

Wind

200 BCChina

1973

Figure 19.10 Development stages from scientific feasibility to significant use of three kinds of energy conversiontechnologies. Solid lines are historical paths, dashed lines are projected paths, and dotted lines arethe most rapid implementation possible based on the history of nuclear energy. (graphs based on [38])

What next? Unless there are large, rapid lifestyle changes to reduce energy use or remarkable advancesin renewable energy production, we will see increased dependence on nuclear energy andcoal for the next century.

Coal is a dirty fuel; burning coal emits greenhouse gases and other serious pollutants.However, fossil fuels will be burned extensively for years to come in order to avoid eco-nomic collapse while we search for alternative energy sources. In reference [39], Jaccardsuggests that carbon capture and sequestration (CCS) methods can allow the burning offossil fuels without releasing greenhouse gases or other pollutants to the atmosphere. Hefurther suggests that fossil fuels represent the cheapest source of clean energy for at leastthe next century. However, developing and applying the required techniques will takemany years.


19.5.1 The ethical implications of a peak in oil and gas production

Developing countries are striving to reach the standard of living enjoyed by developedcountries, and world population is increasing, so world energy consumption levels arealmost certain to increase. If we cannot move away from fossil fuels or restrain the risingconsumption, some very basic questions of fairness and personal sacrifice arise.

• Is it ethical or fair for the current generation to consume non-renewable resourcesinefficiently and thoughtlessly, thus depriving future generations who may needthese resources for survival in the midst of climate change and sharply risingprices?

• Is it ethical or fair for a government to restrict population growth? China, forexample, introduced a “one child” policy many decades ago. Is it fairer to restrictpopulation in an orderly way or to let wars, disease, and famine sort out the winnersand losers?

The ethical issues raised by reaching the peak of oil and gas production are virtuallyidentical to the ethics of climate change. As mentioned previously, sustainability issimple fairness. It is unfair and unethical to harm others through negligence, inefficiency,greed, or abuse. Obviously, we cannot accept the extreme options of wars, disease, andfamine, so we must seek orderly methods to reduce our dependence on fossil fuels,to adopt a less energy-intensive lifestyle, and to increase the availability of renewableenergy.

19.6 Guidelines for environmental practice

The most important guide for engineers is the same as the Hippocratic oath for medicaldoctors: “First, do no harm.” Engineers must be able to say “no” when environmentaldegradation is proposed. In particular, engineers have a specific obligation to followenvironmental regulations and guidelines, so that engineering projects do not make thesustainability problem worse. Environmental guidelines are published by many orga-nizations, but those published by the engineering licensing Associations are among themost relevant, since the codes of ethics of the Associations require engineers to followthem.

In Alberta, for example, the first clause in the APEGA code of ethics is that “Pro-fessional engineers, geologists, and geophysicists shall, in their areas of practice, holdparamount the health, safety and welfare of the public, and have regard for the environ-ment.” The APEGA Guideline for Environmental Practice further explains this duty.The Guideline encourages licensed professionals to be actively involved with environ-mental issues and to anticipate and prevent rather than react to environmental problems.Professionals are urged to seek a golden mean between “the two extremes of absolutepreservation and unfettered development.” One interpretation of this golden mean issustainable development. Professionals should help to formulate environmental laws, toenforce them, and to be true stewards of the environment [40]. Briefly, the Guidelinestates that professional engineers, geologists, and geophysicists should:

Section 19.7 What we can do: personal lifestyles 305

1. Understand and monitor environmental and sustainability issues,

2. Use expertise of environmental specialists when needed,

3. Apply professional and responsible judgment,

4. Ensure that environmental planning and management is integrated into all activitiesthat are likely to have any adverse effects,

5. Include the costs of environmental protection when evaluating the economic viabilityof projects,

6. Recognize the value of environmental efficiency and sustainability, consider full life-cycle assessment to determine the benefits and costs of environmental stewardship,and endeavour to implement efficient, sustainable solutions,

7. Solicit input from stakeholders in an open manner, and strive to respond to environ-mental concerns in a timely fashion,

8. Comply with regulatory requirements and endeavour to exceed or better them; dis-close information necessary to protect public safety to appropriate authorities,

9. Work actively to improve environmental understanding and sustainability practices.

The Alberta Guideline for Environmental Practice was adapted by Engineers Canada,and is now proposed as a national standard [41]. Newfoundland and Labrador, Nova Sco-tia, Ontario, Saskatchewan, and British Columbia have adopted the Engineers Canadaguideline, or have developed similar environmental guides [42, 43].

In summary, engineers have a duty to strive for efficiency, to gather informationbefore making environmental decisions, and to get the best possible advice in order toassess projects and activities for their sustainability. Although the guidelines do notclearly say so, if we are to achieve a sustainable society, engineers must also be preparedto decline to participate in projects or activities that are clearly unsustainable.

19.7 What we can do: personal lifestyles

Pursuing sustainability is important because anything less is equal to treating otherspecies and future generations unfairly. It is unfair and unethical to harm others throughnegligence, inefficiency, greed, or abuse. In addition, every code of engineering ethicsrequires us to make the health, safety, and welfare of the public our first concern (or“paramount” duty). This duty should not fall solely on engineers, although they arenormally part of the solution.

Examples of unsustainable inefficiencies abound. Our consumer society, even withrecycling regulations in place, permits the following:

• Aluminum ore (bauxite) is extracted from Earth’s crust, refined using large amountsof electrical energy, sold as aluminum foil, and discarded after a single use in thou-sands of dispersed landfill sites from which it cannot be recovered economically.

• Computers, television sets, radios, and other electronic products, manufacturedusing exotic minerals and materials, are discarded to landfill, even though they arestill functional, as newer models come onto the market.


• Jet aircraft are a serious obstacle to sustainability. No technical substitutes existfor the jet engines that propel airplanes. The carbon dioxide emitted per passengerin a transatlantic flight is approximately equal to the annual use of gasoline in anautomobile. Jet engines also emit water vapour, which has an effect similar toGHGs when emitted at high altitude. Travel of otherwise well-meaning people, forpurposes as benign as visiting relatives or tourism, is a threat to sustainability [31].

• Plastic bags are used to carry groceries, plastic blister packs encase retail productsfrom electronics to toys, and even chewing gum comes doubly wrapped. Excessivepackaging for convenience or advertising, rather than protection, is the norm.

• Automobiles consume large quantities of fossil fuels, are a major source of green-house gases, and emit other unhealthy chemicals that pollute the air. Massive sub-urbs have grown outside cities, situating adults far from work and children far fromschools. Coffee shops build drive-through lanes that accustom people to wastingenergy while waiting. Automobiles are built and advertised for speeds that are ille-gal, for accelerations that are unnecessary, and for capacities that are never filled.

Reduce, reuse,recycle

The above examples of wasteful consumption are the exact opposite of the sustainabilitystrategy in the slogan “reduce, reuse, recycle.” This practice, if followed conscientiously,is the first step to a sustainable future. For example, if we reduce our driving, heating, oruse of electricity, we immediately reduce the need for fossil fuels.

To begin envisioning the next sustainability step beyond “reduce, reuse, recycle,”consider the thinking of McDonough and Braungart in their book, Cradle to Cradle:Remaking the Way We Make Things [44]. They interpret “reduce, reuse, recycle” as anapproach that “perpetuates our current one-way, ‘cradle to grave’ manufacturing model,dating from the Industrial Revolution, that creates such fantastic amounts of waste andpollution in the first place.” In contrast, McDonough and Braungart propose a “cradle-to-cradle” principle, in which all materials used to create a product are returned to theiroriginal state, recycled to a state of readiness for reuse, or continually recycled. In effect,we discard nothing as waste in our landfills, waterways, or atmosphere. Cradle-to-cradlethinking is a challenge to designers and manufacturers, but it would be a key step towardsustainability.

The energyefficiency paradox(Jevons’ paradox)

Consider the history of the automobile, particularly the evolution of engine fuel econ-omy. Starting with the Model T Ford in 1908, design improvements led to increases inthe room, comfort, power, and fuel economy of automobiles. However, by the late 1960s,room, comfort, and power were given higher priority than fuel economy. Manufacturerswere responding to customer demand, which, in an era of inexpensive gasoline and neg-ligible government regulation, placed a low priority on fuel economy. This all changedwith the 1973 OPEC oil embargo. Fuel prices skyrocketed. Smaller, more fuel-efficientforeign vehicles took a noticeable foothold in the North American market, and a rush todesign smaller cars ensued. Fuel efficiency sold cars for a while, but, by the late 1970s,smog was of greater concern to the public. This resulted in the introduction of catalyticconverters. Catalytic converters reduce engine emissions but they also reduce fuel econ-omy, so for a time, engine designers focused on improving fuel efficiency to regain the

Section 19.8 What we can do: engineering for sustainability 307

losses from catalytic converters. Eventually, however, priorities again focused on room,comfort, and power over fuel economy, as highlighted by the 2001 milestone when thesale of light trucks—SUVs, minivans, and pickups—surpassed car sales in North Amer-ica for the first time. Because light trucks deliver lower fuel economy than cars, theUnion of Concerned Scientists observed in 2001, “With light trucks now accounting formore than half of all vehicles sold, the average new vehicle travels less [distance] ona gallon of gas than it did in 1980” [45]. With the large-scale introduction of hybridvehicles during the 2000s, average fuel economy has improved somewhat, but room,comfort, and power still dominate consumer preferences and continue to offset the ben-efits of efficiency gains.

The above history is an example of the energy efficiency paradox, also known asJevons’ Paradox [46, 47], which states that technological progress that increases effi-ciency often also results in increased energy consumption, which nullifies the benefits ofthe efficiency increase. Jevons’ paradox shows the need for societal change in additionto technological advances.

Rethink The above discussion should make it clear that the key to bringing sustainability changesto our consumer-oriented society is a re-assessment of our priorities and consumption. Inshort, we must rethink expectations and lifestyles. The sustainability mantra of “reduce,reuse, recycle” should be updated to read

Reduce, Reuse, Recycle, RETHINK.

19.8 What we can do: engineering for sustainability

Every code of ethics requires engineers to make the health, safety, and welfare of thepublic our first concern: our “paramount” duty. However, this duty should not fall solelyon engineers because they are not the problem: they are part of the solution. Waste-ful practices, accepted by society for centuries, must change. Fortunately, engineerscan assist society to make these changes by promoting energy efficiency, encouragingresearch into alternative energy sources, modelling alternatives, and showing the envi-ronmental consequences of design decisions.

Recall the two fundamental questions of sustainability: What type of planet do wewant? What type of planet can we get? Engineers have a key role to play in sustainabil-ity, because engineers have the knowledge and skills to determine what is technicallypossible. However, society must decide what it wants. Sustainability requires that ourhuge consumption-driven society must change its attitudes, laws, and way of life. This isa major disruption, and it will require debate, discussion, and courage. Engineers mustprovide feedback from our knowledge of the question “What type of planet can we get?”to help society answer “What type of planet do we want?”

Engineers rarely speak out in political and ethical debates—even in the debates aboutsustainability—but society needs engineers in these debates. The discussion below sug-gests how engineers can help society move toward sustainability.


Modelling Global climate and general circulation models (GCMs) have steadily increased in sophis-tication as new knowledge and detail have been included. A 40-year review of climatemodelling is found in reference [48].

GCMs are sophisticated tools for modelling the atmosphere and the possible effectsof climate change. These models are applicable for the sustainable design of land use,coastal structures, erosion control, buildings, and towns. All models have some uncer-tainty, of course, but uncertain predictions of temperature and climate are more usefulthan complete ignorance. The design engineer must know the capabilities and limita-tions of any model and its result. From the pyramids to the space shuttle, engineers haveused models with varying degrees of uncertainty to yield great designs. It is now time touse GCMs and other models to design for sustainability.

Life-cycle analysis Life-cycle analysis (LCA) evaluates the total environmental impact of a product fromcradle to grave or, in other words, from source material to disposal. The effects con-sidered by some LCAs, for example, are those associated with emissions of carbon,sulphur, and nitrogen oxides, and with phosphates, other chemicals, or the amount ofwater and energy consumed. Specific toxic emissions such as arsenic and lead are alsosometimes considered, and efforts have been made to include mass and economic con-siderations [49].

One application of LCA is for sustainability decision-making. Consider, for exam-ple, the choice between buying either cotton-cloth diapers or biodegradable disposablediapers for a child. Environmental impact should be a factor in the decision. An LCA forthe two alternatives may estimate the CO2 emissions and effects on water and landfillsas follows:

• Cloth: The LCA would likely start with the CO2 emissions from the fertilizer andthe tractor fuel needed to grow the cotton for the cloth diapers. The analysis wouldalso include the water and energy consumed to wash and dry the diapers repeatedlyand the small mass eventually discarded to a landfill.

• Disposable: Correspondingly, for the disposable diapers, the LCA would includethe CO2 emissions from manufacturing a much larger mass of absorbent material,the water and energy used in their manufacture and distribution, and the larger massof diapers sent to a landfill over the length of the child’s infancy.

Before an LCA comparison can be used to decide on the best environmental alter-native, a case-specific analysis is generally required, along with an understanding ofthe effects of alternatives. For example, consider the diaper choice, above. If the clothdiapers are washed in cold water and dried in the open air, they will emit less CO2, con-sume less energy, and contribute less mass to landfills, but will consume more water thanthe disposable diapers. The decision maker must then weigh the environmental-impactfactors; for example, water consumption may be more critical than CO2 emissions in adrought-stricken country.

The movement to create an international LCA standard by the International Orga-nization for Standardization (ISO) [50] is presently hampered by serious restrictions ondata and uncertainties about the correct theoretical scope. For confidentiality, cost, and

Section 19.8 What we can do: engineering for sustainability 309

image reasons, manufacturers are not willing to make the necessary LCA data publiclyavailable. In addition, defining the scope is often difficult. For example, in the cottondiaper analysis above, does one include the energy needed to produce the farmer’s food,or does one simply stop at the tractor and fertilizer energy consumed? In spite of theselimitations, LCA is evolving into a vital tool for sustainability decision-making.

Multidisciplinaryengineering and

systems thinking

Economic concerns and outdated customs are the basic reasons why society is resistingthe attack on global warming, climate change, and the depletion of our non-renewableresources. Engineers must bridge the gap between science and economics to arrive atgood solutions. Scientists attempt to understand the technical issues and economistsdevelop economic models, but it is the engineer who works in the world between thetwo, seeking technical solutions that are economically feasible. The technical–economiclink is but one example of the types of multidisciplinary links that must be exploited inorder to realize a sustainable future.

Multidisciplinary engineering requires multidisciplinary knowledge, for whichexperts in different fields collaborate. It also requires systems thinking, in which it isrecognized that apparently unrelated activities often interact significantly.

The need for multidisciplinary collaboration arises because no individual can be anexpert in all fields.

The need for systems thinking is evident in engineering design optimization: opti-mizing individual subcomponents of a system generally will not optimize the largersystem. For example, typical automotive design methods minimize fuel consumptionand emissions for standard highway and city driving, for typical cycles of acceleration,idling, and cruising. However, standard conditions exist only for a portion of real drivers.The larger system is not optimized. More importantly, optimizing the efficiency of anautomobile that will likely spend its working life transporting only one or two peopledoes not optimize the efficiency of our transportation system as a whole. We need towork toward optimizing the larger system. In brief, we need systems thinking.

The Gaia hypothesis (discussed previously) describes the world as a living organismand is a good metaphor for systems thinking [10]. However, we also need numericalevaluations to bring systems thinking into practice. Life-cycle analysis is an exampleof a systems-thinking tool that helps us to understand the environment and the effect ofhumanity on it.

Multidisciplinary engineering helps us to understand how apparently independentsystems affect one another. For example, although manufacturing, town planning, andearth science may be independent disciplines, no industry can build a factory withoutconsidering the proximity to employees, the distance and the quality of roadways linkingthe factory to raw materials and markets, the availability of water for manufacturing,and many similar factors. Engineers must seek expert advice from non-engineeringdisciplines such as environmental studies, political studies, economics, cultural studies,and psychology. New “linked” disciplines, such as industrial ecology, are beginning tomeet the need for multidisciplinary engineering knowledge and for approaches bettersuited to tackling the problem of sustainability. These linked disciplines will continueto grow.


Next steps As mentioned earlier, Jaccard [39] proposed that we use fossil fuels for many decadesto come in order to avoid economic collapse while we search for alternative energysources. If the required processes can be made to work as well as Jaccard suggests,then we can reduce greenhouse gases and other pollutants, but there is still an urgentneed to develop alternative energy sources. Jaccard’s book won the prestigious 2006Donner Prize for the top Canadian book in public policy and represents a Canadian voicedescribing how humankind can reach a sustainable future. Canada has in developmenttwo large-scale carbon capture and sequestration (CCS) projects with the expectationthat by 2015 the Shell Quest project will begin reducing the Scotford Oil Sands UpgraderCO2 emissions by 35 % [51]. Unfortunately, many other relatively modest and timelyproposals provided by Jaccard and others continue to be ignored by governments [52].

19.9 Conclusion

Ethics and justice require humanity to share equally the burdens of climate change andthe decline of oil production. Although they are different problems, their main causeis the same: excessive consumption of fossil fuels. To maintain our standard of living,we must drastically reduce our dependence on fossil fuels and rapidly move to otherenergy sources. Unfortunately, few people are prepared to deny themselves what theysee as their entitled standard of living. Society must develop the strength to change theseoutdated customs and habits and to pass the legislation needed to achieve sustainability.

As engineers, we have a key role in the move toward sustainability. We must ensurethat our projects and activities achieve maximum efficiency in terms of the energy, mate-rials, and labour consumed. However, efficiency improvements alone will not be enoughto avoid the crises of climate change and the peak of oil production. We must apply sus-tainability concepts to our everyday work, and we must try to lead within our spheres ofinfluence. We need not be martyrs in the fight for sustainability, but for ethical reasons,we should avoid projects or activities that clearly lead to an unsustainable future.

Research, innovation, and new ideas are essential. We must work together to imag-ine, innovate, invent, and create a sustainable future. Fortunately, today’s engineeringstudents live in a world of unparalleled opportunity. The information revolution is stillin its early stages, and it will continue to multiply our strength and intelligence.

Sustainability is the greatest challenge ever presented to engineers. If engineers canhelp society evolve to a high but sustainable standard of living without the predictedproblems of unrest, deprivation, and suffering, it will be our greatest accomplishment.

19.10 Further study

Quick quiz 1 Choose the best answer for each of the following questions.

(a) In 1987, the Brundtland Commission wrote a report that

i. was made into a very popular motion picture.

ii. defined sustainable development in a meaningful way.

Section 19.10 Further study 311

iii. was skeptical about the need for sustainable development.

iv. defined sustainability as an economic golden rule.

(b) Sustainable development is defined as development that

i. is achieved by voluntary effort.

ii. maximizes progress, growth, expansion, and consumption.

iii. does not reduce the ability of future generations to meet their needs.

iv. makes a continuously increasing profit.

(c) Global warming is caused by greenhouse gases (GHGs) that trap heat radiated awayfrom the surface of the planet. The GHGs are emitted by the

i. release of chlorofluorocarbon refrigeration gases.

ii. burning of coal, oil, and wood for heating homes.

iii. combustion of gasoline in automobiles.

iv. all of the above.

(d) Global warming is important because it will

i. lead to climate change, causing storms and floods.

ii. raise global temperatures and cause the extinction of many species.

iii. lead to climate change, causing droughts, agricultural losses, and starvation.

iv. all of the above

(e) The debate over global warming effectively ended

i. in 2001, when Bjorn Lomborg wrote a book about global warming.

ii. in 2006, when Al Gore made a movie about global warming.

iii. in 2007, when the IPCC linked global warming to wasteful energy use.

iv. in 2007, when Canada set intensity-based emission standards.

(f) The efficiency paradox refers to the common observation that

i. improved efficiency can be expected to reduce total energy consumption.

ii. consumer demands for bigger, more powerful products always defeat any effi-ciency improvements.

iii. efficiency improvements cannot be expected to reduce energy consumption.

iv. designers will not improve engine efficiency without government regulation.

(g) A constant, positive energy-consumption growth rate

i. is necessary for sustainability.

ii. increases energy consumption linearly.

iii. increases energy consumption exponentially.

iv. is necessary to maintain a healthy economy.

(h) To have any significant impact on meeting our modern society’s overall energydemand, a newly proven, scientifically feasible renewable-energy technology willrequire at the absolute minimum


i. 20 years.ii. 40 years.

iii. 50 years.iv. 60 years.

(i) The best way for an engineer to work towards a sustainable future is to

i. refuse to work for an oil company.ii. assist clients and employers to achieve whatever they want.

iii. satisfy environmental guidelines and government regulations.iv. assist clients, employers, and society to understand the full impact of their engi-

neering projects on the environment.

(j) Life cycle analysis (LCA)

i. extends a product’s useful life.ii. calculates a product’s life expectancy using fatigue analysis.

iii. evaluates the total environmental impact of a product from cradle to grave.iv. evaluates the total impact of the environment on the product.

2 Develop a life-cycle analysis (LCA) for a car. First, decide on the metrics you willconsider, such as CO2 emissions and energy consumption. Second, consider the LCAboundary. For example, will you or will you not consider the CO2 emissions fromthe mine that extracted the iron ore used to produce the steel in the car? Third, drawa diagram showing the connections among all the elements that go into producing acar and contributing to your LCA metrics calculations. Next, attempt to quantify anLCA-determined environmental impact from a car by using the Greenhouse Gases, Reg-ulated Emissions, and Energy Use in Transportation (GREET) software available fromArgonne National Laboratories at http://greet.es.anl.gov/. Finally, discuss the environ-ment impacts associated with a car.

3 Translate the energy consumption of Canadians into practical terms that would be betterappreciated by the public. Today, Canadians consume energy at a rate of 13.5 kW perperson. Convert this rate into units of 60 W light bulbs per person and 4.5-horsepowerlawnmowers per person. Document how an average Canadian consumes at this rate.What can be done to reduce Canadian energy consumption?

4 Consider a global warming situation in which Earth’s temperature increases 2 ◦C over thenext century. Further assume that the temperature increase is the same everywhere. Tak-ing the average temperature gradient between the equator and the North pole as 30 ◦C,and assuming that the boreal forest-tundra tree-line boundary is currently at a latitude of60◦ North, determine how fast the tree line must move north in order to remain at thesame temperature isotherm. Express your answer in m/day and m/year. Given that theboreal forest is an important global converter of carbon dioxide to oxygen, what are theimplications and challenges of global warming on the boreal forest? Would your answerdiffer if the global warming temperature increase was 1/2 ◦C or 4 ◦C?

Section 19.11 References 313

19.11 References

[1] World Commission on Environment and Development, Our Common Future. NewYork: Oxford, 1987. Brundtland Report, http://www.un-documents.net/wced-ocf.htm (October 30, 2013).

[2] Government of Canada, Federal Sustainable Development Act. Ottawa, ON: Min-ister of Justice, 2013. http://laws-lois.justice.gc.ca/PDF/F-8.6.pdf (November 11,2013).

[3] P. Hawken, The Ecology of Commerce: A Declaration of Sustainability. New York:HarperBusiness, 1993.

[4] Ministry of the Environment, The State of Canada’s Environment. Ottawa: Envi-ronment Canada, 1996.

[5] L. L. Strauss, “Speech to the National Association of Science Writers, New YorkCity,” The New York Times, September 17, 1954.

[6] R. Carson, Silent Spring. Boston: Houghton Mifflin, 1962.

[7] P. R. Ehrlich, The Population Bomb. New York: Ballantine Books, 1968.

[8] P. R. Ehrlich and A. Ehrlich, The Population Explosion. Toronto: Simon and Schus-ter, 1990.

[9] D. H. Meadows, D. E. Meadows, J. Randers, and W. W. Behrens, Limits to Growth:A Report for the Club of Rome’s Project on the Predicament of Mankind. NewYork: Universe Books, 1972.

[10] J. Lovelock, Gaia: A New Look at Life on Earth. New York: Oxford, 1987.

[11] Government of Canada, United Nations Framework Convention on ClimateChange (UNFCCC). Ottawa, ON: Environment Canada, 2010. http://www.climatechange.gc.ca/default.asp?lang=En&n=D6B3FF2B-1 (November 12,2013).

[12] United Nations, Background on the UNFCCC: The International Response to Cli-mate Change. New York: United Nations, 2013. http://www.climatechange.gc.ca/default.asp?lang=En&n=D6B3FF2B-1 (November 12, 2013).

[13] Toronto Star, “Canada inactive on climate front,” December 7, 2009. Edi-torial. http://www.thestar.com/opinion/editorials/2009/12/07/canada inactive onclimate front.html (February 27, 2014).

[14] Government of Canada, Greenhouse Gas Emissions Data. Ottawa, ON: Environ-ment Canada, 2013. http://www.ec.gc.ca/indicateurs-indicators/default.asp?lang=en&n=BFB1B398-1#ghg1 (November 12, 2013).

[15] M. McGrath, “Concentrations of warming gases break record,” 2013. BBC News,November 6, 2013, http://www.bbc.co.uk/news/science-environment-24833148(November 18, 2013).

[16] T. F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung,A. Nauels, Y. Xia, V. Bex, and P. M. Midgley, eds., Climate Change 2013: The


Physical Science Basis. Contribution of Working Group I to the Fifth AssessmentReport of the Intergovernmental Panel on Climate Change. New York: CambridgeUniversity Press, 2013. http://www.climatechange2013.org/report/review-drafts/(November 18, 2013).

[17] International Panel for Climate Change, “Summary for policymakers,” in ClimateChange 2007: The Physical Science Basis. Contribution of Working Group I tothe Fourth Assessment Report of the Intergovernmental Panel on Climate Change(S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor,and H. L. Miller, eds.), New York: Cambridge University Press, 2007. http://www.ipcc.ch/publications and data/ar4/wg1/en/spm.html (October 30, 2013).

[18] M. Wild, D. Folini, C. Schar, N. Loeb, E. G. Dutton, and G. Konig-Langlo, “Theglobal energy balance from a surface perspective,” Climate Dynamics, vol. 40,pp. 3107–3134, 2013.

[19] C. Mora, A. G. Frazier, R. J. Longman, R. S. Dacks, M. M. Walton, E. J. Tong,J. J. Sanchez, L. R. Kaiser, Y. O. Stender, J. M. Anderson, C. M. Ambrosino,I. Fernandez-Silva, L. M. Giuseffi, and T. W. Giambelluca, “The projected timingof climate departure from recent variability,” Nature, vol. 502, pp. 183–187, 2013.

[20] F. Incropera, D. Dewitt, T. Bergman, and A. Lavine, Fundamentals of Heat andMass Transfer. New York: Wiley, sixth ed., 2007.

[21] J. S. Trefil, Human Nature: A Blueprint for Managing the Earth—by People, forPeople. New York: Holt Paperbacks, 2005.

[22] J. H. Davies and D. R. Davies, “Earth’s surface heat flux,” Solid Earth, vol. 1,pp. 5–24, 2010.

[23] W. Munka, “Abyssal recipes II: Energetics of tidal and wind mixing,” Deep SeaResearch Part I: Oceanographic Research Papers, vol. 45, no. 12, 1998.

[24] A. M. Makarieva, V. G. Gorshkov, and B.-L. Li, “Energy budget of the biosphereand civilization: Rethinking environmental security of global renewable and non-renewable resources,” Ecological Complexity, pp. 281–288, 2008.

[25] B. Lomborg, The Skeptical Environmentalist: Measuring the Real State of theWorld. New York: Cambridge University Press, 2001.

[26] A. Gore, An Inconvenient Truth: The Planetary Emergency of Global Warming andWhat We Can Do About It. Emmaus, PA: Rodale Press, 2006.

[27] International Panel for Climate Change, “Summary for policymakers,” in ClimateChange 2007: Synthesis Report (B. P. Jallow, L. Kajfez-Bogataj, R. Bojariu,D. Hawkins, S. Diaz, H. Lee, A. Allali, I. Elgizouli, D. Wratt, O. Hohmeyer,D. Griggs, and N. Leary, eds.), New York: Cambridge University Press, 2007. http://www.ipcc.ch/publications and data/ar4/syr/en/main.html (October 30, 2013).

[28] International Panel for Climate Change, “Summary for policymakers,” in ClimateChange 2013: The Physical Science Basis. Contribution of Working Group I tothe Fifth Assessment Report of the Intergovernmental Panel on Climate Change

Section 19.11 References 315

(T. F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung,A. Nauels, Y. Xia, V. Bex, and P. M. Midgley, eds.), New York: CambridgeUniversity Press, 2013. http://www.climatechange2013.org/report/review-drafts/(November 19, 2013).

[29] IPCC Secretariat, Intergovernmental Panel on Climate Change. Geneva: IPCC,2014. http://www.ipcc.ch (April 2, 2014).

[30] K. Knauer, ed., Global Warming. New York: Time Books, 2007.

[31] G. Monbiot, Heat: How to Stop the Planet from Burning. Toronto: Random HouseAnchor Canada, 2007.

[32] United States Census Bureau, International Programs Data, World PopulationSummary. Washington: U. S. Department of Commerce, 2013. http://www.census.gov/population/international/data/ (November 25, 2013).

[33] BP International, Statistical Review 1951–2011: Statistical Review of WorldEnergy. London: BP p.l.c., 2013. http://www.bp.com/en/global/corporate/about-bp/statistical-review-of-world-energy-2013/statistical-review-1951-2011.html (November 25, 2013).

[34] J. D. Hughes, The Energy Sustainability Dilemma: Powering the Future in a FiniteWorld. Ithaca, NY: Global Sustainability Research Inc., 2012. Howarth-MarinoLab Group, Cornell University, http://www.eeb.cornell.edu/howarth/HUGHES%20Cornell%20Ithaca%20May%202%202012.pdf (November 25, 2013).

[35] E. Wærness, Energy Perspectives: Long-term Macro and Market Outlook.Stavanger, Norway: MPR Strategy and Business Development in Stat-oil, 2013. http://www.statoil.com/en/NewsAndMedia/News/EnergyPerspectives/Downloads/Energy%20Perspectives%202013.pdf (November 27, 2013).

[36] A. Sieminski, “Outlook for shale gas and tight oil development in the U.S.,” inDeloitte Energy Conference, (Washington, DC), U.S. Energy Information Admin-istration, 2013. http://www.eia.gov/pressroom/presentations/sieminski 05212013.pdf (November 27, 2013).

[37] J. D. Hughes, Drill, Baby, Drill: Can Unconventional Fuels Usher In an Era ofEnergy Abundance? Santa Rosa, CA: Post Carbon Institute, 2013.

[38] Nero and Associates, “Technology assessment of national hydroelectric powerdevelopment,” 1981. US Army Engineer Contract DACW72-81-C-0001.

[39] M. Jaccard, Sustainable Fossil Fuels: The Unusual Suspect in the Quest for Cleanand Enduring Energy. New York: Cambridge University Press, 2006.

[40] The Association of Professional Engineers, Geologists and Geophysicists ofAlberta, Guideline for Environmental Practice. Edmonton, AB: APEGA,2004. http://www.apega.ca/pdf/Guidelines/EnvironmentalPractice.pdf (Febru-ary 27, 2014). Guideline list on page 305 adapted with permission.

[41] Canadian Engineering Qualifications Board, National Guideline on Envi-ronment and Sustainability. Ottawa, ON: Engineers Canada, 2006.


http://www.engineerscanada.ca/sites/default/files/guideline enviro with.pdf(November 7, 2013).

[42] L. Thorstad, C. Gale, H. Harris, J. Haythorne, and P. Jones, Guidelines for Sus-tainablility. Vancouver BC: The Associaton of Professional Engineers and Geosci-entists of British Columbia, 1995. http://security.apeg.bc.ca/ppractice/documents/ppguidelines/guides sustainability.pdf (October 30, 2013).

[43] Professional Engineers Ontario, PEO By-Law No. 1. Toronto: ProfessionalEngeers Ontario, 2012. http://peo.on.ca/index.php/ci id/22127/la id/1.htm (Octo-ber 30, 2013).

[44] W. McDonough and M. Braungart, Cradle to Cradle: Remaking the Way We MakeThings. New York: North Point Press, 2002.

[45] Union of Concerned Scientists, “Sales of SUVs, minivans, and pickups surpasscars for first time,” Cambridge, MA, 2008.

[46] B. Alcott, “Jevons’ paradox,” Ecological Econimics, vol. 54, no. 1, pp. 9–21, 2005.

[47] W. S. Jevons, The Coal Question: An Inquiry Concerning the Progress of theNation, and the Probable Exhaustion of Our Coal-Mines. London: Macmillan& Company, 1865.

[48] K. McGuffie and A. Henderson-Sellers, “Forty years of numerical climate mod-elling,” International Journal of Climatology, vol. 21, pp. 1067–1109, 2001.

[49] M. Raynolds, M. D. Checkel, and R. A. Fraser, “The relative mass-energy-economic (RMEE) method for system boundary selection—a means to system-atically and quantitatively select LCA boundaries,” International Journal of LifeCycle Assessment, vol. 5, no. 1, pp. 37–46, 2000.

[50] S. L. Jackson, The ISO 14001 Implementation Guide: Creating an Integrated Man-agement System. Toronto, ON: John Wiley & Sons, Inc., 1997.

[51] Government of Canada, “Oil sands—A strategic resource for Canada, North Amer-ica and the global market: Land use and reclamation,” in Report of the AuditorGeneral, Natural Resources Canada, 2011. http://publications.gc.ca/collections/collection 2011/rncan-nrcan/M164-4-7-1-2011-eng.pdf (November 28, 2013).

[52] J. Simpson, “Who will rid us of this troublesome GST cut?” The Globe and Mail,December 27, 2007.

Documents

complete - Pearson | The world's learning company | Canada...290 Chapter 19 Environmental Sustainability Paul Hawken, in his book The Ecology of Commerce [3], explained sustainability