Engineering and technology have done wonders in improving human welfare. Infant and early childhood mortality have been significantly reduced, average life spans significantly increased, and the overall quality of most peoples’ lives are higher now than ever in the past. Just consider that in the 17th and 18th centuries the pineapple was a rare gift reserved only for royalty while now anyone can walk into a supermarket and purchase a can of pineapple for a few dollars. While a pineapple certainly is not essential to a good life, it is representative of the overall shift in quality of life that was only made possible by advancements in technology.

But these improvements in human well-being have had a cost. Pollution, waste, and climate change are all the result of technological advancement. The extraction and use of fossil fuels for electricity, heat, and transportation is the largest contributor to climate change and among the most polluting sectors of our economy. Industrial manufacturing and construction is not far behind.^[1] And these sorts of industries are only made possible due to the past innovations of engineers and the continued support of the engineering profession.

Engineering’s impact on the environment raises myriad ethical concerns. Many of these concerns relate to issues of fairness: Is it fair that some people – namely those living in wealthy industrialized nations – reap the benefits of environmental destruction while others – those living in poor and unindustrialized nations – pay the costs? Is it fair that humans have spoiled the natural environment, risking the lives of non-human animals and the existence of species, for their benefit? And is it fair that current generations effectively leverage the livelihoods of future generations for their own benefit?

And it should be noted that engineering’s contribution to environmental harms is only increasing with the rise of digital technologies. While such technologies may reduce visible pollution such as paper trash, their existence depends on highly polluting extraction activities. Silicon, lithium, and the other resources that are essential to electronic technology are all in short supply and exceedingly destructive to harvest. And, of course, all these computer systems require massive amounts of energy to run and so the segment of the economy that already most contributes to climate change is only put under more pressure.

All of this has led to increasing interest in how engineers can take seriously their responsibility to hold paramount the welfare of the public, including their ability to engage with nature and the ability of future generations – still members of the public – to live good lives. Of course such concern is not totally new as concern for the environmental impacts of development began in earnest in the 1960s (in the US at least). But increasing concern over climate change as well as greater capability for technological innovation has pushed thinking in new directions.

In this chapter, we’ll explore some ways of thinking about environmental impact and approaches engineers may take to improve their environmental consciousness and design approaches. We begin with some initial thinking about air and water pollution before turning to the contemporary focus on sustainable development.

1. “Sufficiently Clean”: Environmental Laws & Regulation

The first main wave of the environmental movement, especially as it carried over into law and regulation, focused on managing various forms of environmental pollution. The iconic images of Cleveland’s Cuyahoga River on fire in 1969 helped birth the Environmental Protection Agency (EPA) in the United States and led to a focus on “cleaning up the environment”. Many contemporary policies continue with this emphasis on an “acceptably clean environment”. Importantly, however, there is disagreement over how to interpret “acceptably clean” (or “sufficiently clean”), disagreement which has immediate effects on the interpretation and enforcement of these laws. The box below reproduces Harris, Jr., et al.’s summary and assessment of the 6 commonly discussed criteria.

2. Sustainable Development

Environmental law and regulations set minimal standards for thinking about engineering and the environment. But recall that part of what makes an occupation a profession is that its practitioners hold themselves to a higher standard than what is required by law. As such, while environmental law and regulation lags behind in its narrow focus on cleaning up and limiting pollutants, the engineering profession has moved to broader questions about the long-term sustainability of human and nonhuman life. Various engineering codes of ethics include a requirement to “adhere to principles of sustainable development”. But what exactly is sustainable development?

There exists, as one might expect, disagreement over the meaning of sustainable development and the principles that support it. But the best-known contemporary definition comes from the World Commission on Environment and Development (WCED):

Sustainable development is “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”^[3]

The WCED further identified five goals for sustainable development:

1. Economic growth
2. Fair distribution of resources to sustain economic development
3. More democratic political systems
4. Adoption of lifestyles that are more compatible with living within the planet’s ecological means
5. Population levels that are more compatible with the planet’s ecological means

Reflection on this definition and these five goals should make clear the tension that sits at the heart of sustainable development: goals 1-3 are all human-focused while goals 4 and 5 are distinctly environmental. Because sustainable development is still about development, it makes sense that it would maintain at least some of the human-centered concerns that have led to environmental issues in the first place. But we should ask: is sustainable development possible? Are goals 1-3 compatible with goals 4 and 5? Indeed, some have criticized the very notion of sustainable development on the grounds that it is an attempt to combine two incompatible ideas. We turn, in the next section, to investigate this debate and develop our thinking about sustainable development in more detail.

3. How do we Develop Sustainably?

Even once we have accepted that sustainability is a worthwhile goal and that engineers should adhere to principles of sustainable development, we are still faced with the question of how we best adhere to those principles and achieve that goal. To help us fill in the details, we can examine a contemporary debate between two competing frames for thinking about the relationship between sustainability and technology. This is the debate between Ecomodernism and Degrowth. As should become clear, one of these frames accepts the possibility of truly sustainable development while the other is skeptical.^[4]

Ecomodernism is an environmental philosophy that focuses on sustainability through forward technological innovation. Ecomodernists hold that humanity has the power to solve today’s major ecological challenges without making fundamental changes to our behavior and social structures. For the ecomodernist, economic growth is not opposed to sustainable development but rather essential to it as economic growth makes possible technological innovation that will allow us to replace older, environmentally destructive technologies with alternatives. Ecomodernists will tend to support innovations like renewable energy, genetically modified organisms, precision agriculture, and synthetic meat and oppose calls to “downsize” or “return to nature”.

The Degrowth approach takes precisely the opposite view. In contrast to ecomodernism, Degrowth theorists hold that there is an essential tension between economic growth and sustainability. Rather than focus on economic growth, Degrowth theorists emphasize establishing fair social conditions, environmental justice, and re-embedding our ‘economic metabolisms’ in the natural cycles of the biosphere – even if that means less overall growth. Degrowth theorists believe in the regenerative potential of natural environments and tend to oppose technological innovations as wasteful, unnecessary, decadent, or superfluous.

The above descriptions are brief, and of course both approaches have substantial literature and complexities behind them. Nonetheless, we can take this brief description, along with the comparison table below, as a starting point for thinking through some other elements of sustainable development.

3.1. The Jevons Paradox & “Techno-Fixes”

One central element of the disagreement between Ecomodernists and Degrowth theorists is about whether using technology to increase efficiency of resource use will, in fact, have the effect of decreasing resource consumption overall. Ecomodernists think so, but degrowth theorists will generally suggest that human ambition and avarice will just lead to more use of the resource overall. For degrowth theorists, these innovations are mere “techno-fixes” that only kick the problem down the road.

The work of English Economist William Jevons can provide insight into this disagreement. Working in England in the 19th century, Jevons observed that as coal production and use became more efficient it actually led to an increased consumption of goal, rather than a decrease. This flies in the face of standard economic thinking, which holds that supply and demand should inevitably balance out. In the case of coal use, increasing efficiency increased supply presumably to meet demand. But demand just continued to rise. Jevons Paradox, as we now call it, thus shows that when it comes to the use of (some) resources, consumption rises together with production instead of balancing out. In observing this paradox, Jevons concluded that in contrast to standard economic views of the time (and still today) technological progress does not guarantee reduced consumption.

Contemporary applications of the Jevons Paradox focus on two related concepts: Rebound effects and “techno-fixes”. The rebound effect makes sense of the Jevons Paradox: much of the time when the harvesting and use of a resource becomes more efficient it also becomes cheaper and, as a result, people are incentivized to use more of the resource. This has been seen across the globe when it comes to electricity and gasoline production. In both cases, as we have become more efficient at production we have driven costs down and, as a result, increased usage. This makes sense in standard economic models, as well, where demand is “elastic” – how much of it people want or use is at least partly a function of how much it costs. In effect, the Jevons Paradox applies to goods with substantial elastic demand but not to goods with little or no elasticity.

Techno-fix is a more recent idea that loosely builds on the Jevons Paradox and rebound effect ideas. Although there is nothing inherently problematic with “technological solutions”, the term techno-fix is typically used derisively to refer to attempts to solve a problem created by technology with more technology, only to create new and different problems (or simply not fix the ones they were aimed to fix) while simultaneously giving people the false sense of security that the problem has been solved. This sort of issue is perhaps best illustrated by recycling technology, especially plastic recycling technology. As plastics increased in use in the mid-20th century there became increasing social awareness around plastic waste. Recognizing that such concern could lead to a reduction in demand for plastics, plastic manufacturers and chemical companies (such as Dow) began pitching the idea of individuals “recycling” their plastic. However, despite proclamations from the companies, recycling was never a real solution to the issue of plastic waste – it is inefficient, overly costly, and produces substantial pollution. Nonetheless, individuals became convinced that their plastic use was not environmentally harmful so long as they recycled and the result is a world covered in plastic.

Notice the parallels between the Jevons Paradox and techno-fixes: techno-fixes hypothetically make our resource usage more efficient (for instance by creating a production loop) but the result is people feel better about the use of the resource and therefore increase their use, creating a rebound effect. Thus, while discussion of techno-fixes is not identical to the precise economic discussion of the Jevons Paradox, there is a similarity.

3.2. Life Cycle Analysis & Cradle-to-Grave Thinking

One common criticism of existing environmental law and regulation is that it thinks too narrowly about environmental impacts. By focusing almost exclusively on acceptable levels of pollution, we neglect the environmental effects of the materials or products being used, as well as the environmental effects of the manufacturing processes themselves. To broaden our focus, we can appeal to the method of Life Cycle Analysis (LCA). LCA is a type of “cradle-to-grave” thinking that aims to consider the entire life history of a product or process. This includes the extraction of raw materials from the earth, the manufacture and use, and the final disposal.

It is common for us to be overly narrow in our thinking about environmental impacts. Consider, for instance, the increasing opposition to plastic shopping bags and the concomitant rise of reusable shopping bags. Here, the main case against plastic shopping bags comes from the lack of proper disposability – it is not economically feasible to recycle plastic bags and so they end up in landfills (or on the sides of streets). In virtue of being reusable, reusable bags are seen as less of an issue in terms of disposability. However, the creation of reusable bags – be they plastic, cloth, or other – typically involves much greater resource usage and pollution than the creation of plastic bags. And reusable bags tend to have the same disposability issue, albeit further down the line. Thus, the value of an LCA can be seen in giving us a wider understanding of the issue. It may still be that, all things considered, reusable bags are preferable. And, of course, the specific materials and methods matter a lot. But the value of the LCA is in helping us see that the issue is not as cut and dry as popular discussions would have it.

It should be noted that the LCA method is not without its weaknesses, largely related to the difficulty of collecting the relevant data and of making complex comparisons. Nonetheless, the LCA method and Cradle-to-Grave thinking in general can be valuable in promoting sustainability, particularly by encouraging us to think about the environmental impact that comes before manufacturing and use as well as that which comes after.

3.3. Biomimicry & Cradle-to-Cradle Thinking

The LCA method and Cradle-to-Grave thinking are fundamentally linear: we begin with extraction of raw materials and end with disposal. A more recently developed alternative attempts to adopt the circularity of natural processes. This application of biomimicry – the emulation of natural processes in artifactual design – has been dubbed Cradle-to-Cradle Thinking.

Broadly, advocates of Cradle-to-Cradle Thinking (C2C) note that natural processes tend to be highly efficient – only using the energy they need – and that there is no waste in natural processes. Following this, advocates suggest that human beings don’t have a pollution problem but rather a design problem.^[5] Our tendency is to design only for the first use of a product, ignoring potential uses after the product breaks, crumbles, or otherwise becomes (seemingly) useless. C2C advocates William McDonough and Michael Braungart (an architect and chemist, respectively) contrast human design with an ant colony. A colony of ants will handle their waste, grow and harvest their food, build their houses out of recyclable material, and make the soil healthier than it would otherwise be. Ants don’t produce waste. McDonough and Braungart suggest, then, that “To eliminate the concept of waste means to design things—products, packaging, and systems—from the very beginning so that, at the end of a product’s useful life, the inorganic (or ‘technical’) components can be separated from the organic components, the former being ‘upcycled’ into new products and the latter being returned to the earth for reuse in the natural cycle.”^[6]

As an example of C2C thinking, McDonough and Braungart produced their book Cradle to Cradle of compostable and nontoxic materials and ink so that it could simply decompose back into the Earth without adding harmful toxins (notably, the paper is a form of plastic!).

4. Taking Environmental Responsibility Seriously

With the ever increasing threat of climate change, engineer’s will feel ever growing pressure to take their environmental responsibilities seriously. While some have proposed exercising their professional autonomy to refuse to engage in engineering practices that further climate change, others emphasize the compatibility of technological innovation and environmental stewardship. It is likely that any comprehensive approach will require a variety of outlooks, methods, and tools. It may be the case that engineers should simply cease to participate in some activities; but, equally, it is clear that the welfare of the public still depends on engineering projects and technological innovation and so what will be important is finding ways to pursue those projects in a way compatible with concern for the environment. The concepts and methods discussed in this chapter can help in finding that compatibility.