The concept of sustainability has been around for a long time. It is almost a generation since the Brundtland Commission released its 1987 report entitled Our Common Future1, a call to the world to start balancing the competing demands of economic development and environmental protection, leading to development that “meets the needs of the present without compromising the ability of future generations to meet their needs.”

Since then, the concept of sustainable development has been adopted, co-opted and at times abused by literally thousands of governments and organisations around the globe. Nevertheless, over the last thirty years a global consensus has emerged around the central themes of sustainability. Most people now hold as a basic principle that the health of our natural environment is vitally important to our own well-being and prosperity, and that we should conduct ourselves in a way that allows our descendants to live at least as well as we have.

Sustainability’s tangible impact

Unfortunately, however, this widespread awakening to the basic tenets of sustainability has not been reflected in action. On a planetary scale, the last thirty years have seen environmental degradation and natural resource depletion on an unprecedented scale2,3,4. By every measure, the health of the planet has declined considerably during this period; a decline that has in fact been accelerating over the last decade5. The emerging evidence of earlier-than-predicted impacts of climate change on the Earth system is exacerbating the situation6,7,8. It is clear that sustainability as a concept has largely failed to have a perceptible impact on our behaviour, our decision-making, or on the health of the planet we inhabit.

How could such a seemingly powerful and self-evident set of principles, widely held, have achieved so little, over the last generation? Why has sustainability not found its way into our decision-making systems, particularly in engineering design and project delivery? Even though the majority understands that our future well-being and prosperity requires that we protect our environment and halt the ravages of climate change, we continue with business-as-usual.

19th century economics

A large part of the reason that ‘business-as-usual’ has not been affected by the principles of sustainability can be traced back to the origins of our economic system, deep in the 19th century. Adam Smith’s 1776 treatise The Wealth of Nations enshrined in modern economic thought the concept of the competitive free market’s ‘invisible hand’. The value of goods and services was linked explicitly to the labour input required to produce them. At that time in history, we were few and the world was vast, almost limitless it seemed. We could literally take whatever we required from the land and the seas, and there was always more. We could discharge our wastes with near impunity, such was the absorptive capacity of nature. And so the economic system that developed placed no value on any of these ‘external’ assets. The cost of water was the cost required to obtain it. The value of a forest was nil until it was harvested and sold as lumber. Ecosystems were ascribed no value in our accounts, until someone converted them into products for human use. Two hundred years ago, this worked, because there was always enough of everything, always more water, wood, fuel, space, air and fish.

But clearly the world has changed considerably since Adam Smith’s time. We are now six billion, and we will be over nine billion by 20509. More people with greater demands are putting tremendous pressure on natural resources and ecosystems worldwide. Costs for resources of all types, from oil to coal, from food to water, are rising rapidly now all over the world – a direct consequence of rising demand and dwindling supply. But our economic and decision-making systems have not kept up – they remain firmly rooted in centuries’ old ignorance of the value of the natural world that sustains us. Decisions at all levels are still based largely on net present value and internal rate of return expectations that do not include any accounting for the value of natural assets damaged, lost, or used in the process.

What results is a global realisation of the ‘tragedy of the commons,’ a concept tracing its origins back to Aristotle, but popularised by Garrett Hardin in 1968. The concept suggests that when there is free, unrestricted access to and demand for a common resource, such as the bounty of the oceans or the assimilative capacity of the atmosphere, that resource is structurally doomed to collapse through over-exploitation. In essence, with the lack of a price signal that limits demand and access, common assets are used until they disappear. Jared Diamond’s book Collapse describes such an episode on Easter Island that essentially wiped out the civilisation there. The planet as a whole is now on the edge of a global version of the tragedy of the commons.

20th century engineering

The other factor that stands in the way of more sustainable engineering design and project delivery is the tendency to stick with what has worked – ‘business-as-usual.’ Engineers are inherently a conservative fraternity, necessarily guided by convention and established codes of practice. This approach protects against sub-standard and dangerous designs, and assures quality in the delivery of engineering projects, from civil infrastructure to the construction of passenger aircraft. However, the vast majority of current standards were developed in the 20th century, when energy prices were fundamentally stable, water was free, waste could be freely discharged (dilution was the solution to pollution) and the major emerging concerns of global change including the need to dramatically and quickly reduce carbon emissions, did not exist.

Engineering, like economics, needs to adapt to a new reality – a reality described by the sustainability imperative. Project specifications need to begin to take wider energy, carbon, water, biodiversity and community issues into explicit consideration. Changing the specifications allows engineers and designers to bring their creative talents to bear, to find better ways of doing just about everything.

21st century project delivery

Moving towards greater sustainability in engineering design and project delivery requires that economics and engineering evolve to deal with the realities of the 21st century. The fundamental economic analysis that governs decision-making explicitly takes environmental and social sustainability into account, by monetising project impacts on external assets and integrating them into the project economics. By doing this, projects can be designed from the outset to maximise profit, overall human welfare, and a multitude of other competing environmental and social issues10,11. Organisations can do this now, using systems such as WorleyParsons EcoNomicsTM Assessment and the elta© suite of economic evaluation tools.

But personal and corporate altruism is not enough to achieve the kind of sustainability we need: if it were, we would have already arrived. Creation of real market price signals for externalities requires government involvement. In Australia, for example, the coming Federal emissions trading scheme will start to put an effective price on carbon, which will begin the process of internalising the social cost of carbon. Understanding and using both quasi-market prices and the larger social costs of external assets will allow businesses to make better decisions. They can then set specifications that take sustainability into account and make it a key project consideration (guided by the economics), unleashing the creative powers and talents of engineers and designers. If we can send men to the moon and probes to Saturn, we can design and deliver projects that use energy more efficiently, reduce or eliminate carbon emissions, use less water and have smaller impacts on biodiversity and local communities. We may even then find solutions to the wider problems of global change.

Conclusion

Sustainability as a notion is widely accepted, but poorly practiced. In engineering and project delivery this is particularly the case. Even when decision-makers intuitively know the right and best course of action, it is rarely taken, usually because the ‘economics’ don’t work. Typically, we fall back on what we know and what has worked in the past. But every metric of planetary well-being is telling us that we can no longer continue on this course. The impacts of global change are being felt everywhere, by everyone, and are accelerating.

The cause of our present predicament is a combination of out-dated economic thinking, obsolete decision-making systems and previous-century engineering practices and design codes. By explicitly valuing environmental and social sustainability, and including these costs and benefits in a traditional project economic analysis, more sustainable and inherently more profitable and robust project alternatives can be identified. In many cases, these new alternatives will change traditional project specifications, and will require engineering and project delivery that goes beyond business-as-usual.

The economist John Kenneth Galbraith once wrote that “few problems are difficult of solution. The difficulty, all but invariably, is in confronting them. We know what needs to be done; for reasons of inertia, pecuniary interest, passion or ignorance, we do not wish to say so.” More sustainable projects, and a more sustainable world, require that we confront the issues of global change by making them our pecuniary interest. This will provide engineers with the mandate to design and deliver the projects we need for a more sustainable future.