What is Sustainability?

Terms like Sustainable and Renewable are commonly used to describe sources of materials and energy. They are commonly used in conversations relating to the environment and global warming. Multinational mining companies, government organisations and environmental groups alike will generally agree that the world is experiencing a “global transition to sustainable development" (http://www.riotinto.com/SustainableReview/).

But what is sustainability, and what are renewable fuels? Most people have an image in their mind when they use these words, but they are often vaguely defined and differ from person to person. I'm not going to try to define them, as each interpretation is equally valid, but just want to raise some of the ambiguities and do my best to shed some light on the origin of these words and what they generally mean.

Although I can quite confidently say that a Renewable Fuel is a source of energy that can be obtained sustainably, it’s a little more difficult to define sustainability itself.

I could say that sustainable energy is a source of energy that lasts forever. This definition works well until you encounter the second law of thermodynamics, which will tell you that nothing lasts forever. On the other end, we could say that energy is sustainable if we are gone before we have to face the consequences. This works for us but our children might not share this enthusiasm. The first definition is our dream, and the second is the way we’ve acted, but the question remains; what is a reasonable definition of sustainable energy?

The question we have to ask when trying to identify a sustainable source of energy and materials, is “How long will this source last?" and “Are the consequences of using/extracting this source (if any) worth worrying about?". The easy examples for illustrating this are fossil fuels and solar power.

Fossil Fuels are generally not considered sustainable as they won’t forever and have serious foreseeable consequences affecting our generation and the next. The exhaustion of fossil fuel supplies is a realistic prospect, and we could begin seeing a decrease in fossil fuel extraction (known as peak oil) in the very near future. Burning fossil fuels to extract energy produces – amongst other things - greenhouse gases, which are now generally accepted as a cause for global warming. The problems caused by Fossil fuel use are seen by most people as real and occurring now or at least imminently, so they are definitely worth worrying about.

Solar energy on the other hand is by and large considered a renewable source of energy. It does not necessarily produce any toxic byproducts (if the energy to produce the solar devices is clean), and is not depleting any energy sources, but rather making use of energy that we are receiving anyway.

So, without splitting hairs, we can roughly agree that solar energy is sustainable, and fossil fuels are not. But what about all the in-betweens? There could be an enormous amount of uranium in the earth’s crust, enough to potentially power the planet for centuries (Proceedings of the 11th Pacific Basin Nuclear Conference), but is Nuclear Power really sustainable if we cannot ensure that nuclear waste is stored safely? And what if we do split hairs; can solar power really be considered sustainable when the global effort required to convert to solar would cripple our economies, especially in the third world?

I have touched on some uncertainties regarding Sustainability while only discussing energy, an aspect of sustainability that is comparatively simple to define (although the issues it raises are anything but simple). Trying to characterize sustainability in economics and minerals extraction is far more difficult and complex, and you could argue that sustainability in the minerals industry doesn’t exist at all.

In a time when global warming – a pillar in the argument for renewable fuels – is only considered to be a potential risk by some corporations (http://www.exxonmobil.com/corporate/campaign/climate_view.asp), and when the effects of this risk are not yet fully understood, how can we define just what technologies are in fact good for society and which ones are not? In other words, which technologies are sustainable and which ones are not?