Back in the 1950s, a geophysicist named M. King Hubbert predicted that American peak petroleum production would occur in the early 1970s. He was proven absolutely correct. Since then, there has been a relentless decline in flow from the US oil wells. Numerous scientists applying Dr Hubbert’s analytical techniques have since determined that world peak petroleum production, the eponymous `Hubbert Peak’, will be reached before 2010, and indeed may well have been passed by now. It is virtually certain that all reserves of easily extractable petroleum have already been identified, that no more exist. Smaller discoveries will continue to be made in ever more inaccessible areas, but it is all downhill from now on, as far as total oil production is concerned. It has been estimated that petroleum will be virtually depleted within 40 years, probably sooner, considering the burgeoning worldwide demand, particularly from the rapidly developing countries of China and India.

Meanwhile, America, representing less than 5% of the world’s population, consumes 25% of all petroleum, is the largest producer of carbon emissions and casts doubt on the existence or importance of global warming.

Let’s look at the advantages and disadvantages of the various energy sources.

Nuclear fission creates no greenhouses gases but brings to mind the disasters of Three Mile Island and Chernobyl. Despite this, fission provides a large proportion of energy for many countries, including France and Korea, and is likely to take on increasing importance, despite concerns of acquisition of materials by terrorists for building bombs and contentious issues of nuclear waste disposal and decommissioning of old nuclear plants.

The renewable sources of energy, namely photovoltaic, wind, geothermal, hydroelectric and tidal energy tend to be feasible only in specific geographic areas, often with wide fluctuations in availability and currently represent a miniscule contribution.

Some have advocated nuclear fusion and the hydrogen economy as the answers to all our problems. Unfortunately nuclear fusion remains an illusion. The New Scientist magazine editorial of 4th December 2004, quoted the old joke that `fusion energy is just 40 year away from us, and always will be’. Furthermore, liquid hydrogen is difficult, expensive and hazardous to manufacture, handle and transport, is prone to leakage and has only a quarter the energy density of petroleum products. Oil-based fuels are infinitely more user friendly. A lead article in the January 2005 edition of Popular Science magazine elegantly outlined nine myths and misconceptions of the hydrogen economy and why it is not a viable prospect for the near future, even when used in fuel cells.

The drawbacks of the fossil fuels include carbon emissions with attendant global warming, pollution by impurities such as sulphur, or additives such as lead, acid rain and especially the fact that they are non-renewable. Nevertheless, petroleum products continue to be indispensable for the transport industry. Oil-based fuels are a near ideal chemical energy source for reasons of their liquid medium at room temperature, high energy density, easy transportability and storage; and being the only practical fuel for aviation.

I would like to propose better paradigms for our energy futures. In my previous talk I suggested that we should invest in scum.

First, let us outline the criteria for the ideal fuel. It should be a liquid over a wide range of ambient temperatures, be easy to contain and it, or its derivatives, should be a viable aviation fuel. It should be renewable, should not add to the net carbon dioxide load in the atmosphere and should be non or minimally polluting. It should have minimal environmental impact in the event of a spill and be biodegradable and non-toxic. A major bonus would be if it could be used in existing engines with no or minimal modification.

We already have a fuel which nearly fits these criteria. It is called biodiesel, derived from plant oils, currently available at many regular roadside bowsers in Europe. However, we need to greatly improve the efficiency of production of such biomass fuels in order to reduce their costs and increase their availability.

We should strive to bioengineer plant oils, what I term `phytofuels’. I believe we can create plants with far greater oil productivity than the current tradition bio-oil sources such as canola, soyabean or oil palm. But innovation and investment are required. Creation of economically viable `phytofuels’ will involve genetic engineering.

Here are my criteria for the ideal fuel crop:

First, it should grow rapidly and be harvested easily.

Second, it should utilise land, or even lake or marine areas, not otherwise useful for other purposes.

Third, it should efficiently convert sunlight, water, carbon dioxide and nutrients into oil with minimal diversion of energy into the formation of other plant parts. In the extreme situation, such a plant would consist of little more than chloroplasts and oil producing organelles surrounded by a cell membrane, namely, an algal species. Hence my earlier assertion that we should invest in scum. It is entirely feasible to introduce an oil producing gene into a rapidly growing algal species to produce such a plant. Some algae have a very high lipid content, for example Botryococcus braunii has been found to synthesize large amounts of hydrocarbons with oil contents of up to 86% of dry weight. Some micro algae have a doubling time of less than a day.

Fourth, it should not require significant extraneous application of fertilisers. For example, perhaps the nitrogen fixation ability of legumes can be spliced into the genome of the oil crop.

Fifth, if fresh water is in short supply, it should be able to use sea or brackish or artesian water.

Sixth, should it inadvertently escape the confines of the `fuel farms’ it should not proliferate rampantly and pose an ecological hazard. Perhaps a self destruct sequence could be built into its genes or it could be engineered to require an essential nutrient not normally found in the greater environment.

One inescapable criterion, however, will be that such a crop will require lots of sunshine, which Australia obviously possesses in abundance.

Apart from algae, perhaps we can also bioengineer seaweed or kelp for the same purpose in aquatic fuel farms. In all probability there will be no single ideal fuel crop but several different sorts, depending on the local environments where they will be grown, producing different types of oils for different uses.

Biotechnology may also be the key to the production of new renewable polymers and plastics, which, after all, are presently derived from petroleum. But that is a whole other story.

With the development of bioengineered phytofuels solve all our problems? Almost certainly not. At the very least, however, I advocate that phytofuels should replace fossil fuels in the transport industry, and that vehicles with hybrid phytofuel-electric engines should become the environmentally friendly standard.

It is likely that nuclear fission, hydroelectricity, wind power and direct solar power will be important sources for future electricity generation.

We do not know at this time the maximum volumes of oil which can feasibly be produced by bioengineered plants. However there may be another strategy which could far exceed the solar energy gathering efficiency of even the most wildly productive bioengineered oil plants and utilise far less water.

According to the solar energy group of the University of Chicago, the rate at which solar energy is delivered to the entire Earth’s surface, despite cloud cover, rotation of the earth, and other factors, averages a total of 1.2 times 10 to the power of 17 Watts, or 20,000 times the total rate of human consumption. By my own back-of-the-envelope calculation, a 33% efficient solar energy collecting facility will need to be about 30% the area of the Nullarbor Plain, that is, 75,000 square kilometres, to meet all the world’s energy needs, a tiny dot on the map of the world.

Certainly that represents a huge land area, however, we should compare that figure with the estimation by a Utrecht University team, that for wind power to meet the global electricity, not total energy demands of 2001, a land area of 2.4-million square kilometres, about the size of Saudi Arabia, will be required, which one science journalist considered an upbeat assessment.

Nevertheless, 75,000 square kilometres is a very large area, and a single such solar gathering facility will represent a monumental engineering feat far exceeding any in human history. A much more practical and likely scenario is that many such facilities should be built around the world in areas of high solar insolation to collectively add up to such an area.

I believe that, far more efficient than bioengineered `phytofuels’, the direct conversion of light energy to hydrocarbons will ultimately be the way to go; in other words, artificial photosynthesis, to enable the production of what I term a `photofuel’. The aim is to eliminate the biological middleman, the plant.

To me, artificial photosynthesis is the Holy Grail of renewable energy. Where do we currently stand in this matter? Surprisingly, hardly a word is mentioned about this topic in the general science ligterature. It is an idea which deserves far wider publicity and much greater funding.

A few groups around the world are looking into this, including our own CSIRO. The Australian Artificial Photosynthesis Network is a small multidisciplinary group of scientists in Australia and New Zealand who have a particular intgerest in this issue. I quote directly from their website:

`The primary photochemical conversion processes in nature … are much more efficient (about 4 times) than the best silicon based photovoltaic systems. They have been highly `refined’ by evolution to extract the most from the spectrum of solar light flux received at the earth’s surface. For this reason, we regard a program to develop chemically robust, `biomimetic’ photo-electric conversion systems as highly valuable.’

I believe that research into artificial photosynthesis is far more likely to yield breakthroughs than the search for controlled nuclear fusion. After all, we have no precedent for the occurrence of controlled nuclear fusion on Earth and it may never be possible to achieve this. Plants, however, have been quietly performing photosynthesis under ambient conditions for billions of years. We just need to discover how to mimic them. Surely it is not beyond human ability to find out how a primitive unicellular blue-green alga works.

In conclusion, let me use a metaphor to describe our present situation. We are rapidly steaming ahead through dense fog on board a ship very much like the Titanic. Our radar indicates there is a huge iceberg directly in our path (the iceberg is a composite representation of the impending industrial and agricultural collapse consequent to petroleum depletion, as well as the dire effects of global warming). The iceberg is half a mile away. Unfortunately we need two miles of seaway to stop our ship and our rudder is jammed, hence we cannot change course. Our Captain (who represents America) used to be a benevolent and helpful fellow, but has recently been gripped by an aggressive madness. An Arab crewmate named Saudi recently slapped the Captain in the face (remember that in the September 11 hijackings, 15 of the 19 hijackers were Saudi nationals) so the Captain did the natural thing and beat another Arab crewmate named Iraq to a bloody pulp. All those Arabs look alike anyway, so he was fully justified. In any case, he needs Saudi to bring him his food.

We all know how to survive the impending collision with the iceberg: engage full reverse thrust to slow the ship down and lessen the impact, and lower the lifeboats to save the passengers.

The Captain has at different times denied the existence of the iceberg on the radar or dismissed its importance; we can crash through it, no problem, he says. Stoke up the boilers and full speed ahead. He claims it is all a left-wing conspiracy, although he cannot explain how or why those shifty left-wingers could or would fabricate such evidence.

We cannot overpower the Captain and take command. He has adopted a Rambo mentality and carries knives, guns and grenades on his person which he will not hesitate to use. We are either with him or against him, he says. All we carry are tiny nailclippers with spiky bits. The first mate, Britain, who is currently stomping on Iraq’s face with hobnail boots, has come to accept the existence of the iceberg, but has done precious little except make a few token statements.

Some European crew members have begun to lower lifeboats and round up their favourite passengers.

Australia is a lowly midshipman who has always been loyal to the Captain. Despite our tiny stature, we have had the dumb good fortune to be blessed with morbid obesity. Our exuberant rolls of fat (representing our coal and uranium resources) serve as insulation and flotation, hence we will be able to survive much longer than anyone else in the frigid waters after the ship sinks.

Complacency is thus the easy option for us. Let the others freeze and drown, why should we care? We’ll be OK in the short term. However, we also have at our fingertips the operating handbook for the largest lifeboat of all, one that may save most, if not all the passengers. We just need to figure out the instructions for deployment.

What would you do?

Let us dream of a future where human beings live sustainably and have minimal impact on the environment. A future where our descendants will look back and shake their heads in amazement at how greed, short-term agendas, warmongering and wasteful practices dominated our lifestyles and are thankful they have found a better way.