There is little question that oil will one day run out - the issue is more when the reservoirs will run dry. But even if there is enough to see us through the foreseeable future, does the spectre of global warming mean we should in any case rein in our consumption?
As these questions continue to loom large, BBC News Online asked two energy experts with contrasting views to consider the future of energy.
How worried should we be?
Professor Peter Odell, author of Why Carbon Fuels Will Dominate The 21st Century's Global Energy Economy, advises a relaxed approach
We are not running out of oil - we are running into oil. The world has used 15% of all the oil we believe there to be - that leaves 85% untouched.
The world in fact has a record volume of proven oil supplies - and that is true of conventional oil, which lies in reservoirs, and non-conventional supplies, which can be mined from rocks. Canada for example has recently declared 175 billion barrels worth of oil from non-conventional sources in Alberta, making it the second richest producer after Saudi Arabia. Non-conventional supplies may be more costly to get at than conventional, but they are still very much viable.
Of course there will always be those who say that if we continue to burn fossil fuels at the current rate we will be headed for disaster. The people who sound this warning may make loud noises, but they are not taken seriously by any government. It would be politically impossible to take the path they are suggesting - customers would simply not tolerate the expense of the kind of alternatives being put forward.
That is not to say that the threat of global warming is not a warning worth absorbing. But, as scientists have illustrated, it is still a matter for argument. There are some people who deny outright that the use of fossil fuels has anything to do with the rise in temperature, others who note that the climate has changed in other ages when fossil fuels were not being burned. Whatever the truth, there is no doubt that what we are consistently presented with is the worst-case scenario.
And in any case, what exactly should we do about this? The economics of the developing world depend on oil to reach the kind of standards that the West has experienced. Some 50% of people in these countries have no access to electricity. They want it, they need it. So unless we are prepared to pay for them to develop clean alternatives, which we are not, short of invading them, there is nothing we can do about this. We cannot tell the rest of the world that they are not allowed to do what we have done - that they are not allowed to develop.
But my belief is that, regardless of actual supplies, world oil production will peak around 2050 as demand will be levelling off. Natural gas will be the preferred option, as it will have become cheaper, and it will be cleaner than oil. So there is no need to worry - the future of energy is looking bright.
Dr Jeremy Leggett, a former oil industry consultant who joined Greenpeace before setting up solar electric power company Solar Century, believes we must develop alternatives to oil immediately
Society is in an institutionalised state of denial; it has failed to grasp the severity of the problem. Whether or not oil and fossil fuels are running out, we cannot afford to use them. Global warming is a reality.
Burning fossil fuels as we do is dysfunctional at best, suicidal at worst, and certainly will prove environmentally and economically ruinous. I predict an environmental apocalypse, with hundreds of millions of casualties. Food supplies will be threatened by increased flooding, drought and proliferating pests. Epidemics will rage. This is no exaggeration.
But while the outlook is in many ways bleak - I still hold hope for a renaissance. Once the need for change is realised, it could happen very fast indeed.
Enough light falls on the surface of the planet each day to power human society many thousands of times over. Wind could also play a huge role.
How quickly could fossil fuels be replaced? Consider the automobile. Horses were the dominant means of transportation in 1900. The early automobiles, called horseless carriages, were laughed at. They were expensive, slow and unreliable and had few suitable roads to travel on. Then Henry Ford started mass-producing them, bringing down cost sharply. In parallel, he lobbied for better roads. In 1900, 8,000 automobiles were registered in the USA. By 1912, there were over 900,000. Within just a decade, automobiles had gone from nowhere to almost everywhere.
The solarisation revolution can happen as fast as the oil-auto revolution.
People often point to the developing world - asking how we could deny them the right to use fossil fuels as the West has done, the right to develop as the West has done. Well we must lead by example - we must show them that it is possible through other means.
There are likely to be changes needed to our current lifestyles. Air travel is of course a big problem. Society will probably need to become more localised. And admittedly, even when cars are powered with cleaner fuel, at the rate the population is growing it would be impossible to sustain that number of vehicles. So we would have to rein back. But the benefits - like the increase in the standards of living through improved air quality - would be well worth it.
Are you worried? What's your opinion on these two contrasting views?
Each of them is just selling a perspective. As long as we live in a flexible capitalist and democratic society I see no problems as the economic forces of supply and demand will continue to foster adaptive change.
Both views are correct in some sense; while we are referring to "oil" we aren't quite being specific about which type of oil. There are trillions of barrels of it in the form of tar sands, but the problem is the cost of recovery. I feel that we have already passed the cheap phase of oil, and as the price per barrel continues to increase, sources which were previously not economically viable suddenly become reasonable to explore. The greatest fear is that of decreasing supply, and the prospects in the medium term do not look so good; we are at least a decade late in seriously implementing an alternate energy infrastructure, any further delay will cause worldwide economic and possibly demographic collapse due to our complete dependence on oil.
Tanmay Kudyadi, Mumbai, India
There will always be conflicting arguments on this subject. The problem is that there is an appreciable problem with continual burning of fossil fuels as they no doubt cause pollution. The other major factor controlling this continual usage of oil is the financial implications and economics. One could write a missive on this matter, but the bottom line is 'money talks' and all of this is about greed and money and power. This is what needs addressing first.
Jon, Horsham, UK
Whether there is lots of oil left or not is not very relevant - we need a cleaner form of private travel and increase use of rail and canals.
While I hope that Professor Odell's view is correct I would like to know how he defines "proven oil supplies"; is it the amount of oil that can be extracted at commercially feasible costs or is it at substantially higher and possibly at today's rates, uneconomic, costs?
Shaheen Cader, Colombo, Sri Lanka
Until governments and commercial organisations start to recognise that there is more to life than economics then the world is in serious danger. While I am sure that there is plenty of oil, the by-products will kill us all, either directly via pollutants in the air, and water or indirectly via a living hell hole of congestion and consumerism.
Dodger, Sydney, Australia
I am aghast reading these two points of view. What about nuclear power? Fusion technology?
Martin McHugh, Sweden
The only worrying factor is the global warming but we still have sufficient fuel reserves. Oil exploration is not yet done to more than 60% of the land and more than 80% of the sea. So the prospect of discovering more oil is still there. The other fuel resource as mentioned by Professor Peter Odell is natural (hydrocarbon) gas which is available in plenty. It is not yet the time to worry about fossil fuels, but new technology to fuel our machines must be given high priority.
Said al-Mugheiry, Muscat, Oman
Think of the new industries the information technology has brought to the world. New sources of energy could far surpass that in the coming decades as new industries develop to cater to the new modes of transportation, energizing cities and other industries etc. Such new energy development should begin now so the world can adjust to new forms of energy at a gradual pace rather than be forced into such abrupt changes after the world slips into another great depression from forced energy rationalization.
Furthermore, consider what would happen if terrorists were to severely disrupt the Middle East oil supply. Wouldn't this cause an economic depression which would make the great depression look like a mild recession? Instead, new industries could develop employing millions around the globe and we could all live happily ever after, at least for another century.
Joseph Malm, Albuquerque, New Mexico
As the reserve of oil is running low, the price of the oil will increase dramatically as the demands far exceed the supplies. By then, the energy cost of the oil would have been so prohibitively high that we have to switch over to other energy sources such as solar, geothermal or wind. Therefore, the prediction of oil reserves running dry in the future might not be materialising at all. The history of coal business is a prime example. However, for environmental sake, cleaner fuel shall be sought.
KL Choong, Melaka, Malaysia
A more realistic debate about sustainability needs to consider our spiralling global population, the consumption of natural resources in general, a fairer distribution of wealth and more realistic living standards. Energy, although of importance, is just part of a much bigger picture. Unfortunately, these issues do not seem to take precedence in this era of global capitalism where self-interest and short-term profit take precedence over long-term quality of life for all.
Nick Rikker, Barcelona, Spain
I live in Brazil and in 1984 we had problems of supply of petroleum and to solve this problem the government developed an alternative fuel that was originated from alcohol from sugar cane. I had one of these cars and for 10 years I used it without having any problems. On the other hand instead of diesel oil, fuel oils of vegetable origin can be used. During the crisis of 1984 I saw in the University of Sao Paulo (USP) several motors of the diesel type being tested with success and they consumed vegetables fuel oils.
We do have enough space to organize planting so it'll be possible to produce the vegetable combustibles as a substitution to the petroleum combustibles. I'm sure that at the proper time, moved by the necessity, good solutions for this complex problem will appear.
Jose de Alencar Lanna, Rio de Janeiro, Brazil
The oil in the Earth took hundreds of thousands of years to exist. The first oil well was erected in the US in the 1800s. 200 years later we have a crisis worldwide. I've always equated a simple analogy to the oil crisis. What happens when you run a car's engine with no oil? It seizes. Imagine the tectonic plates of the Earth with no lubrication between them. The planet seizes.
Most people who use hard drugs know that they are no good for them, yet they still keep using them. The planet is still in it's "occasionally on the weekends addiction" when it comes to petroleum. "I can stop anytime," doesn't hold water if you don't at least try to quit. Petroleum is the heroin of the race, and everyone is hooked. And like most junkies, it will eventually kill us.
David Fisher, Woonsocket, Rhode Island, USA
Why is there no mention of nuclear power in either of the two views? Is this no longer seen as a viable fuel source in the future?
Andrew Sherwood, Nantwich, Cheshire
Fossil fuels - the more we use, the less remains. The less we use, the longer it will last. Is that so contentious?
Brian, Sheffield, UK
Talk about getting the cart before the horse. Professor Odell says "...customers would simply not tolerate the expense of the kind of alternatives being put forward." Not tolerating a problem doesn't magically make it go away. Using fallacy to promote a point of view, hardly inspires trust in his other arguments.
With any scientific data it is always hard to be certain. Rather it is a matter of risk: If the global warming advocates are wrong, then all that we lose is a few billion dollars sunk into alternative energy sources, which would anyway benefit society. But if the oil industry advocates are wrong then we risk massive flooding of all costal cities, crop failure and other unknown consequences of global warming. To me the choice is clear.
Tony Hyman, Dresden, Germany
Viable energy policy can only be achieved with all party consensuses - long timescales and tough choices do not sit well with four-yearly elections.
Richard Clarke, Abingdon, UK
Running low on oil will not just cause an energy crisis - think of all the other uses of oil. We use plastics in nearly every aspect of life, including food packaging and distribution. How will we preserve food in supermarkets without shrink-wrap? Food production may have to revert to locally grown fresh produce.
Steve, Wivenhoe, UK
I work for Shell (not in production and exploration I might add) and whilst I can see the argument put up by Mr Leggett, I can't see how it can affect the man in the street until there is a viable alternative transport infrastructure to make cars less necessary.
There also needs to be more research into alternatives for other industries that use oil for purposes other than fuel, e.g. plastics, detergents, tyres, chemicals and so on. Until other means of providing feedstocks for these types of materials the sad truth is that fossil fuels are a necessary evil. Work is going on with projects such as bio-diesel but the demand will outstrip the supply. Solar and wind energy can provide alternatives but this implies that all transport and logistics will be dependent on electricity and hence the range and carrying capacity will be reduced.
Sacrifices in life styles and the way we do business will have to be made in order to fulfil Mr Leggett's dream - will mankind be happy to go backwards to the future?
David Stevenson, Manchester, UK
Is global warming all bad? If we flood a few currently populated parts of the world, is there not a strong possibility that others - the steppes, the Sahara will become more user friendly?
Peter, Bredon, UK
I attended the Underwater Technology Conference in Bergen (Norway) last month, and one of the keynote speakers unveiled a map of the North Sea Shelf showing points of every exploratory well drilled on UK and Norwegian sectors. The speaker was using the map to illustrate how Norway's conservative approach to the development of commercial sectors (known as licence blocks) lagged way behind that of the UK, how's region was quite literally saturated with exploration activity. Although, what caught the attention of the attendees was the huge areas which had not yet been explored, either by drilling or seismic.
If the North Sea can be treated as a representative area for the rest of the world, then I feel that the future doesn't look so pessimistic with regards fossil fuels. After all, the worldwide reserve levels which have been discussed in the media recently are proven reserves; it would, after all, be guesswork to estimate the level of reserves in non-surveyed areas.
Phil Teague, Stavanger, Norway.
Complacency about use of oil should be criminalised! It lets everyone off from making difficult decisions now, yet the environmental damage through global warming will only get worse. As Sheik Yamani once said "The stone age didn't finish because we ran out of rocks..."
Martin Turner, Glasgow, UK
I'm pleased to see Dr Leggett proposing solar power. We have too many ideologists pushing wind power, which not only blight the countryside, but do virtually nothing to reduce carbon dioxide emissions.
As anybody who has worked in the energy industry knows, the solution is to reduce demand or improve efficiency, not build windmills, which makes the matching of supply and demand impossible, thus forcing electricity producers to have power stations on standby, burning fossil fuels and operating at a substantially reduced efficiency. Germany has erected thousands, covering areas of outstanding beauty, and substantially reducing the quality of life of many living in these areas. You only have to drive through to see how badly they fit in; I couldn't think of anything worse than living a few hundred metres from a wind-farm.
I have never heard such extreme opinions on the same issue. I would say that a more realistic case is somewhere in the middle. What is really needed is for us to take responsibility for our actions. Developed countries need to reduce consumption to a more reasonable level so that developing countries can use the savings to reach the same level. We use fossil fuels like a spoiled child who does not know the value of money. If we work hard we could incorporate more renewable resources everywhere in the world, improve efficiency, reduce oil consumption, improve our quality of life, and create a healthier environment and a more sustainable consumption structure.
Oil, water, food, health, clean air, friends, etc. are privileges not a human right. They will be taken away if we don't treat them with respect. Use what you need, share what you have and take pleasure in helping others do the same.
Michael Pires, Stockholm, Sweden
What is the basis of existence and for survival? Which is better? To pollute, waste, destroy, afflict, endanger or to repair, solve, save life, give relief and comfort. It is our earth. Do these arguments capture the world in a picture where life and the basis for/of existence become meaningful? It is what the world needs now and not what it wants. Michael Pires, Stockholm says it all. We all must save the world as it's our home.
Daniel Yayock, Jos City, Nigeria
One thing Prof Odell failed to point out is the massive environmental cost of extracting non-convention oil supplies and the fact that they are, axiomatically harder to extract (otherwise we would have tapped these years ago) and therefore more expensive in terms of energy required to physically extract the oil as well as the monetary cost of extraction. Therefore the non-convention oil supplies are still unproven as far as real commercial viability goes. Whether people will accept the environmental damage is also uncertain.
Peter Richardson, Birmingham, UK
Is it energy we really need to worry about? Market driven economies are not willing to embark on 'blue-sky' research because of the capitalist drive for profit. Many alternatives have been cited, but until there is the political will, i.e. less pressure from major transnational business organisations to ensure the provision of a free-market environment, very little will happen until it is too late. Some may think the priority is energy, but what of the more pressing concerns, the provision of clean drinking water!
Gordon, Aberdeenshire, UK
I am deeply concerned. I work in the gas business. I have helped to set up a group to try and raise awareness called Depletion Scotland. I will be attending the third ASPO conference in Berlin in May.
Max Oakes, Edinburgh, UK
Whilst society is obsessed with wealth, I see very little chance of the world becoming a cleaner place. But how many of us would prefer to spend an extra hour in the morning on the bus to work instead of a car?
Simon, Darwen, UK
Push teleworking and video conferencing! We can save lots of energy if we reduce business travel, and I suspect we are at the point where education could start a significant change. And please note people don't need to be "either" a teleworker or commuter - its more likely some of each.
Max Cairns, Morpeth, Northumberland, England
Before we start rationing electricity and air tickets, we need to get our priorities straight. For example, some water companies waste about 15% of the water they pump, just by failing to repair leaks in pipes. And the Government is spending £21bn on road widening, while leaving the railways to rot with no investment and the same incompetent management. We'd be much better off fixing things that don't work and are causing waste, before we start banning anything that people really need to use.
Leggett in the end points perhaps to a synthesis of these two views, on our dilemma with the developing world. If we, who can afford it, invest in research and commercialisation of more environmentally friendly technologies, it will benefit everyone. Knowledge can be free and the price of the technology may drop within reach of the poorer countries. The battle against ozone-harming CFC emissions is a prime example of this.
Both views have valid points, but I certainly swing in favour or Dr Leggett's viewpoint. Wouldn't it be nice to walk around London and not have to breathe in cancerous diesel fumes, and as for more localised society, I can certainly do without a commute to work.
The whole world is dependent on oil and when it runs short I can see nothing but chaos. Getting cars to run on electricity is easy, but can you see trucks, planes, ships running on batteries? Even if you can get planes and trucks to run on liquid Hydrogen or similar fuels, only the rich nations will be able to afford this. High transportation costs will mean higher prices for goods and the poor will suffer.
Ben, London, UK