On your comments about unsustainable: I hate to tell you this but....in the 1970s some MIT systems-analysts grad-students and professors modeled the population grow, to resource usage, and the environment. They published their results in a book called "The Limits to Growth." Their conclusion was that the world would see a population collapse about mid 21st century. Their economic detractors argued against the MIT study. One argument the detractors made was oil was supposed to run out by now. No, the MIT model predicted oil production would max out by now. Oil production capacity has be flat since 2005. The MIT people are still doing these models but with better information and computers. Mary Logan, University of Alaska does an up-to-date presentation on the model Dr. Mary Logan - Whither Complexity?
In 2008 the International Energy Agency (which we all pay taxes to fund) studied 800 fields which produce 2/3rd of the global supply. They wanted to know how fast these fields' production were declining year over year. It's 6.7%. That's how fast they believe the decline rate is on global production. There conclusion?
Here's the quotes:
The projected increase in global oil output hinges on adequate and timely investment. Some 64 mb/d of additional gross capacity — the equivalent of almost six times that of Saudi Arabia today — needs to be brought on stream between 2007 and 2030. Some 30 mb/d of new capacity is needed by 2015. There remains a real risk that under-investment will cause an oil-supply crunch in that timeframe. The current wave of upstream investment looks set to boost net oil-production capacity in the next two to three years, pushing up spare capacity modestly. However, capacity additions from current projects tail off after 2010. This largely reflects the upstream development cycle: many new projects will undoubtedly be sanctioned in the near term as oil companies complete existing projects and move on to new ones. But the gap now evident between what is currently being built and what will be needed to keep pace with demand is set to widen sharply after 2010. Around 7 mb/d of additional capacity (over and above that from all current projects) needs to be brought on stream by 2015, most of which will need to be sanctioned within the next two years, to avoid a fall in spare capacity towards the middle of the next decade.
Press release: IEA Press Releases
The prospect of accelerating declines in production at individual oilfields is adding to these uncertainties. The findings of an unprecedented field-by-field analysis of the historical production trends of 800 oilfields indicate that decline rates are likely to rise significantly in the long term, from an average of 6.7% today to 8.6% in 2030. "Despite all the attention that is given to demand growth, decline rates are actually a far more important determinant of investment needs. Even if oil demand was to remain flat to 2030, 45 mb/d of gross capacity - roughly four times the current capacity of Saudi Arabia - would need to be built by 2030 just to offset the effect of oilfield decline", Mr. Tanaka added
IOW the global oil industry must put online the equivalent of a brand new Saudi Arabia worth of oil ever 5 years just to keep oil capacity where it is at present. Why is that important to do so? Because oil feeds the world and bio fuels cannot possible substitute for the volume of oil the world consumes on a daily bases. For example: the world consumes 88-89 million 42 gallon barrels per day. Image 55 gallon steel drums laid end to end making a pipeline. Those 88 M/bbl would fill 67,200,000 steel drums each day. And since each drum is 3ft tall/long, the volume of oil the global economy consumes one a daily bases would require a pipeline of steel drums stretching 38,182 miles long. That 1 1/2 times around the earth every day. You could ring the earth in steel drums 560 time each year. Half that capacity will be gone within 20-30 years.
These men are oil industry professionals explaining the problem: Acknowledging Peak Oil, featuring Sadad al-Husseini - YouTube
the best single source which attempts tie together the economy, energy needs, and the environment is Chris Martenson's Power Point "The Crash Course." It's divided into 20 chapters. In Chapters 17a,b,c Chris presents a graft showing how global population growth tracts global oil consumption. What happens when global population oil production begins its inevitable decline? The Crash Course | Peak Prosperity