Oil fuels the modern world. It brought great changes to economies and lifestyles in less than 200 years. Nothing else to date can equal the enormous impact which the use of oil has had on so many people, so rapidly, and in so many ways around the world. But oil is a finite resource. The common question "How long will oil be produced?" is the wrong question.
The critical question is "When is the date of the maximum daily amount of world oil production--the peak?"
After that oil will be an irreversibly declining resource facing an increasing demand which cannot be met.
The world passed its peak of rate of oil discoveries in the 1960s, but there is a lag time from discovery to full production. Although estimates differ slightly, it seems clear that the peak of world oil production will be reached at least by 2020, and possibly within the next decade (Campbell 1997; Campbell & Laherrere 1998; Ivanhoe 1995).

Future energy development, providing for the world's future energy needs, currently faces great challenges.
These include an increasing world population, demands for higher standards of living, a need for less pollution, a need to avert global warming, and a possible end to fossil fuels (see Hubbert peak theory).
Without energy, the world's entire industrialized infrastructure would collapse; agriculture, transportation, waste collection, information technology, communications and much of the prerequisites that a developed nation takes for granted.
Depending on the type of fission fuel considered, estimates for existing supply at known usage rates varies from thousands of years for uranium-238 to several decades for the currently popular Uranium-235.
At the present use rate, there are (as of 2007) about 70 years left of known uranium-235 reserves economically recoverable at an uranium price of US$ 130/kg.
The nuclear industry argue that the cost of fuel is a minor cost factor for fission power, more expensive, more difficult to extract sources of uranium could be used in the future, such as lower-grade ores, and if prices increased enough, from sources such as granite and seawater.
Increasing the price of uranium would have little effect on the overall cost of nuclear power; a doubling in the cost of natural uranium would increase the total cost of nuclear power by 5 percent.
On the other hand, if the price of natural gas was doubled, the cost of gas-fired power would increase by about 60 percent Another alternative would be to use thorium as fission fuel.
Thorium is three times more abundant in Earth's crust than uranium, and much more of the thorium can be used (or, more precisely, converted into Uranium-233 and then used).

This issue needs to be addressed and i welcome members here to post what they call as other alternate sources of energies that we rely on in the future????

Certainly there is dearth of energy in future because of exorbitant use of energy resources. To counter this, much efforts have been made by many countries for searching out alternate energy resources especially renewable energy resources.

Through years steps have been taken and some of the forms of renewable energy resources have already been started to be utilized in various forms e.g. ethanol, wind energy, solar energy etc.

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'Thee woh ik shakhs kay tasawar saay - abb woh ranayee khayal kahaan'

yes, its true that engineers and scientist are looking forward to some other resources that would benefit them in various ways.

for example:

car that runs on air, in India soon

A car that runs on air could soon be a reality for Indians.

Tata Motors has signed an agreement with Moteur Development International of France to develop a car that runs on compressed air, thus making it very economical to run and be almost totally pollution free.

Although there is no official word on when the car will be commercially manufactured for India, reports say that it will be sooner than later.

The car -- MiniCAT -- could cost around Rs 350,000 in India and would have a range of around 300 km between refuels. The cost of a refill would be about Rs 90.

An overview of the air car

The technology that MDI vehicles use is not really new. Compressed air technology allows for engines that are both non-polluting and economical.

After ten years of research and development, MDI is prepared to introduce its clean vehicles onto the market. Unlike electric or hydrogen powered vehicles, MDI vehicles are not expensive and do not have a limited driving range. MDI cars are affordable and have a performance rate that stands up to current standards. To sum it up, they are non-expensive cars that do not pollute and are easy to get around cities in.

Two technologies have been developed to meet different needs:

Single energy compressed air engines.
Dual energy compressed air plus fuel engines.
The single energy engines will be available in both MiniCATs and CityCATs. These engines have been conceived for city use, where the maximum speed is 50 km/h and where MDI believes polluting will soon be prohibited.

here is the link:

http://inhome.rediff.com/money/2007/mar/21car.htm

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" Woods are lovely dark and deep But i have promises to keep And miles to go before i sleep "