14. Read the text, suggest the title to it.

Oil is abundant, but known supplies are dwindling. Next to water, oil is the most abundant fluid in the Earth’s upper crust, but most of the proven oil reserves are in a few fields. We are so used to fossil fuels and the devices they power that it is hard to imagine a world without them, but at the rate we are using them and are expected to use them, the reserves will last only a few more decades.

When geologists discuss sources of fossil fuels (or any useful mineral), they distinguish resources and reserves. A mineral resource is the entire amount on Earth – sometimes called the total resource. A reserve is what we can get at now economically, the portion of the resource that we can extract now at a profit. This is sometimes called the proven reserve.

The main question is, when will we reach peak production? This is more important than how long oil will last, because after we reach peak production, less oil will be available, leading to shortages and price shocks. Forecasts put peak in world crude oil production between the years 2020 and 2050. Oil production as we know it now is expected to end by about 2090 in the United States, and world production of oil should be nearly exhausted by 2100. Some economists argue that we will never entirely run out of crude oil, because we will reach a point where finding it and extracting it will cost much more than it can sell for, and when that happens it will no longer be used as a fuel, but as a mineral to be made into comparatively expensive products.

Several decades ago, the known available reserve was about 1.6 trillion barrels. Today, the estimate is just 3 trillion barrels. The increase is due primarily to discoveries in the Middle East, Venezuela, and Kazakhstan. Because so much of the world’s oil is in the Middle East, oil revenues have flowed into that area, causing huge trade imbalances and many political consequences.

Two other sources of oil play a minor role: oil shale and oil sands. Both are sediments that contain low concentrations of oil, but because they are massive, in total they contain a lot of energy. The use of both is insignificant today, but tar sands could become important as oil from well becomes scarce.

Today for every four barrels of oil we consume, we are finding only one barrel. However, this could improve in the future. Recent studies suggest that about 20 % more oil awaits discovery than predicted a few years ago, and that there is more oil in known fields than we thought. As estimated 3 trillion barrels of crude oil may be recovered from remaining oil resources, while world consumption today is about 30 billion barrels per year. Still, the new oil discovered in known fields will not significantly change the date when world production will peak and production will begin to decline.

E. A. Keller, D.B. Botkin. Essential Environmental Science. John Wieley & Sons, Inc., 2007.

15. Answer the questions to the text.

1. What is the difference between the terms “resource” and “reserves”?

2. Why is it so important to know when we will reach oil peak production?

3. Why do economists argue that we will never entirely run out of crude oil?

4. Why does oil available reserve grow?

5. What problems did the discovery of oil cause in the Middle East?

6. What are the other sources of oil?