 Earth has two types of resources, renewable and nonrenewable  At the same time all of earths resources are finite (which means they are limited)

 A resource depletion curve helps to determine the production/amount of material in a reserve  This method created by M. King Hubert  This graph shows when a resource will peak and when it will hit its decline

 Non-renewable resources are put into two groups, Resources and Reserves  Resources can be assumed to exist. They can all have assumed reserves inside of them.  The problem is that resources are not guaranteed to be profitable, or even exist at all.  If a resource is found there are many factors to consider if it can be profitable.  Reserve estimating should only be used for short- range and not for the long term picture.

 When predicting the size you should use a resource depletion curve.  Hubert used this method in his estimation of the U.S. production for oil.  Hubert's estimation lead to many other scientists using this method of estimating a resource.  Determining the amount of energy that we get from all of our energy sources is hard because each energy source is measured differently.

 An average measurement of energy is usually defined as energy content (amount of energy released in one unit of energy)  Common Units of energy are usually Btu and bbl; per pound/per kilogram is measured in Calories and or Joules.

 Coal: Found in Coals Seams, estimated Reserves for U.S. are 501 Billion and 1.1 Billion for the World  Crude Oil: Very hard to determine sizes of resources, on average only 30-40% of a resource is extracted  Natural Gas: Very elusive (but it can be found with oil and by itself), easiest nonrenewable to extract

 Uranium At this point reactors get a 1% energy efficiency from using uranium, we are expected to start to run out of Uranium in the year 2040  Uranium Breeder Reactor: Makes energy release more efficient, and uses less Uranium in the process  Oil Shale: Sedimentary Rock that contains Kerogen, kerogen makes syncrude  Tar Sands: Heavy Tar Like fluid that cannot be pumped to surface through drilling

 The Static Lifetime is the method where it only assumes our consumption of this energy resource does not go up  Equation: Lifetime=Reserve/Constant Use Rate

 This deals with the exponential growth of our consumption rate of an energy resource  Equation: Lifetime=Reserve/Exponentiall Increasing Consumption

 Determining the point at which energy will become scarce is very difficult.