**2. Nature of the decline of fossil fuel**

While fossil fuel is known to be in decline, the nature of the decline and future trends in prices is unclear. Since 1900, the world population has more than quadrupled, and primary energy consumption has increased by a factor of 22.5 (BP Statistical Review 2011). The consumption of fossil fuel has been increasing at the rate of about 1.6 % annually for many years, and oil companies expect consumption at this rate for another two decades (BP Energy Outlook 2030, 2011).

From these estimates of known and future reserves, it is only a question of time, before oil and gas reserves become largely depleted. At the present rates of consumption, it is generally acknowledged that fossil fuel, especially oil and gas, will decline greatly in a few decades. Oil and gas are being produced from increasingly deep reserves, leading to higher production costs. These greater expenses have been at the cost of disposable incomes, and quality of life.
