The article is trying to explain the price time-path of fossil fuels. The Dynamics of Monopoly (1924), written by G.C. Evan and cited by Alpha W. Chiang in Elements of Dynamics of Optimization, deserves the credit. The mathematical model works around Euler’s equation with vertical transversality conditions. The consideration for the time horizon was successful after verifying a lot of environmental journals and articles. According to most environmentalists, by 2030 the fossil fuels shall be exhausted.