Presentation on theme: "Fossil Fuels A non-renewable energy resource. Outline Extrapolating data. Modeling consumption and growth. Fossil Fuels Origins Production Use Future."— Presentation transcript:
Outline Extrapolating data. Modeling consumption and growth. Fossil Fuels Origins Production Use Future
Predicting the Future based on the Past. The Second Law of Thermodynamics tells us that TIME always moves forward, to a point when energy is distributed more evenly and at a single temperature. So we can’t know the future! But since the way in which energy flows is governed by physical laws, can we observe what has happened in the past (data) and use those laws (analyze) to make predictions about the future? Let’s look at a simple example: Population.
World Population 1950-2000 yearpopulation% growth 19502.56 billion1.47 19603.04 billion1.33 19703.70 billion2.07 19804.45 billion1.69 19905.28 billion1.55 20006.07 billion1.41
Looking into the future There seems to be a trend upwards in world population. Assuming that this trend continues, we can try to predict the world’s population even 50 years from now. But which prediction is right?
Exponential growth Growth proportional to N. The rate of growth, r, is the percentage of N added to the total amount, per year. Example: r = 2% growth per year means that.02 N is added to N every year. When N is big, exponential growth is fast! N DOUBLES every DT = 70 ÷ r years. Example: r = 2% means that N doubles every 70/2 = 35 years.
Exponential growth of World Population? Looking at our exponential curve for world population, we find r = 1.76 % So,.0176 N is added to the population every year. N = 6 billion or 6 x 10 9, so 105 million people are being added per year. DT = 70 / 1.76 = 40 years. In 40 years, the population will be 12 billion! Is it true?
US Census Bureau’s Prediction of World Population
US Census Bureau’s prediction, cont. The curve doesn’t fit as well, because the growth rate is changing and probably will continue to change. The Census Bureau predicts a declining growth rate to less than 0.5 % by 2050 and a peak in population shortly thereafter. Exponential growth is NOT SUSTAINABLE over long periods of time.
Non-renewable resources There is a limited number of people at WIU. Exponential growth in friends quickly “consumes” all friend candidates. People can reproduce, but they depend on many non-renewable resources to survive. If population grows exponentially, consumption will also grow exponentially, and overwhelm the available resources.
Fossil Fuels Exponential growth is a very POOR model for the consumption of non-renewable resources. M.K. Hubbert in 1957 made a startling prediction about the production of oil in the US. “Oil Production in the US will peak in 1967.” Assumptions: Oil is a finite resource. Initially exponential growth in demand. Eventual halt and decline in production as the resource becomes more uneconomical to obtain.