GEOL 202 Lecture Notes - Lecture 3: Exponential Growth, Doubling Time, Population Momentum
Document Summary
Population: factoids: global = 7. 1 billion; u. s. = 310 million, growth rate = 2%/yr, doubling time = 70/gr. Rate: adding 70 million people/yr, shows s-shape (sigmoid) growth pattern, the current world population of more than 7 billion people is a cause for concern among many environmentalists. World population growth: over time there has been an exponential, (j-curve) increase in the world population. We occupy the best habitats that have the most abundant resources. What is earth"s carrying capacity: estimates: 8-15 billion people, depends, quality of life desired, ability to innovate inhabit seas, other planets, genetic engineering. Causes of population growth: total fertility rate (tfr) = number babies a woman has in her life, age distribution of population (mostly young or mostly old?, decline in death rate while birth rates stay high. Age structure: the age structure is a distribution of the ages of individuals within a population at a given point in time.
