An analysis of the world's environment and population dynamics with varying carrying capacity, concerns and skepticism

Because of the open-access nature of the environment we consider an ad hoc adjustment of people's environmental footprint to the quality of the environment. The adjustment is motivated by environmental concern, but hindered by skepticism about announced changes in the state of the environment. Changes in the quality of the environment affect Earth's carrying capacity. By expanding the Lotka-Volterra predator-prey model to include these features we show that, despite skepticism, the environment does not deteriorate to a state in which humans cannot exist. We also show that in the ideal case of no skepticism, the interplay between the non-optimally changing environmental concerns and carrying capacity leads the world's environment and human population to a unique interior steady state along an oscillating course. These results require no further technological, social or international progress. (C) 2011 Elsevier B.V. All rights reserved.