Question

What are the assumptions of the growth model: ΔΝ/At rN2 what does this model predict? How would non-renewable resources affect this particular model? (6 pts)

Answer 1

Assumptions:

• All organisms have at least one parent
• Each individual produces the same number of offspring in each time interval
• Population growth is continuous
• Population size increases through births and immigration
• Population size decreases through death and emigration
• Immigration = emigration = 0

dN/dt = rN

This equation is used to estimate population size N at any future time t from population size now (N₀), without resorting to recursion.

The non-renewable resource models consider the input of resource in the economic system, they cannot be used to trace all effects of resource extraction, transformation and derived waste outflow from the economic system. Therefore using these models for analysis gives only partial insights. Moreover, they provide no framework for studying the relationship between for instance the regenerative natural resource base and the use of fossil fuels. It is however important to be able to investigate which limit is reached sooner: the exhaustion of energy or mineral resources, or the critical level of pollution - e.g., one that leads to drastic changes on the biosphere level - that is generated by production and consumption using these resources.