The Global Context, Cycles, and Systems

June 3, 2015

Systems

• A system is a set of components or parts that function together to act as a whole

• Systems are open or closed

• Open systems are not contained within boundaries

• Closed systems are contained

Feedback

• Feedback occurs when the output of the system also serves as an input and leads to further changes in the system

• Negative feedback – occurs when an increase in output leads to a decrease in the output - stabilizing

• Positive feedback – occurs when an increase in output leads to a further increase in the output - destabilizing

Feedback

Environmental Unity

• Environmental unity means that it is impossible to change only one thing in the environment

Environmental Unity

Environmental Unity

Why is Solving Environmental Problems Difficult?

• Exponential growth

• Lag time

• Irreversible consequences

Why is Solving Environmental Problems Difficult?

The Environmental Problem

• Human population growth is overwhelming the environment

• Things that decrease population:– Famine– War– Plague– Climate– Natural disasters

Example: Indonesian Tsunami

• 2004 Indonesian Tsunami killed 230,000 people

• 2015 Nepal Earthquakes killed 7,000

• Human population growth at 1.14% in 2014

• 80 million new humans every year

• US birth rate (2015):

Population Change over Time

• Population – group of individuals of the same species living in the same area or interbreeding and sharing genetic information

• Species – all the individuals that are capable of interbreeding

• 5 key properties of a population are: abundance, birth rates, death rates, growth rates, and age structure

Population

• All populations undergo three distinct phases of their life cycle: – 1-

– 2-

– 3-

• The general study of population changes is called population dynamics

• Age structure diagrams show how a population is distributed. – It divides the population into pre-reproductive,

reproductive and post-reproductive phases.  – The shape of the diagram can show you if a

country is growing rapidly, slowly, or negatively. It can also show is there is zero growth. 

Population Change over Time

Age Structure

Age Structure

World Age Structure

Germany dominance over as demographic crunch worsens

• Germany's workforce will shrink by 6m over the next 15 years, declining even faster than Japan's

• The average number of births per 1,000 population dropped to 8.2 over the five years from 2008 to 2013. Even Japan did slightly better at 8.4

• “No other industrial country is deteriorating at this speed despite the strong influx of young migrant workers. Germany cannot continue to be a dynamic business hub in the long-run without a strong jobs market”

• The German government expects the population to shrink from 81m to 67m by 2060

• Was Gengis Khan history’s greenest mass murderer?

• 700 million tons of carbon removed from atmosphere

• Elevated CO2 making some arid regions greener

• CO2 fertilization effect

Thomas Malthus

Carrying Capacity

• Factors to consider:– Food supply– Land and soil resources– Water resources– Net primary production– Population density– Technology