Humans in the Biosphere

This Island “Earth” What are the limiting factors on an island? – Space, food, fresh water… The Earth is an closed system: – Energy is exchanged but matter is not exchanged – The resources on the Earth are limited Most population are kept under control by natural limits on growth – Food, space, competition, predation, disease… Humans have developed a new way to live by taking control of our environment Since nature cannot complete control our growth, it is our responsibility to do it ourselves

Humans Take Control What is man’s greatest invention? – Agriculture Growing our own food means we are not limited by nature as much What happened after agriculture started? 1)Society formed  jobs, hierarchy, and economics are born 2)Cities are created to increase trade and wealth 3)Suburbs grew from cities (urban sprawl) because they are safer and cleaner 4)Cities fall apart (urban decay) and humans expand outward into nature

Rapid Growth What major moments promoted the sudden jumps in human population? 1)Industrial Revolution  major growth in industry created more money, more jobs, and better education 2)Understanding Medicine  money and growth gives us the resources to improve science which lead to better medicine and longer lifespans 3)Computer Age  computers take technology/science to a place never thought possible and society raises its standard of living

Too Much of Everything Why is a growing population AND higher standards the path to uncontrolled environmental damage? 1)More food is needed  people want meat but 5lbs of wheat is needed to make 1lb of meat 2)More technology  built on rare elements that will get harder to find forcing us to dig deeper into the Earth 3)More energy  both 1 and 2 mean more energy is needed for each person to live the life they want

What is the Answer? Sustainable Development – Society must balance growth with the resources that are available, growth in society, and growth in the economy 2 types of resources: 1)Renewable resources  can be replaced in a short length of time – Trees, animal populations, alternative forms of energy… 2)Nonrenewable resources  can be replaces but will take longer than society can wait – Coal, oil, natural gas, rivers/lakes

Group Discussion Break up into 3 groups Read the question and discuss Write down your thought and be prepared to explain your answers to the class

Discussion Questions Group 1: – In what countries is sustainable development most important? Explain why. Group 2: – How might you stop or slow down the growth of cities as more and more people move to cities looking for work? Group 3: – Do you think governments/society should limit the excess to meat products since raising animals has such a negative impact on an environment? Why?

Effects of Human Growth Deforestation Pollution Water pollution Acid rain Greenhouse effect Intro essay topic