I have six questions from my science course, I will provide the power point of the chapters you need for the question, and you only need to read it, and write one paragraph answer for each one.

viena1992
chapter_13_population_and_growth.pptx

Population and Growth

Chapter 13

What can we do?

There are inherent limitations within our biosphere that limits its capacity to support life.

What can we do as a society and as individuals to create a sustainable environment?

Exponential Growth

The rate of growth of the human population has slowed to about 1.4% per year

All five elements – population, food production, industrialization, pollution, and consumption of renewable resources are increasing

There are two positive feedback loops producing exponential growth - population and industrial capital

The constraints that act to stop exponential growth are negative feedback loops, which become stronger as we approach the carrying capacity of the Earth – famine, pollution, and depletion of natural resources.

Club of Rome

In 1970, the Club of Rome commissioned a computer study to be done at MIT examining the questions dealing with the growth of human population and global economy during the next century.

The Club of Rome is a group of scientists, economists, businessmen, international high civil servants, heads of state, and former heads of state who pool their different experiences from a wide range of backgrounds to come to a deeper understanding of world problems

Questions to be answered included

What will happen if the growth in the world’s population continues unchecked?

What will be the environmental consequences if economic growth continues at its current pace?

What can be done to ensure an economy that provides sufficiently for all and that also fits the physical limits of the Earth?

World3 Model

The group at MIT constructed a computerized global model, World3

The World3 model exists as equations on a computer

It was designed to understand the role of humans as our population approaches the world’s carrying capacity.

It provides us with insights as to what actions should be taken as we approach that limit so as to avoid a dramatic collapse.

World3 model predicted that under the present growth trends in world population, industrialization, pollution, food production and resource depletion, the limits to growth would be reached sometime within the next 100 years with the result that there would be a sudden and uncontrolled decline in both population and industrial capacity

It is possible to alter these growth trends and to establish a condition of ecological and economic stability that is sustainable far into the future.

The sooner we begin working to attain stability the greater will be our chance of success

Carrying Capacity of the Earth

Food is a limiting factor on the population, the amount of food on earth depends directly on the sun’s energy reaching the Earth

How large a population can the Earth sustain based on the total amount of calories per day available as food

The carrying capacity of the Earth is simply the world food production per day divided by the calorie requirement of a well fed person

18 billion people can theoretically be sustained on the surface of the Earth each day

The current population is 6.8 billion

Population Growth and Resources Impact

The sooner we begin working to attain stability the greater will be our chance of success

Population growth drives the requirements for food, water, housing and consumer goods

Food

Greater food production will be necessary to sustain the larger population. More land will be needed for food production and the yield increased

In the past 20 years cultivated land has decreased because of urbanization, erosion, salt buildup and desertification.

Water

Although water usage is stabilizing in industrial countries, it is still found to be growing in developing countries

Within a few decades many countries will confront limits on their water supplies.

Desalinization and detoxification may be a solution for some and conservation for others

Forest

The world’s tropical forests will be used in 30 years if tropical deforestation increases exponentially at the same rate as population growth

In many cases deforestation is followed by erosion, which prevents regrowth

Fossil Fuels

There is only so much easily accessible oil, natural gas, coal, etc. available underground

Usage is growing exponentially and the resource is limited

A solution is to convert to more efficient energy use to slow down the growth and to move to renewable energy sources such as solar and wind power

Materials

Extraction of various material from the ground such as iron, copper, aluminum and lead results in a drop-off in quality

Recycling may help conserve this resource

Pollution

Pollution is rising worldwide

Some species have disappeared as a result, and pollutants decrease the amount of clean water available

Pollution can cause a large-scale breakdown of ecosystems and it is in our best interest to control it as much as possible

Industry

Industry uses energy, materials, water and wood.

It creates pollution

Either we have to slow down its growth or come up with technological innovations to decrease its needs

World3 Model

20 years later the findings were basically the same

The 1992 report warns

This decline is not inevitable

We need comprehensive revisions in policies and practices that perpetuate growth in in material consumption and population

We need to increase the efficiency with which materials and energy are used