Food and Food Supply

1. Define food security and food insecurity.
Food security refers to the people in an area having access each day to sufficient food with sufficient nutrients. It depends on countries having the means to produce or import enough food for its population. Also, a country must make sure that there are no harmful environmental effects that can affect its ability to produce food. Food insecurity means not being able to have either enough food or food with enough nutrients each day.

2. Distinguish between undernutrition, malnutrition, and overnutrition.
Undernutrition occurs when the food an individual eats is not enough to meet its basic energy needs. Malnutrition occurs when the food an individual eats does not contain enough proteins or key nutrients. Overnutrition occurs when the food an individual eats contains more calories or more nutrients than those that are necessary.

3. Describe the effects of diet deficiencies in Vitamin A.
A lack of Vitamin A can cause increased susceptibility to common childhood infectious diseases. Children under 6 who do not get enough Vitamin A can go blind and even die.

4. What is famine? How may it affect: societies, the environment?
Famine is a severe shortage of food in a certain area. There is mass starvation, deaths, and social disruption. Societies become chaotic and many starving people migrate to other areas and there is a frantic search for food and water. Individuals also eat their reserves of grains for future years and they will kill their breeding livestock. This will have an impact on the sustainable yield of an environment, affecting its ability to provide enough food for the population in the future.

5. What three systems provide most of the world’s food?
Wheat rice and corn provide more than half of the calories consumed by the world population.

6. Distinguish among industrialized agriculture and plantation agriculture.
Industrialized agriculture or high-input agriculture is that that uses high amounts of energy such as fossil fuels, a large amount of water, uses commercial fertilizers, pesticides and produces single crops (monocultures) and raises livestock.
Plantation agriculture is a form of industrialized agriculture used in tropical developing countries. It involves growing cash crops on large monoculture plantations that will later be sold to developing countries. Forests are cleared to make room for these plantations and biodiversity is reduced.

7. What is a green revolution? What limits could these have?
The green revolution is a process that helped increase crop yields. It involved three steps: First, monocultures would consist of selectively bred or genetically engineered key crops. Second, use of large amounts of fertilizer, pesticides and water to improve yields. Third, multiple cropping would allow an increase in the amount of crops. The green revolution limits biodiversity and could have adverse effects on the soil profile of an area, thus affecting its ability to yield crops in the future.

Population Growth

Population growth can be defined in terms of birth rate, death, doubling time, migration, and fertility rate.

The total fertility rate (TFR) is the average number of children that each woman has over her lifetime. Calculating this helps show the potential for population change in a country.

TFR > 2.0 = population increase
TFR < 2.0 = population decrease
TFR = 2.0 = stable population

Factors that impact our environment apart from population size, is the amount and distribution of wealth as well as the resource desire and need.

Population Growth and Food Shortages

There are two opposing theories on this subject: one by Thomas Malthus, and the other by Ester Boserup. Malthus states that the population is increasing geometrically while the food supply increases aritmethically. This means that the population will surpass the amount of food available, causing excess individuals to die off.
Boserup on the other hand states that while the population keeps growing it will develop the technology needed to meed the food demand. While Malthus is too pessimistic, Boserup is too optimistic. I think we need to find a middle ground. Also, population keeps growing and each country's demands are different. Will the population grow so much that it will cause a dramatic dieback? Have we surpassed our carrying capacity?

Measuring Population Change

There are 4 main factors affecting population size:

1. Birth rate
2. Death rate
3. Immigration
4. Emigration

To measure population change one needs to know:

1. Crude Birth Rate
2. Crude Death Rate
3. Doubling Rate
4. Natural Increase Rate

The Crude Birth Rate (CBR) is the number of births per one thousand individuals in a population per year. It is calculating by dividing the number of births by the total population size and multiplying by 1000.

CBR=[(Number of Births)/(Population Size)]*1000

The Crude Death Rate (CDR) is the number of deaths per 1000 individuals. It is calculated the same as the CBR.

CDR=[(Number of Deaths)/(Population Size)]*1000

The Natural Increase Rate (NIR) is a percentage found by calculating

NIR=(CBR-CDR)/10

Doubling Time is the time in years it takes for a population to double its size.

Doubling Time= 70/NIR

Human Development Index

The Human Development Index is a measure adopted by the United Nations Development Program as a way of calculating a country's well-being. It combines measurements of life expectancy, standards of living, education and GDP into one single value, which can be used to rank countries.

Taking this into consideration, two broad classifications can be used into which countries can be placed:

• MEDCs: Most economically developed countries
  
• LEDCs: Least economically developed countries

MEDCs are industrialized countries that have high GDPs. Their population is relatively rich and has a relatively low growth rate. These countries also have a high level of resource use.

On the other hand, LEDCs are less or not at all industrialized. These countries may have high natural capital, but it is usually exported to MEDCs where it is processed. LEDCs have lower GDPs and have higher poverty rates. Their population is large and has poor standards of living along with a high population growth rate.

Limiting Factors and Population Growth

Populations can change over time due to many different variables, known as limiting factors. These keep populations in check and can be classified into

• Density dependent factors
• Density independent factors

Density dependent factors are those that, as its name implies, depend on population density. This means that the impact these factors have depends on how many individuals there are. These are usually biotic factors, such as biomass, predation, competition.

Density independent factors are those that affect a population regardless of its size. These are usually abiotic factors. Some examples are pH, temperature, salinity, and also natural disasters such as tornadoes, earthquakes, volcanic explosions.

GROWTH CURVES

Growth rate can be graphed. There are two different types of curves:

• J-curve
• S-curve

Each shows a different type of population growth.

J-curves show exponential growth. The population grows exponentially and then crashes or suffers what is known as a dieback. This is because the population overshoots and exceeds the carrying capacity (K), which is the maximum amount of individuals an ecosystem can support without being affected. This is known as a boom and bust pattern. This growth rate is common in organisms.

S-curves start out as exponential growth, but then stabilize as the population reaches its carrying capacity. This growth rate is consistent with density dependent factors. This is known as a logistic curve.

S- and J-curves are idealized. In nature, both types of limiting factors act on the same population and the result is a combination of both curves.

And what about humans?

Human population seems to be growing exponentially, but in my opinion, seeing the conditions our planet is in, it seems as if we have surpassed our carrying capacity. Is the human population heading for a dieback? How much longer before the population crashes?

Quick notes on Sustainable Yield

Sustainable Yield (SY) refers to the increase in natural capital. It is the natural income that can be exploited each year without depleting the original stock or affecting its potential for replenishment.

If you see it as a business, you could consider sustainable yield as the 'retained profit' of a company. It is the amount that one has left over and can use to invest in other aspects of the business. That money can be used to expand and grow or to improve the business in any other way. It is the same with Sustainable Yield, that increase in natural capital is what is available for use and would not affect the environment. It is like the money a company can use to make itself better without going into debt.

* MSY means the maximum sustainable yield, and it is the one that is of interest commercially speaking.

Some important aspects to consider when calculating sustainable yield are:

• carrying capacity
• population size
• total biomass or energy at a given time
• Rates of change of population, biomass, and energy.

However, there is a convenient formula for calculating Sustainable Yield:

SY= Annual Growth and Recruitment - Annual Death and Emigration

Basically, what this calculates is how many organisms are there at a given point in time. It considers new individuals that came in, and individuals that died or left.

Sustainable Yield can also be calculated by

SY= (Total Biomass or energy at a Time T)+1 - (Total Biomass or energy at a Time T)

This is useful when calculating the changes in SY over a period of time. It would be used when comparing biomass in 2009 and biomass in 2010.


Here is an example on how sustainable yield is important for economic systems. It is a report on the commercial value of estuaries in Australia.
http://www.ozcoasts.org.au/indicators/econ_value_commercial_fisheries.jsp

Also, here is an ecological assessment of rivers and estuaries (also in Australia). This is the type of information that is useful when evaluating an ecosystem and its natural resources.
http://www.anra.gov.au/topics/coasts/pubs/estuary_assessment/est_ass_int_wpdd.html

Economy and Systems

An economic system produces and distributes goods and services by using natural, human and manufactured resources. It works just like an environmental system: it is made up of certain components, require inputs (resources) and produces outputs (good and services).

Economic systems seek to satisfy people's needs and wants in the most efficient and effective way. The success or failure of an economic system is based on how efficiently and effectively it carries out its activities. An economic system is also in charge of the distribution of wealth.

As in any system, there needs to be an input of resources. In an economic system, these resources are known as capital, and it is used to produce goods and services.

Capital can be divided into three categories:

1. Natural Capital
2. Human Capital
3. Manufactured Capital

Natural capital and natural income include natural resources that have value. These are resources that support life. Examples include trees, soil, water, living organisms, etc. Natural capital also includes processes such as photosynthesis and biogeochemical cycles, because these help promote life.

Natural capital in economic systems is extremely important since natural capital yields natural income. In fact, the World Bank calculates a country's wealth by also considering the way it administers its natural resources, along with the other criteria.

Natural resources can be classified into 4 categories by their availability or depending on how long it takes for them to be renewed.

1. Renewable
   
2. Non-renewable
   
3. Replenishable
4. Recyclable

It is possible for a certain resource to fall into more that one category, and there may be ideas that differ depending on each person's point of view.

My Ecological Footprint

The ecological footprint is a measure of how many planets an individual, a family, a community, a city, a country, etc. would need if everyone on Earth lived the way he/she/they did. It takes into account aspects such as your home, your transportation, food, and extra stuff.
There are many ecological footprint test, however I did the one on the WWF page: http://footprint.wwf.org.uk

Here is my result:


If everyone on Earth lived the way I did, we would need 2.16 planets.