PDS AP Environmental Science 5th Period 2010-11

So, this is a nice 3 minute video by National Geographic that ties together ideas from Unit 6 and 7. Lots of humans on the this planet, and they are migrating to urban areas…

You worried yet?

Since many of you enjoyed seeing Hans Rosling’s first TEDTalk, I thought you might enjoy seeing his most recent. This one was given on 10/7/2010 and is called “The Good News of the Decade” and is about the battle against child mortality…and using averages when discussing Africa.

*Note: We only got to spend a few minutes discussing this topic the last day before exams, so I am including this nice post by IanN from last year.

There are two “Human Population Problems” that we discussed in class:

1. The Annual Growth Rate (AGR) of a population is too high, leading to problems with overpopulation.
2. The AGR of a population is too low, leading to problems involving supporting a “graying,” or aging overall population.

Big Picture: How to responsibly address an AGR that is too high.

There are 3 primary methods to addressing an Annual Growth Rate that is too high:

1. Family Planning: This doesn’t just include things like the government handing out condoms. Governments can fight high population growth by promoting sex-ed courses that help people in the community learn how to practice safe sex and avoid unwanted pregnancies. A good example of this method being used would be Thailand, where family planning programs helped to reduce the AGR from 3.2% in 1971 to 1.6% in 1986.
2. Industrialization: Most high AGRs come hand-in-hand with poverty. The poorer a nation’s population is, the less likely it is that the people in the population will use birth control or other means to avoid unwanted pregnancies. By industrializing, a nation increases its Gross Domestic Product (GDP), which in turn allows its population to raise its standard of living by making more money. As a population increases its standard of living, it will begin to be more cautious when it comes to sexual practices, causing its AGR to go down. Many Asian countries helped to reduce their AGR by industrializing and increasing their GDP.
3. Improve Education and Opportunities for Women: One of the biggest causes of a high AGR is the inability of the women in a population to have a say over how many children they have. In these societies, the men essentially decide how many children a woman will have, and a large amount of children (especially sons) is often seen as a positive thing. If women in these societies were to be given greater opportunities, they would be able to get better educations, become working members of society, and get a much greater say in the number of children that they bear. By empowering women, a nation is able to greatly reduce its population’s AGR.

What Can One Nation Do to Regulate Its AGR?

A nation can use policies, laws, regulations, and taxes to help control the growth of its population.

• China cut its Crude Birth Rate (CBR) in half by implementing its One Child Policy in 1972. This is one of the strictest programs in the world. The government gives a ton of incentives such as extra food, larger pensions, better housing, free medical expenses, free school tuition, and salary bonuses to parents who follow the One Child Policy. After the couple has had one child (or two children in select cases), either the woman is required to wear an intrauterine device that greatly reduces the chance of pregnancy or one of them is required to be sterilized. If a couple chooses not to follow the policy, they are faced with a series of penalties, including fines, loss of land grants, and even discharge from the Chinese Communist Party.
• Countries could use tax deductions and tax credits to control AGR. In short, if AGR is too low, the government can offer to reduce people’s taxes if they have more children, and if AGR is too high, the government can offer to reduce people’s taxes if they get sterilized . Tax deductions are expenses you are allowed to use to reduce your gross income that affects how much you are taxes, while tax credits are amounts subtracted directly from the amount of tax you already owe.
• Governments can also use rebates to control a population’s AGR. Rebates are direct payments from the government to you, and can be given in exchange for a couple either having more children or having less children. You are probably most familiar with the rebates that are offered to you after you buy something in a store.

Original post at: http://pdsblogs.org/pdsapes810/2009/12/07/scribe-post-population-solutions/

If you enjoyed the TEDTalk by Hans Rosling, I wanted give a chance to learn more about his work.

First, here is yesterday’s video if you want to watch it again:

Second, if any of you are interested in more about the stats in the presentation go to Dr. Rosling’s web site:
http://www.gapminder.org/
Explore the links and the tutorial. You can study these demographic trends for yourself-you can test ideas in the book by building your own graphs (Gapminder World). Here is one I gave out in class:

Click to Enlarge

*Maybe you are in a global studies class and need research displayed in a very cool format?

Third, here is another 18-minute TEDTalk Hans Rosling gave in 2007 on myths about poverty:

What do you think of Dr. Rosling’s presentations?

http://geographyfieldwork.com/g427.gif

*Note: This is a cross post done by ConnerV in the other class with minor adjustments by Mr. W (in parentheses).

Today in class we talked about the Demographic Transition. We used this model to discuss how countries change over time to fit our four stages.

The four stages were:

1. Pre-Industrial: Countries without industry. Usually don’t have a centralized gov’t system (usually tribal). We didn’t find many (if any) countries that fit this stage.
2. Transitional: These countries are in the transition stage between Pre and Industrialized nations. They are characterized by high birth rates, and high death rates that decrease over time. These death rates decrease over time because the country starts to gain the ability to defeat death through medical advancement (anti-biotics and vaccinations) as well as sanitation and readily accessible food resources. Countries like Rwanda and Ethiopia fit this model (as early stage 2 countries rapid growth as they have high infant mortality rates still).
3. Industrial: This stage describes nations who have low death rates and birth rates that are lowering towards 0% population growth, but aren’t quite their yet. Countries like China and India fit this stage (just entering stage 3, but also USA, Canada, and Australia at the end of the stage).
4. Post-Industrial: This stage describes countries that have low death rates, high life expectancy, and an AGR of zero or even negative %. Germany and Japan fit this model (note the USA may be on the verge of entering it as our population growth stabilizes near ZPG).

Classifying Population Pyramids by Demographic Stage

Monday in class we learned about factors that affect the Crude Birth Rate (CBR) and the Crude Death Rate (CDR). First, however, we viewed a poulation map of the world which is as follows.

The larger the country the larger the total population. We then reviewed the equation for AGR, also called the Rate of Natural Increase, which is (CBR-CDR)/10.

The Factors which affect CBR/ Total Rate of Fertility (TRF)/ Replacement Fertility (RF)

1. As value of kids as labor increases the number of births also increase. The more reliant each parent is on the kids to work for them as labor the more likely it is they produce more offspring for greater efficency.

2. As cost of raising kids increase the number of births decrease.

3. As availability of legal abortion increases the number of births decrease.

4. As the availability of birth control increases the number of births decreases.

5. As infant mortality rate increases the number of births also increases.

6. As the availability of a Pension System increases the number of births decreases.

7. Availability of education/opportunities for women increases the number of births decrease.

8. As the average age of marriage increases the number of births decreases.

9. As urbanization increases the number of births decrease.

10. Religon/Tradition/Gov is the wild card, could increase or decrease the number of births

Factors affecting CDR

1. As medicines increase the number of deaths decrease.

2. As sanitation increases the number of deaths decrease.

3. As conflicts increase the number of deaths also increase (War, etc.)

These are the main 3 for CDR but their are others such as food, natural disastor, etc.

Friday in class we learned about human population growth rates. We watched a video. Here is a link to that http://www.youtube.com/watch?v=4BbkQiQyaYc

The world population is around 6.9 billion people right now.

Up to 1800- 1 billion

1938- 2 billion

1960-3

1975-4

1987-5

1999-6

This graph shows the growth in population over time for humans. It is an exponential J curve; however, the growth rate has actually decreased from 2.19% in 1960 to 1.2 in 2010. We are still growing exponentially but the drop shows that we may be close to an inflection point. It took us 15 years to get from 3 billion to 4 then 12 years from 4 to 5, but it took us another 12 to get to 6. Now in 2010 we still don’t have 7 billion people and it has been 11 years.

Then we did population calculations using the rule of 70 to show doubling time. AGR stands for Annual Growth Rate and is always a percent. In this problem we are trying to find out the doubling time for an AGR of 1.5%.

70/AGR(%) =Doubling Time

70/(1.5%)=46.6 years≈47 years

2010+47=2057

We won’t have calculators so you must do long division by hand to show your work.

The is equation determine the AGR or rate of annual increase as it is sometimes called. CBR is crude birth rate and CDR is crude death rate. CBR is births + immigration and CDR is deaths + emigration. Crude just means out of 1000, but you multiply by 100 and 2 zeros cancel. This equation is essential in the next equation because AGR helps calculate population growth per year.

(CBR-CDR)/10=AGR%

(14-9)/10=.5%

The final thing we did was Rate of Annual Increase. THis is when you want to find how much a population has grown or will grow if it is a projection.  I have attached a picture of one way to do it(3APES at the bottom), but I prefer to take the population say 100 and multiply is by the growth rate say 2%. Then add that to the population. 

100*.02=2+100=102

3APES[1]