Salty and Getting Fresh
The  Economist from March 29, 2012
http://www.economist.com/node/21551514



Photo Summary: This photo is a diagram of a typical water desalination plant. Hundreds of millions of gallons of water are drawn in each day and get transformed into claen drinking water.

Summary: Water desalination is a process in which salty ocean water is used to make clean drinking water. On the west coast this process is now being used to reduce the amount of imported water they use. One plant in California called, Poseidon Resources, is the second largest plant of its kind in America. The plant draws in about 104 million gallons of water for cleaning. At the end, the plant is able to produce 50 million gallons of pure water from the original 104 million gallons. Once the plant is fully running in 2015, it is projected to produce 10 percent of the region's pure water. This process also takes away from the amount of water that has to be taken from fresh water sources such as the Colorado River. However, there is som controversy surrounding the topic. Environmentalists argue that the new plants use way too much energy, and the process is killing marine life. They say that there is a time for desalination, but is not now.

Opinion: I believe that the plants are a great idea. Since 97 percent of earth's water is salt water, this will allow us to have much more clean drinking water. However, I do believe that the amount of water and energy they are using is unacceptable. We do not have a major shortage of water in America by any means, so there is no need for this. These plants should be put on the coasts of Africa in order to get fresh water to a place that is in great need of it.    

Questions:
1) Explain some pros and cons of desalination.

2) What is your opinion on water desalination? Why?

3)Do you think this process will be relied on heavily in the future? Why or why not?

pH Levels of Household Drinking Water

http://www.freedrinkingwater.com/water-education/quality-water-ph.htm

        As we know, depending on the pH level of the substance, we can tell if it's acidic or basic. If the pH level is belwo seven, then the liquid is acidic; if the pH level is above seven, then it is basic. Many different things can cause the water in your household to be either more acidic or basic. Acid water could include metal such as iron, manganese, copper, lead, and zinc. These metals can get into your drinking water through rusty pipes and cause it to be more acidic than it should be. The more acidic water can result in a metallic/sour taste, and color staining in launrdy, sinks and drains; and that's not to mention the health problems. Just as your water can be acidic, it can be basic too. The results of basic water may be an alkali taste to the water, formation of scale deposits on dishes, utensils, and laundry basins, and difficulty in getting soaps and detergents to lather.

Opinion:
Sometimes I had noticed that the water in my house was tasting a little metallic/sour and I would have never know that it had to do with pH levels.  One way to solve this problem would be to get a water softener to regulate the pH levels of the water. A water softener would stop the water from having a 'funny' taste, or causing color staining and scale deposits.

Questions:
1. How can you keep the water from becoming too basic?
2. What can be done to prevent pipes from becoming too rusty, ultimately causing acidic water?
3. What causes hard water stains? Why?

Water Availabilty

Picture: This shows a picture of two African kids that have finally found freshwater to water and are being satisfied.

http://www.unep.org/dewa/africa/publications/aeo-1/148.htm

Summary: 

The freshwater is unevenly distributed across. Fertile areas such as western Africa and central Africa have greater precipitation than northern Africa, the Horn of Africa and southern Africa. Therefore Western and Central areas get more water availability. The average water availability per person in Africa is 5,720 m3/capita/year compared to a global average of 7,600 m3/capita/year. Problems with freshwater availability in Africa are further complicated by highly variable levels of rainfall. As a result, large numbers of people are dependent on groundwater as their primary source of freshwater. In Algeria, for example, more than 60% of people get groundwater for their main source of water and, in Libya, 95% of people get groundwater for their main source of water. Severe droughts were experienced in 1973 and 1984, when almost all African countries suffered reduced rainfall. Even with the reduced rainfall lakes and rivers are being evaporated. In Africa Lake Chad had shrunk 5% which has caused many people to be affected. Africa has the highest population growth in the world and is affected the most by extreme climate changes. To the increase of drought and flooding scientists predict that 25 African countries will experience water scarcity in the next 20 to 30 years. Some of Africa’s water cannot be drunk because of bacteria and pathogens in the water. They need to purify and treat before giving it out.

Opinion/Reaction:

            This topic didn’t surprise me that much because I knew that Africa didn’t have a lot of resources such as water. It is still sad to know that kids have to probably walk miles to receive fresh water for their family to drink. We learned in Social Studies that nations and tribes in Africa do not treat each other very nice. People in Africa will not receive any help from other people who are not in the same tribe for in their borders. Water seems like you have to fight for it and if you don’t win then you will have to find another lake or river. Water availability is not a problem in the U.S as far as I know. In this country all you need is money to get the resources you need. In Africa there isn’t an abundance of freshwater nor in the world. Out of the 75% of water in the world about 3% is fresh and most of that is in the ice caps. Water is considered a limited resource to us and I believe we could run out of it. 

Questions

1)      Do you believe that the water should be evenly distributed across Africa? Why or why not?

2)      Do you think water is considered a limited resource in today’s world?

3)      How do you think people get there water when there has been no rainfall for a while?

Has the Earth reached its carrying capacity?

Date published: Not stated
Article by: Julia Layton

http://science.howstuffworks.com/environmental/green-science/earth-carrying-capacity.htm

In 1798, an English clergyman named Thomas Malthus made a dire prediction: He said the Earth could not indefinitely support an ever-increasing human population. The planet, he said, would check population growth through famine if humans didn't check themselves.

The theory publicized by Malthus is known as the carrying capacity of Earth. Carrying capacity itself is a well-known and widely accepted concept in ecology. It's a very basic idea -- sustainability requires balance. There is a certain population number above which a species starts to damage its habitat, and life as it stands at that moment cannot go on. Typically, it's starvation that kicks in to cull the herds down to a manageable number.
The idea of Earth's carrying capacity goes something like this: Humans need certain resources to survive at subsistence level -- most commonly air, food, water and usually some kind of shelter. A sustainable habitat is one in which supply of and demand for these resources are balanced. The problem, Malthus suggested, is the difference in growth patterns between the human population and food production. He said that while the human population tends to grow exponentially (by a greater amount each year -- a percentage of the total), the food supply will only grow linearly (by a fixed amount each year -- a number, not a percentage). In this model, humans are bound to outgrow the Earth's resources.

Opinion and Reflection:

I think that the earth's carrying capacity will not be reached for a couple hundred years. The advancements in technology are stabilizing our low supply of resources. If we can get our population growth to a 0 where the birth to death ratio equals out then I think we should be fine. The one major major problem is the low supply of water left. Luckily, with the advancements we can use a process called desalination which takes the salt out of ocean water and becomes usable to us. The earth still has a while until humans reach it's carrying capacity though.  



Questions:

1. Do you think the earth will reach it's carrying capacity for humans in the next 100 years?
2. With all the advancements in technology do you think that we will ever reach this carrying capacity?
3. What is earth's carrying capacity and explain why? 

­