Demographic Analysis


Working Partners: Agistrioti Iris, Feiran Yang


The purpose of this post is to introduce some examples of                        “Demographic Data Analysis”, show how analysis should be done involving specific mathematical models to use as tools, and further on perform accurate interpretation of the analysis as depicted in graphs and pyramids. In this post I will demonstrate real examples (using the World Population Data Sheet 2010) on which I will apply the methods and principles of appropriate demographic data analysis as well as convey, as effectively as possible, a compelling picture of the population pyramids.  

 In my effort to accurately depict all of the terms we covered in class, I will also always bear in mind information and details mentioned in our textbook. I will try to cover as many countries’ densities as possible and from a greatest possible variety of regions. My aim is to underline the differences within countries and regions in terms of demographic data and distribution. As mentioned in our textbook, “Within continents, human populations attain their highest densities in eastern, southeastern, and southern Asia” (Molles, 257) and for that reason I have included (in cooperation with my partner), China as a country of demographic interest within my analysis.

 Further on, are stated: my demographic analysis and the results found during class with my partner in a question-answer format:

 Use the World Population Data Sheet for 2010  to answer the following questions:

  1. 1. China and India have the largest populations in the world. Which of these two countries adds more people to its population annually? [Calculate the numbers added by applying the rate of natural increase to the population of each country. Hint: the rate is a percent]

Country Number of people added annually
China 6,690,500
India 17,832,000

These results were calculated by initially finding the rate of  natural increase of each selected country and then multiply it by the population number of each country respectively.


  1. 2.  What proportion of the world’s people live in the following continents/regions and what are the projected proportions by 2025 and 2050?

Continent % living today % by 2025 % by 2050
Asia 60 60 57
North America 5 5 5
Latin America 5.7 5.5 5
Europe 11 9 8
Oceania 0.5 0.6 0.6

The results were found by initially finding the world’s total population. After that, we found separately the populations of each region and compared them (division: /) to the world’s total population. This calculation resulted to 5 different percent rates (for year:2010, today) which we repeated two times more for the years 2025 and 2050 to find the estimated population increase of each region in the future.

 Use the data above and Excel to construct a bar chart showing the regional distributions of the world’s population for the current year, 2025, and 2050. Save your graph.

To perform this step, we transferred all our data (final table with resulting numbers) in an Excel sheet. With the help of the appropriate tools of Excel we managed to construct the necessary bar-chart of the world’s population distribution.


The World’s population is going to be decreased. 2050’s population is going to be smaller it is in 2025, and the population in 2025 is going to be smaller than it is today.


  1. What proportion of the world’s people live in less developed countries (LDCs) and in more developed countries (MDCs) today? What proportion is projected to live in LDCs  and MDCs in 2025 and in 2050?

Countries % of world’s population today % of world’s population in 2025 % of world’s population in 2050
LDCs 82 84 86
MDCs 18 16 14

Again by using the World’s total population (found for question 1), we found the total population living in less developed countries and compared that to the world’s total population number. The result was the percent proportion of total world’s population living in less developed countries. The remaining percentage represented the proportion of total world’s population living in the more developed countries. The same whole procedure was repeated for the years 2025 and 2050.

Discuss with your partner a) the economic and b) the social implications of the changing proportions of the world’s people in LDCs and MDCs. Record your observations.

Having taken into account our results calculated for the % proportions of people living in more or less developed countries, my partner and I concluded to some interesting observations: The proportion of people living in the less developed countries is seemingly going to increase from today until the year 2050, whereas the proportion of people living in the more developed countries is estimated to decrease from today until 2050. This observation could possibly be translated into a possible future forecast of a global economic depreciation. The social implication of this could take the dimensions of possible migration (of people living in more developed countries to move to less developed ones).

  1. 4.      Examine the crude birth rate, crude death rate, and rate of natural increase of any three countries (one being your own country) listed on the World Population Data Sheet.  
Country Crude birth rate (%) Crude death rate (%) Rate of natural increase (%)
Greece 1.1 1 0.1
China 1.2 0.7 0.5
U.S. 1.4 0.8 0.6



The resulting numbers placed in the table above were found in the world’s population data sheet. In particular, the crude birth and death rates were initially in the form of number per 1000 people so these numbers had to be divided by 1000 to find the actual rate percentage.

Discuss with your group partner the mathematical relationship among these three rates. Record your observations.

 The mathematical relationship among the three rates is the following:

The rate of natural increase is the difference between Crude birth rate and Crude death rate (CBR-CDR).

 5.   Select 2 LDCs and 2 MDCs from the data sheet and compute the age-dependency ratios for each.

    Country Age-dependency ratio
    Niger 104
    Guinea 85
    Canada 45
    Germany 51

    After having selected 4 different countries (Niger, Guinea, Canada & Germany), we used the formula of the age-dependency ratio as was given:

    % of population under age 15 +  % of 65 and over X 100
    % of population ages 15-64  
    [Hint: The three percents will equal 100%. ]

    Discuss with your partner the implications of your observations:

    • o        What factors do you think contribute to a high age-dependency ratio?
    • The age-dependency is “dependent” on how well the country is developed. Usually (and as follows from the results calculated in the table of question 5) the less developed the countries, the more people they have in the ages: under 15 or over 64. In contrast, the more developed the countries, the more people they have between the ages: 15 and 64.

    • o        What are some economic and social consequences of a high age-dependency ratio?

    Usually, a high age-dependency ratio represents a low economically productive country. That is because a high age-dependency ratio implies that there are more people under the age of 15 and over the age of 64, both, groups of people that are non-productive and usually non-economically active to contribute in their country’s economical standards. Also, in terms of social consequences, countries of a high age-dependency ratio will require a society of a very well care-system (health care, and social security) for those people who are in the dependent ages.

    Interpreting Age-Sex Graphs 

    In this activity you will construct population pyramids for specific countries and speculate on differences in the quality of life in these countries.

    2.    1.   From the following table select one country from each column (two countries) from for your case.

    Column A Column B
    United Kingdom Bangladesh
    France Macedonia, FYROM
    Germany Egypt
    Israel Ethiopia
    Japan Albania
    New Zealand Thailand
    Russia Turkey
    Greece Vietnam


    From the first column we selected FRANCE and from the second column we selected EGYPT.

    2.  2.  Open the U.S. Census Bureau “International Database,” available at . Select “Data Access”. Select the assigned country (see Table 1 above) from the country list and hit “Submit”. In the new page select “Tables”. In the new page select “Excel” (see somewhere in the middle of your screen where it says: “Download all Tables as Excel”). From the Excel file record the following data for the country you selected.

      Table 1. Demographic indicators for France 
    Demographic Indicators for France 2010
      Midyear population (in thousands) 64768
      Growth rate (percent) 0,5
      Total fertility rate (births per woman) 2
      Crude birth rate (per 1,000 population) 12
      Births (in thousands) 805
      Life expectancy at birth (years) 81
      Infant mortality rate (per 1,000 births) 3
      Under 5 mortality rate (per 1,000 births) 4
      Crude death rate (per 1,000 population) 9
      Deaths (in thousands) 560
      Net migration rate (per 1,000 population) 1
      Net number of migrants (in thousands) 95  

    Table 2. Demographic indicators for Egypt 

    Demographic Indicators for Egypt 2010
      Midyear population (in thousands) 80472
      Growth rate (percent) 2
      Total fertility rate (births per woman) 3
      Crude birth rate (per 1,000 population) 25
      Births (in thousands) 2013
      Life expectancy at birth (years) 72
      Infant mortality rate (per 1,000 births) 26
      Under 5 mortality rate (per 1,000 births) 32
      Crude death rate (per 1,000 population) 5
      Deaths (in thousands) 390
      Net migration rate (per 1,000 population) -0
      Net number of migrants (in thousands) -17


    Population Pyramids

    Population Pyramid of France 

     Population Pyramid of Egypt


    Compare the demographic indicators from the two countries. What generalizations can be made concerning demographic indicators and level of development? [for example, if the birth rate is high, then the level of development is…]. Form at least two generalizations that are supported by the pyramids and data charts.

    After having recorded the tables and population pyramids for our two selected countries we found that the data in the tables as well as the population “movement” as demonstrated in the pyramids show interesting differences between the two countries. 

    One observation we made from the tables and population pyramids was the following:

    The lower the birth-rate of a country, the greater is the chance of this country to be a developed one. Specifically, and according to the tables and graphs, Egypt has a very high birthrate (more than twice the birth rate of France) but France is certainly a much more developed country than what Egypt is.

    Another observation from the demographic data tables is:

    The more developed a country is, the higher its life expectancy. In particular, Egypt’s life expectancy is 72 (birth-years) whereas the life expectancy of France reaches the age of 81 (almost 10 years more than that of Egypt). This observation is somehow expected since more developed countries have also more developed technologies and medicines to sustain a higher life-expectancy than that of less developed countries. However, this is not always and everywhere the case. There are tribes that live with absolutely no technologies (almost zero development) but sustain a very high life expectancy (see “The Baka Pygmies” post in my blog).    


     Molles Jr., Manuel C. Ecology: Concepts and Applications, Fifth Edition. New York: McGraw-Hill, 2010.

     World Population Data Sheet 2010. Population Reference Bureau. USAID. July 2010

     Dr. Grekinis. “Class Activity: Demographic Data and Graphs”. Course Notes. Ecological Principles. Moodle Course home pahe. Dept. of Business Administration, American College of Thessaloniki. 27 November 2010.

     U.S. Consensus Bureau. “International Database”. 27 November 2010.


    Posted in Assignment 8 | Leave a comment

    The careta careta sea turtle

    The purpose of this post is foremost informative where in second scale aims to create critical thoughts about the extinction of the species of careta careta as well as to encourage active response not only to this specific species’ threat of extinction but also to similar threats to other species. Especially when most of the responsibility holds to our hands; the hands of human species, it is more than our duty to at least be aware of the situation.   


    It is, I believe, clear that my topic will regard the species of careta careta and its threats of extinction. However, my goal will be to provide my readers with a wider knowledge (and hopefully more preserving) on threatened species as well as to create a sense of consciousness of this environmental emergency.

     In addition, I will try to relate my topic to as much of the material covered in class as possible. Apart from its informational character, my summary will concern terms as : “Abudance” and “Distribution” as well as some additional characteristics of the species of careta careta. More specifically I will relate my chosen article to terms such as “density”, “location” and “shape” of distribution.

    Apart from my self-interest in this topic I strongly believe that it is a topic of general environmental importance and that people’s ignorance on such emerged issues is at least unacceptable. Hopefully after reading this post my readers will share part of my perception on the importance of this matter, will gain some knowledge on this particular environmental situation and become more sensitive on the careta careta and other species’ threat of extinction. If people manage to promote not only environmental awareness but most importantly environmental consciousness, we will have a great chance to help the environment as a whole and its ecosystems.

    The Careta-careta is one of the seven species of sea turtles in the entire world! Interestingly, although it is considered as a mainly aquatic species, it has lungs and therefore it has to regularly swim upwards and raise its head above the surface of the sea to breathe in. This sea-turtle visits very regularly the shores of beaches simply because its whole reproduction process ends up outside the sea environment.

    Although the reproduction of the careta careta starts within the sea, the mother turtle has to find a preferable sandy shore to dig a burrow and there to lay off its eggs. Two months after the laying of the eggs, approximately a 70% of the eggs will hatch and lead its way towards the sea by pursuing the sunlight. This process takes place usually during the very early hours of sunlight. The careta careta turtle has been recorded in the National Red Book as an endangered species and WWF is an organization that has taken over its protection.

    Zakynthos, an island very close to Corfu (where I was born), accommodates some of the most important beaches were the reproduction of Careta careta is carefully watched and protected by experts.

    The main source that threatens this species is the human factor. Aquatic pollution, extensive fishing, waste exposal and shores’ violation are some of the most important reasons that have led this species to be threatened of extinction. Although this turtle is capable of living up to 80 years, all of the factors mentioned above have managed to turn this into an endangered species; and most importantly, all of these factors are product of human violations.

    This is a summary from an untitled article on the Careta careta turtle found in the official site of WWF ( This is a credible source mainly and most significantly because it was found in an organization site; in particular of the organization of WWF. WWF is a global net of individuals, scientists, volunteers and citizens activated in more than 100 countries. This organization deals with several environmental issues that take place globally under the mission of actively provide scientifically reliable aid to environmental challenges. The organization has a team of 5,000,000 supporters who directly or indirectly contribute to the protection of biodiversity, the promotion of renewable natural resources as well as to the reduction of pollution and mindless consumption.


    WWF Official Site. Organization.





    Picture 5.





    Zakynthos Picture.



    Posted in Assignment6 | Leave a comment

    Ecological footprint of diet

    What is your diet in terms of ecologically equivalent calories? How does this compare to the diets of other animals? This assignment serves the purpose of helping you understand how each one’s diet reflects the diet of other living beings as well as the availability of food in the environment. Through this assignment one can gain the experience of at least considering his diet, more carefully in reflection to his surrounding environment and other living species, but merely understand the translation of his diet in ecologically equivalent calories (and thus, in influence to food sources available).

    It is as to say, that our diet itself (and every living being’s diet) has its own ecological footprint to the environment. As we have in previous assignments and class sessions discussed, ecological footprint is the ecological coincidence of one’s living habits to the environmental sources available.  In terms of energy, the EF determines the amount of energy (in calories) one consumes in relation to the amount of energy that is available to that living being from its surrounding environment. In other words, the EF compares the shortage of environmental sources created by a specific species (or group of species) to the environment’s ability to renew those sources.  

    Let’s have a look to four different types of diet a living being can possibly require:

    Diet Source of diet Number of calories Ecologically equivalent calories Total ecologically equivalent calories
    100% plant Plant 2.000 2.000 2.000
    0% animal Animal 0 0
    90% plant Plant 1.800 1.800 3.800
    10% animal Animal 200 2.000
    50% plant Plant 1.000 1.000 11.000
    50% animal Animal 1.000 10.000
    0% plant Plant 0 0 20.000
    100% animal Animal 2.000 20.000

    1.Humans in position of each diet annually

    If we were in the first category, we would need : 2000×365(days)= 730000 ecologically equivalent calories for a year.

    If we were in the second category, we would need: 1387000 ecologically equivalent calories for a year.

     If we were in the third category, we would need : 11000×365(days)= 4.015.000 ecologically equivalent calories for a year.

     If we were in the fourth category, we would need : 20000×365(days)= 7300000 ecologically equivalent calories for a year.

    2. Strictly plant-based-diet vs strictly meat-based-diet

     If our diet was strictly based on plants (vegetarian diet) we would have to consume 2000 ecologically equivalent calories per day. On the other hand, if our diet was strictly based on meat (100% animal diet), we would have to consume 20000 ecologically equivalent calories per day  which is 10 times the calories of the vegetarian diet. If our diet was strictly plant-based (1st category), and we were to add a 10% of animal meat in our diet, our ecologically equivalent calories would increase by 1800 (total: 3800) per day.

    3. Vegetarian or meat eater?

    Personally, I would consider my diet slightly meat-oriented. My diet is approximately based: 60% on animal meat and 40% on plant food (not that I eat a lot of meat, but it is slightly more in proportion to what I eat from plants). In translation of my 60% animal-food and 40% plant food, my total ecologically equivalent calories are: 12.800 (800 from plant and 12.000 from meat), which is 10.800 calories more than those of someone who eats according to a strictly plant-diet (100%plant).

    4. Globalization of American Style of diet

    According to a very interesting article I read in the internet, although human behavior towards food-gathering has changed dramatically since the very early times (H. sapiens), our organisms seem to have remain stable in terms of food requirements. For instance, in ancient times, humans needed to hunt for meat (hunting required a great amount of effort and thus calories’ consuming) whereas now, humans eat the same amount of meat, only they consume almost anything (in energy) for it.

     The American Style of diet is a very interesting indication of what modern humans consume and how they get to that food. This diet is not only very rich (perhaps too rich) in meat but more importantly, it indicates the almost exclusively passive way of modern humans’ eating.

    If more and more nations started adopting the American Style of diet (a lot of meat), there would probably be inefficiency of animal meat for all the populations (not only of humans but of other meat-eater species as well) . Also, the total ecologically equivalent calories of those populations would grow significantly and this could indicate an increase of cholesterol proportion in humans. Since modern humans have decreased their activity so much, an increase in our diet’s calories could turn very dangerous for our body functions (digesting, blood pressure, amount of cholesterol etc.).

    A global adaptation of the American Style of die might also possibly lead some animals to extinction. As we have many times discussed, food sources on earth are constant in amount, an extreme change in humans’ diet (extreme increase in meat consumption) would probably make some sources of food inefficient and some animals that are most regularly used for meat consumption could be in danger of extinction.

    Finally, another important issue that is raised by this model of development is that estimations show that increase of meat in human diet, increases CO2 proportion on earth, increasing the greenhouse effect. 


    “Meat and meat products in human nutrition in developing countries”. FAO Corporate Document Repository. Retrieved on October 23, 2010 from:

    Challem, Jack. “Paleolithic Nutrition:Your Future Is In Your Dietary Past”.The Nutrition Reporter. Retrieved on October 23, 2010 from:

    Media source. Photo. Retrieved on October 23 from :

    Other pictures. Pictures. Google engine machine. Retrieved on October 23, 2010 from:

    Posted in Assignment 5 | Leave a comment

    Meerkat’s Thermoregulation

    Do you remember “Timon”?

                The species I decided to write about is the Meerkat (like my user-name in wordpress). Meerkat is a small animal that lives in the Kalahari desert of Africa and the most famous Meerkat is “Timon”, from the animation movie: “The Lion King”. I simply adore this little creature because I find it extraordinarily cute and since everyone is familiar with one Meerkat (Timon) I decided to write about this species. The real reason however of this assignment in general is to get us familiarized with the terms we covered in class, like: “thermoregulation”, “endothermic animals”, “ecosystems”, “biomes” etc. Also, we are faced with the task to apply these terms on a real example of our own and this will help us understand the actual dimensions of such terms, what they mean for the living of a species as well as how these are defined.

                As I mentioned earlier, the Meerkat is a small predator animal that belongs to the mongoose family and lives in the Kalahari desert of southern Africa. Their scientific name as species is “Suricata suricatta”, they live in Savanna biomes and are endemic (they live in particular areas and are not wide-spread). The geographical area in which they live is mainly Africa (in particular, the Kalahari desert) where the climate is mainly dry and with great temperature fluctuations. Meerkats are called “The Solar Panel of the Animal World” due to the way they use their dark-skinned, sparsely furred bellies to warm up.

    Meerkats’ thermoregulation


    • In more details..


                Meerkats are small animals that live in the heart of Kalahari Desert in southern Africa. Their scientific name as species is “Suricata suricatta, Herpestidae” and they are small desert predators (their height is approximately 30cm (12 inches) and their weight is 0,9kgr (2 pounds)) which belong to the family of mongoose. As for their light-absorbency meerkats are called “The Solar Panel of the Animal World” due to the way they use their dark-skinned, sparsely furred bellies to warm up. ( Meerkat Information, Fellow Earthlings Wildlife Centre, 2010 ). The biome in which they live is a Savanna biome; merely defined by a grassy ground layer and a distinct upper layer of woody plants. Meerkats are found in the Kalahari desert of south Africa where the annual rainfall varies from 100mm to 500mm determining a considerable dry climate. Average winter temperature is 28°Celcius however, a maximum day temperature is 42°C under shade and can possibly reach 70°C on open sand (Climate of Kalahari Desert; Mean Annual Rainfall, 2010). High temperature fluctuations and scarce food and water availability are characteristics of the dryland ecosystems (of Savanna biomes) where meerkats live in. (Endemic Species of the Kalahari Desert , 2010). Meerkats are endemic species, meaning that they are found in particular regions (Kalahari desert), are not wide-spread and are of great conservation concern.

    • Thermoregulation and mechanisms


            Meerkats, ‘utilize a high proportion of behavioral thermoregulation”. From scientific research it was shown that sun plays a very important role in their body-temperature regulation (solar radiation) as well as: contact lying and “piloerection”.

    “Piloerection” is a defensive mechanism mammals use to protect their bodies from extreme temperatures. It consist of a psychological reaction their nervous system that “causes certain muscles to contract and hair follicles to protrude outwards from the skin”. (D. Jeffress, 2010).

    More precisely and under consideration of Schmidt-Nielsen’s equation we have the following:

    Hs = Hm ± Hcd ± Hcv ± Hr – He


    Meerkats as endothermic animals base their temperature regulation mostly on metabolic rate (Hm) similarly to humans. Increasing metabolic rate increases the rate at which meerkats generate metabolic Heat (a function of blood flow within the body). Piloerection is an example of mechanism meerkats use in order to generate metabolic heat. However, as I mentioned earlier, they also use other ways such as contact lying, which is a function of Conduction (Hcd) to maintain normal body temperature.

    They consist of endothermic animals because thermoregulation is merely based on the function of their own bodies and metabolism. As Molles states “Thermoregulation outside the thermal neutral zone costs energy that could be otherwise dicected toward reproduction” (p.115). Concerning Meerkats, it was found that these animals utilize a high proportion of behavior to minimize energetic costs (Nogge, Gunther (Prof. Dr.),2010). Again that happens as a function of their body metabolism and the blood flow within their organisms and consists of another mechanism these animals use to thermoregulate.  

    Physical Characteristics:

    The typical body temperature of meerkats is approximately: 36,3C and their basal metabolic rate is 1,7290 W. (metabolic rate per mass is: 0,002034 W/g):

    Head and Body Length: 10-14 in (25-35 cm) females slightly larger than males

    Tail Length: 7-10 in (17-25 cm)

    Shoulder height: 6 inches (15 centimeters)

    Weight: 1.3-2.1 lb (626-969 g)

    Typical body temperature: 309ºK or 36.3ºC or 97.3ºF

    Basal metabolic rate: 1.7290 W

    Metabolic rate per body mass: 0.002034 W/g

    (Meerkat, 2010)

    Although their location is defined by very high temperatures, Meerkats are more sensitive to the cold rather than the warm climate and therefore they take advantage of the hot sun that helps them keep heat reservoirs within their bodies for the cold nights.


    Activity Budget:

    The Suricata suricatta is only active during day-time. Even during day however, when air temperature is extreme, these animals minimize their activity and find shelter in the burrows they make to protect themselves. (Meerkat, 2010)

    Need for thermoregulation:

    Meerkats, being animals of the Kalahari Desert in Southern Africa, have the characteristic of a 40% lower metabolic rate in comparison to other animals in the rest parts of the world.  This characteristic (of such a low metabolic rate) enables animals to survive with less food and water.  The Kalahari Desert however, is not the most pleasant area for living since intense heat puts animals at risk of overheating. This makes the ability to efficiently regulate body temperature a necessity for the “Suricata suricatta”.  In addition, body size is a benefit to the animals of Savanna biomes; the smaller the animal the faster the loss and gain of body heat.  




    Endemic Species of the Kalahari Desert. Convection on Biological Diversity. UNEP. Retrieved October 16, 2010 from

    Meerkat Information. Fellow Earthlings’ Wildlife Center, Inc. Retrieved October 16, 2010 from

    Climate of Kalahari Desert; Mean Annual Rainfall. Kalahari. Retrieved October 16, 2010 from

    Molles, M.C. (2010). Ecology. Concepts and Applications. 5th Ed. NY: McGraw-Hill.

    D. Jeffress, (8 Sept 2010).What Is Piloerection. WiseGeek. Retrieved October 16, 2010 from

    Nogge, Gunther (Prof. Dr.). Behavioural Cost Minimisation and Minimal Invasive Blood-Sampling in Meerkats (S. suricatta, Herpestidae). KUPS. Retrieved October 17, 2010 from


    Meerkat. (23 Jan, 2010). Wiki. Retrieved October 17, 2010 from

    Posted in Assignment4 | Leave a comment

    Water scarcity






    PART B.

    1. Have you ever water scarcity, such as drought?

          Luckily, I have never experienced a real drought period to the extent of water scarcity however, a short experience of mine can make imagine how hard it must be. A few years ago I travelled to South Africa for 10 days. Our trip was very well organized and even though we went into the wild, we had entourage that was very well trained. During our visit to Zimbabwe, we dedicated one of our days to visit the Victoria Falls. Only the guides forgot to tell us to take with us at least 3 bottles of water each (3 litres). The daily trip was from early in the morning (07:00 am) until the early evening ( 21:00 pm) and the most organized of us had only a small bottle of water (0.5 litres) each; not to mention the unorganized who didn’t take anything with them. I still remember the feeling, after only 2 hours of walking, my bottle was empty and the distance to cover seemed endless.

          The temperature was approximately 40°C but the climate and environment made you thirsty just by looking at it. Imagine being at a very high spot from where you had the clearest view of the water falls but yet being too far to drink from their water. We were walking in a rain forest for hours without finding a source of drinkable water. Our guides were laughing because we were so vulnerable to water scarcity that it seemed odd to them. (I can imagine they were much more used to such situations than us). By the time we were back the only thing I was thinking about was water! I rushed into the hotel and asked for a glass of water.

          I think it is very interesting to see that for us who live in western civilization cultures, water is so given while there are entire communities of people for which water scarcity is simply an everyday factor they have to live with. I will always remember this experience because it made me think more critically about things I had so far been using and consuming unconsciously. My own experience of water scarcity lasted for only a few hours and I had the feeling I would faint, I really don’t know what I would do in a situation of actual drought and real water scarcity.

          In my example, there was nothing we could really do about our thirst but in a drought period, all I can think of is to minimize your activity (every kind of activity) to prevent yourself from fainting. Now, from a macro-view, I believe every society should have water reservoirs for such emergencies as well as activated technologies to predict such situations (ex: drought). Some of the causes that can lead to water scarcity in large are: human intervention to extend the with of water reservoirs, aquatic pollution and channelization.     

          There have however, been some actions from the part of EU to deal with this. (“EU Against climate change; Adapting to climate change”, ) According to the article, Europe will soon also suffer from significant climate changes, and especially, Southern Europe and the entire Mediterranean basin will suffer from extreme temperatures and drought. “It is estimated that there is potential for saving 40% of the EU’s current water use. A communication issued by the Commission in 2007 to kickstart the debate sets out an initial set of policy options for increasing water efficiency and saving in the EU.”

      2. In some places around the world, water scarcity is a way of life. Why might this be the case? Do people always settle in biomes that are characterized by abundant water supplies, or do some people live in dry, desert climates?

        In our last lecture we learned that even in the deepest levels of the oceans, where there is complete absence of light, there still is life. I remember we compared this kind of life with the one in deserts. “How can living species survive in an environment of absolutely no light?” seems to me a similar question to “How can people live in deserts, under extreme temperatures and drought conditions?”. As an answer to the first question we learned (by surprise), that life is not only nourished by phytoplankton and zooplankton produced by photosynthesis. That there is another procedure that takes place: “chemosynthesis” and which can produce life equally well. The same I believe, stands for deserts and generally areas of water scarcity. Since there is life in such places, there are also the necessary resources; only, perhaps in a different form.

          Also, when speaking about the floor-waters of the oceans we mentioned that the species living in these levels have fully adapted their needs to the existing conditions. (example: We referred to fish which produce light.) In the same way I believe all kinds of species (including humans), have found a way (or ways) to adapt to the conditions of a completely different environment. When we were discussing about different biomes I remember we said, that even in the Mediterranean Woodland biome (where temperature is less extreme than in deserts), we have fire-resistant plants and even animals are amazingly diverse and show several adaptations to drought.  

          Similarly, in deserts (and other water scarcity areas) although, precipitation is lower, the existing life (plants, animals, humans) has adapted to the extreme conditions to survive. (According to our textbook, plants in deserts look very unfamiliar both in shape and colour because they have grown that way to “protect their photosynthetic surfaces from intense sunlight and reduce evaporative water losses”).

    Adaptation to water-scarcity and high temperature:

                  ” In biome, plants living in deserts exhibit adaptations to dryness of soil and high temperatures. They face the problem of insufficient water supply and a higher rate of transpiration.

                  Some plants are ephemeral. They complete their lifecycle in a short, favourable season and survive in a dormant state as seeds through the unfavourable period. Annual plants live in the way.

                 Some other plants have deep root systems. They reach the water table and meet their requirements by absorbing water from it.”(     

     By making a quick research about people living in deserts I was surprised to see that they aren’t so few as I thought. Examples are: the Tuareg (Sahara), the Bedouin (Sahara), the Bushmen of Kalahari, the Aborigines (Australia), the American Indians and people in the desert corridor of Asia. As I read through some interesting websites, I realized that most of this people sustain water scarcity by sharing resources with others. To cope with the difficult physical conditions, the Hopi from the high, dry Colorado plateau harnessed flood-waters to form crude irrigation systems to grow cereals. They share resources, such as labour and food with other families.”( ). Also, their clothing is very important to sustain such conditions. They have to wear clothes that will cover as much as possible from their bodies but yet loose-fitting to prevent themselves from sweating (sweat = evaporation = dehydration of body). 



    1). By how much is the total world population predicted to change between 1950 and 2050?

     Between 1950 and 2050, the world population is about to change from approximately 2,5 billion people to more than 9 billion! In other words, within a period of only 100 years, world population is about to grow to almost 4 times.

     2). By how much is the average world per capita water availability predicted to change between 1950 and 2050?

     The average world per capita water availability between 1950 and 2050, is predicted to change from almost 17000m3, to less than 5000m3. It will be reduced to less than its 1/3.

     3). What is the relationship between the population and per capita water availability? In other words, as population increase, what happens to water availability?

     The relationship between the population and per capita water availability is negative. In other words, this means that as population increases, per capita water availability decreases.

     4). Why do you think this is the case? Why do you see this relationship between population and water availability?

                From one point of view, this observation (of negative relationship between water availability and population) seems like a paradox. We are already struggling to find a solution to water scarcity (this means, that already water scarcity is a problem to human living) and on the other hand, population increases. My question is how will population actually increase under water scarcity that is becoming more and more intense? This could mean that we will find other resources (replace water?), or simply take away all the water that is available from plants and animals.

                On the other hand, it seems perfectly logic as an outcome that as human population increases, water scarcity will become more intense. More people, means more needs and consuming of everything (including water of course). So, if we take population increase as a cause and water availability decrease as an effect, than this observation does indeed make sense.

     5). If the predictions for world population growth and per capita water available come true, in what ways might the world be different in 2050 than it is today?

                If these predictions come true, I believe that the world will become a global desert. Given that resources are somehow limited, or at least their turnover time is limited (more specifically; water), the significantly increased human population will survive only under the expense of other populations (plants and animals). The world will look very different as vegetation will probably be very limited or completely extinct and the same will hold for animals.

                I really hope that these predictions won’t come true or I don’t want to see a world like this. It isn’t only the harm these conditions will bring to plants and animals or the beauty of the landscape but if these predictions are to come true, they will eventually have an effect on human life as well.

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    Water reservoirs, global warming and human influence on Rivers

    How will global warming affect the proportion of the earth’s water that resides in the oceans?

             Global warming has a direct impact on the water of the oceans. Global warming means rise of temperature and rise of temperature melts the polar ice gaps. Although the percentage of water that is “saved” in glaciers is only 2% of the total water on Earth, its melting will result in a significant rise of sea level. In addition, the oceans have a surprisingly fast “turnover time” (the time they need to renew their water) of 3,100 years for 1.3 billion km3 of water. More specifically, the water of the oceans has been multiplied by 30 (in quantity) within the last 100,000 years. It is as to say, that the largest reservoir of water on Earth (the oceans), renew their water so rapidly (relatively to their volume) that it is more likely that their level will rise as a result of Global warming rather than that they will end up in drought.

                The rise of sea levels may seem less or at all harmful to the aquatic life in comparison to drought. However, a significant rise in sea level will probably have as many consequences as those of drought. Perhaps large chains of life would have to migrate upwards in the sea levels or even to other seas. Also, the percentage of salinity would decrease and that might have all forms of results as well.

    II. Rivers and Streams; Human Influences

      During our last lecture we discussed intensively about all water reservoirs around the globe but rivers are the one that strikes my interest in particular. Rivers are more “close” to human reality, needs, interdependence and thus, influence. Not to underestimate the importance of the rest aquatic reservoirs, but rivers is one to which I can relate. As I have said before, I was born and raised up on Corfu; a beautiful island with many environmental emergencies. One of those emergencies is our river “Ποταμός” (Potamos) which took its name from the word: “ποτάμι”, which means: river. Its fountains are located in the villages of:

    “Βαρυπατάδες” (Varipatathes), “Άφρα” (Afra) and “Καλαφατιώνες” (Kalafationes). It has a length of approximately 3.5km and is discharged in Potamos’ gulf (the area around the river is also named Potamos, after the river).

                This river used to be a source of life and survival for the people of Corfu (around 1941-1944), when the island was under Italian-German occupation. Nowadays, its water not only is undrinkable, but so intensely polluted that is threatening a large biological chain of which survival is directly dependent to its water.

    A very close friend of mine, lives in a house in Afra and the garden of the house is bordered exactly next to the river. I remember that from his early age he was struggling with the local government to solve this problem because the situation was running out of control. Not a few times did he take me to the river and showed me corpses of animals in the upland terrestrial environment but also within the river itself (dead snakes and frogs).

    The following were published during the beginning of my friend’s environmental activism (further on, he introduced this case in the Greek Parlement and to the European Parlement but the local government of Corfu was never moved!) You can check out the website he created when he was only 17 years old (some of his articles are in English for you to read): : (Ο Θάνος Καυκαλίδης γεννήθηκε στις 16 Ιουνίου 1987. Είναι μαθητής Λυκείου και μέλος της  Ελληνικής Εταιρείας προστασίας του περιβάλλοντος και πολιτιστικής κληρονομιάς από το 2003. Είναι επίσης μέλος της  WWF, Greenpeace, Ορνιθολογικής Εταιρείας Ελλάδος, ΕΚΠΑΖ και Αρκτούρος : Thanos Kafkalidis was born in 16 June of 1987. He is a high school student and member of the Greek Association for environmental rescue since 2003. Also, he is a member of WWF, Greenpeace, ornithological association of Greece, ΕΚΠΑΖ and “Αρκτούρος” : Arktouros)

    I couldn’t possibly refer to global warming in relation to the river of Corfu because there haven’t been facts to reflect global warming’s influence to the river (nor has it led to drought or potential drought). However, I will not say “luckily, Global warming hasn’t influenced our river” simply because it has been so badly influenced by human intrusion that it couldn’t be worse. According to our textbook rivers have this amazing capacity for recovery and renewal but in the case of our river, I think human toleration has conquered the forces of nature. In the case of Potamos, the only human intrusion has been that of waste disposal (no commerce, significant transportation or irrigation has taken place) and yet the damage is huge and unfortunately, most probably fatal.   


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    relevant to last lecture!

    hello guys! i have publist a post on a tribe in Africa which is threatened to be extinct! these people actually live in the heart of a rain forest and a paper company has started cutting off trees. -relevant to our last lecture! check it out!

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