Environmental Kuznets Curve Using Total Nitrogenisotope.iis.u-tokyo.ac.jp/~kei/tmp/AH2015/Janice...
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Janice Koh ENVIRONMENTAL SCIENCE- PEAK 2ND YEAR
Environmental Kuznets Curve Using Total Nitrogen
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Janice Koh - 380006E
Professor Kei Yoshimura, Kazuo Oki & Keigo Noda
Earth System Science 2
Spring Semester 2015
July 26, 2015
Environmental Kuznets Curve Using Total
Nitrogen – Report
Keywords: EKC, total nitrogen, GDP, GDP per capita, HDI, Happinesss
Contents:
Introduction ………………..……………………………………. Pg 2
Background ………..………………………………………….… Pg 2
Previous study ………………………………………………….. Pg 3
Purpose ………………………………………………………...... Pg 4
Methodology …………………………………………………….. Pg 4
Discussion and Results ………………………………………… Pg 6
Conclusion ………………………………………………………. Pg 13
References ……………………………………………………… Pg 15
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1. Introduction
The research question of this paper is to investigate if an EKC or a U-shaped curve
exists if the x-axis, which is the environmental pollutant is made to be the total nitrogen
of a country, and the y-axis, which are ways of measuring the country’s development
be made to be GDP, GDP per capita, HDI, and Happiness.
The total nitrogen of a country is calculated by taking the country’s total
consumption of nitrogen fertilizer and dividing it by the total area of arable land and
permanent crops area. ‘GDP, which is the Gross Domestic Product is the monetary value
of all the finished goods and services produced within a country's borders in a specific
time period.’1 It is a good measure of the country’s economic health. GDP per capita is
also another indicator, which is obtained by simply taking the GDP divided by the
country’s population. HDI, which is the Human Development Index, is a measure of the
country’s level of social and economic development. It uses the criteria such as the life
expectancy at birth, mean years of schooling, expected years of schooling, and gross
national income per capita.2 Happiness, which is defined by the survey used by Gallup,
is a measure of how people live their lives. The survey is conducted by asking a series
of questions on a persons positive and negative experiences. An example of such
question is ‘How well-rested are you this week?’3
From the results of the EKC, we will be able to determine the priorities of the
country, estimate the turning point, and spot trends and similarities which exists in
developing and developed countries.
2. Background
The Environmental Kuznets Curve (EKC) is a hypothetical inverted-U-shaped curve
between environmental quality and economic development. In general, as income per
capita increases, the environmental pollutant emitted will in the beginning increase,
and after reaching a threshold level, the environmental pollutant emitted will
decrease.4 The EKC can be used to indicate the country’s economic and environmental
development, especially the stage in which the country is in, and also reveals which
form of development is more highly prioritized.
The EKC is divided into two stages: the first stage, where rapid pollution occurs, and
the later stage, where the decline of pollution follows. In the first stage, environmental
1 [Gross Domestic Product (GDP)] 2 [Human Development Index] 3 [Clifton] 4 [Stern, The Environmental Kuznets Curve]
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degradation occurs, as rapid growth depletes natural resources and increases the
emissions of pollutants, putting pressure on to the environment. Also, there is a lack of
interests and financial support into the improvement of environmental conditions from
businesses and the government, as people are more interested into the increasing of
the amount of material output and into the growth of business and jobs.5 In addition,
due to the poor economic condition of the country, investment into costly
environmentally-friendly technologies can simply not be performed.
Soon, the degradation of the environment will reach a turning point, and after which
the improvement of environmental conditions ensues with the increase of income per
capita. A possible reason for this change is for the occurrence of an increase in
awareness, and concern into the importance of the improvement of environmental
conditions by the public, businesses, and the government.6 As people begin to start
valuing the environment, regulatory institutions becomes more effective. As the
economic conditions improve more financial support becomes available for
environmental-friendly technologies to be implemented and later developed. In
essence, the EKC curve greatly depends heavily on what people value, if it is for a
healthy economy or for a healthy environment.
It is to note that not all environmental factors could be applied to EKC, for example,
environmental factors such as biodiversity and land-use change are not applicable, as
they are not reversible, hence, it cannot be applied to the EKC. 7 Also, another
limitation of the EKC is that it is difficult to measure environmental quality and to
obtain actual data on environmental quality.
3. Previous study
A previous study in January 2005 conducted by the Louisiana State University by
researchers Paudel, Krishna P., Hector Zapata, and Dwi Susanto, focused on finding if
an EKC relationship exists when the environmental factors are nitrogen, phosphorous,
and dissolved oxygen. In their paper titled "An Empirical Test of Environmental Kuznets
Curve for Water Pollution," 53 watershed sites in Louisiana were studied, and data from
the years 1985 to 1999 were used. The study employed statistical methods and was able
to derive a U-shaped curve for the environmental factor nitrogen, with a turning point
of approximately $12,972.
5 [Stern, Common , Barbier, Economic Growth and Environmental Degradation: ] 6 [Dinda, Environmental Kuznets Curve Hypothesis: A Survey] 7 [Stern, The Rise and Fall of the Environmental Kuznets Curve]
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4. Purpose
The reasons that nitrogen was chosen as an environmental factor is that it is one of
the limiting factors for phytoplankton bloom in a body of water that leads to the onset
of eutrophication occurring in the body of water. The prevention of eutrophication
allows for the quality of water, and the biodiversity of the lake ecosystem in a body of
water to be maintained.
There are several point sources of nitrogen pollution, such as from the usage of
excess fertilizers, animal manure, soil erosion, storm water, wastewater, fossil fuels,
detergents, lightning, and bacteria fixation. It is hard to determine the concentration
of nitrogen that gets run off into a body of water, as there are many point sources of
pollution. Hence, the total amount of fertilizers used by a country in agriculture is
utilize in the calculation of total nitrogen for the EKC in this research paper. It is also
assumed that when the total amount of fertilizers are reduced, the quality of water
correspondingly improves, which might not be the case in reality. This is based on the
assumption that the presence of less fertilizers corresponds equally to less excess
nitrogen run-off.
The factors GDP, and GDP per capita were chosen because it is a good measure of
the country’s economic output, while HDI gives a good indicator of the country’s level
of social and economic development, and Happiness reveals the contentment level of
the people in the country.
5. Methodology
The methodology used is in this paper is to make graphs, where the values for the
x-axis are GDP, HDI, and Happiness, and the values for the y-axis is Total Nitrogen. For
these graphs, seventeen countries were used and they are the United States, United
Kingdom, Canada, Switzerland, Denmark, Spain, Norway, Ecuador, Columbia, China,
Japan, Indonesia, Malaysia, Singapore, Afghanistan, Bangladesh, and Togo.
Another graph was also made where the units were changed from GDP to GDP per
capita for the x-axis. Also a change of units for total nitrogen was done, in which in one
graph the total kilograms was kg/ha, and in the other only kg was used. The x-axis GDP
per capita remains the same when the units of total nitrogen was changed, which allows
us to discern for any changes when the units for total nitrogen were modified. It is
important to note that different countries from the previous graph were used when the
units are changed. In this graph twelve countries were used, and they are as follows:
United States, United Kingdom, Canada, China, Japan, Republic of Korea, Malaysia,
Indonesia, Brazil, Bangladesh, Afghanistan, and Togo.
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The data obtained for Total Nitrogen in both cases was obtained from Knoema,
which obtained the data from the Food and Agriculture Organization of the United
Nations FAOSTAT/Resource STAT, under the category of Total Fertilizers Consumption,
and the available years of data are from 2002 to 2012.8 Same for GDP, and GDP per
capita the data was also obtained from Knoema, which obtained the data from The
World Bank Data Source. 9 For HDI, the data was obtained from United Nations
Development Programme – Human Development Reports. For the case of Happiness,
only one year was available, and the data was taken from the 2012 Gallup survey. Data
from the years 2002 to 2012 for GDP, GDP per capita, and HDI were available, however,
not so for Happiness.
An additional graph was also made where the y-axis is the amount of nitrogen
present within Kasumigaura Lake and the Arakawa River, measured in the units of
milligrams over liters. The x-axis used will be the GDP of Tokyo and Saitama
respectively in million yen. The years used for Arakawa River is from 2001 to 2009, and
the years used for Lake Kasumigaura is from 2001 to 2012.
In summary:
1st graph
X-axis: GDP, HDI, and Happiness Y-axis is Total Nitrogen
Countries used: United States, United Kingdom, Canada, Switzerland, Denmark,
Spain, Norway, Ecuador, Columbia, China, Japan, Indonesia, Malaysia, Singapore,
Afghanistan, Bangladesh, and Togo.
2nd graph
X-axis: GDP per capita Y-axis is Total Nitrogen (kg/ha) and only (kg)
Countries used: United States, United Kingdom, Canada, China, Japan, Republic of
Korea, Malaysia, Indonesia, Brazil, Bangladesh, Afghanistan, and Togo.
3rd graph
X-axis: GDP of Tokyo and Saitama (in million yen) Y-axis is Total Nitrogen (mg/L)
Place of interest : Lake Kasumigaura and Arakawa River
8 [World Development Indicators ] 9 Ibid.
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6. Discussion and Results
Graph of GDP (constant 2005 US$ in billions) vs Total Nitrogen (kg/ha)
FIGURE 1: GDP (CONSTANT 2005 US$ IN BILLIONS) VS TOTAL NITROGEN (KG/HA) –
(FILE: GDP AND HAPPINESS)
FIGURE 2: CORRELATION COEFFICIENT TABLE OF GDP VS TOTAL NITROGEN
As seen from the graph above, generally, as GDP increases the consumption of
fertilizers also increases. Only five out of seventeen countries had a negative
correlation coefficient, and also to note that these countries United Kingdom, Japan,
Singapore, Spain, and Norway are all already developed countries. In addition, a line is
drawn near the 100 GDP log-scale (constant 2005 US$ in billions), where a turning point
in the EKC curve seems to exist.
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Graph of HDI vs Total Nitrogen(kg/ha)
FIGURE 3: HDI VS TOTAL NITROGEN – (FILE: HDI)
FIGURE 4: CORRELATION COEFFICIENT TABLE OF HDI VS TOTAL NITROGEN
It can be drawn from the graph above, that in general, as HDI increases the
consumption of fertilizers also increases. In addition, from the table we can see that
most of the countries which have a positive correlation coefficient, are developing
countries, while already developed countries have a negative or weak correlation
coefficient. Also, a line, where the supposed turning point exist, is drawn near the 0.8
HDI mark.
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Graph of Happiness vs Total Nitrogen(kg/ha)
FIGURE 5: HAPPINESS (GALLUP) VS TOTAL NITROGEN (KG/HA) – (FILE: GDP AND HAPPINESS)
The graph above depicts, an unclear relationship between happiness and total
nitrogen. As only one year of data is used, it is hard to determine if any or no
relationship exists. More data from more years of survey results on happiness by Gallup
is needed for a conclusion on the relationship between happiness and total nitrogen to
be made.
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Graph of GDP per capita vs Total Nitrogen(kg/ha)
FIGURE 6: GDP PER CAPITA (CURRENT US$) VS TOTAL NITROGEN (KG/HA)
– (FILE: GDP PER CAPITA VS TOTAL NITROGEN)
FIGURE 7: CORRELATION COEFFICIENT TABLE OF GDP PER CAPITA (CURENT US$) VS TOTAL
NITROGEN (KG/HA)
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Similar with the graph of GDP (constant 2005 US$ in billions) vs Total Nitrogen
(kg/ha), GDP per capita generally increase, as the consumption of fertilizers also
increase. Only three out of the twelve countries had a negative correlation coefficient,
and also to note that these countries United Kingdom, Japan, South Korea are
developed countries. In addition, a line, in which a turning point in the EKC curve seems
to exist, is drawn near the 10,000 GDP per capita log-scale (current US$), which is
different from the line drawn at 100 GDP log-scale for the graph of GDP vs Total
Nitrogen.
Graph of GDP per capita vs Total Nitrogen(kg)
FIGURE 8: GDP PER CAPITA (CURENT US$) VS TOTAL NITROGEN (KG)
– (FILE: GDP PER CAPITA VS TOTAL NITROGEN IN KILOGRAMS)
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FIGURE 9: CORRELATION COEFFICIENT TABLE OF GDP PER CAPITA (CURENT US$) VS TOTAL
NITROGEN (KG)
The results of this graph is similar to that of the previous graph. The only
difference from the two graphs is that the country United States shows a negative
correlation coefficient when the units for total nitrogen are in kilograms, and a positive
correlation coefficient when the units for total nitrogen are in kilograms over hectares.
The reason for this change is that over the years 2002 to 2012, there has been a
decreased in the area for arable land in the United States.
Graph of EKC of Arakawa River and Lake Kasumigaura
FIGURE 10: EKC OF ARAKAWA RIVER, TOKYO GDP - (FILE: ARAKAWA AND KASUMIGAURA)
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FIGURE 11: EKC OF ARAKAWA RIVER, SAITAMA GDP - (FILE: ARAKAWA AND KASUMIGAURA)
FIGURE 12: EKC OF KASUMIGAURA LAKE, TOKYO GDP - (FILE: ARAKAWA AND KASUMIGAURA)
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For the Arakawa River, there appears to be a negative correlation between GDP
and total nitrogen (mg/L), when both the GDP of Tokyo and Saitama were used,
whereas for Lake Kasumigaura a positive correlation is seen. The negative correlation
of the Arakawa River, however, does not mean that the conditions of the lake has
improved. An increase in total nitrogen of the Arakawa River can be seen in the years
of 2008 to 2009. The same increase in total nitrogen is also found in the Kasumigaura
River. The reason for the similarity between the three graphs are because that the GDP
used in the three graphs are almost the same. In addition, the coefficient correlation
of all three graphs are relatively small, with the highest value of 0.22 for Lake
Kasumigaura, and the lowest value of -0.05 for Arakawa River vs GDP of Saitama.
7. Conclusion
For the graphs of total nitrogen and GDP or GDP per capita, generally, as GDP or
GDP per capita increases the consumption of fertilizers also increase. However, it is
important to bear in mind that each country has its own turning point. Due to the
availability of only ten years of data for the total nitrogen of each country, it is difficult
to find a turning point, as the countries are either in the 1st stage of increased
environmental pollution, or already in the end stage where environmental conditions
improves. In most cases, a clear turning point of the EKC curve for the environmental
factor of total nitrogen for some countries is not seen. In addition, there is a difference
in the vertical line, which is drawn to indicate the turning point of the EKC, value for
GDP and GDP per capita. For GDP the vertical line value is approximately a hundred
times smaller than the value of that of GDP per capita. However, the units for the two
graphs are different. For GDP the unit was in USD at 2005, and as for GDP per capita
the units used was in current USD. The usage of different units could be one of the
reasons behind the differences in the vertical line value for both graphs.
As for the graph of total nitrogen and HDI, a positive correlation can be seen for
developing countries, whereas a negative or weak correlation is seen in developed
countries. The vertical line for HDI lies around the value of 0.8 for HDI. For the graph
of total nitrogen and happiness, and unclear relationship is seen. As only one year 2012
is used, it was hard to identify any trends or relationships. More data on the Gallup
survey for happiness is needed, over the years for the graph of total nitrogen and
happiness.
Changing the units of total nitrogen from kg/ha to kg, produce almost similar results.
In addition, the vertical line drawn in both graphs has almost the same value. Among
the countries investigated, only one country which is the United States changed from
having a positive correlation coefficient when the units of kg/ha were used to a (Paudel,
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Zapata and Susanto) (Stern, The Rise and Fall of the Environmental Kuznets Curve)
(Dinda, Environmental Kuznets Curve Hypothesis: A Survey) (Dinda, A theoretical basis
for the environmental Kuznets curve) (Stern, Economic Growth and Environmental
Degradation: The Environmental Kuznets Curve and Sustainable Development)negative
correlation coefficient when the units of kg are used.
A study on the Arakawa River and Lake Kasuimigaura, was undertaken in order to
simulate the same results as that of the study conducted in 2005 in Lousiana. The
correlation coefficient for all three graphs are very low. Only the graph of the EKC of
Arakawa River and GDP of Saitama had a negative correlation coefficient. As mention
earlier, having a negative correlation coefficient does not necessarily means that the
conditions on the lake are improving. Since the three graphs, employ almost the same
GDP, some similar trends among the three graphs can be seen.
In conclusion, the EKC curve can be used as an interesting method or a useful tool
to measure the country’s development and the amount of its environmental pollution.
From the graphs produced we can identify the stages of the EKC that a country is in,
and we can compare the performance of one country with that of another. Perhaps, we
could use the results from the EKC to make future decisions regarding the reduction of
environmental pollution. By the comparison of one country’s better performance at
being able to reach development while maintaining a low amount of environmental
pollution, we could pressure another country to take steps, which will not affect the
country’s development, to reduce the amount of environmental pollution in that
country. Hopefully, from the results of the EKC, people will be more aware and
interested of the environmental problems that impends our environment, society, and
future.
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