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Global Warming-


Global warming is the increase in the Earth's average surface temperature. ... Eleven of the last twelve years rank among the twelve warmest years since 1850. ... – PowerPoint PPT presentation

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Title: Global Warming-

Global Warming-
  • Past Trends and Future Projections

Investigation by Edward Sun Nepean High School
Background Information
  • Global warming is the increase in the Earths
    average surface temperature.
  • Global warming is caused by the Greenhouse Effect
    and elevated emissions of greenhouse gases,
    notably carbon dioxide.
  • Naturally occurring greenhouse gases help
    regulate the Earth's climate by trapping heat in
    the atmosphere and reflecting it back to the
    surface. However, human activities have amplified
    this natural process.

Background Information (Cont)
  • In the past century, the mean surface temperature
    on Earth has increased approximately 0.6 degrees
  • Eleven of the last twelve years rank among the
    twelve warmest years since 1850.
  • If global warming is indeed caused by human
    activities, as suggested by many studies, then
    all of us are responsible to do something about

Seeking An Answer
  • Global warming is becoming one of the central
    issues of the world
  • More and more people are becoming aware of the
    undesirable effects global warming could have on
    the Earths climate, due to much propaganda.
  • Global temperatures have been rising and are
    projected to rise further in the future.

The Question
  • What factors have been causing the Earths
    climate to change, and how will it change in the
  • In an endeavour to answer the above question, I
    decided to investigate on the topic of global
  • As there are two parts to this question, data of
    past trends will be analyzed, and predictions for
    the future will be made based on these past

My Hypotheses
  • In the future, the climate of the Earth will
    likely be warmer, the sea levels will likely
    rise, and weather patterns and precipitation will
    be affected. Human activities such as burning
    fossil fuels are responsible for past alterations
    of the Earths climate.
  • Conducting research, analyzing secondary data,
    and studying relationships will help determine
    the precision of these hypotheses.

Variables Examined
The emission of CO2?
The amount of precipitation?
What is the relationship between global warming
The amount of fossil fuel burnt?
The number of motorized vehicles?
Ocean levels?
A Potential Cause
  • As global warming is primarily caused by an
    overabundance of greenhouse gases in the
    atmosphere, we will first consider some factors
    that could cause a rise in the atmospheric
    concentrations of gases such as carbon dioxide
    and nitrogen dioxide.
  • What are some things that produce these gases?

A Potential Cause (Cont)
  • The first to come to mind are cars that line the
    roads of cities, which are increasing in number
    every year.
  • Burning gasoline releases carbon dioxide.
  • As the combustion of gasoline is an absolute
    necessity for cars to run, the number of cars
    escalating through the years must surely mean
    that the amount of greenhouse gases entering the
    atmosphere has been increasing as well.

  • Below is graph of the total number of registered
    vehicles in Canada from year 1990 to 1995

The total number of registered vehicles in Canada
had been increasing at a steady rate in the six
  • Canadas economy was gradually growing, and the
    number of cars on the roads had been on the rise
    at an average rate of 1.33 each year.
  • Now let us examine what effects this had had on
    the emissions of greenhouse gases in Canada.

  • There was an increase in Canadas emissions of
    greenhouse gases at the same time as the number
    of vehicles was mounting.

When graphed onto the same axes, the strong,
positive correlation
0.83427 suggests that the increase in the
number of vehicles may be causing a rise in the
amount of greenhouse gases released into the
atmosphere. When we study the same relationship
for the United States, we find similar, positive
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  • Canada and the United States are selected in a
    cluster sample of countries in North America, as
    they are the dominant producers of greenhouse
  • Since it is shown by many studies that global
    warming is indeed caused by the Greenhouse
    Effect, we may be able to say from studying the
    above relationships that manufacturing more cars
    will contribute to global warming.
  • However, as there are many other factors that can
    cause the Earths climate to change, we cannot
    conclude with certainty that the increase in the
    number of vehicles has caused significant changes
    to the concentration of greenhouse gases in our

Burning of Fossil Fuels
  • Burning fossil fuels is another major contributor
    to atmospheric carbon dioxide concentrations.

  • As we can see from the pie chart in the previous
    slide, about 75 of the worlds energy is
    produced by burning fossil fuels.
  • Let us examine how this affects global warming.
    Here is a graph displaying the total fossil fuel
    CO2 emissions in Canada between 1985 and 2004.

  • Clearly, an increasing amount of carbon dioxide
    is being released from burning fossil fuels.

Now let us compare it with the temperature trend
in the Northern Hemisphere between 1960 and 2005.
  • As much as the temperature deviations fluctuate,
    we can see from the linear trend line that the
    average temperature had been steadily increasing.
    The graph in the next slide clearly shows the
    cause-and-effect relationship between the two

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  • It appears that the amount of fossil fuels burnt
    also has a strong, positive correlation with the
    rise in temperature.
  • From studying the statistics, we learn that
    burning fossil fuels has indeed been producing
    more and more carbon dioxide each year.
  • Since there is much evidence proving that global
    climate change is due to elevated levels of
    greenhouse gases in the atmosphere, it is fair to
    say that burning fossil fuels is definitely a
    contributing factor to the global temperature

Recent Trends and the Future
  • Despite much propaganda attempting to raise
    global awareness regarding global warming, the
    number of cars continues to increase, as do the
    sales of gasoline.

  • If we extrapolate on the graphs, we can easily
    predict that in about five years, the sales of
    gasoline in Canada will exceed 39 billion litres
    per year, while the sales of diesel oil will
    surpass 20 billion litres per year.
  • The implications of this are clear without
    saying more greenhouse gases will be produced,
    which may lead to further changes of the Earths

  • Now let us look at how the climate has been
    affected so far. On the following page is a graph
    on the average annual rainfall amounts in Canada
    between the years of 1989-2003.

  • While there were great variations in the average
    yearly rainfall amounts during this decade and
    half, we can see from the negative slope of the
    trend line that on the whole, rainfall amounts
    had been decreasing.
  • If this trend continues, then further drops in
    the amounts of rainfall can be expected.
  • We can clearly see this by extending the trend
    line on the graph.

On A Global Scale
  • So we have seen that alterations in the climate
    of the northern hemisphere have been occurring.
    Let us see if changes are also taking place on a
    global scale.
  • If the global temperatures have indeed been
    getting warmer, then we can expect to perceive
    visible changes in the Polar Regions, where a
    rise in temperature can cause the ice to melt.
  • Examining the graph on the following slide allows
    us to see the changes that had been occurring in
    the Arctic ice thickness between the years of
    1990 to 1997.

  • As we can see, the sea ice had indeed been
    melting and getting thinner over these seven
  • Because global temperatures have been climbing
    constantly, we can conclude that the ice melting
    is due to global warming.

  • Another question arises from this conclusion
    What happens to the sea level as the ice melts?
    The logical answer is that it will rise. Let us
    see if this is true.

  • As predicted, the sea levels are indeed rising.
    This can also be attributed to the global climate
    changes, as we have already concluded that global
    warming is what causes the ice to melt.
  • Let us examine a recent set of data

  • Assuming current trends will stay the same in the
    future, the likelihood of the Barents Sea level
    rising more than 10 cm in a future year is 4/6 or
  • The probability of the number of years the
    Barents Sea rises over 10 cm in sea level in the
    next twenty years can be shown by a binomial

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  • As we can see from the chart from the previous
    slide, it is most likely that the sea level of
    the Barents Sea will rise over 10 cm in 12 to 15
    years of the future twenty years, if the current
    trend continues. The expected number of years E
    (x) is 20X0.67 13.4 years.
  • Now let us calculate the probability that the
    Barents Sea rises over 10 cm in ten or more of
    the twenty years ahead. Since np20X0.6713.4 and
    nq20X0.336.6 (both greater than 5), it is
    reasonable to use a normal distribution to
  • The mean (µ) will be np13.4, and the standard
    deviation (s) will equal to (npq)½(20X0.67X0.33)

  • P(x gt 9.5)
  • 1 P(x lt 9.5)
  • 1 P(z lt (9.513.4)/2.1)
  • 1 P(z lt -1.86)
  • 1 0.0314
  • 0.97

The normal approximation shows that the
likelihood of the Barents Sea rising over 10 cm
in ten or more of the twenty future years is
about 97. This high probability is also an
indicator of how much the global climate has
changed, and how much it will continue to change
if the current trends persist.
In Conclusion
  • Strong, positive correlations have been found
    between the atmospheric concentrations of
    greenhouse gases and some human activities that
    produce such gases.
  • Analyzing climate patterns allowed calculations
    to be done on the likelihood of further climate
    changes. These calculations show that it is
    extremely likely for the Earths climate to
    continue changing in the future.
  • Looking at the obtained results, it seems that
    global warming has indeed been caused by human
    activities, and the Earths climate will likely
    experience further changes, as stated in the

  • Although the gathered statistics all strongly
    support the hypothesis, they do not confirm its
  • While it is extremely probable that the
    hypothesis is correct, the fact remains that
    there are numerous other factors that can
    contribute to the greenhouse effect, and many
    organizations around the world are taking action
    to slow, if not stop global warming.

Bias in the Data
  • Data were collected from trustworthy websites to
    minimize the number of results that are skewed
    due to various forms of bias.
  • However, in some cases the sample sizes may have
    been too small and may not be representative of
    how the climate of the entire globe has been

End of Presentation
  • Thank you for listening