Global Warming-

Past Trends and Future Projections

Investigation by Edward Sun

Nepean High School

Background Information• Global warming is the increase in the

Earth’s 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 (Con’t)

• In the past century, the mean surface temperature on Earth has increased approximately 0.6 degrees Celsius.

• 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 it.

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 Earth’s 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 Earth’s

climate to change, and how will it change in the future?

• In an endeavour to answer the above question, I decided to investigate on the topic of global warming.

• 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 trends.

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 Earth’s climate.

• Conducting research, analyzing secondary data, and studying relationships will help determine the precision of these hypotheses.

Variables Examined

What is the relationship

between global warming and:

The amount of precipitation?

The emission of CO2?

The number of motorized vehicles?Ocean

levels?

The amount of fossil fuel

burnt?

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 (Con’t)• 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:

Total Number of Motori zed Vehi cl es i n Canada, 1990-1995

y = 239657x - 5E+08R2 = 0. 9431

15200000

15400000

15600000

15800000

16000000

16200000

16400000

16600000

1989 1990 1991 1992 1993 1994 1995 1996

Year

# of

Veh

icle

s

The total number of registered vehicles in Canada had been increasing at a steady rate in the six years.

• Canada’s 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.

Canada' s Greenhouse Gas Emi ssi ons 1990-1995

y = 7. 7114x - 14893

R2 = 0. 7928

450

460

470

480

490

500

510

1989 1990 1991 1992 1993 1994 1995 1996

Year

Mega

tonn

es

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

Total Number of Vehi cl es vs. GHG Emi ssi ons i n Canada

y = 3E- 05x + 6. 32R2 = 0. 696

450

460

470

480

490

500

510

15200000 15400000 15600000 15800000 16000000 16200000 16400000 16600000

Number of Vehi cl es

Mega

tonn

es

=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 correlations.

When graphed onto the same axes, the strong, positive correlation

Total Number of Vehi cl es i n the US, 1991- 2000

y = 4E+06x - 7E+09

R2 = 0. 9912

185, 000, 000

190, 000, 000

195, 000, 000

200, 000, 000

205, 000, 000

210, 000, 000

215, 000, 000

220, 000, 000

225, 000, 000

230, 000, 000

1990 1992 1994 1996 1998 2000 2002

Year

# of

Veh

icle

s

Total Number of Vehi cl es vs. GHG Emi ssi ons i n the US

y = 3E- 05x + 943. 46R2 = 0. 9676

6000

6200

6400

6600

6800

7000

7200

190, 000, 000

195, 000, 000

200, 000, 000

205, 000, 000

210, 000, 000

215, 000, 000

220, 000, 000

225, 000, 000

230, 000, 000

Number of Vehi cl es

MMT

• Canada and the United States are selected in a cluster sample of countries in North America, as they are the dominant producers of greenhouse gases.

• 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 Earth’s 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 atmosphere.

Burning of Fossil Fuels• Burning fossil fuels is another major contributor to

atmospheric carbon dioxide concentrations.

Producti on of Energy

natural gas18%

bi omass14%

hydro6%

coal24%nucl ear

5%

oi l33%

• As we can see from the pie chart in the previous slide, about 75% of the world’s 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.

Total Fossi l Fuel CO2 Emi ssi ons i n Canada

y = 4058. 1x - 8E+06R2 = 0. 9329

0

50000

100000

150000

200000

1984 1989 1994 1999 2004

Year

TMTo

f C2

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

Atmospheri c CO2 Concentrati ons, 1959-2004

280290300310320330340350360370380390

1959 1964 1969 1974 1979 1984 1989 1994 1999 2004

Year

CO2

Conc

entr

atio

ns (

ppm)

Atmospher i c CO2Concent rat i ons (ppm)

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 variables.

Temp. Devi at i on f rom 20- Year Avg. , 1960- 2005

- 0. 4

- 0. 2

0

0. 2

0. 40. 6

0. 8

1

1. 2

1. 4

1950 1960 1970 1980 1990 2000 2010

Year

Temp

.Dev

iati

on (

Hund

redt

h of

Deg

ree

C)

Temp. Devi ati on f rom 20-YearAvg.Li near (Temp. Devi ati on f rom20-Year Avg. )

Fossi l Fuel CO2 Emi ssi ons vs. Temp. Devi at i ons f rom 20-Year Avg.

y = 9E- 06x - 0. 5897

R2 = 0. 8914

0

0. 2

0. 4

0. 6

0. 8

1

1. 2

100000 110000 120000 130000 140000 150000 160000 170000 180000

Fossi l Fuel CO2 Emi ssi ons

Tem

p. D

evia

tion (

Hundre

dth

of

Degre

e C

)

Temp. Devi ati on f rom 20-Year Avg.

(Temp. Devi ati on f rom线性20-Year Avg. )

• 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 rises.

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. Net Sales of Gasoline in Canada, 2002-2006

37,000,000

37,500,000

38,000,000

38,500,000

39,000,000

39,500,000

Net Sal es of Gasol i ne (Thousand Li t res)

Li near (Net Sal es of Gasol i ne (ThousandLi t res) )

Net Sales of Diesel Oil in Canada, 2002-2006

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

Net Sal es of Di esel Oi l ( ThousandLi t res)Li near (Net Sal es of Di esel Oi l(Thousand Li t res) )

• 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 Earth’s climate.

Net Sales of Gasoline in Canada, 2002-2006

37,000,000

37,500,000

38,000,000

38,500,000

39,000,000

39,500,000

Net Sal es of Gasol i ne (Thousand Li t res)

Li near (Net Sal es of Gasol i ne (ThousandLi t res) )

Net Sales of Diesel Oil in Canada, 2002-2006

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

Net Sal es of Di esel Oi l ( ThousandLi t res)Li near (Net Sal es of Di esel Oi l( Thousand Li t res) )

• 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.

Average Annual Rai nf al l i n Canada, 1989- 2003

1000

1100

1200

1300

1400

1500

1600

1700

1986 1990 1994 1998 2002 2006 2010 2014

Year

Am

oun

t of

Rain

fall

(mm

)

Average Annual Rai nf al l(mm)

(Average Annual线性Rai nf al l (mm) )

• 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 years.

• Because global temperatures have been climbing constantly, we can conclude that the ice melting is due to global warming.

Arct i c I ce Thi ckness, 1990- 1997

0

0. 5

1

1. 5

2

2. 5

3

3. 5

1990 1991 1992 1993 1994 1995 1996 1997 1998

Year

Me

an

Ice

Dra

ft (

m)

Mean I ce Draf t (m) (Mean I ce Draf t (m))线性

• 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.

Changes i n Sea Level , Barents Sea (1978- 2000)

- 15

- 10

- 5

0

5

10

15

20

25

30

1975 1980 1985 1990 1995 2000 2005 2010 2015

Year

Change (cm)

Changes i n Sea Level (cm)

Li near (Changes i n SeaLevel (cm))

• 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:

Year Rise in Sea Level (cm)

1995 15

1996 9

1997 15

1998 10

1999 17

2000 18

• 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 67%.

• 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 distribution:

# of Years the Barents Sea Level Rises Over 10 cm (x)

P (x)

0 20C0 (0.67)0 (0.33)20 = 2.35X10-10

1 20C1 (0.67)1 (0.33)19 = 9.53X10-9

2 20C2 (0.67)2 (0.33)18 = 1.83X10-7

3 20C3 (0.67)3 (0.33)17 = 2.24X10-6

4 20C4 (0.67)4 (0.33)16 = 1.93X10-5

5 20C5 (0.67)5 (0.33)15 = 1.25X10-4

6 20C6 (0.67)6 (0.33)14 = 6.37X10-4

7 20C7 (0.67)7 (0.33)13 = 2.59X10-3

8 20C8 (0.67)8 (0.33)12 = 8.53X10-3

9 20C9 (0.67)9 (0.33)11 = 2.31X10-2

10 20C10 (0.67)10 (0.33)10 = 5.16X10-2

11 20C11 (0.67)11 (0.33)9 = 9.52X10-2

12 20C12 (0.67)12 (0.33)8 = 0.1450

13 20C13 (0.67)13 (0.33)7 = 0.1811

14 20C14 (0.67)14 (0.33)6 = 0.1839

15 20C15 (0.67)15 (0.33)5 = 0.1493

16 20C16 (0.67)16 (0.33)4 = 9.47X10-2

17 20C17 (0.67)17 (0.33)3 = 4.53X10-2

18 20C18 (0.67)18 (0.33)2 = 1.53X10-2

19 20C19 (0.67)19 (0.33)1 =3.27X10-3

20 20C20 (0.67)20 (0.33)0 = 3.32X10-4

• 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 np=20X0.67=13.4 and nq=20X0.33=6.6 (both greater than 5), it is reasonable to use a normal distribution to approximate.

• The mean (μ) will be np=13.4, and the standard deviation (σ) will equal to (npq)½=(20X0.67X0.33) ½=2.1

P(x > 9.5)

= 1 – P(x < 9.5)

= 1 – P(z < (9.5–13.4)/2.1)

= 1 – P(z < -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 Earth’s 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 Earth’s climate will likely experience further changes, as stated in the hypothesis

Con’t

• Although the gathered statistics all strongly support the hypothesis, they do not confirm its precision.

• 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 changing.

End of Presentation

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