CIVI 6691 GHG and Control Term Project (Ibrahim Jammal)
1. Submitted to Prof. Dr. Chen
CIVI 6691
Greenhouse Gases and Control
Ibrahim Jammal - ID# 27683642
Project Report
10/27/2016
Air Travel and Climate Change
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Contents
List of Tables.............................................................................................................................. 3
List of Figures ............................................................................................................................ 3
1. Objectives:.......................................................................................................................... 4
2. Introduction (Statement): .................................................................................................. 4
3. Methods to be used in this project.................................................................................... 5
4. Airplanes, emissions and optimization .............................................................................. 5
4.1 Flight altitudes and atmosphere ................................................................................ 5
4.2 Airplanes emissions and impacts............................................................................... 7
4.3 Model: ...................................................................................................................... 10
4.3.1 Jatropha Oil:...................................................................................................... 11
4.3.2 Waste cooking oil biofuel.................................................................................. 11
4.4 Optimization............................................................................................................. 12
4.4.1 Constraints:....................................................................................................... 15
4.5 Cases, Results and Discussions:................................................................................ 15
4.5.1 Minimizing cost 2013:....................................................................................... 15
4.5.2 Stabilization of emissions in 2020:.................................................................... 17
4.5.3 Decreasing the emissions in 2050:.................................................................... 20
5. Mitigation......................................................................................................................... 22
5.1 International Agreements: ....................................................................................... 22
5.2 Individual Initiative:.................................................................................................. 23
6. Future..................................................................................Error! Bookmark not defined.
7. Conclusion...........................................................................Error! Bookmark not defined.
8. References........................................................................................................................ 27
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List of Tables
Table 1 -Airplanes fuel combustion elements contributing to climate and ozone change. ..... 9
List of Figures
Figure 1 - Aviation impacts on the atmosphere........................................................................ 7
Figure 2 - Contrails left behind an airplane............................................................................... 8
Figure 3 - CO2 emissions/passenger calculated on ICAO website........................................... 14
Figure 4 - Ethanol and Biodiesel production increase ............................................................ 18
Figure 5 - Prototype model ..................................................................................................... 25
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1. Objectives:
This Study aims to recognize the impact of air travel on the climate change and its
contribution to the greenhouse gases levels. It also aims to study how to reduce its
impacts and identify the possible alternatives.
2. Introduction (Statement):
Aviation is the fastest and one of the most important mean of transport on earth.
Aircrafts can differ in size, shape and use; from the commercial, personal use to the
military use; from airplanes carrying four passengers, to airplanes carrying up to 853
passengersi.
The biggest part of the industry is made up by the commercial fleets (passenger and
cargo fleets, more than 80%). These airplanes use Jet fuel or aviation turbine
fuel (ATF) to run their gas turbine engines. Jet fuel is a mixture of a large number of
different hydrocarbons (fossil fuel). The combustion of the jet fuel results in the
emission of different types of gases. Some of these gases are a part of the
greenhouse gases; hence they have impacts on the global warming.
These impacts can be negative or even positive. Hence these impacts on global
climate should be studied to minimize the negative impacts and find a way to
increase the positive impacts.
Even though the air travel industry is relatively small compared to other means of
transport, like automobiles, but it has a bigger impact per passenger kilometer on the
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earth climate compared to the other means. Moreover, this sector is growing rapidly,
“since 1990; CO2 emissions from international aviation have increased 83 per cent”ii.
3. Methods to be used in this project
Aviation GHG emission, effects, and management
In this case study, aviation emissions will enumerated, showing their impacts and
effects on climate change. Also how it is possible to manage and limit their impacts.
Moreover, the impacts of the endless increase of the aviation emissions hence the
related increase in the global temperature expected to be calculated.
Optimization
Optimization is used to determine the lowest cost, emissions for current years and to
predict the future scenarios, and it will allow us to determine which field can be
improved to reach emission goals.
4. Airplanes, emissions and optimization
4.1 Flight altitudes and atmosphere
The impacts of the aviation emissions depend mostly on the flight altitude and
whether aircraft fly in the troposphere or stratosphere. The impacts on the
atmosphere can be noticeably different from the effects of the same emissions at
ground level. Flight levels are used to safeguard safe vertical separation between
airplanes; they are defined by a number, which is this nominal altitude in hecto-feet,
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which is a multiple of 500 ft, hence it always ends with 0 or 5. Therefore, a pressure
altitude of, for example, 32,500 feet is referred to as "flight level 325". “Most
commercial airplanes have a service ceiling of about 42,000 feet (12,802 m)”iii and
some commercial jets can reach about 51,000 feet (15,545 m) in altitudeiv, knowing
that the stratosphere starts at 59,000 ft (18000 m); at mid latitudes, it starts at
33,000-43,000 ft (10,000 to 13,000 m) at the poles, it starts at about 26,000 ft (8,000
m). Within the stratosphere layer, temperature increases; as level increases, noting
that the top of the stratosphere has a temperature of about −3°Cv. The increase of
temperature within the stratosphere with altitude is due to the absorption of
the ultraviolet radiation from the sun and the breaking of ozone, noting that clouds
rarely form at this level.
On an important side note, although the biggest time of the flight is spent on high
altitudes, but the part with the biggest impact on the environment is the takeoff and
the landing, hence as livesmartbc.ca advises us to book direct flight instead of
indirect trips, as they mention “direct flight produces less CO2 emissions that an
equivalent flight with many stops.”vi
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4.2 Airplanes emissions and impacts
Figure 1 - Aviation impacts on the atmospherevii
.
The emissions of airplanes can vary from gases of direct impact on climate, like
Carbone dioxide and water, and others with indirect impacts, like formation of
contrails and modified cirrus clouds, production of ozone in the troposphere and
alteration of methane lifetime. Also other emissions like nitrogen oxides, water vapor
and particulates affect stratospheric ozone indirectly by modifying the chemical
balance in the stratosphereviii.
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Figure 2 - Contrails left behind an airplane.
The Table 1, below, shows airplanes important emissions, that have a big impact on
the atmosphere, with summaries of their roles that they play. These emissions are
separated into two groups, depending on how they affect climate: Direct, like CO2,
where the emitted compound can change climate, and indirect, where the climate
species is not the same as the emitted species, like modified cirrus cloud coverage
resulting from particles and particle parent material.
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Noting that, the decrease in ozone, whether in the troposphere or stratosphere, will
augment UV-B radiation and cause a decrease in the Earth's temperature.
Contrariwise, the increase in ozone will cause the reduction of UV-B and cause the
increase in the Earth's surface temperature.
Also, the temperature increase at the Earth's surface caused by the increase of
atmospheric CO2 concentration levels will be followed by the cooling of the
stratosphereix.
This table showed us the importance of the emissions on altitude and the different
impacts of emissions on different altitudes.
Furthermore, the amount of CO2 produced in the combustion process of aviation oil
is determined by the total amount of carbon in the fuel, because CO2 and water are
an inevitable end product of this process. Keeping in mind, that the transport and
processing of the CO2 released by airplanes, into the atmosphere, follows the same
trails of the CO2 emitted by other source. Therefore, “CO2 emitted from aviation
becomes well mixed and indistinguishable from CO2 from other fossil fuel sources,
and has the same effects on climate”x.
4.3 Model:
After a several years of research from airplane engine manufacturers biofuels were
approved for commercial use in July 2011. Knowing that, using biofuel requires no
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modification for the jet enginesxi. Jet Biofuel performs as good as regular Jet A1 fuel,
it even gives better fuel economy than the engine running on traditional Jet A1.
4.3.1 Jatropha Oil:
A study conducted by the Yale School of Forestry on Jatropha Oil, which is a biofuel
that can be used as jet biofuel, estimated that using Jatropha Oil can reduce
greenhouse gas emissions up to 85%. Noting these biofuels do not contain sulfur
compounds, therefore they do not release sulfur dioxide.
Jatropha Oil oil is a bit cheaper than crude oil, costing an estimated $43 per barrel
with the current barrel price of $46 for a barrel of crude oilxii.
On October 28th, 2011 Air China was the first to complete successfully flight by a
Chinese airline that used Jatropha Oil biofuel. The mixture was a 50:50 mix of
conventional jet fuel mixed with Jatropha Oil oil produced by China National
Petroleum Corp. The 747-400 powered one of its four engines on the fuel mixture
during a one hour trip around Beijing international airportxiii.
4.3.2 Waste cooking oil biofuel
In March 2015, Hainan Airlines has completed China's first commercial flight using
biofuel, made from waste cooking oil. The Boeing 737 plane used a 50-50 mix of
conventional jet fuel and biofuel made from waste cooking oil gathered from
restaurants. It is estimated that waste oil in China could produce 500 million gallons
of biofuel annuallyxiv.
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Studies by the U.S. Department of Energy showed that waste cooking biofuel
decreases carbon emissions by 50-80% on a lifecycle basis compared to Kerosene
based jet fuel.xv But the biofuel produced by waste cooking oil is more expensive
than fossil fuel; its price is estimated to be 30% higher than the regular fuel; because
there is a challenge in the large number of pre-treatment procedures, such as
filtration and extraction to reach the level of purity, from used cooking to aviation bio-
kerosene. Noting that, this biofuel price is around 6% higher than regular jet fuelsxvi.
4.4 Optimization
The Numbers used in this case study were based on all US Airlinesxvii This
study was conducted in
Total fuel consumption by all US airlines in 2013: 13.2 billion US Gallons
Total fuel cost to all US airlines in 2013: $40.5 billion USD
Average price per gallon of jet fuel paid by US airlines in 2013: $3.07 USD
Percentage of total US airline costs attributed to fuel in 2013: 34%
Total number of airplanes operated by US airlines in 2013: 3,434
Total number of flights operated by US airlines in 2013: 4.7 million
Average amount of fuel used per flight by US airlines in 2013:
2,790 gallons, $8,575 dollars
f expected system cost ($) every year
ACf: available fossil jet fuel every year (106 Gallons/year)
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ACw : available waste vegetable oil Biofuel from households every year (106
Gallons/year)
ACj: available Jatropha Oil Biofuel every year (106 Gallons/year)
COTf GHG-emission rate for fossil fuel (lb. CO2 Eq. per Gallon)
COTw GHG-emission rate for waste vegetable oil Biofuel (lb. CO2 Eq. per Gallon)
COTw GHG-emission rate for Jatropha Oil Biofuel (lb. CO2 Eq. per Gallon)
DTF total fuel consumption/demand (Gallons/year) (US Airlines)
PTCf cost for purchasing targeted coal ($/Gallon)
PTCw cost for purchasing targeted waste vegetable oil Biofuel ($/Gallon)
PTCj cost for purchasing targeted Jatropha Oil Biofuel ($/Gallon)
TAC total amount of allowed GHG emissions every year (lb. CO2 per year)
TCf target use of jet fossil fuel per year (Gallons/year)
TCf target use of waste vegetable oil biofuel per year (Gallons/year)
TCf target use of Jatropha Oil Biofuel per year (Gallons/year)
Based on the above mentioned numbers:
DTF = 13.2 Billion US gal/year = 13200x106 Gal/year.
PTCf = 3.07$/gal
Waste Cooking oil has 6% higher price, as mentioned above, therefore:
PTCw = 3.25$/gal
While Jetropha oil
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PTCj = 2.86$/gal
TAC = 110 Mton
Figure 3 - CO2 emissions/passenger calculated on ICAO website
According to the above table emissions per passenger are equal to 583.5 Lb. of CO2
per passenger, assuming the plane is Boeing 333 (Capacity 228 passengers) with
occupancy of 200 passengers. Hence the total emissions of the trip is = 116700 lb.
CO2/40072.8 lb. fuel per flight hence equal to =2.91 lb. CO2/Lb. Fuel.
COTf = 19.78 Lb. CO2/gal.
As mentioned above, in the case study, the waste cooking oil biofuel has carbon 50
to 80% less CO2 emission. Assuming 60% less emission, hence:
COTw = 19.78*0.4 Lb. CO2/gal = 7.9 Lb CO2/gal.
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Emissions by Jatropha can be less by up to 85% than the fossil fuel, assuming 65%
less emissions, hence:
COTj = 19.78*0.35 Lb. CO2/gal = 6.9 Lb. CO2/gal.
4.4.1 Constraints:
Availability:
Since the current demand in this case study is 13.2 billion gal., therefore, we
assume the availability of fossil fuel is higher than that, since it is abundant on the
US market, hence:
ACf <= 14000x106 gal./years
ACw <= 2000x106 gal./years
ACj <= 1000x106 gal./years
DTF = TCf + TCw + TCj
TAC<= 0.11 Mt
Hence 19.78xTCf + 7.9xTCw + 6.9xTCj <= 240x109 lb. CO2
Total Cost: 3.07xTCf + 3.25xTCw + 2.86xTCj
4.5 Cases, Results and Discussions:
Solving the above for the following cases:
4.5.1 Minimizing cost 2013:
Minimize the cost according to current demand of the year 2013, adding the use of
Biofuels compared to the original case, using only fossil fuel.
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minimize the costsubjecttoemmisionandresources
Objective function=PTCf*TCf+PTCw*TCw+PTCj*TCj
f= 40,438,484,848
11,508,417,508 691,582,492 1,000,000,000
TCf TCw TCj
st1 11,508,417,508 <= 13,600,000,000 Fossil Fuel availability
st2 691,582,492 <= 2,000,000,000 Waste cooking oil biofuel Availability
st3 1,000,000,000 <= 1,000,000,000 Jatropha oil biofuel Availability
st4 13,200,000,000 >= 13,200,000,000 Fuel Demand
st5 240,000,000,000 <= 240,000,000,000 emissioncap
st6 11,508,417,508 >= 0
st7 691,582,492 >= 0
st8 1,000,000,000 >= 0
Discussions:
To minimize the cost the whole available Jatropha oil biofuel was used, since it has
the lowest cost between the available fuels. The rest of the demand was covered by
Fossil fuel and the waste cooking oil biofuel. Although the waste cooking oil fuel is
more expensive, but has lower emission rates, this is why the rest of the demand
wasn’t covered by the fossil fuel only, so the emissions stay less or equal to the
emission cap. Comparing the total cost reached through the optimization and the
original cost, we notice that the cost reached is bit lower than the original one (40.43
Billions < 40.50 Billions), with lower emissions. Hence the use of biofuels doesn’t
only decrease the emissions; it might be able to decrease the costs too.
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4.5.2 Stabilization of emissions in 2020:
Aviation industry is committed to improve its fuel efficiency by an average of 1.5%
per year, between 2010 and 2020, to stabilize the CO2 emissions. The growth
expected of the aviation industry yearly is 5.3%, as it averaged globally, between
September 2014 compared and September 2013xviii. Also noting that the European
Union, greenhouse gas emissions from aviation increased by 87% between 1990
and 2006xix, this means an annual increase of 5.4%. Hence the growth rate can be
considered constant, using an annual growth of 5.3% the demand in the year 2020,
starting with the year 2013, will be higher by 37.1%, hence 13.2*109x1.371 = 18x109
gal.year.
Noting that the increase in global biodiesel production increased in 2010, a 12
percent increase from 2009xx, as shown in the figure 4 below. Consider the same
rate of increase annually for both waste cooking oil based biofuel and Jatropha
based biofuel. The total increase would be 84% by 2020.
Considering an increase in the budget of 38% from the initial budget/cost, hence it
would be = $55.89 Billion. (Similar to the increase in demand and the aviation sector
considered before for the year 2020).
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Figure 4 - Ethanol and Biodiesel production increase
Solving for the above numbers in excel, with the target is to minimize emissions we
get the following results:
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Stabilizingthe CO₂ emissionsin2020 with the increase of demandand production
minimize the emissiontoreachthe same level as
2013
Objective function=19.78xTCf + 7.9xTCw + 6.9xTCj
f= 290,545,016,000
12,577,200,000 3,680,000,000 1,840,000,000
TCf TCw TCj
st1 12,577,200,000 <= 13,600,000,000 Fossil Fuel availability
st2 3,680,000,000 <= 3,680,000,000 Waste cookingoil biofuel Availability
st3 1,840,000,000 <= 1,840,000,000 Jatrophaoil biofuel Availability
st4 18,097,200,000 >= 18,097,200,000 Fuel Demand
st5 55,834,404,000 <= 55,890,000,000 Budget
st6 12,577,200,000 >= 0
st7 3,680,000,000 >= 0
st8 1,840,000,000 >= 0
Discussions:
After the increase of demand in 2020, the aim was to the aviation industry was to fix
the emissions at the same level, but according to the calculations the goal won’t be
reached (240x109 lb. CO2 in 2013, while it’s 290 x109 lb. CO2 in 2020).
This shows that the production of Biodiesel is still not enough, since all the available
amounts were consumed, despite the big increase. Hence the companies should
use other alternative fuels in addition to the ones mentioned in this study.
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4.5.3 Decreasing the emissions in 2050:
The UNFCCC aims to turn the neutral growth of carbon (between 2010 & 2020) to a
decrease after 2020 to reach the half of the aviation emissions by 2050 compared to
2005 levels. The forecasts/plans are shown in the graph below:
Figure 5 –future aviation emission scenariosxxi
Considering the same demand and production rates, for both, aviation and biofuel
production for the year 2050. But considering the availably of fossil fuel is constant;
since the production of fossil fuel may slow down. The emission cap reduced to less
than 50% of its value in 2005.
Considering the emissions of this sector in 2005 was 144x109 lb. CO2.
Decreasingthe CO₂ emissionsin2050 with the increase of demand and production
minimize the emissiontoreachthe 50% of the 2005
level
Objective function=19.78xTCf + 7.9xTCw + 6.9xTCj
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f= 392,496,000,000
13,600,000,000 10,880,000,000 5,440,000,000
TCf TCw TCj
st1 13,600,000,000 <= 13,600,000,000 Fossil Fuel availability
st2 10,880,000,000 <= 10,880,000,000 Waste cookingoil biofuel Availability
st3 5,440,000,000 <= 5,440,000,000 Jatrophaoil biofuel Availability
st4 29,920,000,000 >= 39,072,000,000 Fuel Demand
st5 92,670,400,000 <= 167,670,000,000 Budget
st6 13,600,000,000 >= 0
st7 10,880,000,000 >= 0
st8 5,440,000,000 >= 0
Discussions:
In this model not all constraints were met, since the increase of biofuel production
wasn’t enough to cover the demand.
Nevertheless the emissions went even higher than the 2020 level by 35%, not
achieving the goal aimed for.
We can conclude that relying on biofuels only is not enough to decrease the
emissions; drastic changes should be done. Changes could be mainly design
changes that can make airplanes lighter and faster, and more fuel efficient.
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5. Mitigation
5.1 International Agreements:
Greenhouse gases from international aviation were not included in the scope of the
first period Kyoto Protocol; unlike domestic aviation and emissions by airports; which
were included in the protocol. As an alternative, nations agreed to work through
the International Civil Aviation Organization (ICAO) to decrease emissions and to
find a solution to the distribution of emissions from global air before the start of the
second period of the Kyoto Protocol in 2009.
On October the 6th 2016, in the city of Montreal, Government, industry and civil
society delegates agreed on a new global market-based measure (GMBM) to
regulate CO2 emissions released by global aviation.xxii Sixty six states representing
more than 85% of the global aviation activity had vowed to take part in a global
market-based measure to reduce aviation emissions; having a main aim 50%
reduction of emissions by 2050, compared to 2005 emissions.
5.2 The use of biofuel and airplane upgrades:
As mentioned before in this report, Biofuels can be used to decrease the emissions
up to 85%. Different types of biofuels have been used in commercial flights, such as
Jatropha Oil, Ethanol and others, and those fuels proved that they are efficient and
they produce less GHGs emissions.
Upgrades to the airplane aerodynamics can also help improve the fuel efficiency,
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and therefore reducing emissions.
Figure 6 - An example of an upgrade - The wingletxxiii
5.3 Individual Initiatives:
Mitigation can be also done on the individual level to limit the flying unless absolutely
necessary. Step taken could be:
Taking closer vacations, therefore shorter trips and less GHG would be
emitted.
Use other means of transportation when possible, especially public transport.
Trains and buses, for example, are much more energy efficient than
airplanes.
Use video-conferences for meetings, when possible, to reduce business air
travel. Corporations profit from reduced costs at the same time reducing
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emissions.
When it is necessary to travel:
Reduce the number of flights taken by combining trips, like visiting
friends/family and business travels.
Take direct flights when possible, since take-offs and landings consume the
most fuel.
Travel during the day, because flights taken at night have a greater impact on
the climate, since the contrails during the daytime have a bigger positive
impact than night, since during the day they reflect sunrays, but during the
night they absorb infrared radiations.
Travel in the economy section, because this yields in less missions per
passenger.
Take lighter luggage, because this contributes in lowering the airplane weight
as well, hence less fuel is consumed by the airplane.
6. Conclusion
Since this sector is always growing, the future effects of the aviation emissions on
the environment are questionable. What measures are going to be taken to reduce
those emissions? What special effects might there be, is there any ecofriendly
alternatives?
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As a result of this report, it can be concluded that the use if biofuels for airplanes is
not enough to reach the desired levels of GHGs emissions, although they might
have a notable impact in the near future, and they don’t require any modification on
airplanes’ design, and they can even perform better than fossil jet fuel.
Also, Environmental organizations consider that using biofuel is not the answer to
reduce airplane emissions, since as some biofuels compete with food crops, causing
deforestation and other harmful land use.
Hence radical modifications should be done to reach the emission goals, such
modifications has been subject of studies.
One of these studies is a study conducted by NASA and MIT engineers. This study
focused on the wing design. The “Digital Morphing Wing” could greatly improve an
aircraft's fuel-efficiency, reduce its emissions and make it fly more smoothly than the
conventional planesxxiv. Such modifications allow a 70 percent reduction in fuel use.
Figure 7 - Prototype model
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At the end, Aviation is like any other GHG emitting sector of transportation,
improvements and solutions are highly needed to reduce its emissions to save our
planet. Although it currently contributes to around 3% our global emissions only, but
every decrease counts. And also noting that it is a hard sector to evolve, especially
in design and safety, this is why more research is needed in this field.
7. Plagiarism Test
Please find my Plagiarism test on the below hyperlink:
https://www.thepensters.com/free-plagiarism-checker-
report.html?id=12d3d40a8602ee5e863515d1484b8ee8_1480652929:9353420
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8. References
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Manufacturer". airbus. N.p., 2016. Web. 25 Sept. 2016.
ii
"Air Travel And Climate Change". David Suzuki Foundation. N.p., 2016. Web. 10 Oct. 2016.
iii
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iv
"Bombardier | Aerospace | Business Aircraft | Bombardier Global XRS Performances".
Www2.bombardier.com. N.p., 2016. Web. 11 Oct. 2016.
v
Seinfeld,J.H.,andS. N.(2006), Atmospheric Chemistry and Physics: From Air Pollution to Climate
Change 2nd ed, Wiley, New Jersey
vi
http://www.livesmartbc.ca/homes/h_calc.html
vii
"IPCC Special Reports On Climate Change". Grida.no. N.p., 2016. Web. 18 Oct. 2016.
viii
Penner, Joyce E. Aviation And The Global Atmosphere. Cambridge: Cambridge University Press,
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ix
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x
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xi Coburn, Davin. "The Next Biofuel Frontier: Jet Engines". Popular Mechanics. N.p., 2016. Web. 30 Nov. 2016.
xii
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xv "Cooking Oil’S Use In Aviation Set To ‘Grow And Become Bigger’". EurActiv.com. N.p., 2016. Web. 30 Nov.
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xviii Larkin, Alice. "Aviation And Climate Change–The Continuing Challenge". N.p., 2016. Web. 1 Dec. 2016.
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Bringingair Transport Into EU Emissions Trading Scheme". Europa.eu. N.p., 2016. Web. 1 Dec. 2016.
xx "Biofuels Regain Momentum | Vital Signs Online". Vitalsigns.worldwatch.org. N.p., 2016. Web. 1 Dec. 2016.
xxi "The Right Flightpath To Reduce Aviation Emissions". www.atag.org/. N.p., 2016. Print.
xxii
"HistoricAgreementReached To Mitigate International Aviation Emissions". Icao.int. N.p., 2016.
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xxiii "Beginner’S Guide To Aviation Efficiency". http://www.atag.org/. N.p., 2010. Print.
xxiv Staedter, Tracy. "Airplane Wing Actively Morphs For More Agile, Efficient Flying". Seeker - Science. World.
Exploration. Seek for yourself.. N.p., 2016. Web. 2 Dec. 2016.
