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Emission Reduction Targets for International Aviation and Shipping

Authors:
DIRECTORATE GENERAL FOR INTERNAL POLICIES
POLICY DEPARTMENT A: ECONOMIC AND SCIENTIFIC POLICY
Emission Reduction Targets for
International Aviation and Shipping
STUDY
Abstract
This study provides an overview of potential CO2 mitigation targets for
international aviation and maritime transport and analyses which targets would
be compatible with the global long-term goal of keeping the temperature
increase below 2°C compared to pre-industrial levels. The analysis supports the
view that it is important to establish targets for both sectors which clearly
indicate that emissions cannot grow in an unlimited and unregulated way.
This study was provided by Policy Department A for the Committee on
Environment, Public Health and Food Safety (ENVI).
IP/A/ENVI/2015-11 November 2015
PE 569.964 EN
This document was requested by the European Parliament's Committee on Environment,
Public Health and Food Safety.
AUTHORS
Martin CAMES, Öko-Institut
Jakob GRAICHEN, Öko-Institut
Anne SIEMONS, Öko-Institut
Vanessa COOK, Öko-Institut
RESPONSIBLE ADMINISTRATOR
Tina OHLIGER
EDITORIAL ASSISTANT
Eva ASPLUND
LINGUISTIC VERSIONS
Original: EN
ABOUT THE EDITOR
Policy departments provide in-house and external expertise to support EP committees and
other parliamentary bodies in shaping legislation and exercising democratic scrutiny over
EU internal policies.
To contact Policy Department A or to subscribe to its newsletter please write to:
Policy Department A: Economic and Scientific Policy
European Parliament
B-1047 Brussels
E-mail: Poldep-Economy-Science@ep.europa.eu
Manuscript completed in November 2015
© European Union, 2015
This document is available on the Internet at:
http://www.europarl.europa.eu/studies
DISCLAIMER
The opinions expressed in this document are the sole responsibility of the author and do
not necessarily represent the official position of the European Parliament.
Reproduction and translation for non-commercial purposes are authorised, provided the
source is acknowledged and the publisher is given prior notice and sent a copy.
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 3
CONTENTS
LIST OF ABBREVIATIONS 4
LIST OF BOXES 6
LIST OF FIGURES 7
LIST OF TABLES 8
EXECUTIVE SUMMARY 9
INTRODUCTION 10 1.
HISTORIC EMISSION TRENDS 12 2.
EFFORTS TO ADDRESS GHG EMISSIONS 16 3.
3.1. Aviation 16
3.2. Shipping 17
EMISSION PROJECTIONS 20 4.
4.1. Global emissions up to 2050 20
4.2. Emissions from international aviation and maritime transport up to 2050 21
CONTRIBUTION TO GLOBAL GHG EMISSIONS 26 5.
APPROACHES TO DETERMINE CONTRIBUTIONS 29 6.
POTENTIAL GHG MITIGATION TARGETS 33 7.
CONCLUSIONS 40 8.
REFERENCES 42
ANNEX 47
Policy Department A: Economic and Scientific Policy
4 PE 569.964
LIST OF ABBREVIATIONS
CAEP
Committee on Aviation Environmental Protection
CDM
Clean Development Mechanism
CNG Carbon Neutral Growth
CO
2
Carbon dioxide
CO
2
eq
Carbon dioxide equivalents
COP
Conference of the Parties
EAG
Environmental Advisory Group
EEA European Economic Area
EEDI
Energy Efficiency Design Index
ETS
Emissions Trading System
EU
European Union
GHG
Greenhouse Gas
GMBM
Global Market-Based Mechanism
GMTF
Global Market-based Measure Task Force
GWP
Global Worming Potential
IATA
International Aviation Transport Association
ICAO
International Civil Aviation Organization
ICS
International Chamber of Shipping
IEA
International Energy Agency
IMO
International Maritime Organization
IPCC
Intergovernmental Panel on Climate Change
LOSU
Level of Scientific Understanding
MBM
Market-Based Mechanism/Measure
MEPC
Marine Environment Protection Committee
MRV
Monitoring, Reporting, Verification
MW
Megawatt
NO
x
Nitrogen Oxide
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 5
RCP
Representative Concentration Pathways
RFI
Radiative Forcing Index
RMI
Republic of the Marshall Islands
SEEMP
Ship Energy Efficiency Management Plan
SLCF
Short-Lived Climate Forcers
SO
2
Sulfur Dioxide
UNFCCC
United Nations Framework Convention on Climate Change
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6 PE 569.964
LIST OF BOXES
Box 1: Non-CO2 contribution of international aviation and shipping to climate
change 13
Box 2: Alternative fuels and propulsions 18
Emission Reduction Targets for International Aviation and Shipping
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LIST OF FIGURES
Figure 1: CO2 emissions from international bunkers (1990-2012) 13
Figure 2: Projected CO2 emissions from international aviation 22
Figure 3: IMO projections of CO2 emissions from international maritime transport 23
Figure 4: Other emission projections for international maritime transport 24
Figure 5: Potential fuel use and CO2 reductions from various efficiency approaches
for shipping vessels 24
Figure 6: Projected emissions from international bunker fuels and the EU target
path 25
Figure 7: International aviation and maritime transport’s share of global GHG
emissions under the RCP 2.6 pathway 27
Figure 8: International aviation and maritime transport’s use of remaining global
CO2 budget from 2020 onwards 27
Figure 9: Potential CO2 emission targets for international aviation 34
Figure 10: Potential CO2 emission targets for international maritime transport 35
Figure 11: Potential CO2 emission targets for international aviation and maritime
transport 35
Figure 12: Potential CO2 emission targets as share of global emissions 39
Policy Department A: Economic and Scientific Policy
8 PE 569.964
LIST OF TABLES
Table 1: Projected change in global mean surface air temperature 21
Table 2: Emission budgets 2020-2100 for international aviation and maritime
transport 34
Table 3: Aggregated CO2 emissions 2020 to 2050 and deviation from 2°C pathway 37
Table 4: CO2 emissions targets compatible with staying below 2°C compared to
2005 emissions 38
Table 5: Summary of historic and projected emissions 47
Table 6: Summary of emission targets 48
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 9
EXECUTIVE SUMMARY
The IPCC finds that the growth of global transport demand could pose a significant
challenge to the achievement of potential emission reduction goals. Due to strong growth
in transport demand, CO2 emissions of international aviation and maritime transport were
and are constantly growing despite considerable efficiency improvements. In 2012, both
sectors together account for about 3
% to 4
% of global emissions depending on whether
global GHG or only CO2 emissions are considered. Initiatives and actions taken by ICAO
and IMO to address GHG emissions started late and have been insufficient from an
environmental perspective to date: they do not take appropriate account of global
decarbonisation requirements. In the long run, measures proposed by IMO and ICAO will
mitigate growth of the sectoral CO2 emissions but not lead to absolute emission
reductions.
If, as in the past, the ambition of these sectors continues to fall behind efforts in other
sectors and if action to combat climate change is further postponed, their CO2 emission
shares in global CO2 emissions may rise substantially to 22
% for international aviation
and 17
% for maritime transport by 2050, or almost 40
% of global CO2 emissions if both
sectors are considered together. Establishing reduction targets for both sectors would
provide clear signals for all actors in these sectors and thus contribute to improving
investment perspectives in both sectors with their long investment cycles.
Based on several criteria, potential mitigation targets for the aviation and shipping
sectors were developed. They range from a somewhat reduced increase of future
emissions over stabilisation at 2020 levels to a full decarbonisation of those sectors by
2050. While full decarbonisation within only 30 years is rather unrealistic, stabilising
emissions at 2020 levels (carbon neutral growth) is clearly not enough. To stay below
2°C, the target for aviation for 2030 should not exceed 39
% of its 2005 emission levels
(50
% below the baseline) and should be -41
% compared to its 2005 emission levels in
2050. The respective targets for shipping are -13
% and -63
% compared to its 2005
emissions in 2030 and 2050, respectively. If non-CO2 impacts are taken into account,
these targets would need to be even more stringent.
Taking into account the estimated mitigation potential within the sectors, it is unlikely
that targets which are compatible with the below 2°C objective can be achieved only with
technological and operational improvements within the sectors. Thus, these potential
targets indicate the extent to which both sectors could contribute adequately to global
GHG mitigation efforts. Achieving these targets may require both encouraging
behavioural change which leads to reduced demand for international transport services
and enabling the offsetting of climate impacts by financing emission reductions in other
sectors. Moreover, it needs to be taken into account that particularly the non-CO2 climate
impacts of aviation will not be reduced if fossil fuels are replaced by hydrocarbons
extracted from renewable energies. Only electrical propulsion, demand reduction or
offsetting remaining emission will enable full decarbonisation of the aviation sector.
These considerations support the view that it is important to establish targets for
international aviation and maritime transport which clearly indicate that emissions cannot
grow unlimited and unregulated. Enhancing the stringency of the targets can be aimed at
in a second step. Yet, aiming for ambitious targets in line with the approaches outlined
above should not prevent agreement on targets which will trigger emission reductions
sooner rather than later.
Policy Department A: Economic and Scientific Policy
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INTRODUCTION 1.
The ultimate objective of the United Nations Framework Convention on Climate Change
(UNFCCC) is to stabilise greenhouse gas concentrations in the atmosphere at a level that
would prevent dangerous anthropogenic interference with the climate system (Article 2,
UN 1992). The Fifth Assessment Report of the Intergovernmental Panel on Climate
Change (IPCC) reinforces evidence that limiting global warming to less than 2°C above
pre-industrial temperatures considerably reduces the risk of triggering accelerated or
irreversible changes in the climate system as well as large-scale adverse impacts. The
report introduces a carbon budget which is based on cumulative carbon emissions over
time. According to this approach, a budget of some 1 000 Gt of greenhouse gas (GHG)
emissions remains, to avoid a global temperature increase of more than 2°C compared to
preindustrial levels (IPCC 2014, p. 10). To remain within this carbon budget, all sectors
need to contribute to global GHG reduction efforts.
Regarding the transport sector, the IPCC finds that the growth of global transport
demand could pose a significant challenge to the achievement of potential emission
reduction goals. In mitigation scenarios which aim to keep the global concentration of
greenhouse gases around 450 ppm or 550 ppm, all transport modes would be required to
improve their fuel efficiency considerably, use more low carbon fuels and adopt
behavioural measures that reduce transport demand and emissions (Sims et al. 2014).
In 2012, the contribution to global CO2 emissions of international aviation and maritime
transport amounted to 1.3
% and 2.2
%, respectively. In both sectors emissions are
predominantly international (62
% and 79
%, respectively), i.e. they are not counted
towards domestic emissions by a specific country. Together, international and domestic
civil aviation and marine transport accounted for 4.2
% of global CO2 emissions (2.1
%
per sector).
Projections indicate that under business-as-usual conditions, aviation and maritime
transport will continue to increase considerably and, since demand growth in transport
service is very likely to be stronger than efficiency improvements in these sectors (ICAO
2013b, IMO 2014), CO2 emissions will continue to increase both in absolute terms and
with respect to their share in global emissions.
In 2011, the International Civil Aviation Organization (ICAO) adopted an aspirational goal
to stabilise the CO2 emissions of international aviation after 2020. Further growth beyond
that date should be offset to achieve Carbon Neutral Growth from 2020 (CNG 2020). The
International Maritime Organization (IMO) discussed a proposal by the Republic of the
Marshall Island (RMI) to agree on a reduction target for international shipping in May
2015 but postponed the discussion to a further meeting. To date, there are no plans to
implement emission reduction targets for these sectors. This lack of adequate targets and
appropriate action from international aviation and shipping risks undermining efforts in
other sectors towards remaining within the 2°C objective compared to pre-industrial
levels.
In its report on the implementation of the 2011 White Paper on transport, the European
Parliament takes the view that the EU at the 2015 Climate Conference in Paris (COP 21)
must promote “the decarbonisation of transport and the development of sustainable
modes of transport, thus contributing to achieving the internationally agreed goal of
keeping global warming below 2 °C” (European Parliament 2015, p. 13, para. 60). In
addition, the coordinators of the ENVI committee underscore “the need for ambitious
targets for aviation and shipping(Liese et al. 2015).
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 11
The aim of this study is to provide Members of the European Parliament with the
necessary expertise to assess what adequate contributions of the two sectors would be in
terms of emission reduction. We start with a summary of the historic CO2 emission trends
in both sectors (Chapter 2). Despite the fact that both international aviation and
maritime transport contribute to climate change beyond their GHG emissions (Box 1), we
focus our quantitative analysis on CO2 only, due to limited availability of consistent data
for non-CO2 impacts. However, since these impacts cannot simply be ignored, we point
out the implications for our conclusions if non-CO2 impacts are taken into account as
well. In Chapter 3 we provide a short overview of efforts undertaken at ICAO and IMO to
address GHG emission of international aviation and maritime transport. In order to
determine the future role of both sectors in terms of global GHG emissions, we examine
emission projections for international aviation and maritime transport (Chapter 4) and
provide estimates of their shares to global GHG emission pathways (Chapter 5). Based
on these considerations we discuss concepts and approaches to determine adequacy in
terms of emissions (Chapter 6) and derive potential emission stabilisation and reduction
targets from these deliberations (Chapter 7). Conclusions of this study are provided in
Chapter 8.
Policy Department A: Economic and Scientific Policy
12 PE 569.964
HISTORIC EMISSION TRENDS 2.
Global greenhouse gas emissions have risen from approx. 40 000 Mt CO2eq in 1990 to
almost 50 000 Mt CO2eq in 2010, an increase of 25
% (van Vuuren, D. P. et al. 2011). In
the same period emissions from international aviation and maritime transport have
increased by 70
% (Figure 1). In absolute terms emissions from bunker fuels rose from
724 Mt CO2 in 1990 to 1 229 Mt CO2 in 2010. Emissions from these two sectors are
strongly linked to the global economic development. The effect of the financial crisis in
2009 but also of the attacks on the World Trade Center in New York in 2001 can be seen
in the historic data. While these events led to a short decrease of emissions, the rising
trend continued in the subsequent years. On average, emissions from both international
aviation and shipping rose by 3.0
% per year between 1990 und 2010. In comparison,
global GHG emissions including bunker fuels only rose by 1.1
% per year during that
period. Consequently, international transport increased its share of global CO2 emissions
from 2.2
% in 1990 to 3.1
% in 2010. In addition to carbon dioxide, emissions from
aviation also impact cloud formation, ozone generation and methane reduction amongst
other effects. These non-CO2 effects increase the impact of aviation on climate change by
a factor of at least 2 (Box 1).
The emission estimates presented above are based on fuel sales for international aviation
and shipping as reported by countries to the IEA (top-down approach). Researchers have
also estimated fuel consumption and therefore emissions based on activity data including
routes, speeds as well as type and size of vessel/aircraft. For aviation these estimates
show a close correlation to fuel sales. The situation is different for maritime transport:
bottom-up models tend to estimate higher fuel consumption than official statistics. In a
study conducted for the IMO both estimates are given for five years with discrepancies
between 18
% and 46
% (IMO 2014, p. 24). The study lists incomplete activity data,
inconsistencies between global fuel export and import data and misallocation of fuel sales
as the main reasons for these differences. The study concludes that the estimates based
on models likely overestimate emissions whereas the fuel sales data is likely to
underestimate them, i.e. that the real fuel consumption is somewhere between the two
estimates. The projections and targets for the shipping sector in this report are based on
the modelled data. For that reason all further graphs are only based on the bottom-up
approach for maritime transport.
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 13
Figure 1: CO2 emissions from international bunkers (1990-2012)
Source: IEA 2014, IMO 2009, IMO 2014, authors’ own calculations
Notes: Top-down data is based on fuel sales whereas bottom-up data is calculated based on ship type and
activity data. The real emission value is likely between those two estimates (see text above the
graph).
The data for all graphs is included in the Annex.
Box 1: Non-CO2 contribution of international aviation and shipping to
climate change
Beyond CO2
emissions, international aviation and shipping contribute to climate change in
other aspects as well. International aviation produces short-lived emissions of NOx and SO2
and leads to cloud formation, the impacts of which are estimated to be two to five times
higher than CO2 emissions from aviation alone (Sausen et al. 2005). NOx and SO2
e
missions have an indirect warming and (a much smaller) cooling effect on global warming
as they produce or destroy GHGs (mainly ozone, methane and sulphate aerosols).
Sulphate aerosols and water vapour additionally lead to contrails and cirrus cloud
formation which contribute to global warming as well. While SO2
emissions can be
estimated rather accurately if the sulphur content of the fuel is known, there is generally
high uncertainty with regard to the exact radiative forcing of the other indirect effects of
aviation. Also, different methodologies for the estimation of CO2, SO2 and NOx are used by
countries in their national reporting on emissions under the UNFCCC (Graichen & Gugele
2006). Fuglestvedt et al. (2010) produced GWP values for contrails, water vapour and
contrail-induced cirrus, which show large variations as well. Yet, generally, the non-CO2
impact of aviation on climate change is measured by means of the Radiative Forcing Index
(RFI) which is a ratio of the radiative forcing of the non-CO2 effects of aviation at a given
point of time and the radiative forcing of aviation-based CO2 emissions, accumulated since
1950. The IPCC (1999) established the RFI of aviation in 1992 to be in the range of 2-4.
The
graphic below illustrates the different climate impact of aviation in terms of radiative
forcing. It shows the high uncertainty of the best estimates for each radiative forcing
component. Furthermore, the level of scientific understanding (LOSU) is shown in the right
column.
Policy Department A: Economic and Scientific Policy
14 PE 569.964
Source: Lee et al. 2009
According to Lee et al. (2010), the radiative forcing from global aviation from pre-
industrial times to 2005 is estimated to be 55 MW m-2 excluding the effect of cirrus clouds
(78 MW m-2) and including cirrus. This forcing is equal to 3.5
% of current anthropogenic
forcing, yet with a high uncertainty range of 1.3-10
%. Overall, non-CO2 climate impacts of
aviation are estimated to contribute 49
% (excluding contrail cirrus) and 64
% (including
contrail cirrus) to the total forcing of the sector (Deuber 2013). According to Lee et al.
(2010), the total effect of aviation is 1.3-1.4 times higher than the effect of CO2 alone
(excluding aircraft-induced cloudiness; GWP 100). If aircraft-
induced cloudiness is
included, this ratio increases to 1.9-2.0, i.e. the impact of aviation on the climate is about
twice as high as the impact of the CO2 emissions alone.
Due to the continuous growth of international aviation, the share of the sector of total
global emissions can be expected to increase. If endeavours to achieve decarbonisation by
2050 are taken seriously and if effective measures to reduce the CO2 impact of the
aviation sector are implemented, the relative weight of non-CO2 contributions of the sector
will increase even further in the future. Yet, so far, the non-CO2 effects of aviation remain
unregulated (Deuber 2013).
Non-CO2 effects from international shipping result from the emissions of short-lived
climate forcers (SLCFs) as well, mainly in the form of black carbon and SO2 that forms
aerosols. Black carbon has a warming effect in the atmosphere and also on the ground
when it is deposited on snow and ice surfaces. By contrast, SO2 has a cooling effect on the
climate. Yet, the climate impacts of SLCFs resulting from shipping vary, depending on
different atmospheric conditions and sensitivity to high and low latitudes. Additionally,
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 15
shipping generates indirect climate effects through the perturbation of greenhouse gases
such as CH4 and O3 due to chemical interactions with NOx emitted from ships (Eide et al.
2013). The combined climatic impact of CO2 and non-CO2 emissions
of international
shipping is an initial cooling on timescales of decades to centuries which do not, however,
outweigh the long-term warming effects due to the persisting effect of long-lived GHGs
(ACCESS 2015; Eyring et al. 2010; UNEP 2011). So far there is no multiplier for non-CO2
effects from shipping due to there being a lower level of scientific understanding in this
regard.
Policy Department A: Economic and Scientific Policy
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EFFORTS TO ADDRESS GHG EMISSIONS 3.
GHG emissions from international aviation and maritime transport have been addressed
since the first UNFCCC Conference of the Parties in 1995 in Berlin (COP 1, UNFCCC
1995). However, an agreement on how to allocate these emissions a share of which
occur above international waters and thus do not fit into the territorial approach under
the UNFCCC in which individual countries are responsible for the emissions on their
territory was not met before the adoption of the Kyoto Protocol in 1997. Pursuant to
Article 2.2 of to the Kyoto Protocol, Annex I Parties (industrialised countries) shall thus
pursue limitation or reduction of emissions of greenhouse gases […] from aviation and
marine bunker fuels, working through the International Civil Aviation Organization and
the International Maritime Organization, respectively (UNFCCC 1998). The distinction
between industrialised and developing countries further complicated efforts to address
GHG emissions from both sectors, since their regulations are based on non-discrimination
and non-preferential treatment of all ships and aircraft, independently of their nationality.
Only in recent years has some progress been made in both organisations on initiatives to
limit GHG emissions of international aviation and shipping. Nevertheless, there have been
no plans to date to establish global legally binding absolute caps on greenhouse gas
emissions for these two sectors, let alone implement emission reduction targets.
3.1. Aviation
As early as 2001, ICAO had decided that an emissions trading system (ETS) is the most
appropriate instrument to address GHG emissions from international aviation. With
Resolution A-33-7, Appendix I, the ICAO Assembly endorses the development of an
open emissions trading system and requests the Council to develop as a matter of
priority the guidelines for open emissions trading(ICAO 2001, pp. 28-31). Since then,
however, little progress had been made. Only at its 37th Assembly, ICAO (2010) agreed a
global aspirational goal of Carbon Neutral Growth by 2020 (CNG 2020).1 In 2013, ICAO
established working groups for developing a Global Market-Based Mechanism (GMBM) to
achieve this goal. According to its work program, the mechanism should be adopted in
2016 and come into force in 2020.
One of the main drivers for establishing ICAO working groups for the development of a
GMBM was the European Union’s (EU) decision in 2008 to include aviation in its ETS (EU
2009). From the beginning of 2012, carriers which called airports in the EU had to report
their CO2 emissions on routes within as well as to and from the EU. By the end of 2012,
non-EU carriers increasingly complained about the EU’s inclusion of aviation into its ETS.
To address these complaints and to prevent a global aviation dispute, the ICAO’s
Secretary General established the working groups for the development of the GMBM. At
the same time, the EU agreed to limit the geographical coverage of its aviation ETS to
the territory of the European Economic Area (EEA) from 2013 to 2016 as an approach to
provide ICAO with some leeway for developing a GMBM.
The main design elements of the GMBM are discussed by the ICAO’s Environmental
Advisory Group (EAG) and by the Global Market-based Measure Task Force (GMTF)
established for developing the GMBM. Within EAG the core design features are being
elaborated while GMTF, an expert group within the Committee on Aviation Environmental
1 Earlier in 2010, the International Aviation Transport Association (IATA) had already set a goal of
carbon neutral growth from 2020 and a 50
% absolute reduction in carbon emissions by 2050
compared to 2005 levels (IATA 2013).
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 17
Protection (CAEP), has been assigned the task of developing rules for monitoring,
reporting and verification (MRV) of CO2 emissions and quality and eligibility criteria for
offset units. So far, the GMTF has agreed on a number of general principles to ensure
environmental integrity but is unlikely to provide specific recommendations on how to
meet these requirements due to considerable uncertainties as to which types of offset
units will be available post-2020.
The EU has highlighted the need for a sectoral emission reduction target for international
aviation consistent with the global below 2°C objective. It suggested setting the target
at -10
% below 2005 levels by 2020 (Council of the European Union 2009) and supports
a regular review of the environmental ambition (Council of the European Union 2015). In
the EAG, the EU stresses the need to increase the ambition within ICAO and requests a
review clause to allow the target to be strengthened in the medium term, e.g. to align it
with IATA's -50
% by 2050 target. Moreover, the EU is constructively engaging in
discussions to ensure that the design of the GMBM actually enables that the CNG2020
target is met and is not being undermined by exemptions.
3.2. Shipping
In view of the growth projections of world trade, technical and operational measures
alone would not be sufficient to satisfactorily reduce the amount of GHG emissions from
international shipping. From July 2007, IMO therefore considered several MBMs as an
option to address GHG emissions. Governments and observer organisations proposed
possible MBMs, ranging from a GHG fund, trading schemes and efficiency systems to the
introduction of a levy. In this context Norway suggested potential targets for
international shipping in January 2010 (MEPC 2010). These proposals were based on the
philosophy that the economic effort for reducing GHG emissions in the shipping sector
should be the same as in other sectors. Under the UNFCCC the EU has been advocating
a -20
% emission reduction target below 2005 levels by 2020 for the sector as a whole
(Council of the European Union 2009).
Although an expert group undertook a feasibility study and impact assessment evaluating
the extent to which each proposed mechanism could incentivise reducing GHG emissions
from international shipping, no decision has been taken yet with regards to which MBM
proposal should be further developed. Also a one-week long working group meeting in
March 2011 dedicated to MBMs was unable to identify a preferred MBM.
However, in 2011 IMO adopted two efficiency measures to address GHG emissions (IMO
2015b):
the Energy Efficiency Design Index (EEDI) sets compulsory energy efficiency
standards for new ships built after 2013, and
the Ship Energy Efficiency Management Plan (SEEMP) requires ships to
develop a plan to monitor and possibly improve their energy efficiency.
Despite efficiency improvements brought about by these measures and by market forces,
emissions are projected to increase by 50 to 250
% in the period up to 2050 (IMO 2014).
This trend risks undermining the efforts that are being made in order to stay on a
trajectory that will keep the average global temperature increase below 2°C compared to
pre-industrial levels. Unlike under ICAO, countries have so far not agreed on an emission
limitation or reduction target in the IMO.
In 2013, the European Commission therefore tabled a legislative proposal to establish a
CO2 monitoring, reporting and verification (MRV) system for ships entering EU ports. The
proposal was adopted by the European Council and Parliament in late 2014, came into
force in April 2015 and will apply to port calls from 2018 onwards (European Parliament
Policy Department A: Economic and Scientific Policy
18 PE 569.964
and Council 2015). According to this regulation the Commission shall assess every two
years the maritime transport sector's overall impact on the global climate including
through non-CO2-related emissions or effects.(Art. 21,5).
In March 2015, the Republic of the Marshall Islands (RMI) submitted a paper to the
Marine Environment Protection Committee (MEPC), in which the RMI requests IMO “to set
clear net emission reduction targets in line with the UNFCCC’s ultimate objective” (MEPC
2015), as well as the development of measures to achieve these targets. The RMI is a
small island state. However, it is the third largest ship register of the world, which puts
some weight behind its initiative. However, the MEPC agreed “to focus on further
reduction of emissions from ships through the finalisation of a data collection system”
and postponed the discussion on a mitigation target to a future session (IMO 2015a).
Box 2: Alternative fuels and propulsions
Several options exist to reduce emissions from aviation and shipping through the use of
alternative fuels and other renewable energies. For shipping, renewable energy is used
in the form of wind energy (soft sails, fixed wings, rotors, kites and conventional wind
turbines), photovoltaics in hybrid models with other energy sources, wave energy,
hydrogen fuel cells, biofuels and super capacitors charged with renewables. Taking into
account technical limitations as well as concerns with regard to the sustainability of the
options, hybrid modes have the greatest potential in spurring the deployment of
alternative energy sources in international shipping. However, the infrastructure lock-in
of existing investments, limited R&D finance, the risk adversity of inves
tors and the
different classes and scales of ships are major barriers to driving actual deployment of
existing renewable energy options, and so far, there has not yet been sufficient
demonstration of commercially viable solutions in order to change this pattern (IRENA
2015).
For aviation, alternative fuels include liquid hydrogen, methane, kerosene manufactured
by different processes (e.g. the Fischer-Tropsch process
to produce a synthetic
lubrication oil and synthetic fuel from coal, natural gas or biomass), liquid hydrogen and
biofuels. In the context of biofuels, the use of so-called second generation biofuel
feedstocks including Jatropha, Camelina and Halophytes which cannot be used as food
for humans and animals and can (partly) be grown in non-arable areas, and third
generation biofuels which are derived from algae are being discussed (ATAG 2009; Lee
et al. 2010).
In terms of production possibilities, costs, environmental considerations in production
and transport, advantages, disadvantages and usability, biodiesel, synthetic kerosene
and liquid hydrogen (LH2) are being discussed as the most promising options. All three
options reduce fuel cycle carbon emissions, while liquid hydrogen would furthermore
eliminate emissions of all carbon bearing species, in
cluding soot and sulphur oxides
(thus producing only H2O and NOx as combustion products). A transition to LH2 would
entail profound changes as the engines as well as the airframes would have to be
redesigned (Lee et al. 2010).
However, replacing fossil fuels
by alternative fuels with less GHG emissions does not
eliminate the entire negative impact of aviation on global warming. If non-CO2
combustion effects from aircraft in the upper atmosphere are taken into account, the
relative merit of such Synthetic Paraffinic Kerosene (SPK) fuel compared to conventional
jet fuel decreases considerably (an SPK fuel option with zero life cycle GHG emissions
would entail a 100
% reduction in GHG emissions, but reduce the actual climate impact
by only 48
% when estimated in a 100-
year time window and on the basis of the
nominal climate modelling assumption set outlined herein). This means “that methods of
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 19
tracking climate change mitigation that rely exclusively on relative well-to-wake life
cycle GHG emissi
ons as a proxy for aviation climate impact may overestimate the
impact of alternative fuel use on the global climate system (Stratton et al. 2011).
Further challenges implied by replacing conventional fuels with biofuels relate to the risk
of direct and indirect land use change associated with some biofuels, the energy
necessary to produce and transport them, and other social and environmental issues
such as the production of other pollutants such as nitrous oxide. Also, further research
in emerging feedstocks, building new infrastructure for biofuel production and
supporting policies would be necessary in order to increase the economic viability of
biofuels (Gençsü & Hino 2015).
Policy Department A: Economic and Scientific Policy
20 PE 569.964
EMISSION PROJECTIONS 4.
While CO2 emissions from international aviation and maritime transport were only
responsible for 3.5
% of the global CO2 emissions in 2012, this share is expected to
increase considerably in the coming decades: projections from both sectors show a
strong increase in emissions while global GHG emission trajectories need to decline to
achieve the 2°C target. Both ICAO and IMO have commissioned studies to project
demand for services and emissions from their respective sectors up to 2050 under
different assumptions (ICAO 2013b, IMO 2014). These studies also evaluated the
potential for emission reductions from technological and operational measures within
their sectors.
In 2011 climate scientists developed Representative Concentration Pathways, a set of
global GHG emission trajectories used in the climate models. The idea of these pathways
is to provide a set of scenarios to be employed by the various climate models to be able
to compare and combine results. Each pathway is linked to different levels of radiative
forcing and therefore temperature increases of the earth. The global carbon budget
approach is an alternative to emission pathways: it determines the total aggregated
emissions since pre-industrial times without using a specific target path.
The combination of global emission pathways, budgets and sectoral projections allows an
analysis of the role of and challenges facing international transport for achieving the 2°C
target (Chapter 5).
4.1. Global emissions up to 2050
Representative Concentration Pathways
The four Representative Concentration Pathways (RCP) differ, inter alia, in their
assumptions on economic development, population growth, share of fossil fuels in the
energy system, total energy consumption and land use (van Vuuren et al. 2011). Of
these, only the RCP 2.62 pathway is compatible with a global mean surface air
temperature increase below 2°C (Table 1) by the end of the 21st century. To achieve this,
the scenario assumes a rapid decline of GHG emissions after peaking in 2020 and a
complete decarbonisation of the world by 2090. Emissions of methane and N2O also
decline but much more moderately. In comparison, emissions in the RCP 4.5 and RCP 6.0
pathways peak only in 2040 and 2060 respectively and decline at much lower rates
afterwards. In the highest concentration pathway, emissions do not peak before 2100.
The RCP 4.5 pathway is expected to lead to a temperature increase of 2.4 C compared to
1850-1900 levels but the uncertainty range still includes a warming below 2°C. In line
with the international goal and objective of the EU’s climate policy only the RCP 2.6 and
to a limited extent the RCP 4.5 scenarios are included in the next chapters of this
analysis.
2 The numbers of the RCPs indicate the level of anthropogenic radiative forcing in W/m2 in the year
2100.
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 21
Table 1: Projected change in global mean surface air temperature
Source: IPCC 2013, p. 23, authors’ own calculations
Notes: Likely temperature ranges calculated from projections as 5−95
% model ranges. These ranges
are then assessed to be likely ranges after accounting for additional uncertainties or different
levels of confidence in models.
Carbon budget approach
The idea of determining cumulative global GHG budgets instead of emission targets for
specific years was proposed by Meinshausen et al. (2009). It focuses on the long-term
perspective instead of short- to medium-term goals as adopted under the Kyoto Protocol
and the Copenhagen Accord. In this approach total CO2 emissions since pre-industrial
times need to stay below 2 900 Gt CO2 to have a likely probability (>66
%) to limit
anthropogenic warming to less than 2°C. Almost two thirds of this quantity was already
exhausted by 2011, i.e. only 35
% of the budget remains for all subsequent years. The
total available budget increases with reduced probabilities to stay below 2°C:
3 010 Gt CO2 with a probability of >50
% or 3 300 Gt CO2 with a probability of >33
%
(IPCC 2013, p. 27).
4.2. Emissions from international aviation and maritime transport up to 2050
Aviation
In 2013 the Committee on Aviation Environmental Protection of the ICAO finished its
assessment of “present and future impact and trends of aircraft noise and aircraft engine
emissions (ICAO 2013b). It includes projected fuel burn and therefore CO2 emissions
from international aviation for the period of 2005 to 2050 in a baseline scenario as well
as a high and a low demand scenario. The impact of technological and operational
improvements is given for the baseline scenario (Figure 2). According to this assessment,
the improvements have a potential to reduce CO2 emissions by 33
% in 2050 compared
to the baseline. Despite this, emissions are still projected to be seven times higher in
2050 than in 1990; without the improvements, projections are ten times above 1990
levels in 2050. Other projections of CO2 emissions from international aviation show a
similar trend but are on the lower bound of the ICAO range.
The data used by ICAO for technological and operational improvements are based on the
optimistic scenario (ICAO 2013a, p. 23) but this might not be realistic: Kharina &
Rutherford (2015, p. 16) analysed historic trends in energy efficiency improvements for
new aircraft and found that the industry is lagging behind ICAO’s efficiency goals. Instead
of achieving a reduction of 27-31
% compared to a set of reference aircraft by 2020, the
target will only be met in 2032. The same time lag of 12 years also exists for the 2030
efficiency goal. The authors conclude that “it appears unlikely that ICAO can achieve its
higher-level technology goals without additional policy support”.
There is general consensus in the literature that technical and operational measures will
not be able to offset emission growth in the coming decades. Bows-Larkin (2015) notes
Mean Likely range Mean Likely range
- °C relative to the reference period of 1850-1900 -
RCP 2.6 1.6 1.0 to 2.2 1.6 0.9 to 2.3
RCP 4.5 2.0 1.5 to 2.6 2.4 1.7 to 3.2
RCP 6.0 1.9 1.4 to 2.4 2.8 2.0 to 3.7
RCP 8.5 2.6 2.0 to 3.2 4.3 3.2 to 5.4
2046-2065
2081-2100
Policy Department A: Economic and Scientific Policy
22 PE 569.964
that only more radical long-term technical options such as blended wing bodies or
hydrogen fuels will be able to reduce emissions beyond a 1-2
% annual energy efficiency
improvement. Such options require setting up new infrastructure and are not easily
implemented. In addition, new aircraft models only penetrate slowly into the market with
emissions being driven by older models. Retrofitting of aircraft and infrastructure can
help in reducing emissions of the existing fleet. Bows-Larkin is also sceptical about the
possible impact of operational measures: reduced congestion and improved throughput
of airspace and airports would lead to increased aviation growth increasing absolute
energy consumption. She concludes that, albeit unpopular, demand-side reductions are
necessary and no more challenging than other options which are in line with global
emission constraints. In 2025 at the latest, annual demand growth would need to reach
zero and decrease by 4-6 % p.a. thereafter (Bows-Larkin 2015). Chèze et al. (2012)
analysed the anticipated technological progress in the aviation sector up to 2025 and
concluded that none of the nine scenarios included in the study would even be
compatible with “limiting global warming to 3.2°C compared to the preindustrial era” and
much less so with 2°C pathways.
Figure 2: Projected CO2 emissions from international aviation
Source: IEA 2014, ICAO 2013b, Lee et al. 2013
Notes: Data for all graphs disaggregated by transport mode is included in the Annex.
Shipping
The Third IMO GHG Study 2014 (IMO 2014) includes projections of emissions from
international maritime transport up to 2050. The four different scenarios use the
Representative Concentration Pathways (Chapter 4.1) and the other long-term socio-
economic scenarios to forecast demand for international shipping. For each scenario,
three different mitigation options are also calculated. They differ in their fuel mix, impact
of Emission Control Areas and assumptions on energy efficiency. Figure 3 shows
projected emissions under three different scenarios as well as the effect of the most
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 23
ambitious mitigation option on the reference scenario.3 Identical to the case of aviation,
the technological and operational improvements reduce CO2 emissions in 2050 by 33
%.
Despite this, they are still projected to increase by a factor of almost four compared to
1990. Without these improvements, the growth would be six-fold.
Other studies show a similar range of baseline emissions and upper/lower bounds (Figure
4). With a 39 % reduction in 2050 Bazari & Longva (2011) estimate a similar impact of
the agreed Energy Efficiency Design Index (EEDI) and the Ship Energy Efficiency
Management Plan (SEEMP). In a White Paper by the International Council on Clean
Transportation, Wang & Lutsey argue that more reduction is possible within the sector
only by applying existing technologies and practices. If all ships achieved the energy
efficiency of the top 5
% of the current fleet disaggregated in nine ship types/sizes by
2035, global emissions from international maritime transport would decline despite the
demand growth (Wang & Lutsey 2013). The most important measure to achieve such a
level of efficiency is designing for and operating at lower speeds (Figure 5).
Figure 3: IMO projections of CO2 emissions from international maritime
transport
Source: IEA 2014, IMO 2009, IMO 2014
Notes: Data for all graphs disaggregated by transport mode is included in the Annex.
3 For consistency reasons and to enhance the reader-friendliness of this analysis, the IMO scenarios
have been named in an identical way to the nomenclature used by ICAO. The IMO study does not
provide a baseline but rather four scenarios without identifying one as the central estimate. The three
scenarios included in this report show the range of the scenarios in the 3rd IMO GHG study.
Policy Department A: Economic and Scientific Policy
24 PE 569.964
Figure 4: Other emission projections for international maritime transport
Source: IMO 2009, IMO 2014, Bazari & Longva 2011, Wang & Lutsey 2013
Figure 5: Potential fuel use and CO2 reductions from various efficiency
approaches for shipping vessels
Source: Wang & Lutsey 2013
Aviation and shipping
Combining both projections shows the range of total CO2 emissions from the two sectors
combined (Figure 6). The graph and all subsequent analysis are based on the projections
by ICAO/IMO. As a reference, the graph also includes the historic emissions of all
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 25
greenhouse gases and the EU’s target path up to 2050. It shows that, if unchecked,
international aviation and shipping will, in 2050, emit about as much as the European
Union today but without any indications of reducing or at least stabilising emissions.
Figure 6: Projected emissions from international bunker fuels and the EU
target path
Source: IEA 2014, ICAO 2013b, IMO 2009, IMO 2014, EEA 2015, Council of the European Union 2011,
authors’ own calculation
Notes: EU emissions are based on all GHG excluding land-use, land-use change and forestry. For
2050, the upper limit of the EU’s ambition of 80-95
% below 1990 is used.
Data for all graphs disaggregated by transport mode is included in the Annex.
Policy Department A: Economic and Scientific Policy
26 PE 569.964
CONTRIBUTION TO GLOBAL GHG EMISSIONS 5.
Based on the data included in chapter 4, it is possible to estimate the potential impact of
international aviation and maritime transport on global GHG emissions under the
different scenarios and budgets. Figure 7 shows the share of global CO2 emissions under
the RCP 2.6 pathway that relates to international aviation and maritime transport in the
various emission scenarios. In the baseline scenario international transport would be
responsible for almost 40
% of the available global CO2 emissions in 2050. If all
technological and operational improvements deliver the expected impact, the sectors
would still be responsible for 25
% of global permissible CO2 emissions of a 2°C path. The
comparison is based on CO2 emissions only because the RCP 2.6 scenario has very
different emission pathways for the different greenhouse gases. The underlying reason is
that CO2 emissions from some sources such as combustion of fossil fuels can be
mitigated much easier than CH4 and N2O emissions from other sources such as
agriculture.
The impacts of the emissions from the two sectors on the total permissible carbon budget
after 2020 are shown in Figure 8. The budget is based on a likelihood of at least 66
% of
limiting anthropogenic global warming to under 2°C (for more details, see Table 2).
Under this approach emissions from international bunker fuels will consume over 11
% of
the remaining global carbon budget after 2020 within 30 years. Both sectors will use
almost the same share of the total available global budget in that period: aviation 5.9
%
and maritime transport 5.3
%. It has to be noted that the global budget is a long-term
budget, i.e. not just for the period up to 2050. With the high emission levels in 2050 and
the still strongly growing trends, the two sectors would use up an ever increasing share
of the remaining global budget in the subsequent decades. This would severely restrict
the available budget for all other sectors and countries requiring them to go beyond their
share of emission reductions. Bows-Larkin et al. (2015) noted that so far “no sector has
openly discussed cuts over and above the scale necessary for a reasonable chance of
avoiding the 2°C rise”.
An approach to determining a fair budget for international aviation and maritime
transport is discussed in chapter 7.
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 27
Figure 7: International aviation and maritime transport’s share of global GHG
emissions under the RCP 2.6 pathway
Source: ICAO 2013b, IMO 2014, van Vuuren, D. P. et al. 2011
Notes: Data for all graphs disaggregated by transport mode is included in the Annex.
Figure 8: International aviation and maritime transport’s use of remaining
global CO2 budget from 2020 onwards
Source: ICAO 2013b, IMO 2009, IMO 2014, IPCC 2013, p. 27
Notes: The total budget is calculated to give a probability of at least 66
% to stay below 2°C.
Data for all graphs disaggregated by transport mode is included in the Annex.
Policy Department A: Economic and Scientific Policy
28 PE 569.964
If, as in the past, the ambition of these sectors continues to fall behind efforts in other
sectors and if action to combat climate change is further postponed, their CO2 emission
shares in global CO2 emissions may rise substantially to 22
% for international aviation
and 17
% for maritime transport by 2050, or almost 40
% of global CO2 emissions if both
sectors are considered together.
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 29
APPROACHES TO DETERMINE CONTRIBUTIONS 6.
In addition to ICAO’s above-mentioned CNG 2020, several other suggestions for potential
contributions of international aviation and maritime transport to global GHG mitigation
efforts can be identified. Cames et al. (2015) provide an overview of these proposals
which is supplemented by a more recent proposal by ICS:
In 2009, before the climate conference in Copenhagen, the EU suggested an
emission reduction target of -10
% for international aviation and -20
% for
maritime transport by 2020 compared to 2005 (Council of the European Union
2009).
In 2010, Norway suggested two targets for international shipping based on
growth scenarios A1B and B2 of IPCC’s Third Assessment Report (IPCC 2001). The
targets are based on the philosophy that the economic effort to reduce emissions
in the shipping sector should be the same as in other sectors (MEPC 2010).
Also in 2010, IATA agreed to a target of keeping CO2 emissions of international
aviation from 2020 to 2030 at the level of 2020 and to reduce emissions by 50
%
compared to 2005 from 2030 to 2050 (IATA 2013).
Later in 2010, ICAO agreed to freeze the sector’s CO2 emissions at its 2020 level
(CNG 2020) and to accommodate further emission growth by means of technical
and operational measures as well as by extending the use of biofuels. The
emission reduction which cannot be achieved by measures within the sector
should be addressed by the purchase of offsets from other sectors in order to
achieve carbon neutral growth (ICAO 2010).
In 2014, the Tyndall Centre suggested a target for maritime transport. Based on
the assumption that the shipping sector’s current share in global GHG emissions
should at least remain constant and using carbon budgets for an emission
pathway compatible with staying below 2°C, they derive targets which are 70-
80
% below the emission levels of 1990 (Tyndall Centre 2014).
In 2015, the International Chamber of Shipping (ICS) promised that international
shipping will deliver a -50
% reduction of CO2 emissions per tonne mile by 2050
including by means of further technical and operational measures and preferably
an emission levy (Einemo 2015, 2015, ICS 2015).4
This overview illustrates that there are a number of somewhat heterogeneous and not
fully distinguishable criteria which may be considered for the development of mitigation
targets:
Time horizon: Does the target have a short- or medium-term orientation of 5-15
years or is it derived from a long-term perspective, potentially striving for
decarbonisation?
Reference: How is the target quantified? Is it an absolute emission target or is a
performance target indexed to an activity data such as the tonne mile?
Shape: Is the target determined for a single year, provided as a trajectory for the
entire target period or based on a budget of remaining emissions?
Comparability: Is the target compared to efforts elsewhere, either in terms of
emission reductions or in terms of estimated mitigation costs?
4 There are various interpretations of the ICS’s target proposal. We used the most stringent one for this
paper. In other interpretations the target would actually exceed the baseline emissions.
Policy Department A: Economic and Scientific Policy
30 PE 569.964
Origin: Does the target refer to the currently known mitigation potential or is it
derived from scientifically justified mitigation requirements for staying below 2°C?
Time horizon: While at the beginning of global climate policy in the 1990s it was
acceptable to focus on emission reductions within the next couple of years, evidence
provided by the IPCC suggests that the time remaining to address climate change is
shrinking and that global emissions need to peak sooner rather than later. It would thus
be short-sighted to focus only on the next steps without a clear vision towards the
ultimate goals. Targets agreed today need to be derived from the ultimate goal of staying
below 2°C. They may include intermediate steps to verify whether the target path is met
but a purely stepwise approach may provide the wrong signals.
This is even more relevant for sectors with long investment cycles of 30 years or more.
Investment decisions taken today are still likely to contribute to GHG emissions in 2050.
A long-term goal also provides clear signals to the covered entities to consider potential
GHG mitigation options in their short- and long-term decisions.
Reference: Performance indicators such as CO2 emissions per tonne mile can inform the
discussion on the challenges and ambition of a target. They also provide clear
information to the stakeholders of the covered activities. However, they may also
obscure a lag of ambition. If the growth of the activity data is stronger than the efficiency
improvement of performance indicator, absolute emissions continue to grow despite an
ambitious looking efficiency target. Moreover, to determine whether the global effort to
reduce GHG emissions is sufficient to stay below 2°C, indexed targets need to be
transformed into absolute targets so that the global effort can be aggregated.
Shape: Individual target years can be more easily negotiated and communicated.
However, GHG emissions accumulate in the atmosphere. Climate change is caused by the
accumulation of GHG in the atmosphere over long periods of time rather than by the
emissions of one single year. Individual target years, therefore, need to be converted
into trajectories which cover all years of the envisaged period. Such a trajectory will also
allow determination of the extent to which the remaining budget of global GHG emissions
will be utilized.
Comparability: There are mainly two dimensions to how a target could be compared
with efforts elsewhere. Comparability could either be given in terms of emission
reductions or in terms of economic efforts, i.e. similarity of the cost burden. However,
before looking at these dimensions, it needs to be determined what the suitable
reference for comparison is, i.e. should a target be compared to the global average,
certain other sectors, a group of countries, etc.
Opinions on the appropriate reference for comparison with international aviation and
maritime transport may differ among the stakeholders involved. In the first place they
are industrial sectors similar to sectors such as electricity generation, steel or cement
production. They are equally important to the global economy and to economic
development as other economic sectors but not more or less important than, for
example, electricity, chemicals or retail. Since all other sectors are likely to be
extensively covered by the post-Paris global mitigation targets, international aviation and
shipping need to be covered by similar requirements. Otherwise production abroad would
be implicitly subsidised via local production through inappropriate low transport prices
and thus again induce higher GHG emissions.
If international aviation and maritime transport were two additional countries, several
evidences suggest that they would be industrialised countries rather than developing
countries. ATAG (2014), for example, claims that aviation would rank 21st in terms of
gross domestic product (GDP), be larger than several members of the G 20 and have
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 31
about the same size as Switzerland. The European Community Shipowners’ Association
(ECSA 2015) suggests that the European shipping industry contributes 147 billion to
the European GDP. Extrapolating this figure based on UNCTD’s shipowner statistics
(UNCTAD 2014, pp. 33–37) to the world at large, the shipping industry would rank 23rd.
But not only in terms of size both sectors rank among the top ones. Also with regard to
productivity the European aviation and shipping industry are 38
% and 60
%,
respectively, above the EU average (Oxford Economics 2015, p. 14). Even if these figures
are not necessarily fully representative for the world at large, they still give a strong
indication that these sectors are well advanced and highly industrialised.
Which of the dimensions is the more appropriate basis for comparison depends to some
extent on the purpose of the target. If the target should be exactly met through
mitigation activities solely within a sector, a comparison of the marginal abatement cost
would be essential. A significant difference in the marginal abatement cost would indicate
that global GHG mitigation efforts would, on average, induce higher costs than necessary
or that the costs of global GHG mitigation could be reduced if the sectoral targets were
aligned based on marginal abatement costs.
While in theory a comparison of marginal abatement costs seems to be a straight forward
option, it is quite difficult to implement. Marginal abatement cost curves are compiled
from bottom-up estimates of the mitigation potential of individual technical and
operational measures and estimates of the average cost to implement this potential. Both
estimates depend on a number of assumptions, such as global fuel prices, technological
development and innovation, interest and exchange rates, etc. In addition, the potentials
and costs of the estimates may overlap so that the aggregated potential may be smaller
than just the sum of the individual potentials, though it will be difficult to determine the
extent to which measures overlap. An example of this are energy efficiency measures
and the introduction of renewable energies: the larger the share of renewables the lesser
the impact on GHG emissions that can be achieved through efficiency improvements.
Due to these and other limitations of marginal abatement cost curves, Kesicki & Ekins
(2011) and Vogt-Schilb & Hallegatte (2014) call for caution when applying these curves
in policy design. Since the information required for deriving adequate marginal
abatement cost curves are mainly private and/or confidential data, often only implicitly
but not explicitly known, it is conceptually virtually impossible to derive adequate
marginal abatement cost curves. One way to overcome this hurdle is to determine
targets independently of marginal abatements cost curves but allowing entities, covered
by these targets, to offset emissions through some kind of trading mechanism if
mitigation can be achieved more cheaply elsewhere.
In other words, a comparison in terms of emission reductions would be both sufficient
and actually implementable if the target is not considered as a so-called closed target
for the covered entities. A closed target may only be achieved through technological and
operational mitigation activities in the respective sector whereas an open target may also
be achieved through offsets from sources beyond the scope of the target.
Origin: This criterion refers to the perspective from which a target is derived. On the one
hand, there is the perspective from within the two sectors. Stakeholders often claim that
there are intrinsic incentives to reduce GHG emissions because fuel costs represent a
relatively large share of the operational costs. Future mitigation potentials depend on the
pace of technological progress. These arguments originate from the question of what is
achievable within the sector. On the other hand, there is the global long-term
perspective, which looks at which global efforts are required to prevent severe damage
due to climate change. Both perspectives are relevant and neither can be entirely
ignored. Nevertheless, if the precautionary principle of environmental policy is adequately
Policy Department A: Economic and Scientific Policy
32 PE 569.964
respected, the global perspective needs to be given preference over the particular
perspective from within the sector.
Objective criteria like those elaborated above and their scientific analysis are often the
starting point for processes which aim at determining a target. However, these objective
criteria also usually involve a number of subjective judgments or assumptions. Often
several not directly compatible criteria are combined in a heuristic way to a compound
criterion. Nevertheless, the decision on a target finally is and remains a normative
decision which can be informed by objective and transparent analysis but not directly
derived from such analysis. Targets need to accommodate diverging interests and are
thus the result of a negotiation process in which political powers and negotiation tactics
may play a greater role than objective analysis.
Based on these criteria we have developed a number of potential mitigation targets for
international aviation and maritime transport which will be explained and illustrated in
the following chapter.
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 33
POTENTIAL GHG MITIGATION TARGETS 7.
By taking into account the projections illustrated in Chapter 4 and the considerations
elaborated in Chapter 6 we have identified a number of potential targets for international
aviation and maritime transport:
Constant share (blue lines): For these target proposals we assume that the
share of global GHG emissions from international aviation and maritime transport
projected for 2020 is kept constant in the future. Applying this assumption to the
RCP 2.6 (dashed blue line) and 4.5 (continuous blue line) pathways, two target
trajectories can be plotted.
EU target path (green lines): This is based on the assumption that international
aviation and maritime transport could be considered as additional countries and
that they resemble an industrialised rather than a developing country. From a
European perspective it is then appropriate to apply the same reduction path as
for the EU, albeit in a reduced time-frame. The Council of the European Union
(2009) has declared a reduction of its GHG emissions by 80 to 95
% by 2050
compared to 1990 levels. Together with the respective targets for 2008-2012
(-8
%), 2020 (-20
%) and 2030 (-40
%) target paths consistent with the EU’s own
ambition can be sketched.
Budget approach (yellow line): Taking up the concept of a remaining global
carbon budget together with international aviation and maritime transport’s 2020
share in global GHG emissions, the respective sectoral target path consistent with
the carbon budget can be derived (see also Table 2, p. 34).
Carbon neutral growth (dashed grey line): ICAO has agreed to keep its CO2
emissions constant from 2020 onwards (CNG 2020). By applying this target to
maritime transport both an individual as well as a combined target trajectory can
be illustrated.
Industry proposals (continuous grey line): IATA suggested starting with carbon
neutral growth from 2020 onwards and reducing international aviation’s emissions
by 50
% by 2050 compared to 2005. ICS “is confident” that emissions per tonne
mile will be reduced by 50
% by 2050 compared to 2005.
Under the carbon budget approach, a global total of 2 900 Gt CO2eq can be emitted
across all sectors between 1861 and 2100 to stay below an anthropogenic warming of
2°C with a likelihood of above 66
%. Of this budget 1 890 Gt have already been emitted
by 2011 and another approx. 200 Gt are projected in all RCPs by 2019. The remaining
budget of 810 Gt CO2eq is then distributed to international aviation and maritime
transport based on their share of global GHG emissions in 2020, leaving a total budget of
12 Gt and 15 Gt respectively for the two sectors after 2020.
The target trajectories in the subsequent graphs are plotted from 2020 onwards, mainly
because the implementation of policies and instruments aiming at achieving these targets
will take time before they come into force even if decisions on the targets for
international aviation and maritime transport were taken immediately.
The following figures illustrate these potential targets in the context of the baseline
projection and the estimated CO2 reduction potential within the sectors, for both
international aviation (Figure 9) and maritime shipping (Figure 10) individually and
aggregated for both sectors together (Figure 11).
Policy Department A: Economic and Scientific Policy
34 PE 569.964
Table 2: Emission budgets 2020-2100 for international aviation and
maritime transport
Source: IPCC 2013, p. 27, van Vuuren, D. P. et al. 2011
Figure 9: Potential CO2 emission targets for international aviation
Source: Authors’ own calculations based on IEA 2014, ICAO 2013b, van Vuuren, D. P. et al. 2011, Thomson
et al. 2010, IATA 2013, IPCC 2014, ICAO 2010
Notes: Data for all graphs disaggregated by transport mode is included in the Annex.
The potential targets for both the individual sectors and their aggregate can be clearly
distinguished in terms of their slope towards 2050. The budget approach, targets based
on a constant share of the CO2 emissions in the RCP 2.6 scenario and the EU’s target
path would result in clearly descending GHG emission trends in both sectors and be
compatible with limiting the increase in global temperature to below 2°C.
about as likely as
not (>33%)
more likely than
not (>50%)
likely
(>66%)
Global budget 1861-2100
[Gt CO
2
]3 300 3 010 2 900
Used budget (emissions 1861-2019)
[Gt CO
2
]-2 090 -2 090 -2 090
Remaining budget 2020-2100
Global
[Gt CO
2
]1 210 920 810
Aviation
[Gt CO
2
]18.7 14.2 12.5
Shipping
[Gt CO
2
]22.1 16.8 14.8
Likelihood to stay below 2°C
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 35
Figure 10: Potential CO2 emission targets for international maritime transport
Source: Authors’ own calculations based on IEA 2014, IMO 2009, IMO 2014, van Vuuren, D. P. et al. 2011,
Thomson et al. 2010, IATA 2013, IPCC 2014, ICS 2015
Notes: Data for all graphs disaggregated by transport mode is included in the Annex.
Figure 11: Potential CO2 emission targets for international aviation and
maritime transport
Source: Authors’ own calculations based on IEA 2014, ICAO 2013b, IMO 2009, IMO 2014, van Vuuren, D.
P. et al. 2011, Thomson et al. 2010, IATA 2013, IPCC 2014, ICAO 2010, ICS 2015
Notes: Data for all graphs disaggregated by transport mode is included in the Annex.
0
1 000
2 000
3 000
4 000
5 000
6 000
1990 1995 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Mt CO
2
International bunkers
Baseline
Technological & operational improvements
Constant share of global CO2 emissions (RCP 4.5)
Constant share of global CO2 emissions (RCP 2.6)
EU target path (min)
EU target path (max)
Industry proposal
Carbon neutral growth 2020
Budget approach
Policy Department A: Economic and Scientific Policy
36 PE 569.964
If the world would strive towards a 4.5 RCP, emissions of both sectors would develop
similarly to the carbon neutral growth approach and remain more or less 10
% above
2020 levels. The approaches based on the carbon budget decrease to almost zero
emissions in 2050. Even under such an ambitious target the cumulative emissions in the
30 year period would reach 95
% of the total budget. To leave some more budget for the
period after 2050 it would therefore be necessary to start with higher emission
reductions in 2020.
The trajectories of the respective industries look quite different, though. The IATA’s
target proposal would result in slightly more emission reduction in 2050 than the RCP 2.6
constant share trajectory but with much higher aggregated emissions. The ICS’
trajectory is even above the sectors mitigation potential. Both proposals together
compensate each other to some extent.
The figures also illustrate that all potential targets, except one, are more stringent than
the operational and technical potential identified by IMO and ICAO. If these targets would
be considered as absolute caps for each sector, this would certainly induce severe
changes within the sectors and at the global economy. However, these trajectories
should not be considered as absolute caps but rather indicate to which extent both
sectors could contribute to an adequate share to global GHG mitigation efforts, either
through mitigation of GHG emissions within their sectors or through taking responsibility
for emission reductions to be achieved in other sectors.
Table 3 provides an overview of the aggregated CO2 emissions over the period 2020 to
2050 under the different target scenarios. The scenarios are compared to the RCP 2.6
target path because it represents an emission pathway where the world at large would
stay below 2°C (Linthorst et al. 2015).
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 37
Table 3: Aggregated CO2 emissions 2020 to 2050 and deviation from 2°C
pathway
Source: Authors’ own calculations
The overview illustrates that the mitigation targets derived from the EU’s mitigation
path and from the budget approach would, in both sectors, be compatible with the
global below 2°C objective. Carbon neutral growth, on the other hand, would clearly
not be sufficient in the long term. In terms of the proposals put forward by industry,
the findings are mixed. While the shipping sector’s proposal is certainly not
compatible, the aviation sector’s proposal may still be compatible with the global
long-term goal. This mainly depends on the year by which carbon neutral growth is
turned into a declining trajectory. In our analysis we assumed that the decline would
start in 2030. Under this assumption international aviation’s aggregated emissions
are 17
% above the RCP 2.6 aggregate and in 2050 slightly below the RCP 2.6 target
path. However, the more the decline from carbon neutral growth is postponed, the
stronger the deviation of aviation from a trajectory which is compatible with the
global long-term goal. None of these targets include non-CO2 effects from aviation
(Box 1) and are therefore only part of the necessary contribution of the sector
towards achieving 2°C.
These target scenarios can be translated into targets for certain years. Table 4
provides an overview of the scenarios which are compatible with staying below 2°C
objective.
Gt CO
2
Deviation
from
RCP 2.6
International transport
Baseline 91.3 179%
Technological & operational improvements 73.6 125%
Industry proposal 56.8 73%
Constant share of global CO2 emissions (RCP 4.5) 55.5 69%
Carbon neutral growth 2020 50.9 55%
Constant share of global CO2 emissions (RCP 2.6) 32.8 0%
EU target path (min) 31.5 -4%
EU target path (max) 29.6 -10%
Budget approach 26.0 -21%
Aviation
Baseline 48.4 222%
Technological & operational improvements 36.8 145%
Constant share of global CO2 emissions (RCP 4.5) 25.4 69%
Carbon neutral growth 2020 23.3 55%
Industry proposal 17.6 17%
Constant share of global CO2 emissions (RCP 2.6) 15.0 0%
EU target path (min) 14.4 -4%
EU target path (max) 13.5 -10%
Budget approach 11.9 -21%
Shipping
Baseline 42.9 142%
Technological & operational improvements 36.8 107%
Industry proposal 39.2 121%
Constant share of global CO2 emissions (RCP 4.5) 30.1 69%
Carbon neutral growth 2020 27.6 55%
Constant share of global CO2 emissions (RCP 2.6) 17.8 0%
EU target path (min) 17.1 -4%
EU target path (max) 16.0 -10%
Budget approach 14.1 -21%
Policy Department A: Economic and Scientific Policy
38 PE 569.964
Table 4: CO2 emissions targets compatible with staying below 2°C compared
to 2005 emissions
Source: Authors’ own calculations
Notes: The target proposed by the shipping industry is not compatible with the below 2°C objective
and is therefore not included in this table.
In 2020, CO2 emissions from international aviation and maritime transport are projected
to be 79
% and 12
%, respectively, above their 2005 emission levels. By 2050, emissions
from international aviation need to be between -41
% and -96
% lower than in 2005. For
maritime transport, the range is -63
% to -98
%. The lower ambition is based on a
constant share of global CO2 emission under the RCP 2.6 scenario. However, a constant
share of historic emissions favours polluters and penalizes especially least developed
countries with very low emissions in the reference year. Based on their structure and size
both sectors are closer to industrialized countries than developing countries and should
therefore reduce their share of global emissions (Chapter 6). Taking the EU target path
as a reference for these sectors, the 2050 target for aviation needs to be between -64
%
and -91
% below 2005 emission levels. The target for shipping needs to be in the range
of -78
% to -94
% below the 2005 emission level for 2050. Shipping targets are more
ambitious than those for aviation compared to 2005. This is due to the much stronger
growth of emissions between 2005 and 2020 in the aviation sector.
If international aviation or maritime transport were to continue to evade their
responsibility, their share in global emissions may rise considerably. Figure 12 illustrates
how the share of international bunkers would develop under the potential target
trajectories.
2020 2030 2040 2050
International transport
Constant share of global CO2 emissions (RCP 2.6) 35% 5% -34% -55%
EU target path (min) 35% 8% -37% -73%
EU target path (max) 35% 8% -44% -93%
Budget approach 35% -9% -53% -97%
Aviation
Constant share of global CO2 emissions (RCP 2.6) 79% 39% -12% -41%
Industry proposal 79% 79% 15% -50%
EU target path (min) 79% 44% -16% -64%
EU target path (max) 79% 44% -25% -91%
Budget approach 79% 21% -38% -96%
Shipping
Constant share of global CO2 emissions (RCP 2.6) 12% -13% -45% -63%
EU target path (min) 12% -10% -48% -78%
EU target path (max) 12% -10% -53% -94%
Budget approach 12% -25% -61% -98%
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 39
Figure 12: Potential CO2 emission targets as share of global emissions
Source: Authors’ own calculations based on IEA 2014, ICAO 2013b, IMO 2009, IMO 2014, van Vuuren, D.
P. et al. 2011, Thomson et al. 2010, IATA 2013, IPCC 2014, ICAO 2010, ICS 2015
Notes: Data for all graphs disaggregated by transport mode is included in the Annex.
All mitigation scenarios start in 2020. Between 2012 and 2020 emissions are expected to
grow by 24
%, which corresponds to 4.4
% of the global CO2 emissions in 2020. Even if
both sectors pursued the carbon neutral growth trajectory after this date, their share
would triple between 2020 and 2050, provided that the world at large pursued an
emission trajectory compatible with the RCP 2.6. This is in conflict with the shipping
industry’s own ambition5 and supports the view that striving for carbon neutrality is
hardly ambitious enough from the perspective of mitigation requirements. In the longer
term, emissions of both sectors need to be reduced in absolute terms if they intend to
comply with their global responsibility (Bows-Larkin 2015; Merk 2015; Smith et al.
2015).
5 "The shipping industry therefore accepts that the CO2 emission reduction which ships must aim to
achieve should be at least as ambitious as the CO2 emissions reduction agreed under any new United
Nations Climate Change Convention." (ICS 2013).
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
1990 1995 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Share of RCP2.6 Pathway (CO
2
)
International bunkers
Baseline
Technological & operational improvements (baseline)
Constant share of global CO2 emissions (RCP 4.5)
Constant share of global CO2 emissions (RCP 2.6)
EU target path (min)
EU target path (max)
Industry proposal
Carbon neutral growth 2020
Budget approach
Policy Department A: Economic and Scientific Policy
40 PE 569.964
CONCLUSIONS 8.
Due to strong growth in transport demand, CO2 emissions of international aviation and
maritime transport were constantly growing in the past despite considerable efficiency
improvements. On average they grew by 2.9
%/yr in aviation and by 3.0
%/yr in
maritime transport and they are expected to grow even more strongly in the future
(4.4
%/yr and 2.9
%/yr, respectively). In 2012, both sectors together account for about
3
% to 4
% of global emissions, depending on whether global GHG or only CO2 emissions
are considered.
Initiatives and actions taken by ICAO and IMO to address GHG emissions started late and
have been insufficient from an environmental perspective to date: they do not take
appropriate account of global decarbonisation requirements. ICAO has agreed to carbon
neutral growth from 2020 onwards but policies to ensure that this target is achieved will
not be adopted before autumn 2016. Even this target is only aspirational, i.e. non-
binding and without concrete responsibilities for countries or operators. IMO has agreed
to technical and operational measures in 2011. In the long term, these measures will
mitigate growth of the sectoral CO2 emissions but not lead to absolute emission
reductions. A sectoral CO2 mitigation target was suggested by the Republic of the
Marshall Islands in spring 2015 but serious discussions on establishing a target were
postponed to a future IMO meeting.
If, as in the past, the ambition of these sectors continues to fall behind efforts in other
sectors and if action to combat climate change is further postponed, their CO2 emission
shares in global CO2 emissions may rise substantially to 22
% for international aviation
and 17
% for maritime transport by 2050, or almost 40
% of global CO2 emissions if both
sectors are taken together (Chapter 5). Establishing reduction targets for both sectors
would provide clear signals for all actors in these sectors and thus contribute to
improving investment perspectives in both sectors with their long investment cycles.
Mitigation targets are normative decisions which ultimately can only be informed
scientifically. Adequacy cannot be determined by analysis and research alone but has to
be determined and negotiated by policy makers. However, a number of somewhat
heterogeneous and not fully distinguishable criteria to assess the adequacy of targets can
be identified, including the time horizon of the target (short-, medium- or long-term), the
reference (absolute or relative/indexed), the shape (single year target, trajectory or
budget), the comparability in terms of emission reductions or mitigation costs and, last
but not least, whether the targets originate from bottom-up estimated mitigation
potentials or from global mitigation requirements.
Based on these criteria a number of potential mitigation targets for both sectors have
been identified (Chapter 7). These potential targets range from a somewhat reduced
increase of future emissions over a stabilisation at 2020 levels to a full decarbonisation of
those sectors by 2050 derived from a global carbon budget approach. Fully decarbonising
these sectors within only 30 years is certainly too ambitious and ultimately unrealistic.
However, stabilising emissions at 2020 levels (carbon neutral growth) is certainly not
enough. If global decarbonisation requirements are taken seriously, a clear downward
trend of emissions needs to be established sooner rather than later. To stay below 2°C,
the target for aviation for 2030 should not exceed 39
% of its 2005 emission levels (50
%
below the baseline) and should be -41
% compared to 2005 emission levels in 2050. The
respective targets for shipping are -13
% and -63
% compared to its 2005 emissions in
2030 and 2050, respectively (Table 4). If the EU target path were taken as a reference
for these sectors, aviation’s target for 2050 needs to be between -64
% and -91
%
compared to 2005 emission levels, while the 2050 target for the shipping sector would
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 41
range from -78
% to -94
% compared to 2005 emissions . If non-CO2 impacts are taken
into account, these targets would need to be even more stringent.
Taking into account the estimated mitigation potential within the sectors, it is unlikely
that these targets can be achieved only by technological and operations improvements.
In particular the targets which are compatible with the below 2°C objective are
significantly below mitigation potentials within the sectors. As a result these potential
targets should not be considered as sectoral caps. They rather indicate the extent to
which both sectors contribute adequately to global GHG mitigation efforts. Achieving
these targets may require both encouraging behavioural change which leads to reduced
demand for international transport services and enabling the offsetting of climate impacts
by financing emission reductions in other sectors. Moreover, it needs to be taken into
account that particularly the non-CO2 climate impacts of aviation will not be reduced if
fossil fuels are replaced by hydrocarbons extracted from renewable energies. Only
electrical propulsion, demand reduction (Bows-Larkin 2015) or offsetting remaining
emissions will enable full decarbonisation of the aviation sector.
These considerations support the view that it is important to establish targets for
international aviation and maritime transport which clearly indicate that emissions cannot
grow unlimited and unregulated. Enhancing the stringency of the targets can be aimed at
in a second step. Yet, aiming for ambitious targets in line with the approaches outlined
above should not prevent agreement on targets which will trigger emission reductions
sooner rather than later.
Policy Department A: Economic and Scientific Policy
42 PE 569.964
REFERENCES
ACCESS (2015). Shipping in the Arctic: Links to air pollution and climate change.
Available at http://www.access-eu.org/modules/resources/download/access/
fichiers_pdf/ACCESS-PolicyBrief2-Final.pdf, last accessed on 13 Oct 2015.
ATAG (2009). Beginner's guide to aviation biofuels. Available at http://www.atag.org/
component/downloads/downloads/60.html, last accessed on 01 Sep 2015.
ATAG (2014). Facts & Figures. Available at http://www.atag.org/facts-and-
figures.html, last accessed on 29 Sep 2015.
Bazari, Z. & Longva, T. (2011). Assessment of IMO mandated Energy Efficiency
Measures for International Shipping: Estimated CO2 Emissions Reduction from
Introduction of mandatory technical and operational Energy Efficiency Measures for
Ships (No. MEPC 63/INF.2).
Bows-Larkin A. (2015). All adrift: aviation, shipping, and climate change policy.
Climate Policy, pp. 122. doi:10.1080/14693062.2014.965125.
Bows-Larkin A.; Anderson K.; Mander S.; Traut M. & Walsh C. (2015). Shipping charts
a high carbon course. NATURE CLIMATE CHANGE, (Vol. 5), pp. 293295.
Cames, M.; Graichen, V.; Faber, J. & Nelissen, D. (2015). Greenhouse gas emission
reduction targets for international shipping (Discussion paper on behalf of the Federal
Environment Agency). Available at http://www.oeko.de/oekodoc/2241/2015-023-
en.pdf, last accessed on 18 Jun 2015.
Chèze, B.; Chevallier, J. & Gastineau, P. (2012). Will technological progress be
sufficient to effectively lead the air transport to a sustainable development in the mid-
term (2025)? (Working Paper Series No. 2012-07). Available at http://
www.chaireeconomieduclimat.org/wp-content/uploads/2012/05/12-02-Cahier-R-2012-
07-Cheze-Chevallier-Gastineau.pdf, last accessed on 14 Oct 2015.
Council of the European Union (2009). Council Conclusions on EU position for the
Copenhagen Climate Conference. Available at http://www.consilium.europa.eu/
uedocs/cms_data/docs/pressdata/en/envir/110634.pdf, last accessed on 26 Sep 2015.
Council of the European Union (2011). Conclusions European Council 4 February 2011
(Conclusions REV 1, pp. 115).
Council of the European Union (2015). Council conclusions on the preparations for the
21st session of the Conference of the Parties (COP 21) to the United Nations
Framework Convention on Climate Change (UNFCCC) and the 11th session of the
Meeting of the Parties to the Kyoto Protocol (CMP 11) (18/09/2015). Available at
http://data.consilium.europa.eu/doc/document/ST-12165-2015-INIT/en/pdf, last
accessed on 26 Sep 2015.
Deuber, O. (2013). Metric choice for trading off short- and long-lived climate forcers
A transdisciplinary approach using the example of aviation. Available at https://
opus4.kobv.de/opus4-tuberlin/files/5266/deuber_odette.pdf, last accessed on 01 Sep
2015.
ECSA (2015). Updated study highlights the economic importance of shipping. Available
at http://www.ecsa.eu/9-latest-news/188-updated-study-highlights-economic-
importance-of-shipping, last accessed on 29 Sep 2015.
EEA (2015). EEA greenhouse gas data viewer. Available at http://www.eea.europa.eu/
data-and-maps/data/data-viewers/greenhouse-gases-viewer.
Eide M.; Dalsøren S.; Endresen Ø.; Samset B.; Myhre G.; Fuglestvedt J. & Berntsen T.
(2013). Reducing CO2 from shipping - do non-CO2 effects matter? Atmospheric
Chemistry and Physics, 13, pp. 4183–4201.
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 43
Einemo U. (25 Sep 2015). Conflicting messages on shipping ahead of Paris climate
talks. Bunkerworld News. Available at http://www.bunkerworld.com/news/Conflicting-
messages-on-shipping-ahead-of-Paris-climate-talks-138973, last accessed on 29 Sep
2015.
EU (2009). Directive 2008/101/EC of the European Parliament and of the Council of 19
November 2008 amending Directive 2003 87 EC so as to include aviation activities in
the scheme for greenhouse gas emission allowance trading within the Community
(OJ L 8, 13.01.2009, pp. 3–21). Available at http://eur-lex.europa.eu/LexUriServ/
LexUriServ.do?uri=OJ:L:2009:008:0003:0021:en:PDF, last accessed on 15 Aug 2014.
European Parliament (2015). Implementation of the 2011 White paper on transport -
European Parliament resolution on the implementation of the White Paper on
Transport: taking stock and the way forward towards sustainable mobility
(2015/2005(INI)) (09/09/2015). Available at http://www.europarl.europa.eu/sides/
getDoc.do?pubRef=-//EP//NONSGML+TA+P8-TA-2015-0310+0+DOC+PDF+V0//EN,
last accessed on 28 Sep 2015.
European Parliament and Council (2015). Regulation (EU) 2015/ 757 on the
monitoring, reporting and verification of carbon dioxide emissions from maritime
transport (29/04/2015). Available at http://eur-lex.europa.eu/legal-content/EN/TXT/
PDF/?uri=CELEX:32015R0757&from=EN, last accessed on 26 Sep 2015.
Eyring V.; Isaksen, Ivar, S.A.; Berntsen T.; Collins W.; Corbett J.; Endresen Ø.;
Grainger R.; Moldanova J.; Schlager H. & Stevenson D. (2010). Transport impacts on
atmosphere and climate: shipping. Atmospheric Environment, 44(37), pp. 47354771.
doi:10.1016/j.atmosenv.2009.04.059.
Fuglestvedt J.; Shine K.; Berntsen T.; Cook J.; Lee D.; Stenke A.; Skeie R.; Velders G.
& Waitz I. (2010). Transport impacts on atmosphere and climate: Metrics.
Atmospheric Environment, 44(37), pp. 4648–4677.
doi:10.1016/j.atmosenv.2009.04.044.
Gençsü, I. & Hino, M. (2015). Raising ambition to reduce international aviation and
maritime emissions. Available at http://2015.newclimateeconomy.report/wp-content/
uploads/2015/09/NCE-Aviation-Maritime_final.pdf, last accessed on 21 Sep 2015.
Graichen, J. & Gugele, B. (2006). Greenhouse gas emissions from aviation
(ETC/ACC Technical Paper No. 2006/3). Available at http://acm.eionet.europa.eu/
docs/ETCACC_TechnPaper_2006_3_ghg_emissions_aviation.pdf, last accessed on 31
Aug 2015.
IATA (2013). Resolution on the Implementation of the Aviation “CNG2020” Strategy
(2013), last accessed on 28 Sep 2015.
ICAO (2001). Resolutions Adopted at the 33rd Session of the Assembly (2001), last
accessed on 14 Sep 2015.
ICAO (2010). Resolutions Adopted by the Assembly, A37-19 Consolidated statement
of continuing ICAO policies and practices related to environmental protection Climate
change (November 2010). Available at http://www.icao.int/Meetings/AMC/
Assembly37/Documents/ProvisionalEdition/a37_res_prov_en.pdf, last accessed on 26
Sep 2015.
ICAO (2013a). Environmental Report 2013: Aviation and Climate Change. Available at
http://cfapp.icao.int/Environmental-Report-2013/files/assets/common/downloads/
ICAO_2013_Environmental_Report.pdf.
ICAO (2013b). Present and future trends in aircraft noise and emissions (Assembly
28th Session No. Working paper). Available at http://www.icao.int/Meetings/a38/
Documents/WP/wp026_en.pdf, last accessed on 18 Jun 2015.
Policy Department A: Economic and Scientific Policy
44 PE 569.964
ICS (2013). Shipping World Trade and the Reduction of CO2 Emissions. Available at
http://www.shortsea.be/html_nl/publicaties/documents/shipping-world-trade-and-the-
reduction-of-co2-emissions.pdf, last accessed on 30 Sep 2015.
ICS (2015). Delivering CO2 Emission Reductions. Available at http://www.ics-
shipping.org/docs/shipsandco2-cop21, last accessed on 28 Sep 2015.
IEA (2014). CO2 emissions from fuel combustion 2014. Paris. Available at https://
www.iea.org/media/freepublications/stats/
CO2_Emissions_From_Fuel_Combustion_Highlights_2014.XLS.
IMO (2009). Second IMO GHG Study 2009: Update of the 2000 IMO GHG Study. Final
report covering Phase 1 and Phase 2 (No. MEPC 59/INF.10). Available at http://
www.ce.nl/?go=home.downloadPub&id=941&file=7625_FinalReportDN.pdf, last
accessed on 14 Oct 2015.
IMO (2014). Reduction of GHG emissions from ships - Third IMO GHG Study 2014.
Final report. London.
IMO (2015a). Marine Environment Protection Committee (MEPC), 68th session, 11-15
May 2015Marine Environment Protection Committee (MEPC), 68th session, 11-15 May
2015. Available at http://www.imo.org/en/MediaCentre/PressBriefings/Pages/19-
MEPC-68-outcome.aspx.
IMO (2015b). Technical and Operational Measures. Available at https://www.imo.org/
en/OurWork/Environment/PollutionPrevention/AirPollution/Pages/Technical-and-
Operational-Measures.aspx.
IPCC (1999). Aviation and the global atmosphere. IPCC Special Report: Summary for
Policymakers. Available at https://www.ipcc.ch/pdf/special-reports/spm/av-en.pdf,
last accessed on 01 Sep 2015.
IPCC (2001). Climate Change - Third Assessment Report: Working Group I: The
Scientific Basis. Available at https://www.ipcc.ch/ipccreports/tar/wg1/index.htm.
IPCC (2013). Working Group I contribution to the IPCC fifth Assessment Report
Climate Change 2013: The physical science basis. Technical Summary. Available at
http://www.climatechange2013.org/images/uploads/WGIAR5_WGI-
12Doc2b_FinalDraft_TechnicalSummary.pdf, last accessed on 03 Sep 2014.
IPCC (2014). AR5 Synthesis Report - Climate Change 2014. Available at http://ar5-
syr.ipcc.ch/ipcc/ipcc/resources/pdf/IPCC_SynthesisReport.pdf, last accessed on 23 Jul
2015.
IRENA (2015). Renewable energy options for shipping: Technology brief. Available at
http://www.irena.org/DocumentDownloads/Publications/
IRENA_Tech_Brief_RE_for%20Shipping_2015.pdf, last accessed on 31 Aug 2015.
Kesicki F. & Ekins P. (2011). Marginal abatement cost curves: a call for caution.
Climate Policy, 12(2), pp. 219–236. doi:10.1080/14693062.2011.582347.
Kharina, A. & Rutherford, D. (2015). Fuel efficiency trends for new commercial jet
aircraft: 1960 to 2014 (White Paper).
Lee D.; Fahey D.; Forster P.; Newton P.; Wit R.; Lim L.; Owen B. & Sausen R. (2009).
Aviation and global climate change in the 21st century. Atmospheric Environment,
43(22-23), pp. 35203537. doi:10.1016/j.atmosenv.2009.04.024.
Lee D.; Pitari G.; Grewe V.; Gierens K.; Penner J.; Petzold A.; Prather M.; Schumann
U.; Bais A. & Berntsen T. (2010). Transport impacts on atmosphere and climate:
Aviation. Atmospheric Environment, 44(37), pp. 46784734.
doi:10.1016/j.atmosenv.2009.06.005.
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 45
Lee, D. S.; Lim, L. L. & Owen, B. (2013). Bridging the aviation CO2 emissions gap:
why emissions trading is needed. Available at http://www.cate.mmu.ac.uk/wp-
content/uploads/Bridging_the_aviation_emissions_gap_010313.pdf.
Liese, P.; Groote, M.; Girling, J.; Gerbrandy, G.-J.; Eickhout, B. & Pedicini, P. (2015).
Letter to Minister Carole Dieschbourg and Minister Francois Bausch. Available at
http://www.transportenvironment.org/sites/te/files/
150914_Coordinators%20letter%20to%20Lux%20Presidency.pdf.
Linthorst, G.; Beer, J. de; Blok, K. & Meindertsma, W. (2015). Sectoral
Decarbonization Approach (SDA): A method for setting corporate emission reduction
targets in line with climate science. Available at http://sciencebasedtargets.org/wp-
content/uploads/2015/05/Sectoral-Decarbonization-Approach-Report.pdf, last
accessed on 29 Oct 2015.
Meinshausen M.; Meinshausen N.; Hare W.; Raper, S. C. B.; Frieler K.; Knutti R.;
Frame D. & Allen M. (2009). 2009: Greenhouse gas emission targets for limiting global
warming to 2°C. Nature, (458), pp. 11581162.
MEPC (2010). Alternative emission caps for shipping in 2020 and 2030, Submitted by
Norway (No. MEPC 60/4/23). London.
MEPC (2015). Setting a reduction target and agreeing associated measures for
international shipping: Submitted by the Marshall Islands (No. MEPC 68/5/1).
Merk, O. (2015). Shipping and Climate Change: Where are we and which way
forward?: Policy Brief. Available at http://www.internationaltransportforum.org/jtrc/
PolicyBriefs/PDFs/2015-10-12.pdf.
Oxford Economics (2015). The economic value of the EU shipping industry update,
last accessed on 29 Sep 2015.
Sausen R.; Isaksen I.; Grewe V.; Hauglustaine D.; Lee D. S.; Myhre G.; Köhler M. O.;
Pitari G.; Schumann U.; Stordal F. & Zerefos C. (2005). Aviation radiative forcing in
2000: an update on IPCC. Meteorologische Zeitschrift, 14(4), pp. 555561.
Sims R.; R. Schaeffer; F. Creutzig; X. Cruz-Núñez; M. D’Agosto; D. Dimitriu; M. J.
Figueroa Meza; L. Fulton; S. Kobayashi; O. Lah; A. McKinnon; P. Newman; M.
Ouyang; J. J. Schauer; D. Sperling & G. Tiwari (2014). Transport. In O. Edenhofer, R.
Pichs-Madruga, Y. Sokona, E. Farahani, S. Kadner, K. Seyboth, . . . J. C. Minx (Eds.),
Climate change 2014, mitigation of climate change. Contribution of Working Group
III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change
(pp. 599–670). Cambridge, United Kingdom and New York, NY, USA.: Cambridge
University Press. Available at http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/
ipcc_wg3_ar5_full.pdf.
Smith T.; Traut M.; Bows-Larkin A.; Anderson K.; McGlade C. & Wrobel P. (2015).
CO2 Targets, Trajectories and Trends for International Shipping.
Stratton R.; Wolfe P. & Hileman J. (2011). Impact of Aviation Non-CO2 Combustion
Effects on the Environmental Feasibility of Alternative Jet Fuels. Environmental Science
& Technology, 45(24), pp. 1073610743. doi:10.1021/es2017522.
Thomson, A.; Calvin, K.; Smith, S.; Kyle, G.; Volke, A.; Patel, P.; Delgado-Arias, S.;
Bond-Lamberty, B.; Wise, M.; Clarke, L. & Edmonds, J. (2010). RCP4.5: A Pathway for
Stabilization of Radiative Forcing by 2100. Available at http://asr.science.energy.gov/
publications/program-docs/RCP4.5-Pathway.pdf.
Tyndall Centre (2014). High Seas, High Stakes. Manchester. Available at http://
www.globalmaritimehub.com/custom/domain_2/extra_files/attach_358.pdf, last
accessed on 28 Sep 2015.
Policy Department A: Economic and Scientific Policy
46 PE 569.964
UN (1992). Framework Convention on Climate Change (1992). Available at http://
unfccc.int/resource/docs/convkp/conveng.pdf, last accessed on 26 Sep 2015.
UNCTAD (2014). Review of Maritime transport 2014. Available at http://unctad.org/
en/PublicationsLibrary/rmt2014_en.pdf, last accessed on 29 Sep 2015.
UNEP (2011). Bridging the emissions gap. A UNEP synthesis report. Available at
http://www.unep.org/pdf/unep_bridging_gap.pdf, last accessed on 10 Oct 2014.
UNFCCC (1995). Decision 4/CP.1 Methodological issues (06/06/1995). Available at
http://unfccc.int/resource/docs/cop1/07a01.pdf, last accessed on 26 Sep 2015.
UNFCCC (1998). Kyoto Protocol to the United Nations Framework Convention
on Climate Change. Available at http://unfccc.int/resource/docs/convkp/kpeng.pdf,
last accessed on 25 Jun 2014.
van Vuuren D.; Edmonds J.; Kainuma M.; Riahi K.; Thomson A.; Hibbard K.; Hurtt G.;
Kram T.; Krey V.; Lamarque J.-F.; Masui T.; Meinshausen M.; Nakicenovic N.; Smith
S. & Rose S. (2011). The representative concentration pathways: an overview.
Climatic Change (Climatic Change), 109(1-2), pp. 5-31. doi:10.1007/s10584-011-
0148-z.
van Vuuren, D. P.; Stehfest E.; den Elzen, M. G. J.; Kram T.; van Vliet J.; Deetman
S.; Isaac M.; Klein Goldewijk K.; Hof A.; Mendoza Beltran A.; Oostenrijk R. & van
Ruijven B. (2011). RCP2.6: exploring the possibility to keep global mean temperature
increase below 2°C. Climatic Change (Climatic Change), 109(1-2), pp. 95-116.
doi:10.1007/s10584-011-0152-3.
Vogt-Schilb A. & Hallegatte S. (2014). Marginal abatement cost curves and the
optimal timing of mitigation measures. Energy Policy, 66, pp. 645653.
doi:10.1016/j.enpol.2013.11.045.
Wang, H. & Lutsey, N. (2013). Long-term potential for increased shipping efficiency
through adoption of industry-leading practices: ICCT White Paper. Available at http://
www.theicct.org/sites/default/files/publications/ICCT_ShipEfficiency_20130723.pdf,
last accessed on 14 Oct 2015.
Emission Reduction Targets for International Aviation and Shipping
PE 569.964 47
ANNEX
Table 5: Summary of historic and projected emissions
Source: IEA 2014, IMO 2009, IMO 2014, ICAO 2013b, Lee et al. 2013, authorsown calculations.
1990 2000 2010 2020 2030 2040 2050
int. Aviation
[Mt CO
2
]256 352 458
int. Maritime (bottom-up)
[Mt CO
2
]468 647 771
Bunker Fuels
[Mt CO
2
]724 999 1 229
Baseline
[Mt CO
2
]752 1 195 1 751 2 716
Techn. & op. Improvements
[Mt CO
2
]752 976 1 299 1 807
High demand
[Mt CO
2
]800 1 366 2 160 3 443
Low demand
[Mt CO
2
]651 833 1 066 1 438
Lee et al. Baseline
[Mt CO
2
]625 883 1 233 1 644
Baseline
[Mt CO
2
]890 1 100 1 600 2 100
Techn. & op. Improvements
[Mt CO
2
]890 1 100 1 300 1 400
High demand
[Mt CO
2
]910 1 200 1 900 2 800
Low demand
[Mt CO
2
]870 971 1 100 1 200
Baseline
[Mt CO
2
]1 642 2 295 3 351 4 816
Techn. & op. Improvements
[Mt CO
2
]1 642 2 076 2 599 3 207
High demand
[Mt CO
2
]1 710 2 566 4 060 6 243
Low demand
[Mt CO
2
]1 521 1 804 2 166 2 638
Baseline [%] 2.0% 4.1% 9.5% 21.9%
Techn. & op. Improvements [%] 2.0% 3.4% 7.1% 14.6%
High demand [%] 2.1% 4.7% 11.7% 27.7%
Low demand [%] 1.7% 2.9% 5.8% 11.6%
Baseline [%] 2.4% 3.8% 8.7% 16.9%
Techn. & op. Improvements [%] 2.4% 3.8% 7.1% 11.3%
High demand [%] 2.4% 4.1% 10.3% 22.5%
Low demand [%] 2.3% 3.3% 6.0% 9.7%
Baseline [%] 0.2% 2.6% 6.1% 11.2%
Techn. & op. Improvements [%] 0.2% 2.5% 5.4% 9.1%
High demand [%] 0.2% 2.9% 7.1% 13.6%
Low demand [%] 0.2% 2.3% 4.7% 7.7%
Baseline [%] 0.1% 1.3% 3.1% 5.9%
Techn. & op. Improvements [%] 0.1% 1.2% 2.6% 4.5%
High demand [%] 0.1% 1.5% 3.7% 7.2%
Low demand [%] 0.1% 1.0% 2.2% 3.7%
Baseline [%] 0.1% 1.3% 3.0% 5.3%
Techn. & op. Improvements [%] 0.1% 1.3% 2.8% 4.5%
High demand [%] 0.1% 1.5% 3.4% 6.4%
Low demand [%] 0.1% 1.3% 2.5% 4.0%
Baseline [%] 0.2% 2.6% 6.1% 11.2%
Techn. & op. Improvements [%] 0.2% 2.5% 5.4% 9.1%
High demand [%] 0.2% 2.9% 7.1% 13.6%
Low demand [%] 0.2% 2.3% 4.7% 7.7%
Share of global GHG budget for
2020-2100
Int.
Aviation
Int.
Maritime
Bunker
Fuels
Historic
Bunker Fuels
Projections
Int.
Aviation
Int.
Maritime
Bunker
Fuels
Share of global emissons
(RCP2.6)
Int. Aviation
Int. Maritime
Policy Department A: Economic and Scientific Policy
48 PE 569.964
Table 6: Summary of emission targets
Source: IEA 2014, IMO 2009, IMO 2014, ICAO 2010, ICAO 2013b, van Vuuren, D. P. et al. 2011, IATA
2013; Thomson et al. 2010, ICS 2015, IPCC 2014, authors’ own calculations.
1990 2000 2010 2020 2030 2040 2050
ICAO Baseline
[Mt CO
2
]256 352 458 752 1 195 1 751 2 716
ICAO techn. & op. Improvements
[Mt CO
2
]752 976 1 299 1 807
Constant share of 2020 global emissions (RCP 4.5)
[Mt CO
2
]752 822 850 831
Constant share of 2020 global emissions (RCP 2.6)
[Mt CO
2
]752 582 368 248
EU target path (min)
[Mt CO
2
]752 602 351 150
EU target path (max)
[Mt CO
2
]752 602 313 38
Carbon neutral growth 2020
[Mt CO
2
]752 752 752 752
Industry proposal
[Mt CO
2
]752 752 481 209
Budget approach
[Mt CO
2
]752 506 261 15
IMO Baseline
[Mt CO
2
]468 647 771 890 1 100 1 600 2 100
IMO techn. & op. Improvements
[Mt CO
2
]890 1 100 1 300 1 400
Constant share of 2020 global emissions (RCP 4.5)
[Mt CO
2
]890 973 1 005 983
Constant share of 2020 global emissions (RCP 2.6)
[Mt CO
2
]890 689 436 294
EU target path (min)
[Mt CO
2
]890 712 415 178
EU target path (max)
[Mt CO
2
]890 712 371 45
Carbon neutral growth 2020
[Mt CO
2
]890 890 890 890
Industry proposal
[Mt CO
2
]890 1 139 1 388 1 637
Budget approach
[Mt CO
2
]890 599 309 18
Baseline
[Mt CO
2
]724 999 1 229 1 642 2 295 3 351 4 816
Techn. & op. Improvements
[Mt CO
2
]1 642 2 076 2 599 3 207
Constant share of 2020 global emissions (RCP 4.5)
[Mt CO
2
]1 642 1 796 1 855 1 814
Constant share of 2020 global emissions (RCP 2.6)
[Mt CO
2
]1 642 1 272 804 542
EU target path (min)
[Mt CO
2
]1 642 1 314 766 328
EU target path (max)
[Mt CO
2
]1 642 1 314 684 82
Carbon neutral growth 2020
[Mt CO
2
]1 642 1 642 1 642 1 642
Industry proposal
[Mt CO
2
]1 642 1 891 1 869 1 846
Budget approach
[Mt CO
2
]1 642 1 106 569 33
ICAO Baseline [%] 0.9% 1.2% 1.3% 2.0% 4.1% 9.5% 21.9%
ICAO techn. & op. Improvements [%] 2.0% 3.4% 7.1% 14.6%
Constant share of 2020 global emissions (RCP 4.5) [%] 2.0% 2.8% 4.6% 6.7%
Constant share of 2020 global emissions (RCP 2.6) [%] 2.0% 2.0% 2.0% 2.0%
EU target path (min) [%] 2.0% 2.1% 1.9% 1.2%
EU target path (max) [%] 2.0% 2.1% 1.7% 0.3%
Carbon neutral growth 2020 [%] 2.0% 2.6% 4.1% 6.1%
Industry proposal [%] 2.0% 2.6% 2.6% 1.7%
Budget approach [%] 2.0% 1.7% 1.4% 0.1%
IMO Baseline [%] 1.7% 2.2% 2.1% 2.4% 3.8% 8.7% 16.9%
IMO techn. & op. Improvements [%] 2.4% 3.8% 7.1% 11.3%
Constant share of 2020 global emissions (RCP 4.5) [%] 2.4% 3.3% 5.5% 7.9%
Constant share of 2020 global emissions (RCP 2.6) [%] 2.4% 2.4% 2.4% 2.4%
EU target path (min) [%] 2.4% 2.4% 2.3% 1.4%
EU target path (max) [%] 2.4% 2.4% 2.0% 0.4%
Carbon neutral growth 2020 [%] 2.4% 3.1% 4.8% 7.2%
Industry proposal [%] 2.4% 3.9% 7.5% 13.2%
Budget approach [%] 2.4% 2.1% 1.7% 0.1%
Baseline [%] 2.6% 3.5% 3.4% 4.4% 7.9% 18.2% 38.8%
Techn. & op. Improvements [%] 4.4% 7.1% 14.1% 25.8%
Constant share of 2020 global emissions (RCP 4.5) [%] 4.4% 6.2% 10.1% 14.6%
Constant share of 2020 global emissions (RCP 2.6) [%] 4.4% 4.4% 4.4% 4.4%
EU target path (min) [%] 4.4% 4.5% 4.2% 2.6%
EU target path (max) [%] 4.4% 4.5% 3.7% 0.7%
Carbon neutral growth 2020 [%] 4.4% 5.6% 8.9% 13.2%
Industry proposal [%] 4.4% 6.5% 10.1% 14.9%
Budget approach [%] 4.4% 3.8% 3.1% 0.3%
Share of global emissons (RCP2.6)
Int. Aviation
Int. Maritime
Bunker Fuels
Int. Aviation
Int. Maritime
Bunker Fuels
2050 target proposals
... International aviation accounts for approximately 65% of total aviation emissions or 1.3% of all anthropogenic CO 2 emissions (ICAO, 2016). In addition to this, the sector further contributes to global warming with its non-CO 2 emissions, which are estimated to have a radiative forcing 1 effect at least equal to that of its CO 2 emissions (Cames et al., 2015). In fact, estimates of climate impacts of all direct and indirect GHG emissions of global aviation expressed as radiative forcing indicate a more substantial current contribution of the sector at almost 5% of anthropogenic warming (Lee et al., 2009). ...
... Compared to the major emitting sectors, these figures of aviation's current contribution to greenhouse gas emissions may not seem very high. Nevertheless, the fast growth in air traffic and the associated increase in jet fuel consumption mean that by 2050 global aviation could account for over 22% of all anthropogenic CO2 emissions (Cames et al., 2015). ...
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... In addition, a signi cant increase in ight passenger miles around the world is estimated to grow by 4-5 percent between 2019 and 2038 (Mazareanu, 2019). This implies that commercial aviation will have a much greater climate impact in the future than now, unless more sustainable and e cient greenhouse gas (GHG) emission solutions are developed (Cames et al., 2015). ...
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