Po

ste

r Te

mp

late

from

ww

w.m

an

ch

es

ter.a

c.u

k/p

ho

tog

rap

hic

s

Faculty of Engineering & Physical Sciences www.tyndall.ac.uk

The shipping sector has publicallydeclared its intention to make its faircontribution to global efforts to avoiddangerous climate change. The 3rd IMOGHG report (Smith et al. 2014) estimatesthat for the period 2007–2012,international shipping accounted for2.6% of annual global CO2 emissions onaverage. Given the long lived nature ofmany greenhouse gases, avoidingdangerous climate change requiresmaintenance of an emission budget. TheIPCC (2014) calculate a carbon budgetof 960-1,550 Gt CO2 from 2011 to 2100,reflecting 32-61% chance of exceeding 2°C.

Requiring that international shippingmaintains its current share of globalemissions implies a budget of 33.5 GtCO2 (Table 1). Assuming that the mainship types, Dry Cargo, Oil andContainers maintain their recentproportion of 70% of total emissionsmeans that a 50% chance of exceeding2 °C allows a budget of 23 Gt CO2 forthese categories.

.

Introduction

Scenario Framing: Demand

Method

Analysis Analysis

Conclusions

References

IPCC, 2013. Working group iii. mitigation of climate change. chapter 6: Assessing transformation pathways. Fifth Assessment Report, Final draft version

Smith et al. Third IMO GHG study 2014. International Maritime Organization (IMO) London, UK, 2014.

The author would like to acknowledge the assistant of Solmaz Haji at the University College London Energy Institute in the production of this poster.

In order to explore the implications of a2°C future on the shipping sector, ascenario for the future demand forshipping is projected based on 2010tonnage estimated using the TIAM-UCLenergy systems model whilst maintainingthe level of growth in trade implied by the3rd IMO GHG report associated with RCP2.6. Transport work is estimated basedon projections of haul length (km ornautical miles) in order to maintain therequired time at sea for each vessel bysize and type. The projected transportwork is summarised in Figure 1.

As can be seen from estimates above,the growth in transport work and thefailure to limit emissions in the short termrequires a fully decarbonised fleet by2040. Peaking emissions by 2020 allowsfor some leeway but zero/low carbonoptions such as hydrogen fuel cells orbiofuels are none the-less an essentialcomponent in satisfying the emissionbudgets. However under a carbonconstrained future it is likely that sectoralcompetition for such fuels will be highand therefore operational measures toreduce (even zero carbon) fuel demandbecomes more important. This makesspeed reduction an equally importantaspect in meeting a challenging budget.By way of example, Table 2 summarisesthe main supply side interventions for thecontainer fleet assuming a 2020 peak.

Chance of avoidance 32% 50%

Emission Budget 22.5 Gt CO2 33.5 Gt CO2

Opportunities and challenges for decarbonising the shipping sector

Tyndall Centre for Climate Change Research, School of Mechanical, Aerospace and Civil Engineering, University of Manchester

Conor Walsh

Figure 2: Impact of emission peaking date on emission trajectory in order to satisfy a 50% of exceeding 2°C. .

Figure 3: Shipping emission scenario generation tool method.

Figure 4: Required aggregate EEOI assuming emissions peak in 2020. Container EEOI is estimated on the right hand axis.

Table 2:. Summary of emission reduction measures for the container fleet.

Figure 1: Projected transport work demand in terms of tonne km for bulk goods and Twenty foot Equivalents (TEU) for unitised goods. Containers demand is projected in terms of TEU km.

The trajectory (2010-2050) required tomeet the emission budgets will dependon assumptions as to when emissionswill peak. If it is assumed that shippingemissions continue to grow at ratesexperienced in recent years (Smith et al.2014), the point at which emissions willpeak will increase the stringency ofemission reduction targets. This isdemonstrated for the budget of 23 GtCO2 shown in Figure 2.

In order to generate estimates of futureshipping emissions commensurate withan emission pathway, a bespokeshipping emission accounting tool, ASKC is used (Figure 3).

Within the model tonnage demand isallocated to fleet segments based onoverall fleet productivity (dwt/tonne)which also dictates the required level offleet turnover.

Transport work is estimated bycalculating a haul length necessary tomaintain a given time at sea (days/yearper vessel), or for a given haul length,speed and utilization capacity, a time atsea is generated. The relationshipbetween engine size, and ship size aswell as operational speed provides aprovisional estimate of primary energydemand which can then be augmentedusing different estimates of energyreduction due to technology or choice offuel.

Within this scenario significant growth incontainer and dry bulk demand projectedwithin this scenario places significantpressure on the shipping sector. Theenergy efficiency operational index(EEOI) being the carbon intensity oftransport work required to meet theemissions budget is presented inFigures 4 and 5.

A substantial increase in the quantity oftransport demand necessitates asignificant response by several elementsof the wider shipping sector. Portinfrastructure and supply chain partnersmust accept an increased journey timeassociated with a reduction in speed.Ship builders and owners must beprepared for widespread uptake ofenergy efficacy technologies but that willbe contingent on their availability andeffectiveness in their first instance.

Ship scrapping age will likely have to bereduced to 20 years to ensure increasedpenetration of more efficient ships.

Perhaps the most crucial element is theavailability of zero carbon emissionoptions, will be required to be widelyavailable in some form by 2030 and nearubiquitous after 2040. Hydrogen fuelcells are chosen in this example butother options may include nuclearpowered ships or near total biofueldemand.

As much of the elements whichdetermine emissions, such as the shipsthemselves, have long lives and oftenfixed properties, a drastic near termreduction in emissions is difficult toforesee. Therefore the medium term(post 2030) is likely to be pivotal,suggesting current measures such asthe energy efficiency design index(EEDI) or slow steaming are critical inaffording some measure of time for thewider system level changes (such as fuelavailability) to made available by thetime more drastic reductions inemissions are necessary.

Figure 5: Required aggregate EEOI assuming emissions peak in 2030. Containers EEOI is estimated on the right hand axis.

The severe increase in transport workdemand is presented here as a dramaticexample but does highlight the potentialscale of changes necessary in the faceof a continued increase in demand and adeferred emission peak.

At the risk of oversimplification, thescenario presented demonstrates thepotential value in aligning more effectiveemission reduction interventions with theelements most responsible for emissionssuch as large container vessels.

Given the numerous determinants ofshipping emissions, sectoraldecarbonisation will require theengagement of many actors at a systemlevel and is beyond the gift of theshipping sector on its own.

Table 1: Cumulative Emission Budgets (2011-2100) for international shipping.

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

200,000

2010 2020 2030 2040 2050

109tkm

or  109  TEU

 km

Oil Dry Bulk Container (TEU)

Scenario Framing: Peak

0

200

400

600

800

1,000

1,200

1,400

2010 2020 2030 2040 2050

Mt CO

2

0

10

20

30

40

50

60

70

80

90

0

1

2

3

4

5

6

7

8

9

2010 2020 2030 2040 2050

g CO

2TEU nm

g CO

2tonne nm (Dry and OIl)

Oil Bulk Container

0

10

20

30

40

50

60

70

80

90

0

1

2

3

4

5

6

7

8

9

2010 2020 2030 2040 2050

g CO2 TEU

 nm

g CO2 tonne nm (Dry and OIl)

Oil Bulk Container

2010 2020 2030 2040 2050

Design considerations

Reduced design speed and engine Size

Reduction in design speed 25% 30% 33% 30%

Capacity Utilisation 60% 60% 80% 80% 80%

Energy savings  New build Tech na 10% 20% 30% 30%

Energy Savings Retrofit Tech na na 10% 10% 10%

Fuel TypeLSFO/MDO

LSHFO/MDO

LSHFO/MDO, H2

fuel cells on new  vessels >50,00 TEU

LSFO/HFO. All ships built after 2040 

utilise  H2, fuel cells.

Biofuel % 0% 0% 10% 30% 50%