The 1.5oC Transition:
Challenges and Opportunities
Elmar Kriegler
IPCC SR1.5 Chapter 2 Side Event, COP24, Katowice
12 December 2018

Systems transitions in 1.5°C pathways
Limiting warming to 1.5°C would require rapid, farreaching changes on an unprecedented scale:
Deep emissions cuts in all sectors and regions
A range of low carbon technologies
Behavioural changes
Sustainable land management
Carbon dioxide removal from the atmosphere
Investment into system transitions & low carbon options

with a systems perspective and global coordination.
Peter Essick / Aurora Photos

Joeri Rogelj - CLA Chapter 2 – IPCC SR1.5

Sequenceof Systems
Transitions
Re-directing investments
Carbon neutral economy
from fossils to low carbon
and efficiency solutions

Peakin 2020
Steepemissions
reduction

Electrification of end uses
Low carbon fuels
Carbon removal
Challenges:• Freight transport,aviation, shipping• Heavy industry

Carbonneutrality

SR1.5 Fig. SPM3b

Power sector
decarbonization
Coal phase-out
Efficiency improvements
REDD+Net CO2
removalCompensate residual emissions(incl. agricultural N2O emissions)Compensate budget overshoot1.5°C pathways can put different emphasis on
demand- vs. supply-side vs. CO2 removal

Demand-side measures (energy intensity, diets) and early
emissions reduction reduce need for carbon dioxide removal
SR1.5 Fig. SPM3b

Energy system transitions
Global primary energy• Fossil fuel eductions vary with fuel type: coal the most, gas the least• Limited amount of fossil CCS (predominantly gas)
• Solar, wind, bionenergy with CCS gain the mostSR1.5 Chap. 2 Fig. 2.15

Electricity system transitions
Full decarbonisation by mid-century• Gas supplies 3-11% of electricity (depend. CCS)
• Coal is phased out as source for electricity (0-2%)• Renewables supply 70-85% of electricity
SR1.5 Chap. 2 Fig. 2.16

Systems transitions: Energy use
in industry, transport, buildings
CO2 emissions from industry in 2050:• 75-90% reduced from 2010 levels
Compared to 50-80% for 2°C

Share of low-emission final energy intransport:• 35-65% in 2050
Compared to 25-45% for 2°C

Electricity share of final energy in buildings:• 55-75% in 2050
Compared to 50-70% for 2°C
Gerhard Zwerger-Schoner / Aurora Photos

SR1.5 Chap. 2 Fig. 2.20

Energy investments needed in 1.5-2oC pathways
upscaled by roughly a factor of six (range offactor of 4 to 10) by 2050 compared to 20152016-2050

12%830 billion USD

IPCC SR1.5.
Chap. 2 Fig. 2.28

Systems transitions
Carbon Dioxide Removal (CDR)
All 1.5°C pathways use CDR in the range of 100-1000 GtCO2
over the 21st century, to• Compensate residual emissions of CO2• Achieve net negative CO2 emissions for overshoot
BECCS and AFOLU CDR are predominant options
in 1.5°C pathways• BECCS: 0-1 GtCO2/yr in 2030, 0-8 GtCO2/yr in 2050
Assessed max. 2050 potential: 5 GtCO2/yr• AFOLU: 0-5 GtCO2/yr in 2030, 1-11 GtCO2/yr in 2050
Assessed max. 2050 potential: 3.6 GtCO2/yr
Gerhard Zwerger-Schoner / Aurora Photos

Range of CDR measures
Portfolio of CDR measures would limit individual deployment andtherefore sustainability issues for each single measure••
•
••
•
•
•

Soil carbon enhancement, biochar and land restoration
Afforestation
BECCS using energy crops
BECCS using algae
Direct Air Capture + Geological storage (DACCS)
Enhanced Weathering
Artificial ocean alkalinization
Carbon capture and usage (e.g. carbon fiber / wood)

Terrestrial storage
Early deployment
Geological storage
Medium-Long term

Mineralisation
Medium-Long term

9

System transitions: Land-use changes
to provide food, feed, fibre, bioenergy, carbon storage,
biodiversity and other ecosytem services

Food Crops
Energy Crops
ForestOther Natural Land
PastureSource: IPCC SR1.5 Chap. 2, Fig 2.10

For comparison: current global
cropland area is ca. 1500 mha
P2P3P4

P1

Need for sustainable land management in 1.5oC pathways
10Linkages between 1.5°C pathways and sustainable development(the linkages do not show costs and benefits of mitigation)

SR1.5 Fig. SPM4

https://data.ene.iiasa.ac.at/iamc-1.5c-explorer

Q&ASystem transitions - general trends
I.

Improve energy efficiency
Limiting final energy demand in 2050
to +20 to -10% rel. to 2010 levels

II.

Decarbonize the power sector(carbon-intensity of electricity about 0 or negative in 2050)

III.

Electrify energy end use(mobility, buildings, industry)

IV. Subs. residual fossil fuels with low-carbon options(e.g. gas for heating, petrol for driving with bio-based fuels)• Different roles for different type of fuelsPeter Essick / Aurora Photos

Joeri Rogelj - CLA Chapter 2 – IPCC SR1.5

Wide range of CCS that is deployed
across 1.5-2oC pathways: Fossil CCS• Smaller use of fossil CCS in energy
supply systems in 1.5°C pathways
compared to 2°C pathways• llustrative pathways:
No coal, < 25 EJ gas• Smaller use of fossil CCS in lowovershoot pathways• Declining use of CCS over timeGas with CCS (EJ)(c)

Coal with CCS (EJ)(b)

Wide range of CCS that is deployed
across 1.5-2oC pathways: BECCS
Coal with CCS (EJ)

Bioenergy with CCS (EJ)
(a)

(b)

Gas with CCS (EJ)(c)

• Dominant source of CCS in 1.5°C
pathways• Larger use of BECCS in overshootpathways• Similar use of BECCS in low overshoot
1.5°C and lower 2°C pathwaysWide range of CCS that is deployed
across 1.5-2oC pathways: Total CO2 stored
Coal with CCS (EJ)

Bioenergy with CCS (EJ)
(a)

(b)

Gas with CCS (EJ)
(c)

(d)

Cumulative
CO2 stored

400-1000 GtCO2No CCS

Marginal abatement cost in 1.5°C pathways

Cost discounted at 5%/yr to 2020.
SR1.5 Chap. 2 Fig. 2.26