Rapid global transformations
towards net zero CO2 emissions
Keywan Riahi
International Institute for Applied Systems Analysis (IIASA)
riahi@iiasa.ac.at

ALPS Symposium, 8 March 2021

Remaining carbon budget for 1.5C

Joeri Rogelj - CLA Chapter 2 – IPCC SR1.5•

580 GtCO2 left (50% chance of 1.5°C)
420 GtCO2 left (66% chance of 1.5°C)+- 250 GtCO2 depends on what is done on non-CO2+- 400 GtCO2 geophysical uncertainty•

Currently, 42 +- 3 GtCO2/yr annually•

200 GtCO2 budget differences are about 5 year of currentemissions and imply roughly a 10 year variation in the midcentury timing of reaching net zero CO2 emissions.

•Advances in methods and understanding have resulted in a300 GtCO2 increase since AR5

Why 1.5C?
Population at risk of multisectoral impacts in 2050

2010 Poverty in numbers:~ 700 million in extreme poverty (<2$/day)~ 2.2 billion vulnerable to poverty (<10$/day)
Byers et al. (2018, ERL) feeding into the IPCC 1.5C

World GHG Emissions
NDC
No net negative CO2 emissions
With net negative CO2 emissions•So far focus on end-of-century scenario design→ temperature overshoot•New scenario design (Rogelj et al, 2019)•Focuses on the remaining near-term carbon
budget until net zero CO2 emissions arereached•Time of net zero is the time when temperature isstabilized (avoiding overshoot)•Key question is what does it mean to achievetemperature objectives without net negativeemissions
andwithout
temperature
overshoot•ENGAGE: Nine global modelling teams

World GHG Emissions
NDC
No net negative CO2 emissions
With net negative CO2 emissions

Time when global net zero CO2 emissions is reached

Without net negative emissions …
- Carbon neutrality needs to be reached earlier 10-20yrs- Feasibility frontier moves by about 100-200 GtCO2- 1.5˚C (with a likely chance) is getting out of reachWorld GHG Emissions
NDC
No net negative CO2 emissions
With net negative CO2 emissions

World GHG Emissions
NDC
No net negative CO2 emissions
With net negative CO2 emissions

Non-CO2 ”tail” emissions consistent withdifferent temperature stabilization levels

Global Investment Portfolios for 1.5 and 2C
Average annual investments 2010 to 2050investment

Fossil power
Fossil Exraction

T&D, storage
disinvestment

Nuclear & CCS

Renewables

Efficiency

2°C compared to baseline
McCollum et al, 2018, Nature Energy

Global Investment Portfolios for 1.5 and 2C

disinvestment

investment

Average annual investments 2010 to 2050

1.5°C compared to baseline
McCollum et al, 2018, Nature Energy

Economic losses and gains
Gains of rapidtransformations,avoiding net
negative emissions

Costs of rapidtransformations towards
net zero emissions

Long-term GDP is higher without reliance on net
negative emissions and without overshootWhat does carbon neutrality mean?
SECTORAL emissions sources and sinks

Different strategies across models

Illustrative zero emissions pathway

Timing of sectors for zero emissions(compared to the timing of the overall system)

What does carbon neutrality mean?
REGIONAL emissions sources and sinks

Different strategies across models

Illustrative zero emissions pathway

Timing of regions for zero emissions(compared to the timing of the overall system)2 Perspectives on Meeting 1.5°C
GHG Emissions Profiles

Overshoot as
supply-side options
scale slowly, but need massive
long-term deployment
for high demand scenarios

Inertia in policy,social & technology
changeNegative emissions, e.g. BECCS“Conventional” 1.5 C Scenario

Rapid Transformation
driven by end-use changes(innovation & behavior)
Granular, distributed supply side
options lead the way for scalingother mitigation options, rapid change
under low demand“Grand Restoration”
sink enhancement via
returning land to nature

LED Scenario narrativeNew Trends in Social and Technological Change• Changing consumer preferences (e.g. diets)• Value change enabling new lifestyles and behaviors (service rather thanownership)• New business models (sharing & circular economy)• Pervasive digitalization and ICT convergence• Rapid innovation in granular technologies and integrated digital services

Social Change: Change in Car Driving
Licenses held by Young
Trends: near-term: <50%, long-term: ~0?
Location

Austria 2
Germany
Great Britain
Great Britain
Israel 2
Israel 2
JapanJapan
NorwayNorwaySwedenSwedenSwitzerland
USAUSAUSA

year ayear b

2010
2008
1995
1995
2005
2009
2001
2001
1991
1991
1983
1983
1994
1983
1983
1983

2015
2017
2008
2008
2015
2016
2009
2009
2009
2009
2008
2008
2015
2014
2014
2014

age group % of age group withdrivers licensechangeyear ayear b %-points
17-18
39
28-1118-24
71
66-5
17-20
43
36-7
21-29
74
63-11
17-18
34
30-4
19-24
65
64-1
16-19
19
17-2
20-24
79
75
-41974
55
-19
20-24
85
67-18
1970
49-21
20-24
78
63-15
18-24
71
61-10
18
80
60
-20
1986
69
-17
20-24
91
77-14

Location

Austria 1
FinlandFinlandIsrael 1
Israel 1
Netherlands
Netherlands
Spainyear ayear b2006
1983
1983
1983
1983
1985
1985
1999

2010
2008
2008
2008
2008
2008
2008
2009

age group % of age group withdrivers licensechangeyear ayear b%-points
17-183239718-1937
68
31
20-295182
31
19-244264
2225-346278
16
18-192545
20
20-246464015-243750
13Note in particular much larger prevalence of declining driving license ownershipand shift from growth to decline trends in Austria and Israel around 2008/2010(for Finland, Netherlands, Spain no more recent data available to uncover similar trend breaks)
Data sources: Sivak & Schottle, 2011; Delbosc & Currie, 2013; National Statistics, 2017 for Austria, Germany, Israel, SwitzerlandMobility: 'usership‘ vs. ownershiplumpylarge unit size
high unit costindivisiblehigh risk

TechnologyUnit Size

granularsmall unit size
low unit cost
modularlow risk

Source: Grubler,
ESA class material

Granularity Benefits: faster learning

Higher Learning with Smaller Unit Scale after Accounting for Economies of Scale

De-scaled Learning Rate (Cumula ve Number of Units)'De-scaled' Learning Rates(per doubling of cumula ve numbers of units)
40%
30%

y = -0.02ln(x) + 0.0822
R² = 0.33179

smaller units

geothermal-> more units

20%
10%-> more
opportunities toexperiment

0%-10%-20%-30%-40%
1.E-04-> more learning

nuclear
1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

Average Unit Size (MW)Healey, S. (2015). Separating Economies of Scale and Learning Effects in Technology Cost Improvements. IR-15-009.
International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria.

Granularity Benefits: equal distribution
per capita energy services in the global South
Food - kcal/day/capita
3200

North2020

Thermal comfort - m2/capita
35North2020

30

3000

252800Decent Standards of Living

2600
2400

2015

Decent Standards of Living102200

52000

0
LED2020

LED2050

LED2020

Consumer goods - items/capita
30North2020

Mobility - passenger-km/year/capita
12000

2510000

208000

15LED2050

North2020

Decent Standards of Living

6000

10Decent Standards of Living
54000
2000

0
LED2020

LED2050

0LED2020

LED2050

Resource Impacts of Digital Convergence
Resource Impacts of Digital Convergence
Power449 Watts

5 Watts

75 kWh

2.5 Watts

0.1 kgStand-byenergy use

72 Watts
Updated (Malmodin & Lundén, 2018; Bento, 2016)
from Grubler et al, 2018. Pictorial representation based on Tupy, 2012.

Embodiedenergy

1706Watts
kWh4491WeightPowerEmb

72 Watts

26 kg

Stand-byenergy use

Thank you.
Keywan Riahi
riahi@iiasa.ac.at

Note PRELIMINARY results of ENGAGE – UNDER EMBARGO, please do not circulate outside the meeting
3/10/2021

23, date

World GHG Emissions
NDC
No net negative CO2 emissions
With net negative CO2 emissions

Nine global IAMs
AIMCOFFEE
GM-E3
IMAGE
MESSAGEix-GLOBIOMPOLESREMIND-MagPie
TIAM-ECNWITCHEnergy for Poverty Eradication
Energy for ‘Decent Living’Household energy
poverty
Clean Cooking AccessElectricity Access
Energy Services• Thermal Comfort• Hygiene• Social Connectivity

Health
Education
Mobility

Supporting
Infrastructure
Rao & Min, Soc. Ind. Res., 2018

Decent Living Standards – Material basis for
Well-being
DLS Indicators
Dimension

Unit

Food

kCal,
Micronutrition

Shelter
Comfortm2, Durable(ºC, RH)

Basic
appliances

Stove, TV,
FridgeHealth/Educ$$

Clothing

Kg

Water/Sanit

Access, m3

Mobility

P-km

Rao & Min, Soc. Ind. Res., 2018

Decent Living Standards – Current Conditions

Kikstra et al, In Prep

Cooling ‘Poverty’?
?

Mastrucci et al., Energy & Bldgs, 2019

What is the scope for reducing coolingdemand with
passive and advanced coolingtechnologies?

Global Mobility Gaps – Leapfrog
Opportunity?
Scope for SharedMobility?

Kikstra et al, In Prep

> 70 Exajoules( based on current mode shares)Low-Carbon
Investment
Shares

1.5C zero-carbon / renewables share ~80%

Coal is phased out with only small
investment into CCS

McCollum et al, (under embargo – do not cite or quote)

Regional Investments (1.5 vs 2C)
2015-2050, compared to baseline❖ Most of the investments in Asia
due to growth & decarbonization❖ OECD second, focus on
capacity replacement

McCollum et al, 2018, Nature Energy

Regional Disinvestments (1.5C vs 2C)
2015-2050, compared to baseline❖ Most of the disinvestments
in fossil resource countries❖ Middle East/Africa, Asia,
OECD

McCollum et al, 2018, Nature Energy