Priyadarshi Shukla, IPCC WGIII Co-Chair
Distinguished Professor
Global Center for Environment and Energy
Ahmedabad University

Emission Pathways andSystem Transitions:

An Assessment of IPCC Special
Report on 'Global Warming of 1.5°C’

Presented in:24th AIM International Workshop
NIES, Tsukuba, Japan
November 5, 2018

Understanding Global
Warming of 1.5°C

Where are we now?
Since pre-industrial times, human activities have caused
approximately 1°C of global warming.
• Already seeing consequences for people, nature andlivelihoods• At current rate, would reach 1.5°C between 2030and 2052
• Past emissions alone do not commit the world to1.5°C
Ashley Cooper / Aurora Photos

Projected Climate
Change, Potential Impacts
and Associated Risks

Impacts of global warming 1.5°C
At 1.5°C compared to 2°C:
• Less extreme weather where people live, including
extreme heat and rainfall• By 2100, global mean sea level rise will be around 10
cm lower but may continue to rise for centuries• 10 million fewer people exposed to risk of rising seas
• Up to several hundred million fewer people exposed
to climate-related risk and susceptible to poverty by2050
Jason Florio / Aurora Photos

Impacts of global warming 1.5°C
At 1.5°C compared to 2°C:
• Lower impact on biodiversity and species• Smaller reductions in yields of maize, rice, wheat• Lower risk to fisheries and the livelihoods that
depend on them
• Global population exposed to increased water
shortages is up to 50% less

Emission Pathways and System
Transitions Consistent with 1.5°C
Global WarmingCarbon Budget (GtCO2)•Using global mean surface temperature (GMST) methodology,
the remaining carbon budget is 770 Gt CO2 for a 50%
probability of limiting warming to 1.5°C and 570 Gt CO2 for a66% probability•

The remaining carbon budget is being depleted by current
emissions of 42+3 Gt CO2 per year.

•Additional carbon release from future permafrost thawing andmethane release from wetlands would reduce budgets by up to100 Gt CO2Source: C1.3 SPM

Greenhouse gas emissions pathways• To limit warming to 1.5°C, CO2 emissions fall byabout 45% by 2030 (from 2010 levels)
Compared to 20% for 2°C• To limit warming to 1.5°C, CO2 emissions would needto reach ‘net zero’ around 2050
Compared to around 2075 for 2°C• Reducing non-CO2 emissions would have direct andimmediate health benefits
Source: C1 SPM

Figures SPM3a & SPM3b

SPM3a: Global emissions pathway characteristics

Pathways:- limiting warming to 1.5°C with no or limited(less than 0.1°C) overshootSPM3a: Global emissions pathway characteristics

Pathways:- limiting warming to 1.5°C with no or limited(less than 0.1°C) overshoot- with high overshoot (at least 0.1°C and larger)

SPM3a: Global emissions pathway characteristics

Pathways:- limiting warming to 1.5°C with no or limited(less than 0.1°C) overshoot- with high overshoot (at least 0.1°C and larger)

SPM3a: Global emissions pathway characteristics

SPM3a: Global emissions pathway characteristics

SPM3b: Characteristics of four illustrative pathways
Breakdown of global net anthropogenic CO2 emissions
Three contributions to global net anthropogenic CO2 emissions• CO2 emissions from fossil fuel and industry• Net CO2 emissions from agriculture, forestry, and other land use (AFOLU)• CO2 removal by bioenergy with carbon capture and storage (BECCS)SPM3b: Characteristics of four illustrative pathways
Breakdown of global net anthropogenic CO2 emissions
Four carefully selected illustrative pathways:

SPM3b: Characteristics of four illustrative pathways

Set of pathway characteristics,
carefully selected to illustrate:• Climate outcome andemissions implications• Energy system transition• Carbon dioxide removal (CDR) andland implications

SPM3b: Characteristics of four illustrative pathways

Feasibility Indicators for ‘1.5°C’ Consistent Pathways
Characteristics

Indicators to Assess Feasibility of Mitigation Options

Economic

Cost-effectiveness; Absence of distributional effects;
Employment & productivity, enhancement potential

TechnologicalTechnical scalability; Maturity; Simplicity; Absence of risk

Institutional

Political acceptability; Legal & administrative feasibility
Institutional capacity; Transparency & accountability potential

Socio-cultural

Social co-benefits (health, education); Public acceptanceSocial & regional inclusiveness; Intergenerational equity
Human capabilities

Environmental/ Reduction of air pollution; Reduction of toxic waste
Reduction of water use; Improved biodiversity
EcologicalGeophysicalPhysical feasibility (physical potentials); Limited use of land;
Limited use of scarce (geo)physical resources; Global spread

Source: Table 4.10

Changes at Unprecedented Scale• Limiting warming to 1.5°C would require changes onan unprecedented scale
Rapid and far-reaching transitions all sectors
A range of technologies
Behavioural changes
Increased investment in
low carbon options
Source: C3 SPM

Aligning Ambition and Actions• National pledges are not enough to limit warming to1.5°C (D1 SPM)
• Progress in renewables would need to be mirroredin other sectors.
• The solutions required to limit warming to 1.5ºC areavailable. What is required is to speed and scale up
implementation.
• These solutions confer synergies with sustainabledevelopment

SPM4|

Indicative linkages between mitigation andsustainable development using SDGs (the linkages

do not show costs and benefit)

Questions?
Q&A