A presentation I gave at the launch of the 2°C magazine (in Norwegian). I discuss past trends in carbon dioxide emissions, emission scenarios, and carbon budgets. http://klimastiftelsen.no/nytt-2c-magasin-operasjon-nullutslipp/ https://energiogklima.no/to-grader https://www.tekna.no/kursarkiv/frokostseminar-med-tekna-klima-2c-lansering-34982/#om-kurset

1. Global Carbon Budget 2017
Glen Peters (CICERO)
Frokostseminar med Tekna Klima: 2°C-lansering, 1/12/2017 (NMBU,Ås)

2. Emission trends to 2017

3. Land-use change was the dominant source of annual CO2 emissions until around 1950
Others: Emissions from cement production and gas flaring
Source: CDIAC; Houghton and Nassikas 2017; Hansis et al 2015; Le Quéré et al 2017; Global Carbon Budget 2017
Total global emissions by source

4. Total global emissions: 40.8 ± 2.7 GtCO2 in 2016, 52% over 1990
Percentage land-use change: 42% in 1960, 12% averaged 2007-2016
Land-use change estimates from two bookkeeping models, using fire-based variability from 1997
Source: CDIAC; Houghton and Nassikas 2017; Hansis et al 2015; van der Werf et al. 2017;
Le Quéré et al 2017; Global Carbon Budget 2017
Total global emissions

5. Global emissions from fossil fuel and industry: 36.2 ± 2 GtCO2 in 2016, 62% over 1990
Projection for 2017: 36.8 ± 2 GtCO2, 2.0% higher than 2016
Estimates for 2015 and 2016 are preliminary. Growth rate is adjusted for the leap year in 2016.
Source: CDIAC; Le Quéré et al 2017; Global Carbon Budget 2017
Emissions from fossil fuel use and industry
Uncertainty is ±5% for
one standard deviation
(IPCC “likely” range)

6. Global emissions from fossil fuels and industry are projected to rise by 2.0% in 2017
The global projection has a large uncertainty, ranging from +0.8% to +3.0%
Source: CDIAC; Jackson et al 2017; Le Quéré et al 2017; Global Carbon Budget 2017
Emissions Projections for 2017

7. Share of global emissions in 2016: coal (40%), oil (34%), gas (19%), cement (6%), flaring (1%, not shown)
Source: CDIAC; Le Quéré et al 2017; Global Carbon Budget 2017
Emissions from coal, oil, gas, cement

8. Future pathways

9. We are uncertain about the future, so we use emission scenarios to explore the key uncertainties
IPCC Sixth Assessment Report will be based on a new generation of scenarios
Five Shared Socioeconomic Pathways (SSPs) have been developed to explore challenges to adaptation and mitigation.
Shared Policy Assumptions (SPAs) are used to achieve target forcing levels (W/m2). Marker Scenarios are indicated.
Source: Riahi et al. 2016; IIASA SSP Database; Global Carbon Budget 2017
New generation of emissions scenarios

10. The “baseline” scenarios assume no climate policy, a world which no long exists
The emission pledges submitted to the Paris Agreement move away from the baselines of >3.5°C in 2100
Five Shared Socioeconomic Pathways (SSPs) have been developed to explore challenges to adaptation and mitigation.
Shared Policy Assumptions (SPAs) are used to achieve target forcing levels (W/m2). Marker Scenarios are indicated.
Source: Riahi et al. 2016; IIASA SSP Database; Global Carbon Budget 2017
Baseline with no climate policy
Emission pledges

11. Most studies suggest, depending on post-2030 assumptions, the
emission pledges will lead to 2.5°C to 3.5°C warming
Five Shared Socioeconomic Pathways (SSPs) have been developed to explore challenges to adaptation and mitigation.
Shared Policy Assumptions (SPAs) are used to achieve target forcing levels (W/m2). Marker Scenarios are indicated.
Source: Riahi et al. 2016; IIASA SSP Database; Global Carbon Budget 2017
Nationally Determined Contributions
Emission pledges

12. There is generally a large gap between emission pledges and what is required in the Paris Agreement
The size of the gap depends on what “well below 2°C” means
Five Shared Socioeconomic Pathways (SSPs) have been developed to explore challenges to adaptation and mitigation.
Shared Policy Assumptions (SPAs) are used to achieve target forcing levels (W/m2). Marker Scenarios are indicated.
Source: Riahi et al. 2016; IIASA SSP Database; Global Carbon Budget 2017
Keeping “well below 2°C”
Emission pledges

13. To avoid 2°C of warming, global CO2 emissions need to decline rapidly and cross zero emissions after 2050
Rich countries would need to reach zero earlier (e.g., 2040), and electricity generation even earlier (e.g., 2030)
Source: Riahi et al. 2016; IIASA SSP Database; Global Carbon Budget 2017
Pathways that avoid 2°C of warming
Emission pledges

14. Most scenarios go below zero, but the gross emissions (fossil fuels, industry, land-use change) are generally well
above zero by the end of the century
Source: Riahi et al. 2016; IIASA SSP Database; Global Carbon Budget 2017
Pathways that avoid 2°C of warming

15. To avoid 2°C of warming, most scenarios remove large amounts of carbon dioxide from the atmosphere
Negative emissions / Carbon Dioxide Removal shown here was bioenergy with carbon capture and storage (BECCS)
Source: Riahi et al. 2016; IIASA SSP Database; Global Carbon Budget 2017
Pathways that avoid 2°C of warming

16. Carbon budgets

17. Many nuances, but put simply integrate these pathways from the red dot to a point in the future
(e.g., time peak warming is reached or 2100)
Source: Riahi et al. 2016; IIASA SSP Database; Global Carbon Budget 2017
Carbon budget for 2°C of warming

18. Many nuances, but put simply integrate these pathways from the red dot to a point in the future
(e.g., time peak warming is reached or 2100)
Source: Riahi et al. 2016; IIASA SSP Database; Global Carbon Budget 2017
Carbon budget for 2°C of warming

19. <2.0°C, >66%
Typical phrases: “We have already used two-thirds of the carbon budget”, “no space for more fossil fuels”
Historical emissions 1870-2016: 2100GtCO2. All values rounded to the nearest 50 GtCO2
The remaining quotas are indicative and vary depending on definition and methodology (Rogelj et al 2016).
Source: IPCC AR5 SYR (Table 2.2); Le Quéré et al 2016; Global Carbon Budget 2016
One number to save the world!
2100
GtCO2
Indicative range
450-1050GtCO2
800
GtCO2

20. Negative emissions allows “carbon debt”: Emit more than allowed, as long as paid back with negative emissions
Source: Riahi et al. 2016; IIASA SSP Database; Global Carbon Budget 2017
Carbon budget for 2°C of warming

21. • Model type (“simple” versus “complex” models)
• Climate uncertainty
• “Conceptual” uncertainties
– Different ways of defining budgets
• Definition of 1.5°C or 2°C
– Baseline period, incorporation of uncertainties, etc
• Non-CO2 mitigation (CH4, N2O, SO2, black carbon, etc)
– More non-CO2 mitigation, greater allowable CO2 emissions
Key uncertainties with carbon budgets

22. Summing the 2°C emission scenarios gives the carbon budget (66% chance), with large uncertainty ranges
Carbon Capture and Storage (CCS) and “Negative Emissions” allows the use of more fossil fuels
Note: Totals are not always consistent because medians are not additive, and some columns have different numbers of scenarios
Source: Peters (2016)
Carbon budget ≠ Fossil fuels
Non-CO2
emissions
No CCS
New study

23. • Simple way to communicate challenges
– …“simple” means trade-off with complexity
– Main message: emissions need to go to zero!
• Be aware it is uncertain, no single magic number
– Climate uncertainty
– Non-CO2 uncertainty
• Conceptual challenges
– Carbon capture and storage, and carbon dioxide removal
– Carbon dioxide budget, not a fossil fuel budget
Using the carbon budget

24. The path forward

25. To keep in a carbon budget for 2°C, Chinese emissions would have to go to zero around to 2050
Chinese emission pledge is to peak emissions by 2030
Source: Peters et al 2015; Global Carbon Budget 2016
From carbon budget to “fair” pathways
Grey region is where Chinese
emissions needs to go if the world
is to stay below 2°C
Earlier peak if:
• Faster declines in emission intensity
• Slower GDP growth
• Combination of both

27. The current pledges of the “top 4” countries takes all the remaining emission space
Source: Peters et al 2015; Global Carbon Budget 2016
Who takes the “emission space”

28. Oslo is the only region that I know that has a pledge consistent with avoiding 1.5°C
It is fair and ambitious, and now the challenge is to meet the challenge!
Source: Peters et al 2015; Global Carbon Budget 2016
Does Oslo make a “fair” contribution?

29. The path forward

30. Mitigation will be an engineering feat (+ behavioral, political, social)
Natural sinks decrease with mitigation, but mitigation requires “engineered sinks” (CO2 removal)
Source: Rockström et al (2017)
Engineering our way “well below” 2°C

31. Peters_Glen
cicero.oslo.no
cicerosenterforklimaforskning
glen.peters@cicero.oslo.no
Glen Peters