A presentation I gave to a conference on "the way to climate neutrality" hosted by the Danish Ministry for Energy, Utilities, and Climate (13 November, 2018)

1. Emissions scenarios and the need
for carbon dioxide removal
Glen Peters (CICERO Center for International Climate Research, Oslo, Norway)
On the road to climate neutrality (Copenhagen, 13/11/2018)

2. The Paris Agreement

3. • Article 2: “Holding the increase … to well below 2°C …
pursue efforts to limit … to 1.5°C …”
• Article 4: “global peaking … as soon as possible …
undertake rapid reductions … achieve a balance between
… sources and … sinks … in the second half of this
century”
The Paris Agreement (goals)
Source: Peters (2017)

4. The Paris Agreement (concept)
Nationally
Determined
Contributions
(NDCs)
Global
Stocktake
(are we on track?)
Raise
ambition
(currently taking
us to 3°C in 2100)(Every five years)
(new)

5. Why carbon dioxide removal?

6. We have already emitted a lot of CO2, and thus we can only emit a little more to stay under 1.5°C (or 2°C).
1Gt CO2 equals 1 billion tonnes CO2
Emission pathways

7. We have already emitted a lot of CO2, and thus we can only emit a little more to stay under 1.5°C (or 2°C).
The dark grey area is an approximate carbon budget of 250GtCO2 from 2017 to 2100 (consistent with 1.5°C).
1Gt CO2 equals 1 billion tonnes CO2
Emission pathways
Illustrative pathway consistent
with the Paris Agreement’s
“well below 2°C” (~1.5°C)

8. If we (deliberately) allow CO2 emissions to decline slower in the short-term, then we ‘overshoot’ the carbon budget,
and then must repay that ‘carbon debt’ by removing carbon from the atmosphere at a planetary scale.
1Gt CO2 equals 1 billion tonnes CO2
Emission pathways with overshoot
Illustrative pathway consistent
with the Paris Agreement’s
“well below 2°C” (~1.5°C)

9. To reach zero emissions in 2050, we need to start planetary-scale carbon dioxide removal (negative emissions) now!
It is likely that we cannot get positive emissions to zero, thus, we will always need some level of negative emissions
1Gt CO2 equals 1 billion tonnes CO2
Carbon dioxide removal
CO2 removal needed for
* Offset hard to mitigate sectors
* Offset earlier emissions

10. To reach zero emissions in 2050, we need to start planetary-scale carbon dioxide removal (negative emissions) now!
It is likely that we cannot get positive emissions to zero, thus, we will always need some level of negative emissions
1Gt CO2 equals 1 billion tonnes CO2
Carbon dioxide removal

11. • The temperature level (1.5°C vs 2°C vs …)
• Rate and scale of short-term mitigation
• Remaining emissions from hard-to-mitigate sectors
• Non-CO2 emissions (CH4, N2O, aerosols, …)
• Availability of CO2 removal technologies (at scale)…
• (Or, adapt to higher levels of warming…)
The scale of CO2 removal depends on:

12. 1.5°C emission scenarios

13. This “stylised scenario” is based on the median of IPCC Special Report on 1.5°C “no or low overshoot” scenarios
It shows the weight of published literature, not the pathway we need to follow.
Data: IAMC 1.5°C Scenario Explorer (hosted by IIASA)
CO2 Emissions in a 1.5°C world

14. This “stylised scenario” is based on the median of IPCC Special Report on 1.5°C “no or low overshoot” scenarios
It shows the weight of published literature, not the pathway we need to follow.
Data: IAMC 1.5°C Scenario Explorer (hosted by IIASA)
Energy system in a 1.5°C world
Fossils
Non-fossils
Bioenergy

15. The land impact from afforestation are often higher than bioenergy.
For reference: India has an area of about 330 million hectares, Australia 770, Brazil 850, China 960, …
Data: IAMC 1.5°C Scenario Explorer (hosted by IIASA)
Bioenergy versus afforestation

16. Most carbon capture and storage is used for bioenergy with CCS.
For a 1MtCO2 per year facility, >5000 needed by 2050 which is one new facility every second day…
Data: IAMC 1.5°C Scenario Explorer (hosted by IIASA)
Carbon Capture & Storage

17. The Paris Agreement “balance”

18. Balance in sources and sinks of GHG emissions between 2050 and 2100
Most 1.5°C scenarios reach that criteria, less than half the 2°C reach that criteria
Data: IAMC 1.5°C Scenario Explorer (hosted by IIASA)
GHG emissions (Paris, Article 4)

19. Summary

20. • Carbon dioxide removal is probably unavoidable
– Don’t forget, we already do it at small scale (afforestation)
• CO2 removal is not the problem, it is the scale
• Less CO2 removal requires more of something else…
• The Paris Agreement is designed as incremental
• Scenarios are designed to optimally achieve Paris
– Reality likely to follow a very different path…
Summary

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