A presentation I gave to Bachelor of Political Science students at NTNU, to give an overview of the climate challenge

1. The climate challenge…
Glen Peters (CICERO Center for International Climate Research, Oslo, Norway)
NTNU Political Science (Trondheim – remote presentation, 24 August 2020)

2. Where have we been, where are we going?

3. Data: Global Carbon Project (2019); own calculations
Where have we been?

4. CO2 emission have a 50% reduction by 2030, net-zero by 2050, around 15GtCO2 (gross) negative emissions by 2100
Data: Global Carbon Project (2019); IAMC 1.5°C Scenario Explorer (hosted by IIASA); own calculations
What does 1.5°C look like?
Nationally Determined Contributions
(emission pledges)

5. CO2 emission have a 25% reduction by 2030, net-zero by 2075, around 10GtCO2 (gross) negative emissions by 2100
Data: Global Carbon Project (2019); IAMC 1.5°C Scenario Explorer (hosted by IIASA); own calculations
What does 2°C look like?
Nationally Determined Contributions
(emission pledges)

6. Emission trends to 2019
Where have we been?

7. Global fossil CO2 emissions up 63% since 1990 & ~4% sine the Paris Agreement in 2015
Estimates for 2017 and 2018 are preliminary; 2019 is a projection based on partial data.
Source: Global Carbon Budget 2019
Global Fossil CO2 Emissions
Oil crises
USSR
GFC

8. CO2 emissions are decomposed into components:
Population * [GDP/Population] * [Energy/GDP] * [CO2/Energy]
Data: Global Carbon Budget 2019; Figure: Glen Peters
Kaya Identity

9. Emissions have declined in Europe & North America, but rising in the developing world
Source: Global Carbon Budget 2019
Emissions by region

10. Renewable energy is growing exponentially (~15% per year), but too slowly to displace fossil fuels
This figure shows “primary energy” using the BP substitution method (non-fossil sources are scaled up by an assumed fossil efficiency of 0.38)
Source: BP 2019; Global Carbon Budget 2019
Energy use by source

11. Renewable energy is growing exponentially (~15% per year), but too slowly to displace fossil fuels
This figure shows “primary energy” using the BP substitution method (non-fossil sources are scaled up by an assumed fossil efficiency of 0.38)
Source: BP 2019; Global Carbon Budget 2019
Energy use by source

12. Electricity dominates fossil CO2 emissions, but growth has slowed. Road dominates the transport sector.
Industry important on aggregative, but made of many smaller industries. Don’t forget “others” & bunkers…
Source: IEA Energy Balances (2019)
Sectors (up to 2017)

13. Fossil CO2 emissions are ~70% of global greenhouse gas emissions, CO2 from land-use change ~10%, other ~20%.
Most non-CO2 and CO2 from LUC are related to food & agriculture…
Source: Emissions Gap Report (2019) – Not used published
Don’t forget non-CO2 emissions

14. The climate challenge

15. Every new molecule of CO2 added to the atmosphere will cause temperatures to keep rising…
Continued emissions lead to continued temperature increase: CO2 emissions must go to zero!
1Gt CO2 equals 1 billion tonnes CO2
Temperature versus cumulative emissions
Stylized figure

16. 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

17. 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 (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)

18. 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)

19. 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
‘Negative’ emissions
Illustrative pathway consistent
with the Paris Agreement’s
“well below 2°C” (~1.5°C)

20. 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
‘Negative’ emissions

21. The Paris text “well below 2°C…pursuing…1.5°C” seems to say between 1.5°C and 2°C, but ambiguous time period…
Data: IAMC 1.5°C Scenario Explorer (hosted by IIASA); own calculations
The Paris temperature window

22. First: Offset residual gross positive emissions, that are too expensive (hard) to mitigate – dark green
Second: ‘Turn back the clock’ by removing CO2 from the atmosphere to draw down temperature – light green
Source: Fuss et al (2020)
The role of negative emissions

23. If only net-zero CO2 emission are desired, then can get unusual build up and then decline of CO2 removal
Source: Fuss et al (2020)
The role of negative emissions

24. Illustrative 1.5°C pathway

25. CO2 emission have a 50% reduction by 2030, net-zero by 2050, around 15GtCO2 (gross) negative emissions by 2100
Data: Global Carbon Project (2019); IAMC 1.5°C Scenario Explorer (hosted by IIASA); own calculations
What does 1.5°C look like?

26. What are the “key characteristics” of 1.5°C? These are stylised, but based on average scenario outputs.
Data: Global Carbon Project (2019); IAMC 1.5°C Scenario Explorer (hosted by IIASA); own calculations
CO2 Emissions in a 1.5°C world
This is not an emission,
but to give an idea of
the scale of CCS

27. What are the “key characteristics” of 1.5°C? These are stylised, but based on average scenario outputs.
Data: Global Carbon Project (2019); IAMC 1.5°C Scenario Explorer (hosted by IIASA); own calculations
Energy system in a 1.5°C world
Fossils
Non-fossils
Bioenergy

28. …where are we heading?

29. Data: Global Carbon Project (2019)
CO2 emissions continue to grow

30. Data: Global Carbon Project (2019); Riahi et al. 2016; Rogelj et al. 2018; IIASA SSP Database;
The future is uncertain…

31. Data: Global Carbon Project (2019); Riahi et al. 2016; Rogelj et al. 2018; IIASA SSP Database;
What if we had no climate policy?
RCP8.5

32. Data: Global Carbon Project (2019); Riahi et al. 2016; Rogelj et al. 2018; IIASA SSP Database;
What if we had a little climate policy?

33. Data: Global Carbon Project (2019); Riahi et al. 2016; Rogelj et al. 2018; IIASA SSP Database;
What if we had maximum climate policy?

34. Data: Global Carbon Project (2019); Riahi et al. 2016; Rogelj et al. 2018; IIASA SSP Database;
Decision making under uncertainty…

35. Many climate impact studies focus on RCP8.5 (worst case fossil intensive world with no climate policy)
RCP8.5 may be ok for impact studies, but policy should be referenced to a more likely pathway (~RCP6.0, 4.5?)
Source: Global Carbon Project (2019); IIASA SSP Database; Hausfather & Peters (2020); own calculations
Where are we heading?
Where we are
heading
Climate
risks
Transition
risks

36. Looking under the bonnet…

37. Coal consumption is levelling out globally, baseline pathways like RCP8.5 are highly unlikely (if even realistic)
Steep drop in coal required for 1.5°C & 2°C, same message from IPCC & IEA
Source: Global Carbon Project (2019); IIASA SSP Database; IEA WEO (2019); own calculations
Coal Consumption

38. IEA sees oil consumption coming to a peak ~2030s based on stated policies
After adjusting for 2020 mismatch, IEA probably sees more rapid declines in oil than IPCC for 1.5°C and 2°C
Source: Global Carbon Project (2019); IIASA SSP Database; IEA WEO (2019); own calculations
Oil Consumption

39. Gas consumption has a very large spread across scenarios, 1.5°C and 2°C could see gas grow or decline
IEA is more pessimistic on gas than IPCC in 1.5°C and 2°C scenarios
Source: Global Carbon Project (2019); IIASA SSP Database; IEA WEO (2019); own calculations
Gas Consumption

40. Building one CCS facility (of 1MtCO2/yr, Sleipner) per week until 2050 will give 1.5GtCO2/yr, one a day 11GtCO2/yr
IEA is generally quite conservative on CCS, and very conservative on CO2 removal (basically assumes none)
Source: Global Carbon Project (2019); IIASA SSP Database; IEA WEO (2019); own calculations
Carbon Capture and Storage

41. Models are often critiqued for being too conservative on renewables (wind & solar)
When considering mitigation scenarios, there is not too much difference between IEA and IPCC.
Source: Global Carbon Project (2019); IIASA SSP Database; IEA WEO (2019); own calculations
Solar

42. …time scales

43. Irrespective of the short-term emission pathway, the next decades will have increasing climate impacts…
There are some short-term benefits of mitigation as well, reduced local air pollution, new jobs, etc
Source: Rogelj et al 2018; Riahi et al. 2016; IIASA SSP Database; NASA GISS
A lot of pain, not much gain?
Paris pledges
Paris goal
CO2
Benefits
°C
Little gain

44. Take home messages

45. • To stabalise climate requires zero CO2 emissions
• Pathways to 1.5°C or 2°C are at the limits of feasibility
• Fossils out, renewables in, large-scale CCS & CO2 removal
• What is the role for targets versus pragmatism?
Take home messages

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