Effort sharing approaches

Transcription

1 Effort sharing approaches For regional carbon budgets and emission pathways 1

2 Rationale Global emission pathways 1 Cost optimal allocation across regions Effort sharing allocation based on equity principles Conventional More novel Effort-sharing outcomes can be useful to start a discussion: around the fairness around cost-optimal allocation to improve ambitions for NDCs 2

3 Objective and research question Objective: determining fair emission reduction targets Using carbon budgets novel methodology flexibility and freedom to choose pathway but only long lived GHGs Using GHG emission pathways conventional methodology fixed pathway for all GHGs Research question: Can we derive a wide set of carbon budgets and pathways Based on effort sharing approaches? Based on Climatic Change paper (submitted): Implications of various effort sharing approaches for national carbon budgets and emission pathways Nicole J. van den Berg 1 Heleen L. van Soest 1,2* Andries F. Hof 1,2 Michel G. J. den Elzen 1 Detlef P. van Vuuren 1,2 Wenying Chen 3 Laurent Drouet 4,5 Johannes Emmerling 4,5 Shinichiro Fujimori 6 Niklas Höhne 7 Alexandre Köberle 8 David McCollum 9 Roberto Schaeffer 8 Swapnil Shekhar 10 Saritha Sudharmma Vishwanathan 11 Zoi Vrontisi 12 Kornelis Blok 13 3

4 Equity principles and effort sharing approaches Responsibility Equality Per capita Convergence (PCC) Equal cumulative per capita Emissions (ECPC) *RCI Greenhouse development Immediate equal rights (GDR) per capita (Historical) Population Emissions BAU (IEPC) Emission share *Responsibility-Capacity Index (RCI) Ability to Pay (AP) GDP per capita Capability / need Sovereignty Grandfathering (GF) Cost-optimal (CO) Cost-effectiveness Adapted from (Höhne et al. 2013) 4

5 Variables, settings & parameters Grandfathering (GF*) Immediate Equal Per Capita Emissions (IEPC*) Per Capita Convergence (PCC*) Settings Parameters Start year 2010, 2015, 2020 End year 2020, 2050, 2100 Global carbon budget 400, 1000, 1600 GtCO 2 Global reduction target 1.5 C, 2 C (with >66% or >50%) CO 2 category Incl. LULUCF, energy & industry, energy Carbon budgets: weighting factor (emissions share population share) Emission pathways: convergence year 2050, 2075, 2100 Equal Cumulative Per Historical start year 1850, 1970, 1990 Capita (ECPC*) Discount factor Future discount factor Yes or no Greenhouse Development Historical start year 1850, 1970, 1990 Rights (GDR*) Weighting factor RCI (capacity responsibility) Ability to Pay (AP*) Participation threshold Yes or no 5

6 Carbon budget approach /2010 emissions (in years) (Capability) (Responsibility) 6

7 Emission pathways approach 2030/2010 (as %) 7

8 Conclusions Effort sharing approaches lower carbon budgets for developed countries compared to cost optimal budgets (except GF*) i.e. cost optimal approaches cannot be regarded as fair (according to effortsharing approaches) However, results are sensitive to parameters chosen within approaches, e.g. AP* choice of GDP and participation threshold ECPC* historical start year and discount rates Budget approach always less than BAU budgets while emission pathway approach sometimes higher than BAU (e.g. India) on the short term Effort sharing approaches that: 1. Calculate required reduction targets relative to BAU budgets (e.g. GDR*) 2. take into account historical emissions (e.g. ECPC*) when determining carbon budgets can lead to (large) negative remaining carbon budgets for developed countries 8

9 Future work: Multi model comparison of mitigation costs With and without flexible mechanisms (emission trading) Check feasibility if no emissions trading is allowed Analyse costs and financial transfers with emissions trading Using Ability to Pay and Per Capita Convergence approaches Based on emission pathways, not on budget approach Global and national models involved 9

10 Thank you for your attention! 10

11 Equations 11

12 Carbon budget approach (direct) & emissions approach (indirect) (in years) (C) (R) Different and similar results for budget approach and emissions pathways approach depending on effort sharing approach 12

13 Sensitivity analyses 13