Leçons du 5 ème rapport du GIEC et perspectives pour la négociation climat

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1 Leçons du 5 ème rapport du GIEC et perspectives pour la négociation climat Franck Lecocq, CIRED Joint research unit of ENPC, CNRS, EHESS, CIRAD, APT Lead Author, IPCC AR4 and 5, WGIII Conférence Coriolis, Ecole Polytechnique, 9 mars Photo : Mairie Paris

2 Centre International de Recherche sur l Environnement et le Développement Campus du Jardin Tropical, Paris Created in 1972 by Ignacy Sachs to study conditions of articulation between environment and development 4 IPCC lead authors in AR5, 105 different publications referenced in AR5 2 Photo : Mairie de Paris

3 Introduction! The IPCC Working Group III (WGIII) 5 th Assessment Report (AR5) is available online at This presentation draws on: The report Summary for Policy Maker The Technical Summary The full Report Presentation material prepared by the WGIII co-chairs! The findings and interpretations in this presentation are solely those of the author. They do not necessarily represent the views of other authors or of the IPCC. 9 March

4 IPCC reports are the result of extensive work from scientists around the world. 1 Summary for Policymakers 1 Technical Summary 16 Chapters 235 Authors 900 Reviewers More than 2000 pages Close to 10,000 references More than 38,000 comments 9 March

5 13-17 July April 2014 A writing process that spans five years 9 March

6 IPCC AR5 WGIII report outline " " " " 9 March

7 GHG emissions accelerate despite reduction efforts. Most emission growth is CO2 from fossil fuel combustion and industrial processes. Source: See next slide 9 March

8 GHG emissions accelerate despite reduction efforts. Most emission growth is CO2 from fossil fuel combustion and industrial processes. 9 March

9 Per capita emissions remain very different across regions and countries. 9 March

10 Emissions differ depending on whether they are attributed on the basis of territory or of final consumption 9 March

11 GHG emissions rise with growth in GDP and population; long-standing trend of decarbonisation of energy reversed. 9 March

12 Without more mitigation, global mean surface temperature might increase by 3.7 to 4.8 C over the 21 st century. 9 March

13 Range of assumptions underlying the scenarios presented in the previous slide 9 March

14 Mitigation requires major technological and institutional changes including the upscaling of low- and zero carbon energy. 9 March

15 Delaying mitigation is estimated to increase the difficulty and narrow the options for limiting warming to 2 C. 9 March 2015 Source: See next slide 15

16 Delaying mitigation is estimated to increase the difficulty and narrow the options for limiting warming to 2 C.(II) 9 March

17 Mitigation requires changes throughout the economy, and in particular in bioenergy and/or carbon sequestration in biomass 9 March

18 Estimates for mitigation costs vary widely.! Reaching 450ppm CO 2 eq entails consumption losses of 1.7% (1-4%) by 2030, 3.4% (2-6%) by 2050 and 4.8% (3-11%) by 2100 relative to baseline (which grows between 300% to more than 900% over the course of the century see slide No.12).! These figures do not include the benefits of mitigation (in terms of avoided climate damages) Because research has not yet produced models that jointly evaluate in details the impacts of climate change and the implications of mitigation policies, For the same reason, they also exclude other benefits (e.g. improvements for local air quality).! Cost estimates are based on a series of assumptions, notably: On the availability of technology over time On the way the economic system is represented in the model. 9 March

19 The IPCC AR5 WGIII report includes detailed analysis of demand-side mitigation options. 9 March

20 Substantial reductions in emissions would require large changes in investment patterns. 9 March

21 Climate policies have been developed everywhere. 9 March

22 We are now having experience of implementing mitigation policies (Ch.13-15)! Sector-specific policies have been more widely used than economy-wide policies.! Regulatory approaches and information measures are widely used, and are often environmentally effective.! Since AR4, cap and trade systems for GHGs have been established in a number of countries and regions.! In some countries, tax-based policies specifically aimed at reducing GHG emissions alongside technology and other policies have helped to weaken the link between GHG emissions and GDP! The reduction of subsidies for GHG-related activities in various sectors can achieve emission reductions, depending on the social and economic context. 9 March

23 Ch.4, 6, and each sectoral chapter includes review of co-benefits and adverse side-effects. (Extrait de la Table 6.7). Potential co-benefits (green arrows) and adverse side-effects (orange arrows) of the main sectoral mitigation measures; arrows pointing up/down denote a positive/negative effect on the respective objective/concern; a question mark (?) denotes an uncertain net effect. Cobenefits and adverse side-effects depend on local circumstances as well as on the implementation practice, pace and scale (see Tables 7.3, 8.4, 9.7, 10.5, 11.9, 11.12). Column two provides the contribution of different sectoral mitigation strategies to stringent mitigation scenarios reaching atmospheric CO2eq concentrations of ppm in The interquartile ranges of the scenario results for the year 2050 show that there is flexibility in the choice of mitigation strategies within and across sectors consistent with low concentration goals (see Sections 6.4 and 6.8). Scenario results for energy supply and end-use sectors are based on the AR5 Scenario Database (see Section 6.2.2). For an assessment of macroeconomic, cross-sectoral effects associated with mitigation policies (e.g., on energy prices, consumption, growth, and trade), see Sections 3.9, 6.3.6, and The uncertainty qualifiers in brackets denote the level of evidence and agreement on the respective effects. Abbreviations for evidence: l=limited, m=medium, r=robust; for agreement: l=low, m=medium, h=high. 9 March

24 Effective mitigation will not be achieved if individual agents advance their own interests independently.! Existing and proposed international climate change cooperation arrangements vary in their focus and degree of centralization and coordination.! Issues of equity, justice, and fairness arise with respect to mitigation and adaptation.! Climate policy may be informed by a consideration of a diverse array of risks and uncertainties, some of which are difficult to measure, notably events that are of low probability but which would have a significant impact if they occur. 9 March

25 Implications for climate negotiations! Question asked to IPCC was: Under which conditions can humanity reach +2 C?! A: This target remains feasible provided (a) rapid and decisive mitigation action! A: This target remains achievable at reasonable cost provided (a) rapid and decisive mitigation action (b) land-use availability (large-scale bioenergy and/or carbon sequestration) (c) assumptions about smooth economic functioning embedded in IAM models are valid 9 March

26 Short-term and finance, two under-explored elements! Missing from the literature (and therefore from the IPCC reports) Focus on +2 C target means focus on long run equilibria ( )! Limited information on short-term to medium-term transition How does one get to the decarbonization path? Especially in a context of deep economic crisis?! Key issue: Articulation between decarbonization and other development objectives at country level 9 March

27 Environment / development articulation! France: Articulation between decarbonization, public deficit, labour taxes and pension finance! Brazil: Articulation between bioenergy, use of potential oil resources, and decarbonization! South Africa: Articulation between decarbonization, economic growth, and reducing unemployment! Link to the Intended Nationally Determined Contributions (INDCs) 9 March

28 Financing! White elephant in the room! Limited public resources in context of economic crisis! At the same time, large private savings in search of investment opportunities! Issue: Create incentives to direct savings towards low-carbon investments! Emerging literature captured in Ch.16 9 March

29 Conclusions! A report central to raising awareness over what is needed to reach +2 C! A report slightly less informative about other key objectives of the negotiation because the literature is not there!! An issue of science programmation well in advance European research agenda, Future Earth, etc.! An emerging issue about ex post assessment of mitigation (and adaptation) policies 9 March

30 Our Common Future Under Climate Change! Une grande conférence scientifique internationale en préalable à et dans le cadre de COP21! A l invitation de la communauté française du GIEC! 7 10 juillet 2015, Palais de l UNESCO! Appel à sessions ouvert Octobre

31 Do not hesitate to dive into the TS and full report! 9 March

32 Annexes 9 March

33 Insights from sectoral chapter. Energy supply (Ch.7)! Highest emitting sector (14.4 GtCO 2 /year)! Stabilizing GHG concentrations in the atmosphere requires a fundamental transformation of energy supply, with phasing out of fossil energies and substitution with lowcarbon alternatives.! In the scenarios, the decarbonation of electricity is faster than the decarbonation of over components of the sector.! The report notably includes a thorough analysis of CCS technologies. 9 March

34 Insights from sectoral chapter. Transport (Ch.8)! Emissions from the transport sector are significant (6.7 GtCO 2 in 2010)! Sectoral studies suggest a larger mitigation potential than assessed in AR4.! In the short run, the decarbonation potential is limited, but the potential for energy efficiency is high.! Demand-side mitigation measures have large potential, with growing literature. 9 March

35 Insights from sectoral chapter. Buildings (Ch.9)! Emissions from the sector have doubled over the past 40 years (8.8 GtCO 2 )! Lock-ins are important in this sector.! Despite rapid emissions growth in the baseline, energy demand can be stabilized, or even reduced by Increase in the empiric literature on low-emissions buildings! Because of significant barriers in this sector, regulation measures are more efficient than price instruments alone The chapter includes detailed analysis of ongoing energy efficiency programs in buildings 9 March

36 Insights from sectoral chapters Industry (Ch.10)! Industry represents about 30% of total GHG emissions (13 GtCO 2 eq in 2010)! Diffusion of best practices and technologies could reduce energy intensity by 25% in the sector! On the other hand, reducing absolute emissions requires to go beyond energy efficiency, Recycling, radical product innovation, demand reduction, etc.! There exist a large mitigation potential for non- CO 2 gases 9 March

37 Insights from sectoral chapters. Agriculture, forestry et other land use (Ch.11)! Emissions have stabilized since AR4 (9-12 GtCO 2 ), their share is decreasing! Among supply-side measures, most efficient are reducing deforestation and forest management, and in agriculture cropland and pasture management (at 20 USD/tCO2-eq) and soil restoration at 100$/tCO 2 e.! Demand-side mitigation measures remain largely unexplored; but diet change and waste reduction in food production chains could have important mitigation potential.! Large-scale deployment of biomass energy offers promises and risks Impact on land-use Importance of local solutions 9 March

38 Insights on sectoral chapters: Human settlements, infrastructure and spatial planning (Ch.12)! Cities account for more than half of primary energy consumption and of associated CO 2 emissions! The majority of infrastructure and cities in the World have yet to be built Most important mitigation opportunities are probably in developing countries.! There exists a large variety of climate plans at city scale, but their implications in terms of emission reductions are not clear. 9 March