Our Common Future Under Climate Change

International Scientific Conference 7-10 JULY 2015 Paris, France

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Thursday 9 July - 17:30-19:00 UPMC Jussieu - Amphi Herpin

4402 (a) - Low carbon pathways for staying below 2°C: Global requirements

Parallel Session

Lead Convener(s): E. Kriegler (Potsdam Institute for Climate Impact Research, Potsdam, Germany)

Convener(s): V. Bosetti (Fondazione Eni Enrico Mattei, Milano, Italy), K. Jiang (Energy Research Insititute, Beijing, China), N. Nakicenovic (International Institute for Applied Systems Analysis and Global Carbon Project, Laxenburg, Austria), O. Edenhofer (Potsdam Institute for Climate Impact Research (PIK), Potsdam, Germany)

17:30

The Challenges of 2°C: an Overview of Emissions Reductions, Decarbonization Strategies, Technologies, and Economic Costs

L. Clarke (Pacific Northwest National Laboratory (PNNL), College Park, MD, United States of America)

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The Challenges of 2°C: an Overview of Emissions Reductions, Decarbonization Strategies, Technologies, and Economic Costs

L. Clarke (1)
(1) Pacific Northwest National Laboratory (PNNL), Joint Global Change Research Institute, College Park, MD, United States of America

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The long-term goal of limiting temperature change to less than 2C will require deep reductions in greenhouse gas emissions. Net global CO2 emissions, in particular, must eventually be brought to or below zero to meet this or other long-term temperature goals. Emissions reductions of this magnitude will require large-scale transformations in human societies, from the way that we produce and consume energy to how we use the land surface. The more ambitious the stabilization goal, the more rapid this transformation must occur. A natural question in this context is what are meaningful “transformation pathways” towards stabilization; that is, how do we get from here to there? This presentation provides an overview and introduction for understanding transformation pathways to 2C and other temperature goals.

This presentation will draw heavily from a large body of scenario research summarized in Chapter 6 of the Working Group 3 contribution to AR5. Over 1000 new scenarios published since AR4 were collected from integrated modeling research groups, many from large-scale model intercomparison studies and synthesized in WG3. These scenarios provide important information on key questions such as the near-term emissions reductions consistent with meeting long-term goals, the costs of mitigation, and the energy and land system transformations. In comparison to AR4, new scenarios have considered more ambitious concentration goals, a wider range of assumptions about technology, and more possibilities for delays in global mitigation and fragmented international action than those published previously..

Drawing on this literature, the presentation will address several questions that provide context for understanding transformation pathways. First, to what degree is it possible to link between near-term emissions reductions with the goal of limiting temperature change to less than 2C or other goals? While it is possible to draw some conclusions about this link, the relationship is heavily influenced by assumptions of what sorts of future emissions reductions are feasible. Further, the relationship between any temperature goal and emissions and concentrations is highly uncertain, meaning that this relationship can only be expressed in terms of the probability that temperature will remain below 2C. Second, what are some key characteristics of transformation pathways that maintain likely temperature change below 2C? Key characteristics include emissions reductions rates, sectoral emissions reductions, economic costs, and technology transformations. Finally, to what degree can scenarios inform questions about which pathways are more feasible than others? Mitigation actions inherently involve a wide range of tradeoffs that link to social and policy objectives such as economic growth, energy and food security, the distribution of economic costs, local air pollution, other environmental factors associated with different technology solutions, and economic competitiveness. All of these linkages will influence the likelihood and feasibility of different pathways. Assessments of feasibility must, in addition, account for the rapidity at which social and technological systems would need to change to maintain temperature change below 2C.

17:43

Staying below 2°C: What are the implications of and requirements for short-term policies?

G. Luderer (Potsdam Institute for Climate Impact Research, Potsdam, Germany), E. Kriegler (Potsdam Institute for Climate Impact Research, Potsdam, Germany)

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Staying below 2°C: What are the implications of and requirements for short-term policies?

G. Luderer (1) ; E. Kriegler (1)
(1) Potsdam Institute for Climate Impact Research, Potsdam, Germany

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Current efforts to mitigate climate change are not in line with mitigation pathways stabilizing global warming below 2°C in a cost-optimal way. Over the past decade, global greenhouse gas emissions have further increased and are projected to reach 50-59 GtCO2e by 2020. This is much higher than emission levels in mitigation scenarios that assumed comprehensive mitigation action towards 2°C stabilization from 2010. The discrepancy between the long-term ambition of climate policy, i.e. limiting global warming to 2°C, and the weakness of mitigation action raises  important questions: What are the consequences of delaying comprehensive climate policies? What are requirements for policies and measures to keep the 2°C target within reach?

This presentation will draw on a number of recent studies based on integrated energy-economy-climate models (AMPERE, LIMITS and RoSE multi-model intercomparison projects, as well as single-model studies) to address these questions. There are a number of robust, policy-relevant insights that emerge from these studies about the adverse consequences of a further delay of comprehensive mitigation action:

  • Due to the tight constraint on cumulative CO2 emissions implied by the 2°C limit, higher than optimal emissions in the near-term have to be compensated by lower emissions in the long term. This implies a much faster pace of emission reductions in the medium term. Scenarios with high 2030 emission levels feature post-2030 emission reduction rates that are roughly twice as high as those in scenarios with optimal timing of mitigation efforts.
  • At the same time, a lack of meaningful mitigation action in the near-term reduces the longer-term mitigation potential. This is due a further lock-in into carbon intensive infrastructure, and insufficient up-scaling of low-carbon technologies. As a consequence, the deep emission reduction required become more difficult to achieve.
  • The deep long-term emission cuts also imply a greater reliance on specific technologies and reduced societal choices. In particular, in case of weak short-term policies the 2°C limit can only be kept with large-scale deployment of bioenergy and CCS.
  • A further delay of mitigation action results in greater overall costs of the mitigation effort, and a more unequal distribution of these costs over time. In particular, we find that a further delay substantially increases the economic costs during the transition from a weak to a comprehensive climate policy regime, thus raising the barrier to the low-carbon transformation.
  • Finally, replacing fossil fuels by climate-friendly alternatives comes with several co-benefits, in particular in the form of decreased air pollution and improved energy security. Delaying climate policy implies that crucial co-benefits, such as decreased air pollution and improved energy security, are foregone.

The presentation will further explore how enhanced near-term action and post-2020 policies can reduce these adverse effects, thus helping to keep the 2°C target within reach.

 

17:56

The energy transformation in 2°C pathways: upscaling technology, investment needs, stranded assets and the role of energy demand

V. Krey (International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria), C. Bertram (Potsdam Institute for Climate Impact Research, Potsdam, Germany), J. Eom (KAIST Business School, Seoul, Republic of Korea), N. Johnson (International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria), D. Mccollum (International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria)

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The energy transformation in 2°C pathways: upscaling technology, investment needs, stranded assets and the role of energy demand

V. Krey (1) ; C. Bertram (2) ; J. Eom (3) ; N. Johnson (1) ; D. Mccollum (1)
(1) International Institute for Applied Systems Analysis (IIASA), Energy program, Laxenburg, Austria; (2) Potsdam Institute for Climate Impact Research, Potsdam, Germany; (3) KAIST Business School, Graduate school of green growth, Seoul, Republic of Korea

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A major challenge in limiting temperature change to 2°C compared to pre-industrial levels is the transformation of the energy system which requires rapid upscaling of low-carbon technologies to significantly reduce GHG emissions. Deploying the energy technologies needed to initiate a sustained energy system transformation requires continued research and development as well as significant investments to be mobilized by the global economy.

The timing of mitigation action and in particular the stringency of near-term climate policy determines the challenge we are facing now versus the challenge we may face in a couple of decades. While delaying stringent climate action has the benefit of allowing for more development space over the coming decade or two, it amplifies the need to rapidly decarbonize the energy system thereafter if temperature change should be contained to 2°C or less. An important implication of weak near-term climate policies is the need to prematurely retire carbon-intensive infrastructure such as coal power plants, coal mines or oil wells, once moving to a more stringent climate regime. This trade-off particularly affects developing nations that are still in the process of building up a large part of their infrastructure.

In this contribution we will present results on technology upscaling, investment and decarbonization rates from integrated, model-based scenario studies. These will be put into the context of historical developments, both at the level of countries and regions and at the level of individual technologies.

In addition, the decarbonization of the energy supply sector needs to be complemented by a switch to low-carbon energy carriers in the end-use sectors as well as the reduction of energy demand, both of which are key strategies to reduce GHG emissions. In particular the latter is shown to provide additional flexibility for an energy system transformation by hedging against potential resistance to large-scale deployment of energy supply technologies and by reducing stranded assets as well as generating multiple non-climate benefits.

18:09

Global Energy and Climate Outlook: Road to Paris – Economic Assessment of Low Emission Levels under World Action Integrating National Contributions

Z. Vrontisi (European Commission (DG JRC-IPTS), Seville, Spain)

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Global Energy and Climate Outlook: Road to Paris – Economic Assessment of Low Emission Levels under World Action Integrating National Contributions

A. Labat, (1) ; B. Saveyn, (2) ; Z. Vrontisi (2) ; T. Vandyck, (2) ; M. Perry (1) ; A. Kitous, (2)
(1) European Commission (DG Climate Action), Brussels, Belgium; (2) European Commission (DG JRC-IPTS), Institute for prospective technological studies, Seville, Spain

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On 25 February 2015, the European Commission has set out its Communication, "The Paris Protocol - a blueprint for tackling global climate change beyond 2020” in the EU’s Energy Union package. This paper presents the modelling work undertaken in the context of the abovementioned EC communication regarding the economic impacts of post-2020 global climate change mitigation policies. The analysis presented here mainly lies on results from the economic model GEM-E3, combining the work undertaken with the energy systems model POLES for the purposes of the EC preparation for the global climate negotiations. It focuses on possible ways to stay below 2°C through processes established in the run-up to Paris COP21 by studying a combination of domestically determined mitigation targets for the period beyond 2020.

The GEM-E3 model is a recursive dynamic computable general equilibrium model which covers the interactions between the economy, the energy system and the environment. The model is calibrated to the 2004 base year of the GTAP 8 database. This version of the model represents 21 sectors, 10 power technologies and 25 regions, including all major economies. The six Kyoto greenhouse gasses represented are CO2, SF6, PFC, HFC, CH4, and N2O. The POLES model is a global sectoral simulation model for the development of energy markets.

The GEM-E3 and POLES models share a harmonised Baseline with population and economic growth projections based on the UN and OECD. The projections do not consider the impacts from unabated climate change. In this Baseline scenario, global emissions would increase at unsustainable levels: from 48 GtCO2e in 2010, 61 GtCO2e in 2030 to 68 GtCO2e in 2050. Along such trajectories, the world is at risk to experience a global temperature increase of +4°C, with sizeable impacts on sustainable growth and vulnerable groups in all regions. The Global Mitigation scenario is in line with staying below 2°C, with global GHG emissions peaking in 2020 and reaching about 43 GtCO2e in 2030, still higher than in 1990 (+20%) but lower than in 2010 (-10%).

The economy-wide impacts are twofold. Firstly there are direct costs of mitigation due to regional emission constraints and the reallocation of resources for the mitigation effort. Secondly there are indirect costs or benefits from changes in competitiveness, production patterns, investment and relative prices of energy, labour and capital. It is seen that carbon-intensive sectors need to adjust their investments in order to reduce their emissions, and sectors with a low emission-intensity are affected according to their level of openness to emitting sectors. The effects analysed include GDP, sectoral activity, exports and imports, employment, private consumption and investment. The results indicate that, although due to reallocation of resources created by a global mitigation effort, negative impacts on GDP are seen for all regions, in effect, climate change mitigation policies only marginally reduce the yearly economic growth rates in fast-growing low-income regions. A decomposition analysis of the drivers of GDP change gives a further insight on the impacts of the global mitigation policies.

Another dimension of the analysis is the choice of policy instruments. For this purpose, we compare the use of free allocation of permits with the use of auctioning or taxation. The revenues of auctioning or taxation are recycled as a lump-sum to households, a reduction in labour taxes or in indirect taxation on consumption and investment. It is found that, depending on their regional economic characteristics, for the majority of the regions the optimum recycling of permit auction revenues is to lower indirect taxes while for some countries it is best to use emissions revenues to reduce taxes on labour. Economic costs can be reduced further if the auction revenues are not used only for tax reductions but are combined with a financial scheme. 

18:22

Comment on transitional requirements of 2C scenarios and historical experience

C. Wilson (University of East Anglia, Norwich, United Kingdom)

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Comment on transitional requirements of 2C scenarios and historical experience
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18:30

Q&A session

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Q&A session
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18:50

Brief presentation of Posters

O. Dessens (UCL Enegy Institute, London, United Kingdom), S. Mori (Tokyo University of Science, Noda, Chiba, Japan), C. Von Stechow (MCC Berlin, Berlin, Germany), J. Rogelj (IIASA, Laxenburg, Austria), C. Bertram (Potsdam Institute for Climate Impact Rese

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Brief presentation of Posters
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