Introduction

The Working Group III Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) presents an assessment of the literature on the scientific, technological, environmental, economic and social aspects of the contribution of six renewable energy (RE) sources to the mitigation of climate change. It is intended to provide policy relevant information to governments, intergovernmental processes and other interested parties. This Summary for Policymakers provides an overview of the SRREN, summarizing the essential findings.

The SRREN consists of 11 chapters. Chapter 1 sets the context for RE and climate change; Chapters 2 through 7 provide information on six RE technologies, and Chapters 8 through 11 address integrative issues (see Figure SPM.1).

References to chapters and sections are indicated with corresponding chapter and section numbers in square brackets. An explanation of terms, acronyms and chemical symbols used in this SPM can be found in the glossary of the SRREN (Annex I). Conventions and methodologies for determining costs, primary energy and other topics of analysis can be found in Annex II and Annex III. This report communicates uncertainty where relevant.

Renewable energy and climate change

Demand for energy and associated services, to meet social and economic development and improve human welfare and health, is increasing. All societies require energy services to meet basic human needs (e.g., lighting, cooking, space comfort, mobility and communication) and to serve productive processes. [1.1.1, 9.3.2] Since approximately 1850, global use of fossil fuels (coal, oil and gas) has increased to dominate energy supply, leading to a rapid growth in carbon dioxide (CO2) emissions.

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Fig. 2.2: From Bauen, A. and Co-authors, 2009. Bioenergy; A Sustainable and Reliable Energy Source: A Review of Status and Prospects. IEA Bioenergy: ExCo:2009:06 108pp. Reprinted with permission from IEA Bioenergy Implementing Agreement.

Fig. 2.3: From Dornburg, V. and Co-authors, 2010. Bioenergy Revisited: Key Factors in Global Potentials of Bioenergy. Energy & Environmental Science, 3, pp. 258-267. Reprinted with permission from the Royal Society of Chemistry.

Fig. 2.4: From Fischer, G., E. Hizsnyik, S. Prieler, M. Shah, and H. van Velthuizen, 2009. Biofuels and Food Security. The OPEC Fund for International Development (OFID) and International Institute of Applied Systems Analysis (IIASA), Vienna, Austria, 228 pp. Reprinted with permission from International Institute for Applied Systems Analysis.

Fig. 2.5(b): From de Wit, M., and A. Faaij, 2010. European biomass resource potential and costs. Biomass and Bioenergy, 34(2), pp. 188-202. Reprinted with permission from Elsevier Ltd.

Fig. 2.6: From Bauen, A. and Co-authors, 2009. Bioenergy; A Sustainable and Reliable Energy Source: A Review of Status and Prospects. IEA Bioenergy: ExCo:2009:06 108 pp. Reprinted with permission from IEA Bioenergy Implementing Agreement.

Fig. 2.8: From Sikkema, R., and Co-authors, 2011: The European wood pellet markets: current status and prospects for 2020. Biofuels, Bioproducts and Biorefining, 5(3), pp. 250-278, DOI: 10.1002/bbb.277. Reprinted with permission of John Wiley and Sons.

The Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) of the IPCC Working Group III provides an assessment and thorough analysis of renewable energy technologies and their current and potential role in the mitigation of greenhouse gas emissions. The results presented here are based on an extensive assessment of scientific literature, including specifics of individual studies, but also an aggregate across studies analyzed for broader conclusions. The report combines information on technology specific studies with results of large-scale integrated models, and provides policy-relevant (but not policy-prescriptive) information to decision makers on the characteristics and technical potentials of different resources; the historical development of the technologies; the challenges of their integration and social and environmental impacts of their use; as well as a comparison in levelized cost of energy for commercially available renewable technologies with recent non-renewable energy costs. Further, the role of renewable energy sources in pursuing GHG concentration stabilization levels discussed in this report and the presentation and analysis of the policies available to assist the development and deployment of renewable energy technologies in climate change mitigation and/or other goals answer important questions detailed in the original scoping of the report.

The process

This report has been prepared in accordance with the rules and procedures established by the IPCC and used for previous assessment reports. After a scoping meeting in Lübeck, Germany from the 20th to the 25th of January, 2008, the outline of the report was approved at the 28th IPCC Plenary held in Budapest, Hungary on the 9th and 10th of April, 2008.

Overview of Climate Change and Renewable Energy

Background

All societies require energy services to meet basic human needs (e.g., lighting, cooking, space comfort, mobility, communication) and to serve productive processes. For development to be sustainable, delivery of energy services needs to be secure and have low environmental impacts. Sustainable social and economic development requires assured and affordable access to the energy resources necessary to provide essential and sustainable energy services. This may mean the application of different strategies at different stages of economic development. To be environmentally benign, energy services must be provided with low environmental impacts and low greenhouse gas (GHG) emissions. However, the IPCC Fourth Assessment Report (AR4) reported that fossil fuels provided 85% of the total primary energy in 2004, which is the same value as in 2008. Furthermore, the combustion of fossil fuels accounted for 56.6% of all anthropogenic GHG emissions (CO2eq) in 2004. [1.1.1, 9.2.1, 9.3.2, 9.6, 11.3]

Renewable energy (RE) sources play a role in providing energy services in a sustainable manner and, in particular, in mitigating climate change. This Special Report on Renewable Energy Sources and Climate Change Mitigation explores the current contribution and potential of RE sources to provide energy services for a sustainable social and economic development path. It includes assessments of available RE resources and technologies, costs and co-benefits, barriers to up-scaling and integration requirements, future scenarios and policy options.

Introduction

Emission trading has become one of the most important policy instruments for controlling greenhouse gas emissions. The Kyoto Protocol introduced an intergovernmental emissions trading system that runs from 2008 to 2012 and in which countries accepted economy-wide caps and the possibility to trade so-called Assigned Amount Units. Participation of developing countries is possible through the Clean Development Mechanism (CDM) (Stripple and Lövbrand, this volume, Chapter 11). With its International Transaction Log the climate secretariat provides the institutional infrastructure for these trading mechanisms. Complementing the Kyoto trading system, the European Union has established a company-level EU emissions trading scheme in 2005, with its second trading period running in parallel to the Kyoto system (van Asselt 2010). The EU emissions trading scheme regulates about 10 000 facilities that currently emit around 2 gigatonnes carbon dioxide per year (Skjærseth and Wettestad 2008).

In addition to these developments, an increasing number of industrialized countries are implementing or planning to set up national cap-and-trade systems, including Australia, New Zealand, the United States, Canada and Japan. On the sub-national level, the Regional Greenhouse Gas Initiative, the Western Climate Initiative and the Midwestern Greenhouse Gas Accord have emerged in the United States, while the Japanese provinces of Kyoto and Tokyo consider the introduction of regional emissions trading. In 2007, several of these national and sub-national initiatives and the European Union inaugurated the International Carbon Action Partnership with the explicit aim of exploring options for linking the domestic trading systems in the broader perspective of creating a global carbon market (Bergfelder 2008).