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.

Executive Summary

Historically, economic development has been strongly correlated with increasing energy use and growth of greenhouse gas (GHG) emissions. Renewable energy (RE) can help decouple that correlation, contributing to sustainable development (SD). In addition, RE offers the opportunity to improve access to modern energy services for the poorest members of society, which is crucial for the achievement of any single of the eight Millennium Development Goals.

Theoretical concepts of SD can provide useful frameworks to assess the interactions between SD and RE. SD addresses concerns about relationships between human society and nature. Traditionally, SD has been framed in the three-pillar model—Economy, Ecology, and Society—allowing a schematic categorization of development goals, with the three pillars being interdependent and mutually reinforcing. Within another conceptual framework, SD can be oriented along a continuum between the two paradigms of weak sustainability and strong sustainability. The two paradigms differ in assumptions about the substitutability of natural and human-made capital. RE can contribute to the development goals of the three-pillar model and can be assessed in terms of both weak and strong SD, since RE utilization is defined as sustaining natural capital as long as its resource use does not reduce the potential for future harvest.

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.