Climate Change and Nuclear Power 2020

• Éditeur: International Atomic Energy Agency
• Année: 2020
• ISBN:
  9789201152206
• Sujet: Technik & Maschinenbau
• Sous-sujet: Maschinenbau

This publication provides an update on the current status of nuclear power and prospects for its contribution, together with other low carbon energy sources, to ambitious mitigation strategies that will help the world limit global warming to 1.5°C in line with the 2015 Paris Agreement. Since 2000, the IAEA has issued such information and analysis regularly, in order to support those Member States that choose to include nuclear power in their energy system as well as those considering other strategies. The focus of the 2020 publication is on the significant potential of nuclear energy, integrated in a low carbon energy system, to contribute to the 1.5°C climate change mitigation target, and the challenges of realizing this potential. Energy system and market related factors affecting the transition to a low carbon energy system are reviewed. This edition also outlines developments needed to realize the large scale capacity increase required to rapidly decarbonize the global energy system in line with limiting global warming to 1.5°C.

1. INTRODUCTION

1.1. Background

Climate change is widely recognized as a major threat to humanity and much of the natural world. Increasing atmospheric concentrations of greenhouse gases (GHGs) are driving changes in global and regional temperatures, precipitation patterns and other climate attributes, increasing the risk of extreme weather events and sea level rise, and impacting human health, livelihoods, food security and water supply, as well as biodiversity on land and in oceans [1, 2]. Displacement from climate events could result in millions of climate refugees around the world. Carbon dioxide (CO2) emissions from burning fossil fuels and other industrial activities, along with emissions from agriculture and land use, are the principal drivers of climate change.

With the adoption of the Paris Agreement in 2015, nearly all parties to the United Nations Framework Convention on Climate Change (UNFCCC) agreed to prepare nationally determined contributions (NDCs) to control GHG emissions and limit the increase of global mean surface temperature to below 2°C relative to pre-industrial levels. Since then, increasing scientific understanding of the significant risks associated with warming of 2°C [2], along with increasing societal concern, have established the need for more urgent and ambitious action to avoid the worst impacts of climate change by limiting warming to 1.5°C by the end of the century.

Reflecting this urgency, the United Nations Secretary-General convened the Climate Action Summit in September 2019 and called on world leaders to enhance their NDCs by 2020 with the aim of reducing emissions by 45% by 2030 and achieving net zero emissions by 2050. Expectations that the 25th Conference of the Parties (COP25) to the UNFCCC in December would build on this momentum attracted significant international media and public attention to the event. However, the outcome of COP25 was considered disappointing [3–5], and further efforts are needed to improve climate strategies and ramp up ambition in NDCs. In particular, delegates failed to agree on key modalities for establishing a carbon market to facilitate increased ambition, and on support for developing countries in finance, technology and capacity building [6]. However, 72 countries (plus the European Union (EU)) representing around 15% of global CO2 emissions from energy, signalled their goal of achieving net zero GHG emissions by 2050 [7, 8]. Additional countries have adopted similar targets following COP25.

According to the Intergovernmental Panel on Climate Change (IPCC) Special Report on Global Warming of 1.5°C (SR15) [2], in order to limit the average global temperature increase to 1.5°C, global energy production and use need to be fully decarbonized by around 2050, with rapid reductions in emissions starting immediately. The electricity sector faces the immense challenge of shifting almost entirely to low carbon energy sources in just 30 years, from a system dominated today by fossil fuels, as illustrated in Fig. 1. Since energy infrastructure tends to have a lifespan measured in decades, immediate action is needed to make this rapid transition possible.

The potential of nuclear power — which currently supplies almost 30% of low carbon electricity [9, 10] — to contribute to this transformation is illustrated in the long term 1.5°C pathways considered by the IPCC, which envisage a substantial increase in global nuclear generation (of 100–500% by 2050 in the IPCC’s four illustrative pathways) [2]. Nuclear power’s role in mitigation is also recognized in a recent report from the International Energy Agency (IEA), a special body of the Organisation for Economic Co-operation and Development (OECD), entitled Nuclear Power in a Clean Energy System [11]. Besides electricity generation, nuclear power could provide a significant contribution to decarbonizing the non-electric energy sector, an undertaking that has proved to be more challenging. For instance, the share of polluting fossil fuels in the global energy mix is not yet decreasing (as of 2019, it remained at about 63%, the same level as in the 1990s [12]).

To provide a platform to discuss objectively the scientific and technical aspects of the role of nuclear power in combating climate change, the IAEA held its first International Conference on Climate Change and the Role of Nuclear Power in October 2019, with over 500 participants from 79 Member States and 18 international organizations [13]. Delegates called for urgent and ambitious climate action, making use of all low carbon energy sources to slash emissions and avoid the worst impacts of climate change. Participants also heard how, with constant technical innovation and advancement, nuclear power is becoming more sustainable and flexible in terms of integration with other low carbon energy sources, which further enhances its potential in supporting a low carbon energy transition. Content from a selection of materials presented during the conference is cited in this publication.

1.2. Objective

This publication provides an update on the current status and prospects of the contribution of nuclear power, together with other low carbon energy sources, to ambitious climate change mitigation. This is the eleventh edition of Climate Change and Nuclear Power, which the IAEA first issued in 2000 to support both those Member States that choose to include nuclear power in their energy system and those considering other mitigation strategies. The focus of the 2020 edition is on the significant potential of nuclear energy in climate change mitigation that aims to reach the 1.5°C target, and the developments and challenges of realizing this potential in a low carbon energy system.

1.3. Scope

This publication explains the complementary role of nuclear energy in an energy system with ambitious GHG emissions mitigation, together with other low carbon sources. Multiple organizations are analysing the necessary decarbonization of the energy system, and many of their scenarios, including all four illustrative scenarios from the IPCC’s SR15, include a substantial increase of global nuclear power capacity, many of them above the IAEA’s projections of future nuclear capacity [10]. This publication also elaborates on how this energy source could be optimally enabled to take its place in an integrated decarbonized energy system and outlines developments needed to realize the large scale capacity increase required to rapidly decarbonize the global energy system in line with limiting global warming to 1.5°C. In this edition, the focus will be on developments in the deployment of nuclear power in the energy system, rather than on developments in nuclear technology itself. To that effect, the role of nuclear power includes maintaining existing low carbon capacity by extending the life of the current nuclear fleet as well as expanding low carbon capacity through the construction of new facilities.

1.4. Structure

This publication provides a review of the low carbon energy transformation required to limit warming to 1.5°C, including a comprehensive assessment of the potential role of nuclear power in climate change mitigation and key elements in realizing this potential. This ...