The world is transforming its energy system from one dominated by fossil fuel combustion to one with net-zero emissions of carbon dioxide (CO2), the primary anthropogenic greenhouse gas. This energy transition is critical to mitigating climate change, protecting human health, and revitalizing the U.S. economy. To help policymakers, businesses, communities, and the public better understand what a net-zero transition would mean for the United States, the National Academies of Sciences, Engineering and Medicine convened a committee of experts to investigate how the U.S. could best decarbonize its transportation, electricity, buildings, and industrial sectors. This report, Accelerating Decarbonization of the United States Energy System, identifies key technological and socio-economic goals that must be achieved to put the United States on the path to reach net-zero carbon emissions by 2050. The report presents a policy blueprint outlining critical near-term actions for the first decade (2021-2030) of this 30-year effort, including ways to support communities that will be most impacted by the transition.

This study presents options to fully unlock the world’s vast solar PV potential over the period until 2050. It builds on IRENA’s global roadmap to scale up renewables and meet climate goals.

In Transforming California, Stephanie Pincetl argues that the transformation of nature in order to enhance economic development lies at the heart of much of the state's recent history. She sees late-twentieth-century California on a path of continued environmental degradation, gripped by cynicism about government. Transforming California describes the evolution of the state's institutions of government as they apply to land use and development, and it shows how land-use decisions affect people's quality of life and their daily interactions with each other and with their environment. Pincetl offers an alternative vision for the renewal of the democratic spirit and process in California and for a reconciliation with nature.

Special edition compiled in partnership with Frontiers sponsored by the Clean Air Task Force. The realisation of Net Zero by 2050 will require the ability for strategy developers, operational planners and decision makers to better manage uncertainty, complexity and emergence. The application of the orthodox set of decision support tools and processes that have been used to explore deep decarbonisation options to 2050 have blinded decision makers to uncertainty, complexity and emergence. Tools have often been used which are inappropriate to the types of decisions being made – a competency which has been glaringly revealed during the C-19 Pandemic. This Frontiers Research Topic will highlight the need for an interdisciplinary, mixed methods approach bringing together insights from modelling, decision science, psychology, anthropology, and sociology to form a compendium of current best practice for decision making for the net zero transformation and new research frontiers. Develop greater awareness amongst policymakers, practitioners and academics as to the importance of: • Understanding the nature of uncertainty when dealing with problems associated with the Net Zero Energy System Transformation; • Increasing importance of deliberative processes to map different value sets beyond least cost; • Acknowledging that decision making under uncertainty requires competency-based training leading to a full appreciation of the tasks at hand. Suggested areas within scope are listed in points 1-12 below. Authors are free to choose specific areas of interest, and to combine these where useful. In general, it will be useful to consider practical application of [ideas], e.g • development of `Use Cases’ and `Decision Making Contexts’ may be useful, e.g. National Govt establishing its Carbon Budget; Institution setting up its investment portfolio. • understanding of how decisions are being made within different jurisdictions, political cultures, and types of organizations (public/private). What is the role of `Decision Context' i.e. organisational decision-making structures, cultures, the role of zeitgeist and dominant narratives, or the relation between academic expertise and policy-makers. 1. Decision making from an end-to-end perspective and the need to take a holistic and interdisciplinary perspective [Editorial Cover Article]. 2. Gap between what policy makers and decision makers around net zero climate policy seek to address and what decision support tools can actually do. Why that gap is increasing (if it is)? 3. Understanding the nature of uncertainty when applying the relevant decision support tool and processes. Not all uncertainty can be addressed within the decision support tool itself. Role of optimism bias; potential role of least worst regret approaches etc 4. What different decision support tools can inform decision makers around net zero climate policy and need for a basket of tools. 5. Why parametric decision support tools and models are pre-eminent - the role of consolidative modelling and exploratory modelling. The inertia of modelling approaches: why it is so hard to break modelling paradigms? 6. What decision science informs us about how decisions are actually made - the importance of process, the role of transparency and deliberation with analysis. 7. Processes that address the biases identified in decision science and impact of identity politics on deliberative decision making. 8. Why decision making under deep uncertainty requires competency-based training, deep subject matter expertise and systemic knowledge. 9. Ministerial and policy making and the decision support requirements: US, EU, UK & China 10. The role of narratives and how uncertainty can be communicated to societal audiences. Storylines and other narrative approaches 11. How to develop participatory approaches allow multiple values, diversity of stakeholders in which climate communication and decision making exists in an iterative exchange with policy. We have started the journey e.g. the role of climate assemblies… what next? 12. Decision making under deep (climate) uncertainty by the financial sector We acknowledge the funding of the manuscripts published in this Research Topic by the Clean Air Task Force. We hereby state publicly that the Clean Air Task Force has had no editorial input in articles included in this Research Topic, thus ensuring that all aspects of this Research Topic are evaluated objectively, unbiased by any specific policy or opinion of the Clean Air Task Force.

This Intergovernmental Panel on Climate Change Special Report (IPCC-SRREN) assesses the potential role of renewable energy in the mitigation of climate change. It covers the six most important renewable energy sources - bioenergy, solar, geothermal, hydropower, ocean and wind energy - as well as their integration into present and future energy systems. It considers the environmental and social consequences associated with the deployment of these technologies, and presents strategies to overcome technical as well as non-technical obstacles to their application and diffusion. SRREN brings a broad spectrum of technology-specific experts together with scientists studying energy systems as a whole. Prepared following strict IPCC procedures, it presents an impartial assessment of the current state of knowledge: it is policy relevant but not policy prescriptive. SRREN is an invaluable assessment of the potential role of renewable energy for the mitigation of climate change for policymakers, the private sector, and academic researchers.

The United States and China are the world's top two energy consumers and, as of 2010, the two largest economies. Consequently, they have a decisive role to play in the world's clean energy future. Both countries are also motivated by related goals, namely diversified energy portfolios, job creation, energy security, and pollution reduction, making renewable energy development an important strategy with wide-ranging implications. Given the size of their energy markets, any substantial progress the two countries make in advancing use of renewable energy will provide global benefits, in terms of enhanced technological understanding, reduced costs through expanded deployment, and reduced greenhouse gas (GHG) emissions relative to conventional generation from fossil fuels. Within this context, the U.S. National Academies, in collaboration with the Chinese Academy of Sciences (CAS) and Chinese Academy of Engineering (CAE), reviewed renewable energy development and deployment in the two countries, to highlight prospects for collaboration across the research to deployment chain and to suggest strategies which would promote more rapid and economical attainment of renewable energy goals. Main findings and concerning renewable resource assessments, technology development, environmental impacts, market infrastructure, among others, are presented. Specific recommendations have been limited to those judged to be most likely to accelerate the pace of deployment, increase cost-competitiveness, or shape the future market for renewable energy. The recommendations presented here are also pragmatic and achievable.