In the aftermath of the pandemic, global demand for infrastructure is booming. National plans around the world show that infrastructure is likely to provide the backbone for a resurgence in public expenditure, and to support growth in economies badly hit by the pandemic.As all the biggest powers and blocs (the EU, the US, China, and Japan) have recently announced their plans for climate or carbon neutrality, the room and need for green and sustainable infrastucture are greatly expanding. Decarbonisation and digitalisation will be underpinning this latest investment drive in infrastructure, with sustainability and ESG principles at its core. However, infrastructure expenditure will not come without risk: after the pandemic, the world will be left with the highest levels of public andprivate debt since World War II, and the sustainability of key investment decisions must be carefully evaluated.How to foster quality and sustainable infrastructure investment? What role for the private sector? What future for sustainable mobility? What kind of policies will countries adopt to reach carbon neutrality?

This paper complements previous work on the economics of different energy resources by examining the growth potential of alternative electricity supply infrastructures as constrained by innate physical limits. Coal-fired generation meets the criteria of longevity (abundance of energy source) and scalability (effective capability to expand to the multi-terawatt level) which are critical for a sustainable energy supply chain, but it carries a very heavy carbon footprint. Renewables and nuclear power meet both the longevity and climate friendliness criteria. However, they vary in terms of their ability to deliver net energy at a scale needed for meeting a huge global energy demand. The low density of renewable resources for electricity generation and the current intermittency of many renewables limit their ability to achieve high rates of growth. And a significant global increase in nuclear power deployment could engender serious risks related to proliferation, safety, and waste disposal. Unlike renewable sources of energy, nuclear power is an unforgiving technology because human lapses and errors can have ecological and social impacts that are catastrophic and irreversible. The transition to a low carbon economy is likely to prove much more challenging than some optimists have claimed.

'The publication of World in Transition: Towards Sustainable Energy Systems is timely indeed. The World Summit on Sustainable Development gave great prominence to this challenge, but failed to agree on a quantitative, time-bound target for the introduction of renewable energy sources. The German Advisory Council on Global Change (WBGU) has now produced a report with a global focus, which is essential in view of the global impacts of climate change. The report provides a convincing long-term analysis, which is also essential. Global energy policies have to take a long-term perspective, over the next 50 to 100 years, while providing concrete guidance for decision-makers to implement now. There is an urgent need to secure energy supplies for the 2.4 billion people who still depend upon traditional biomass, while avoiding dangerous climatic changes. Our one world must close the gap between industrialized countries' surfeit and developing countries' poverty. Policies will need to consider both the broader environmental and specific climate constraints. I recommend this book very warmly to everyone concerned with global energy issues' Klaus Topfer, Executive Director, United Nations Environment Programme World in Transition: Towards Sustainable Energy Systems underscores the urgent need to transform global energy systems so that the world's population has access to energy based on renewable sources. This is necessary to protect the global climate and to free those in developing countries trapped by energy poverty. Such an approach would also yield a peace dividend by reducing dependence upon regionally concentrated oil reserves. The authors stress that such a reconfiguration of energy systems is both feasible and fundable if rapid and resolute action is taken in the coming two decades. To this end, they propose a roadmap with specific milestones, making this an indispensable contribution to the scientific and policy debates on these critical issues and essential reading for those engaged with them.

For policymakers. p. 1.

This book offers an authoritative analysis of the state-of-the art in energy and climate research and policy. It starts by describing the current status of technologies that are expected to have an influence on the energy systems of the future. For an adequate evaluation, it presents the latest findings on the effects of energy supply and consumption as well as of the emissions on both the environment and people’s health. This is followed by an extensive discussion of the economic and social problems related to climate change, the need for energy transitions, and other issues that may require public investment and international agreements. The book reviews the problem of energy policy from a global perspective, providing readers with the technical, political, economic and ethical background needed to understand the current situation and work at better solutions for a sustainable, just and prospering world.