Energy requirements and carbon emissions for a low-carbon energy transition.

Achieving the Paris Agreement will require massive deployment of low-carbon energy. However, constructing, operating, and maintaining a low-carbon energy system will itself require energy, with much of it derived from fossil fuels. This raises the concern that the transition may consume much of the energy available to society, and be a source of considerable emissions. Here we calculate the energy requirements and emissions associated with the global energy system in fourteen mitigation pathways compatible with 1.5 °C of warming. We find that the initial push for a transition is likely to cause a 10-34% decline in net energy available to society. Moreover, we find that the carbon emissions associated with the transition to a low-carbon energy system are substantial, ranging from 70 to 395 GtCO2 (with a cross-scenario average of 195 GtCO2). The share of carbon emissions for the energy system will increase from 10% today to 27% in 2050, and in some cases may take up all remaining emissions available to society under 1.5 °C pathways.

National responsibility for ecological breakdown: a fair-shares assessment of resource use, 1970-2017.

BACKGROUND: Human impacts on earth-system processes are overshooting several planetary boundaries, driving a crisis of ecological breakdown. This crisis is being caused in large part by global resource extraction, which has increased dramatically over the past half century. We propose a novel method for quantifying national responsibility for ecological breakdown by assessing nations' cumulative material use in excess of equitable and sustainable boundaries. METHODS: For this analysis, we derived national fair shares of a sustainable resource corridor. These fair shares were then subtracted from countries' actual resource use to determine the extent to which each country has overshot its fair share over the period 1970-2017. Through this approach, each country's share of responsibility for global excess resource use was calculated. FINDINGS: High-income nations are responsible for 74% of global excess material use, driven primarily by the USA (27%) and the EU-28 high-income countries (25%). China is responsible for 15% of global excess material use, and the rest of the Global South (ie, the low-income and middle-income countries of Latin America and the Caribbean, Africa, the Middle East, and Asia) is responsible for only 8%. Overshoot in higher-income nations is driven disproportionately by the use of abiotic materials, whereas in lower-income nations it is driven disproportionately by the use of biomass. INTERPRETATION: These results show that high-income nations are the primary drivers of global ecological breakdown and they need to urgently reduce their resource use to fair and sustainable levels. Achieving sufficient reductions will likely require high-income nations to adopt transformative post-growth and degrowth approaches. FUNDING: None.

Economics for people and planet-moving beyond the neoclassical paradigm.

Despite substantial attention within the fields of public and planetary health on developing an economic system that benefits both people's health and the environment, heterodox economic schools of thought have received little attention within these fields. Ecological economics is a school of thought with particular relevance to public and planetary health. In this article, we discuss implications of key ecological economics ideas for public and planetary health, especially those related to critiques of gross domestic product as a measure of progress and economic growth as the dominant goal for economic and policy decision making. We suggest that ecological economics aligns well with public health goals, including concern for equality and redistribution. Ecological economics offers an opportunity to make the transition to an economic system that is designed to promote human and planetary health from the outset, rather than one where social and environmental externalities must be constantly corrected after the fact. Important ideas from ecological economics include the use of a multidimensional framework to evaluate economic and social performance, the prioritisation of wellbeing and environmental goals in decision making, policy design and evaluation that take complex relationships into account, and the role of provisioning systems (the physical and social systems that link resource use and social outcomes). We discuss possible interventions at the national scale that could promote public health and that align with the prioritisation of social and ecological objectives, including universal basic income or services and sovereign money creation. Overall, we lay the foundations for additional integration of ecological economics principles and pluralist economic thinking into public and planetary health scholarship and practice.