The choice of carbon inequality metrics can significantly influence demand-side mitigation policies and their equity outcomes. We propose integrated carbon inequality metrics, including juxtaposing carbon inequality with economic inequality, disparity ratios across income and age groups, and structural income–urbanization inequality patterns. We then apply these new metrics and use the household expenditure survey data from China Family Panel Studies as a case study to examine household consumption-based carbon emissions in China. We assess the extent to which household consumption patterns, household expenditure, age, and urbanization contribute to the gap in per-capita household carbon footprints (CF) across income groups. We find that in relative terms, the top 20% income group accounts for 38% of total emissions, whereas the bottom 20% emit about 8% in China. Per-capita CFs vary slightly widely in their inequality than expenditure. The CF disparity ratios of all eight consumption categories across provinces concentrate around 4.5. CF disparity ratios of households with elderly members range from 1 to 3 and decrease with increasing household size. Rural CF-Gini exhibit a slightly wider range (0.15 to 0.52) than urban CF-Gini (0.16 to 0.42). Per capita CF of urban inhabitants was substantially larger than that of the rural ones, with 8.83 tCO2 per capita in urban regions vs. 2.68 tCO2 in rural regions. This study provides a nuanced understanding of within-country disparities to inform equitable demand-side mitigation solutions.

[This corrects the article DOI: 10.1371/journal.pone.0235654.].

Australia is a highly urbanised country, with over 85% of people living in city environments, so the lifestyles of city dwellers and the infrastructure of cities are critical to addressing sustainability issues. Australian cities have embraced the Doughnut Economics framework for sustainability; however, methodologies and data to comprehensively assess environmental and social sustainability are underdeveloped and locally focused, undermining the effectiveness of targets set. This research compares social outcomes of capital cities and regional areas within Australia with 12 environmental stressors and shows that consumption-based, environmental footprints are between 1.7 and 44 times higher than global averages. The most critical environmental issue is biodiversity loss within Australia while the most critical social issues are living standards in remote and regional communities, and inequality. The sustainability challenges for different actors, planetary boundaries, and economic sectors in Australia vary substantially, especially when viewed from a consumption rather than a production perspective.

Abstract Non-technical summary Neoclassical economics (NCE) theory and neoliberal economics practice together form one of the principal driving forces of environmental destruction and social injustice. We critically examine ten key hypotheses that form the foundations of NCE, and four other claims. Each fails to satisfy one or more of the basic requirements of scientific practice. Hence, NCE is fundamentally flawed, is irrational in the common meaning of the word, and should not be used as a guide for government policies. Because NCE is socially constructed, it can be replaced with an interdisciplinary conceptual framework that is compatible with ecological sustainability and social justice. Technical summary Neoclassical economics (NCE) is widely regarded as providing theoretical justification for neoliberal notions such as ‘governments should minimize regulation and spending, and hence leave major socioeconomic and environmental decisions to the market’. A large body of literature finds that NCE is largely responsible for environmental destruction and social inequality. As NCE is claimed to be a science and has appropriated terminology (without the content) from physics, we examine critically its basic hypotheses and four other claims from a viewpoint of natural scientists and an ecological economist, each a sustainability researcher. This paper defines NCE in two ways: as a theoretical structure for economics based on (1) the hypotheses of methodological individualism, methodological instrumentalism and methodological equilibration, and (2) the three hypotheses named above together with seven other common hypotheses of NCE. We find that each hypothesis and claim fails to satisfy one or more basic requirements of scientific practice such as empirical confirmation, underlying credible or empirical assumptions, consistency with Earth system science, and internal consistency. Sensitivity analysis is rare and ability to predict is lacking. Therefore, we recommend that neoclassical microeconomics be reformed and neoclassical macroeconomics be abandoned and replaced with a transdisciplinary field such as social ecological economics. Social media summary Conventional economics, a driver of environmental damage and social inequality, fails examination by sustainability scientists.

Globalization intensifies the demand for agricultural products from specific regions, resulting in intensive farming practices that can exacerbate local cropland soil phosphorus (P) depletion, thereby undermining long-term food security. By integrating global data on international trade and soil-P reserves and deficits from 1970 to 2017, we demonstrate that the contribution of trade to global soil-P deficits increased from 7% in 1970 to 18% in 2017, with 54% of this impact driven by non-food consumption. Over these 48 years, developing regions exported a net of 5.8 Mt P through agricultural trade, resulting in a net increase of 13 Mt soil-P deficits. These deficits are primarily concentrated in regions with low soil-P reserves, such as sub-Saharan Africa, Latin America and Southeast Asia, thereby heightening the risks of soil-P depletion in these areas and amplifying long-term concerns about food security. This insight underscores the imperative for a broader perspective on food security-prioritizing national soil productivity rather than merely boosting the availability of food in the global market when shaping global trade policies. The growing global demand for agricultural products from specific regions leads to farming practices that can exacerbate soil-phosphorus depletion, with consequences for long-term food security. This study quantifies the contribution of trade to global soil-phosphorus deficits from 1970 to 2017.

There is an urgent need to accelerate progress on the Sustainable Development Goals (SDGs) and recent research has identified six critical transformations. It is important to demonstrate how these transformations could be practically accelerated in a national context and what their combined effects would be. Here we bridge national systems modelling with transformation storylines to provide an analysis of a Six Transformations Pathway for Australia. We explore important policies to accelerate progress, synergies and trade-offs, and conditions that determine policy success. We find that implementing policy packages to accelerate each transformation would boost performance on the SDGs by 2030 (+23% above the baseline). Policymakers can maximize transformation synergies through investments in energy decarbonization, resilience, social protection, and sustainable food systems, while managing trade-offs for income and employment. To overcome resistance to transformations, ambitious policy action will need to be underpinned by technological, social, and political enabling conditions.

The planetary boundary framework identifies nine areas of key environmental risk globally. The causes of climate change are well understood as a serious and existential threat; however the other eight areas of concern have a much more limited understanding of what is driving their continued increase.This research utilises Global Resource Input Output Assessment (GLORIA) multiregional input-output (MRIO) tables to map 15 footprint indicators across 51 sectors and seven global regions, identifying key sectors driving planetary boundary impacts and suggesting targeted interventions for sustainability.The relative role of emission intensity and total expenditure is shown, and potential trade-offs and synergies between sectors and indicators are identified. High-impact footprint clusters are identified as food and textiles, and the built environment, with moderate impacts from the services and energy sectors. These relationships are compared to several transformation agendas, identifying overlooked relationships and drivers, including the predominant role of commercial buildings and infrastructure in built environment impacts and the correlation between greenhouse gas emissions and air pollution. The primary driver of plastic use footprints is seen to be the built environment, however as a whole chemical pollution levels remain a significant unknown, and the challenge to globally stop the flow of further dangerous substances and clean up existing contaminated sites is large.By providing a detailed breakdown of planetary boundary drivers this work enables decision-makers to understand the risks and issues associated with economic purchases across all critical environmental pathways simultaneously to better prioritise action for a stable planet.

This article presents a comprehensive economy-wide material flow analysis of the Australian economy in 2019, examining the domestic extraction, trade, end-of-life flows, and recycling for all materials. The results highlight Australia's role as a natural resource supplier, with metals and fossil fuels being primary contributors. Through material flow analysis, we found that in 2019 Australia extracted 2587 Mt of natural resources, exported a substantial fraction (1459 Mt), and used 917 Mt to fulfill domestic needs. The recycling flows and circularity metrics are also explored, with an end-of-life recycling rate of 51.1% and an overall circularity rate of 5.1%. An additional assessment of Australia's consumption-based material footprint highlights mobility and housing as the dominant material-using sectors. These results contribute to understanding Australia's material consumption patterns, indicating significant reliance on foreign semifinished and finished products, and provide insights into the potential for enhancing economic circularity.

In 2019 the Australian Capital Territory (ACT) government stated an ambition to prioritise reduction of Scope 3 greenhouse gas emissions, the size of which had not been fully quantified previously. This study calculated the total carbon footprint of the ACT in 2018, including Scope 1, 2 and 3 emissions and modelled scenarios to reduce all emissions in line with a 1.5 ? target approach. This is the first time a multi-scale analysis of local, sub-national and international supply chains has been undertaken for a city, using a nested and trade-adjusted global multi-region input-output model. This allowed for the quantification of global origins and destinations of emissions, which showed that the 2018 carbon footprint for the ACT was approximately 34.7 t CO2-eq/cap, with 83% attributed to Scope 3. Main contributions came from transport, electricity, manufacturing and public administration and safety, with emissions generated primarily in Australian States and Territories. Modelling in accordance with a 1.5 ? warming scenario showed a plausible reduction to 5.2 t CO2-eq/cap by 2045 (excluding offsets or carbon dioxide removal technologies), with remaining emissions predominantly embodied in inter-national supply chains. This study demonstrates the radical changes required by a wealthy Australian city to achieve 1.5 ? compliance and identifies sectors and supply chains for prioritising policies to best achieve this outcome.

Previously, anthropogenic ecological overshoot has been identified as a fundamental cause of the myriad symptoms we see around the globe today from biodiversity loss and ocean acidification to the disturbing rise in novel entities and climate change. In the present paper, we have examined this more deeply, and explore the behavioural drivers of overshoot, providing evidence that overshoot is itself a symptom of a deeper, more subversive modern crisis of human behaviour. We work to name and frame this crisis as 'the Human Behavioural Crisis' and propose the crisis be recognised globally as a critical intervention point for tackling ecological overshoot. We demonstrate how current interventions are largely physical, resource intensive, slow-moving and focused on addressing the symptoms of ecological overshoot (such as climate change) rather than the distal cause (maladaptive behaviours). We argue that even in the best-case scenarios, symptom-level interventions are unlikely to avoid catastrophe or achieve more than ephemeral progress. We explore three drivers of the behavioural crisis in depth: economic growth; marketing; and pronatalism. These three drivers directly impact the three 'levers' of overshoot: consumption, waste and population. We demonstrate how the maladaptive behaviours of overshoot stemming from these three drivers have been catalysed and perpetuated by the intentional exploitation of previously adaptive human impulses. In the final sections of this paper, we propose an interdisciplinary emergency response to the behavioural crisis by, amongst other things, the shifting of social norms relating to reproduction, consumption and waste. We seek to highlight a critical disconnect that is an ongoing societal gulf in communication between those that know such as scientists working within limits to growth, and those members of the citizenry, largely influenced by social scientists and industry, that must act.

Seeking to meet sustainability targets, cities are promoting a number of circular economy initiatives. Whether or not these actions help cities to approach sustainable resource management is often unclear. To identify, prioritize and monitor resource-efficient strategies, cities can look for targets and indicators among the Sustainable Development Goals (SDGs). While the SDGs provide useful goals, they lack applicable and accurate indicators for cities. To address this shortcoming, we link the SDGs to the urban circular economy by looking at the urban metabolism and identify monitoring needs and gaps. Although consumption-based footprint indicators are the most suitable approach, these are barely covered in the SDGs. We propose a framework facilitating transdisciplinary projects and experimentation to assess resource footprints and prioritize circular strategies in cities. Our discussion will guide practitioners and academics towards a sustainable circular transformation in cities.

The penetration rates of both electric vehicles (EVs) and distributed energy resources (DERs) have been increasing rapidly as appealing options to address the global problems of carbon emissions and fuel supply issues. However, uncoordinated EV charging activities and DER generation result in operational challenges for power distribution systems. Therefore, this article has developed a hierarchical transactive energy (TE) framework to locally induce and coordinate EV charging demand and DER generation in electric distribution networks. Based on a modified version of the alternating direction method of multipliers (ADMMs), two fully decentralized (DEC) peer-to-peer (P2P) trading models are presented, that is, an hour-ahead market and a 5-min-ahead real-time market. Compared to existing P2P electricity markets, this research represents the first attempt to comprehensively incorporate alternating current (ac) power network constraints into P2P electricity trading. The proposed TE framework not only contributes to mitigating operational challenges of distribution systems, but also benefits both EV owners and DER investors through secured local energy transactions. The privacy of market participants is well preserved since the bid data of each participant are not exposed to others. Comprehensive simulations based on the IEEE 33-node distribution system are conducted to demonstrate the feasibility and effectiveness of the proposed method.

Today, more than 700 cities worldwide have made net-zero pledges. Managing these bold targets, however, is not easy given the complexity of urban systems. Although holistic mitigation efforts are vital, individual sectors are likely to face their own challenges and require tailor-made solutions. This Voices asks: what are the challenges and opportunities in transforming cities toward net-zero carbon emissions?

Communicating the finiteness of the Earth system at sub-global scales is necessary to guide human activities within a safe operating space. Despite the numerous efforts committed to downscaling planetary boundaries (PBs) at multiple scales, neither top-down nor bottom-up approaches adequately account for the spatial heterogeneity and integrity of local and global natural systems. To overcome these shortcomings, we developed a hybrid approach that combines bottom-up aggregation and top-down adjustment for downscaling five crucial PBs (i.e., climate change, nitrogen and phosphorus cycles, freshwater use, and land use change) to Chinese provinces and industries. In addition to the widely applied equity principle, we further incorporated the eco-efficiency principle into the downscaling of PBs under the proposition that safeguarding finite PBs should be reconciled with the pursuit of maximizing human welfare. Environmental sustainability at multiple scales was subsequently assessed with the complementary use of environmental footprints and downscaled PBs. The results demonstrate that 1) China suffers from severe unsustainability because of the transgression of PBs for phosphorus and nitrogen cycles, carbon emissions, and cropland use; 2) provinces in West and North China perform worse than other provinces in terms of the eco-efficiency in manufacturing industries, including Electronic equipment, Textiles, and Wood processing and furnishing, rendering these industries that are more unsustainable; and 3) industries with varying eco-efficiencies account differently for the provincial PBs. Construction dominates the provincial shares of carbon PBs, whereas Agriculture and Food processing and tobacco contribute most to the other four PBs. Our findings suggest that improving eco-efficiency in most manufacturing industries is the key to saving resources, reducing emissions, and safeguarding local boundaries.

Transitioning to net-zero greenhouse gas (GHG) emissions by 2050 is becoming increasingly urgent, requiring accelerated efforts to decarbonise all economic sectors, including transport, a growing emissions source. A transition to battery electric vehicles (BEV) would accelerate the decarbonisation of road transport and provide other benefits. But in Australia, BEV uptake has been negligible, and the scale and pace required to reach net-zero emissions by 2050 has not been addressed to date. This study applies a national-scale integrated macroeconomic model (iSDG-Australia) to project Australia’s future road transport demand, vehicle mix, energy consumption and GHG emissions by 2050. It models five scenarios incorporating different levels of economic and population growth, vehicle longevity, ambitions for BEV uptake, fleet renewal, forced phase-out of fossil-fuelled vehicles and shifts to renewable electricity. Scenario projections are benchmarked on their zero-emission vehicle mix, fuel and electricity consumption, GHG emissions, and broader social and economic impacts. We conclude the scale and pace of change must be transformational rather than transitional, requiring urgent policy action. An ambitious and rapid transition to 100% BEVs in new vehicle sales, accelerated fleet renewal, and a shift to renewable electricity generation could achieve a net-zero outcome for Australia’s road transport sector by 2050.

Achieving net zero operational and embodied greenhouse gas (GHG) emissions in the built environment is recognised in Australia and globally as a key strategy to address climate change and achieve the United Nations Sustainable Development Goals (SDGs). However, gaps in knowledge remain regarding potential national pathways to achieve this outcome in Australia. This study further extends and applies a national-scale integrated macroeconomic simulation model to explore coherent pathways to net zero emissions in the built environment sector by 2050. The scope of the study includes residential and commercial buildings and both operational and embodied emissions. It applies scenario analysis incorporating different levels of climate ambition, including a shift to renewable energy, electrifying buildings, improving energy efficiency and replacing carbon-intensive materials. We find that a high ambition scenario (Scenario 2) delivers a 94% reduction in GHG emissions by 2050 when compared against business-as-usual, placing a net-zero target within reach. Improvements on Australia's SDGs performance are also attained. Through subsequent pathways analysis we find that achieving net zero or even net negative operational and embodied emissions is feasible with more ambitious action in key areas, including increasing the share of mass-timber buildings and reducing end-of-life losses in sequestered carbon.

William F Lamb1,2,∗, Thomas Wiedmann, Julia Pongratz, Robbie Andrew, Monica Crippa, Jos G J Olivier, Dominik Wiedenhofer, Giulio Mattioli, Alaa Al Khourdajie, Jo House, Shonali Pachauri, Maria Figueroa, Yamina Saheb, Raphael Slade, Klaus Hubacek, Laixiang Sun, Suzana Kahn Ribeiro, Smail Khennas, Stephane de la Rue du Can, Lazarus Chapungu, Steven J Davis, Igor Bashmakov, Hancheng Dai, Shobhakar Dhakal, Xianchun Tan, Yong Geng, Baihe Gu and Jan Minx 1 Mercator Research Institute on Global Commons and Climate Change, Torgauer Straße 12–15, 4 EUREF Campus #19, 10829 Berlin, Germany 2 School of Earth and Environment, University of Leeds, LS2 9JT Leeds, United Kingdom 3 Sustainability Assessment Program, School of Civil and Environmental Engineering, UNSW Sydney, Sydney, Australia 4 Max Planck Institute for Meteorology, Bundesstrasse 53, 20146 Hamburg, Germany 5 Department of Geography, Ludwig-Maximilians-Universität Munich, Luisenstrasse 37, 80333 Munich, Germany 6 CICERO Center for International Climate Research, Oslo, Norway 7 European Commission, Joint Research Centre, Ispra, VA, Italy 8 PBL Netherlands Environmental Assessment Agency, Den Haag, The Netherlands 9 Institute of Social Ecology, University of Natural Resources and Life Sciences, Schottenfeldgasse 29, 1070 Vienna, Austria 10 Department of Transport Planning, TU Dortmund University, August-Schmidt-Straße 10, 44227 Dortmund, Germany 11 Centre for Environmental Policy, Imperial College London, London, United Kingdom 12 School of Geographical Sciences, University of Bristol, University Road, BS8 1SS Bristol, United Kingdom 13 International Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, 2361 Laxenburg, Austria 14 Department of Management Society and Communication, Copenhagen Business School, Copenhagen, Denmark 15 Openexp, 17 Bd Lefebvre, 75015 Paris, France 16 Integrated Research for Energy, Environment and Society, University of Groningen, 9747AG Groningen, The Netherlands 17 Department of Geographical Sciences, University of Maryland, College Park, MD 20742, United States of America 18 School of Finance and Management, SOAS University of London, WC1H 0XG London, United Kingdom 19 Institute of Blue andGreenDevelopment,Weihai Institute of Interdisciplinary Research, ShandongUniversity,Weihai 264209, People’s Republic of China 20 Federal University of Rio de Janeiro (Universidade Federal do Rio de Janeiro—UFRJ), Transport Engineering Programme (Programa de Engenharia de Transportes—PET), COPPE-UFRJ, Rio de Janeiro, Brazil 21 Energy and Climate Change Consultant, 25 Troubridge Walk, CV22 7LP Rugby, United Kingdom 22 Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States of America 23 Great Zimbabwe University, School of Natural Sciences, Off Old Great Zimbabwe Road, Box 1235, Masvingo, Zimbabwe 24 Department of Earth System Science, University of California, Irvine, CA, United States of America 25 Center for Energy Efficiency—XXI, Moscow, Russia 26 College of Environmental Sciences and Engineering, Peking University, Beijing, People’s Republic of China 27 Department of Energy, Environment and Climate Change, School of Environment, Resources and Development, Asian Institute of Technology, Klong Luang, Pathumthani 12120, Thailand 28 Institutes of Science and Development, Chinese Academy of Sciences, No. 15, Zhongguancun Beiyitiao, Haidian District, Beijing, People’s Republic of China 29 School of International and Public Affairs, Shanghai Jiao Tong University, No. 1954 Huashan Road, Shanghai, People’s Republic of China ∗ Author to whom any correspondence should be addressed.

Transitioning to passenger battery electric vehicles (BEV) can mitigate climate change impacts of road transportation. We develop a novel BEV policy model, nesting it within a national-scale macroeconomic system dynamics model (iSDG-Australia) to simulate a suite of policy pathways. We model combinations of infrastructure support and subsidies, which bring forward the price-parity tipping point, thus rapidly accelerating BEVs’ share of new car sales. However, ongoing complementary charging infrastructure investment is critical to reach 100% new BEV car sales by 2050 in Australia. Even with a rapid transition, the modelled fleet would not achieve net-zero greenhouse gas emissions by 2050 due to vehicle longevity; and suddenly ceasing financial incentives could retard BEV sales by a decade. Based on our assumptions, results suggest emissions reductions are maximised by the fastest transition of the passenger vehicle fleet to BEVs, entailing government policy support from 2020 to 2050, for both adequate infrastructure deployment (AUD17.9b) and vehicle rebates (AUD19.5b), which achieves earlier BEV price-parity with fossil-fuelled vehicles.

City-level CO2 emissions inventories are foundational for supporting the EU’s decarbonization goals. Inventories are essential for priority setting and for estimating impacts from the decarbonization transition. Here we present a new CO2 emissions inventory for all 116,572 municipal and local government units in Europe, containing 108,000 cities at the smallest scale used. The inventory spatially disaggregates the national reported emissions, using 9 spatialization methods to distribute the 167 line items detailed in the National Inventory Reports (NIRs) using the UNFCCC Common Reporting Framework (CRF). The novel contribution of this model is that results are provided per administrative jurisdiction at multiple administrative levels, following the region boundaries defined OpenStreetMap, using a new spatialization approach. Project website: openghgmap.net